The participant was no ordinary subject. Standing 186 centimeters tall and weighing 103.7 kilograms at study entry, he carried eleven years of professional experience and sixteen bouts into the observation window, which preceded a scheduled fight against a highly ranked opponent. His coaching staff prospectively recorded every training session, and the data tell the story of a textbook taper. In the forty-eight hours before the first blood collection, he completed 195 minutes of training with an internal load of 1,310 arbitrary units and six rounds of sparring. By the final collection, those figures had collapsed to 60 minutes, 240 units, and zero sparring rounds. Sleep quality scores barely moved throughout, and body mass drifted down by just 1.6 kilograms, with no rapid weight-loss or dehydration procedures applied.

Fasting morning blood was drawn on five occasions, on 10, 13, 17, 20, and 23 May 2024, always at 07:30 after at least ten hours of overnight fasting, at least fourteen hours after the previous training session, and fifteen minutes of seated rest before venipuncture. Tubes were centrifuged within thirty minutes, and plasma was aliquoted and stored at minus eighty degrees Celsius until all assays and spectroscopic measurements were performed in a single analytical run. Conventional laboratory methods quantified twelve biochemical variables: creatine kinase (CK), C-reactive protein (CRP), glucose, cortisol, testosterone, total and reduced glutathione, oxidized glutathione calculated from the other two fractions, malondialdehyde, zinc, and the derived testosterone-to-cortisol and glutathione ratios. Crucially, FTIR was never used to quantify any of these analytes; the laboratory results served as reference values against which the spectral data were examined for co-variation.

The FTIR workflow itself was strikingly economical. Just four microliters of plasma were deposited onto a calcium fluoride window, dried at room temperature for roughly ten minutes, and then placed on the diamond ATR crystal of a Nicolet iS50 spectrometer. Background spectra were collected before each measurement, and spectra were recorded from 400 to 4,000 inverse centimeters at a resolution of 4 inverse centimeters using 32 scans per spectrum. Each plasma sample was measured eight times under identical conditions, yielding 40 spectra from five biological observations. Between consecutive measurements the diamond crystal was cleaned with seventy percent ethanol and thoroughly dried. Preprocessing in OPUS 7.0 software included Rubberband baseline correction and vector normalization, after which the eight technical replicates per sample were averaged into a representative mean spectrum.

The biochemical picture painted by conventional assays was coherent with recovery. CK activity fell from 495 units per liter on the first day to 183 on the day before the fight, a sixty-three percent decline consistent with decreasing myocellular damage and progressive cell membrane repair during tapering. The baseline value, though elevated relative to the non-training population, is typical for elite combat sports athletes in a load accumulation phase, and heavyweight athletes’ large muscle mass predisposes them to larger enzyme releases at the same relative load. CRP dropped from 0.27 to 0.13 milligrams per deciliter, a positive indicator, since even small oscillations within the laboratory norm carry physiological implications and a persistently elevated pre-competition CRP would signal incomplete adaptation and heightened risk of immunosuppression. Testosterone rose from 15.23 to 17.55 nanomoles per liter, although the fitted slope was not distinguishable from zero, and the testosterone-to-cortisol ratio climbed from 3.4 to 4.1, a barometer many sports scientists regard as key to the balance between anabolic and catabolic processes.

Cortisol, by contrast, refused to follow the textbook script. Reducing training volume during tapering should, from a classical physiological perspective, produce a clear drop in this adaptive hormone, which mobilizes energy substrates through gluconeogenesis, proteolysis, and lipolysis. Instead, cortisol oscillated within a narrow band of 426 to 481 nanomoles per liter across all thirteen days, showing a coefficient of variation of just 4.4 percent. The researchers interpret this stability not as poor recovery but as anticipatory stress, a phenomenon well described in sports psychophysiology. High-ranking sporting events trigger strong activation of the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis as psychological pressure mounts, the upcoming confrontation is visualized, and fear of failure builds. The cerebral cortex and amygdala signal the hypothalamus, which releases corticotropin-releasing hormone, stimulating the anterior pituitary to secrete adrenocorticotropic hormone and thereby sustaining cortisol synthesis in the adrenal cortex.

The oxidative stress panel added its own nuance. Malondialdehyde, the primary marker of lipid peroxidation, remained stable between 0.62 and 0.81 micromoles per liter, suggesting the athlete’s antioxidant defenses neutralized free radicals in real time before they could damage membrane lipids. Total glutathione, however, showed the only slope whose ninety-five percent confidence interval excluded zero, rising at 41.0 micromoles per liter per day, and reduced glutathione climbed alongside it. The largest between-day variability was recorded for the reduced-to-oxidized glutathione ratio at 133.9 percent, though this figure was driven largely by a single low oxidized glutathione value. Zinc, glucose, and the glutathione ratios completed the panel, with cortisol and glucose showing the smallest relative fluctuations of all measured parameters.

Then came the spectroscopy. The spectra exhibited consistent vibrational profiles, with the same molecular vibrations visible in every sample: C-H out-of-plane aromatic bands at 671 and 699 inverse centimeters, thymine N-H vibrations at 721 and 797, nucleic acid C-C stretching at 846 and 929, phosphate stretching at 1,024 and 1,260, amide vibrations at 1,376, 1,542, 1,642, and 3,272, protein and lipid CH2 and CH3 vibrations at 1,415 and 1,458, and lipid C=O, CH2, and CH3 vibrations at 1,711 through 3,065. A screening analysis of 264 correlations between 22 spectral peaks and 12 biochemical variables identified four regions of interest. Total glutathione correlated negatively with bands at 671, 699, and 721 inverse centimeters, reduced glutathione with 671 and 699, and cortisol correlated positively with the band at 3,009, which is typically assigned to stretching vibrations of cis-unsaturated acyl chains. Linear regression yielded apparent in-sample R-squared values of 0.80 to 0.92 for the glutathione bands and 0.77 for cortisol.

The researchers are emphatic that these numbers must not be mistaken for validated calibrations. With only five biological observations, six of the 264 spectral-biochemical coefficients reached an uncorrected p-value below 0.05, yet with this number of tests approximately thirteen nominal results could be expected purely by chance, and none survived Benjamini-Hochberg false discovery rate correction. The regression bands were selected based on their correlations within the same five observations later used to fit the models, a procedure that inflates R-squared values and makes them represent fit to the analyzed sample rather than predictive capability. The cortisol band poses a particular interpretive puzzle: at a plasma concentration of roughly 450 nanomoles per liter, cortisol is far too scarce to contribute measurably to the 3,009 band’s intensity. One unverified hypothesis invokes an indirect relationship in which cortisol stimulates lipolysis and co-occurs with changes in the circulating pool of unsaturated fatty acids, but confirming this would require simultaneous fatty acid profiling. For glutathione, the authors speculate that protein S-glutathionylation and deglutathionylation processes might alter the local environment of sulfur-containing and aromatic residues, though all three signals were weak and located in the region with the lowest signal-to-noise ratio in the spectra.

What the study does establish is narrower but genuinely useful: that repeated ATR-FTIR measurements of plasma are technically feasible and visually consistent under realistic pre-competition conditions, using a sample volume of just four microliters. The eight technical replicates per sample illustrate within-sample consistency but do not establish quantitative repeatability across independent runs, operators, instruments, or measurement days, and the single-participant design precludes any estimate of inter-individual variability. All assays and spectra were acquired in a single analytical run, eliminating between-run drift but also precluding independent replication of the entire analytical process, and samples underwent a single freeze-thaw cycle that may have been particularly significant for the unstable reduced glutathione fraction. The authors conclude that their findings are preliminary and hypothesis-generating, that they provide no evidence that ATR-FTIR enables quantitative determination of glutathione or cortisol, and that it cannot yet be used to assess competitive readiness. Confirmation of such capabilities, they write, requires studies involving adequately large and diverse groups of participants. Still, the vision is tantalizing: a technique that images the metabolite fingerprint of an athlete’s blood almost instantaneously, in training camps where every hour of recovery counts, could one day transform how fight-week readiness is read, one infrared spectrum at a time.

Subject of Research: Application of FTIR to detect changes in blood plasma during a pre-competition period in a professional heavyweight boxer

Article Title: Application of FTIR to detect changes in blood plasma during a pre-competition period in a professional heavyweight boxer

Article References: Król, P., Depciuch, J., Reich, A., Cebulski, J., Obmiński, Z., Kasicki, K., Czarny, W., Różański, Ł., & Rydzik, Ł. (2026). Application of FTIR to detect changes in blood plasma during a pre-competition period in a professional heavyweight boxer. Frontiers in Physiology, 17, Article 1845333. https://doi.org/10.3389/fphys.2026.1845333

Image Credits: AI Generated

DOI: 10.3389/fphys.2026.1845333

Keywords: Application, FTIR, detect, changes, blood, plasma, during, pre-competition, period, professional, heavyweight, boxer

The team collected samples in October 2022, during the Amazonian dry season, when falling water levels cut the hydrological connections between the lake, adjacent channels, and the main river. This low-water phase matters because reduced connectivity tends to trap particles within the lake rather than flushing them out. The researchers chose two contrasting areas: one dominated by artisanal fishing activity, with boats, nets, and lines in regular use, and another marked by riverside dwellings, visible solid waste, and direct domestic use of the water. At seven points in each area, spaced ten meters apart along the margins, they drew six liters of near-surface water from the top thirty centimeters and scraped 150 grams of sediment from the upper five centimeters of the lake bed.

The laboratory work followed rigorous contamination-control protocols. Water samples were vacuum-filtered through paper filters with a five-micrometer pore size, while sediments were dried, subjected to density separation in saturated salt solution to float plastic particles away from mineral grains, and then treated with hydrogen peroxide to digest organic matter. The researchers wore only cotton clothing in the field, rinsed glass containers with filtered water, and ran sixteen blank controls, fourteen in the field and two in the laboratory. Just three particles appeared in those blanks, roughly 1.5 percent of the count in the environmental samples, indicating that background contamination was minimal and that the particles they counted were genuinely present in the lake.

The numbers were striking. Surface water concentrations ranged from zero, in a single sample where no particles were found, to 1,000 microplastics per cubic meter, with a mean of 405 plus or minus 298. Sediments held between 7 and 307 particles per kilogram of dry sediment, averaging 77 plus or minus 104. Perhaps the most telling result was what the researchers did not find: no statistically significant difference in concentrations between the fishing area and the settlement area. Both human activities, it seems, are feeding plastic into the lake at comparable rates, whether through worn fishing gear and boat materials on one side or inadequate waste disposal and untreated effluents on the other.

The physical character of the particles told its own story. In surface water, the particles were overwhelmingly fibers, predominantly blue and red, with sizes spanning 115 to 3,615 micrometers. In sediments, the picture split by land use: fragments dominated near the human settlements, consistent with the breakdown of domestic plastic waste, while fibers were more abundant in the fishing zone, where synthetic nets, lines, and ropes shed filaments as they wear. Sediment particle sizes also differed significantly between the two areas, with smaller to intermediate particles concentrated near the settlements and larger ones near the fishing grounds. The authors caution that because source-specific morphology was not statistically tested, these attributions remain plausible interpretations rather than proven links.

To identify what the particles were actually made of, the team turned to Fourier-transform infrared and Raman spectroscopy, analyzing roughly eight percent of the visually identified particles. Polyethylene emerged as the most frequently identified polymer, a finding that points to everyday sources such as packaging, bags, and household items. The spectra also revealed something less expected: copper phthalocyanine pigments, specifically Pigment Blue 15 and Pigment Green 7, the same organic colorants used in paints, coatings, and dyed plastics. One Raman spectrum showed the characteristic polyethylene bands, including carbon-carbon stretching signals near 1063 and 1130 inverse centimeters, alongside the fingerprint of Pigment Blue 15. The researchers note that such pigments can accelerate photodegradation under ultraviolet light, potentially speeding the fragmentation of plastic debris and the release of degradation products.

The ecological implications are significant. Blue fibers are a known hazard in aquatic food webs because fish and invertebrates can mistake them for prey, and previous work by some of the same team has already documented microplastics in catfish species sold in local markets near Lake Canaçari. Smaller particles, with their high surface-to-volume ratios, tend to stay suspended longer and interact readily with clays and organic matter, forming aggregates that settle into the sediment. In a low-energy floodplain lake during the dry season, when water exchange with the river is minimal, these particles may accumulate where fish feed and where riverside communities harvest their food. The Amazon’s limited sanitation infrastructure, particularly the absence of wastewater treatment and organized solid waste collection, ensures a continuous supply of new material.

The study also carries a broader geographic message. Model-based estimates suggest the Amazon River discharges somewhere between 38,000 and 182,000 tons of plastic to the ocean each year, though the wide range reflects sparse data. Floodplain lakes like Canaçari sit squarely within this conveyor belt. The authors propose that the lake functions simultaneously as a transport pathway, a redistribution zone, and a retention compartment for microplastics, storing particles during low water and potentially releasing them when the flood pulse reconnects the system. If that hypothesis holds, floodplain lakes could modulate the timing and magnitude of plastic delivery from the Andes to the Atlantic, a dynamic that global plastic transport models have largely ignored.

The researchers are careful about the limits of their work. Sampling covered a single dry-season campaign with modest spatial coverage, land-use categories were defined from qualitative field observations, and the salt-based density separation used for sediments may have under-recovered denser polymers such as PVC or PET. Only a subset of particles received spectroscopic confirmation, and degraded, pigment-coated particles sometimes resisted identification. They call for future studies spanning multiple hydrological seasons, deeper sediment cores, quantitative measures of human pressure, and denser separation solutions to capture the full polymer spectrum. Even so, the baseline is now established: an Amazonian floodplain lake, far from any city, carries microplastics in its water and its bed, and the particles bear the chemical signatures of both fishing livelihoods and everyday domestic life. Managing the Amazon’s plastic problem, the study suggests, will require monitoring strategies that follow the region’s dramatic seasonal pulse of water rather than treating the river system as a static environment.

Subject of Research: Microplastic contamination in the surface water and sediments of an Amazonian floodplain lake

Article Title: Microplastic contamination in surface water and sediments of Lake Canaçari, Central Amazon, during the dry season

Article References: Guimarães, G. D. A., da Fonseca, R. V., de Moraes, B. R., Ando, R. A., de Azevedo Rodrigues, I. J., Perotti, G. F., Sant’Anna, B. S., & Hattori, G. Y. (2026). Microplastic contamination in surface water and sediments of Lake Canaçari, Central Amazon, during the dry season. Environmental Monitoring and Assessment, 198(11), Article 1221. https://doi.org/10.1007/s10661-026-16079-2

Image Credits: AI Generated

DOI: 10.1007/s10661-026-16079-2

Keywords: microplastics, Amazon, Lake Canaçari, floodplain lake, polyethylene, Raman spectroscopy, FTIR, sediments, fishing activity, water pollution, Pigment Blue 15, dry season

The strain at the heart of the work, designated BWBTDIPO1 and deposited in GenBank under accession number PQ517523, was isolated from a waste-dumping zone in Kolkata. That provenance matters. Bacteria that thrive in garbage dumps are often exposed to complex, recalcitrant organic matter, and the team suspected such an environment might select for organisms capable of dismantling lignocellulose — the tough composite of lignin, cellulose, and hemicellulose that makes plant waste so resistant to decay and so expensive to process industrially. Their hunch proved correct. When the researchers offered the bacterium ground, sterilized sugarcane bagasse as its sole carbon source in submerged fermentation, the microbe grew vigorously and secreted riboflavin into the surrounding medium.

The numbers are compelling. Over a 78-hour fermentation at 30 degrees Celsius and 120 rpm, the bacterium achieved a specific growth rate of 0.325 per hour, corresponding to a generation time of roughly 2.13 hours, and produced 397 ± 15.8 milligrams of riboflavin per liter of culture — equivalent to 19.85 ± 2.0 milligrams of the vitamin for every gram of bagasse consumed. The team screened four mineral salt medium formulations to find the optimal recipe, and yeast extract peptone mineral salt medium, or YPMSM, emerged as the clear winner. The authors attribute this to the synergistic nutritional boost provided by yeast extract and peptone, which supply vitamins, nucleotides, peptides, and growth factors that support flavin biosynthesis and the enzymatic machinery needed to break down the biomass.

The growth curve told a classic batch-fermentation story with a twist. The bacterium lingered in a lag phase until about the sixteenth hour — a period the researchers interpret as physiological adaptation to the complex, lignin-rich substrate — then exploded into exponential growth between hours 18 and 40, before settling into a stationary phase. Riboflavin production tracked this trajectory closely, accelerating sharply after hour 18 and continuing into the late exponential and early stationary phases before peaking at hour 78. This pattern suggests the vitamin is produced through a combination of growth-associated and non-growth-associated mechanisms, a detail the authors say will be critical for timing cell harvesting and product recovery in any future industrial scale-up.

Confirming that the yellow-green metabolite really was riboflavin required a two-pronged analytical approach. Ultraviolet-visible spectrophotometry of the acidified ethanol extract revealed absorption peaks at 226 and 266 nanometers, matching the signature of riboflavin’s isoalloxazine chromophore. Thin-layer chromatography on silica gel plates, using a methanol-to-water mobile phase of 70:30, produced a retention factor of 0.83 — identical to that of a commercially purchased riboflavin standard run alongside the sample. Earlier work by the same group had already achieved a higher yield of 459.31 milligrams per liter using Luria Bertani broth, a glucose-rich synthetic medium, but the current process substitutes a zero-cost agricultural waste for that expensive feedstock, dramatically improving the economics even at a slightly lower titer.

Perhaps the most technically revealing portion of the study concerns what happened to the bagasse itself. The researchers subjected treated and untreated biomass to a battery of compositional assays. Alkali lignin solubilization increased measurably after bacterial treatment, with optical density at 465 nanometers rising from 0.359 in untreated samples to 0.443 in treated ones. Acid hydrolysis revealed a dramatic 65.33 ± 3.4 percent reduction in acid-insoluble lignin — the most condensed and structurally resistant lignin fraction — falling from 0.75 grams of residual dry biomass to just 0.26 grams. Meanwhile, the dinitrosalicylic acid assay showed reducing sugar concentrations more than tripling, from 0.205 to 0.617 milligrams per milliliter, direct evidence that the bacterium was hydrolyzing cellulose and hemicellulose polymers into fermentable monosaccharides such as glucose, xylose, and arabinose.

Physicochemical characterization painted the same picture at the molecular and microscopic scales. Fourier-transform infrared spectroscopy revealed shifts and disappearances in peaks associated with lignin-carbohydrate complexes: the aromatic skeletal vibration near 1,634 wavenumbers shifted to 1,607, the crystalline cellulose CH2 wagging peak at 1,317 vanished entirely, and a new peak appeared at 1,244 wavenumbers, consistent with disruption of aryl-alkyl ether linkages binding hemicellulose to lignin. X-ray diffraction showed a sharper, more intense cellulose diffraction peak in treated samples, indicating that removal of amorphous lignin and hemicellulose had exposed the crystalline cellulose microfibrils beneath. Field-emission scanning electron microscopy provided the most visceral confirmation: where untreated bagasse displayed a dense, smooth, intact fibrillar architecture, the bacterially treated material was riddled with erosion, fragmentation, pore formation, and pronounced cracking.

To explain these observations mechanistically, the team turned to computational biology. Using KEGG global metabolic pathway mapping, they constructed a hypothetical framework for how the bacterium might be routing biomass-derived carbon through its metabolism. The analysis suggests three interconnected routes: lignin-derived aromatic compounds funneled into the tricarboxylic acid cycle, cellulose hydrolyzed to cellobiose and glucose before entering glycolysis, and hemicellulose-derived pentose sugars like xylose and arabinose assimilated through the pentose phosphate pathway. The authors are careful to emphasize that these pathways are predictive annotations, not experimentally validated mechanisms, and will require genomic, transcriptomic, proteomic, metabolomic, and enzyme-activity studies to confirm. Still, the architecture is consistent with lignocellulose degradation strategies documented in other bacteria and provides a plausible explanation for how biomass carbon ends up as riboflavin.

The significance of the work extends well beyond one bacterium and one vitamin. Global riboflavin production still relies heavily on chemical synthesis routes that demand multistep reactions, expensive catalysts, and energy-intensive operations, while most biological production depends on genetically modified organisms such as engineered Escherichia coli and Corynebacterium glutamicum. A wild-type strain that achieves competitive yields from free agricultural waste sidesteps both problems. India, one of the world’s leading sugarcane producers, generates enormous quantities of bagasse annually, and disposing of it poses persistent environmental challenges. Coupling that waste stream to nutraceutical manufacturing embodies the waste-to-wealth vision of the circular bioeconomy, and the authors note the approach aligns with broader sustainability goals.

Considerable work remains before a Kolkata dump-dwelling microbe can feed a factory. The researchers themselves flag the next steps: whole-genome sequencing to identify the genes governing both lignocellulose degradation and flavin biosynthesis, process optimization to push yields higher, techno-economic analysis, and life cycle assessment to verify the environmental credentials at scale. They also point out that the strain produced its riboflavin without any external supplementation of cofactors or amino acids, a simplicity that bodes well for cost-sensitive industrial adoption. If those efforts succeed, the humble bagasse pile behind every sugarcane juice cart could become a feedstock for one of the world’s most widely consumed vitamins — proof that sometimes the most valuable chemistry is already happening, quietly, in the dirt of a garbage dump.

Subject of Research: Bacterial bioconversion of sugarcane bagasse waste into riboflavin (vitamin B2)

Article Title: Sustainable bioconversion of sugarcane bagasse into valorizable riboflavin by Microbacterium proteolyticum BWBTDIPO1, characterization and in-silico mechanistic pathway prediction

Article References: Paul, I., Kali, S., Saha, S., Guha, P., Dasgupta, S., & Halder, G. (2026). Sustainable bioconversion of sugarcane bagasse into valorizable riboflavin by Microbacterium proteolyticum BWBTDIPO1, characterization and in-silico mechanistic pathway prediction. Frontiers in Chemical Engineering, 8, Article 1895508. https://doi.org/10.3389/fceng.2026.1895508

Image Credits: AI Generated

DOI: 10.3389/fceng.2026.1895508

Keywords: riboflavin, vitamin B2, sugarcane bagasse, Microbacterium proteolyticum, lignocellulosic biomass, submerged fermentation, biorefinery, waste-to-wealth, circular bioeconomy, KEGG pathway analysis, FTIR, biodegradation

The forensic pedigree of soil evidence is older than most people realize. In 1904, the German forensic pioneer Georg Popp used soil recovered from the pant cuffs of a suspect in the Eva Disch murder case, comparing it to soil from the bean field where the victim was found and to soil along a pathway leading from the suspect’s home to the crime scene. Confronted with the soil analysis and other evidence, the suspect Karl Laubach confessed. What has changed since Popp’s era is not the principle but the technology: where early investigators relied on visual comparison of color and texture, modern analysts can interrogate the molecular bonds within soil particles and let algorithms do the discriminating.

FTIR spectroscopy works by shining infrared light across a sample and measuring which wavelengths are absorbed. Every chemical bond vibrates at characteristic frequencies in the micron range, and when those vibrations match the incoming infrared radiation, the energy is absorbed and recorded as a dip in the spectrum. Soil is a complex mixture of organic matter, sand, clay, minerals, and salts, and it may also contain heavy metals introduced by mining, tanning, and other industrial activities depending on the pH and land use. Compounds such as humic and fulvic acids in the natural organic matter, along with clays that carry permanent dipoles, all interact with the infrared beam. The result is a spectrum packed with absorptions at specific wavenumber values that can be assigned to functional groups using correlation charts, from the hydroxyl stretches of clay minerals near 3,700 wavenumbers to the silicate stretches below 1,000.

The technique’s appeal for forensic work is practical as much as scientific. FTIR is non-destructive, rapid, and requires little to no sample preparation, making it ideal for analyzing the trace quantities of soil that typically survive on footwear, tools, or vehicle mats. Eleven of the fourteen studies reviewed used attenuated total reflectance FTIR, in which the sample is pressed against a crystal and the evanescent wave penetrates only a few microns, while three older studies prepared samples as potassium bromide pellets. One study compared ATR with diffuse reflectance infrared Fourier transform spectroscopy and found the DRIFTS approach yielded notably lower classification error, 27 percent versus 57 percent with ATR data under linear discriminant analysis, suggesting that how the spectrum is collected matters as much as what is collected.

The geographic scope of the reviewed research is genuinely global. Studies analyzed soils from Australia, India, the United States, the United Kingdom, China, Turkey, Brazil, and North Macedonia, with sample sizes ranging from five to several hundred. The sampling protocols varied enormously. Chauhan and colleagues collected ten samples from within a 10 by 10 meter area in eighteen cities across five Indian states, while de Caritat and colleagues analyzed 324 samples from 268 locations across North Canberra, collecting five samples from each 1 by 1 meter plot and combining them. Sangwan’s team gathered 232 samples across 29 locations in Haryana, India, and e Silva’s group collected 284 samples across the Curitiba Metropolitan Region of Brazil. Sampling depths ranged from the top half inch to a full meter, and some studies deliberately collected both surface and sub-surface samples, reasoning that surface soil is what embeds in shoe treads while deeper soil might indicate digging.

Sample preparation is where the field shows its cracks. Drying temperatures ranged from gentle air drying over several days to ovens set at 110 degrees Celsius, and one study heated fine fractions at 650 degrees Celsius in a muffle furnace to strip away organic material entirely. Sieving mesh sizes ranged from 38 micrometers to 2.8 millimeters, and some groups ground and homogenized samples while others did not. Newland’s team in Western Australia went further, hand-picking quartz grains from sieved samples under a microscope and subjecting them to sonication, centrifugation, and resuspension before drying them into thin films. These choices are not trivial: high temperatures and long drying times can alter the constituency of the organic portion of soil, and the review warns that such alterations could compromise the very spectral features that make each soil unique.

Once spectra are collected, typically across the 4,000 to 400 wavenumber range at 4 wavenumber resolution with 64 scans, the real analytical power emerges from chemometrics. Twelve of the fifteen papers applied statistical methods rather than relying on visual comparison alone. Principal component analysis was the most common tool, used in eleven studies, often combined with linear discriminant analysis or partial least squares discriminant analysis. Preprocessing steps such as normalization, baseline correction, and smoothing were applied before modeling, and several groups removed spectral regions associated with ATR crystal interference or deemed non-relevant. The review notes that statistical analysis removes interpreter variation and leads to higher discriminating power, whereas visual inspection, though sometimes successful, depends on the skill and training of the examiner and can be unreliable.

The reported results are remarkable in places. Woods and colleagues achieved 99.7 percent discrimination across 29 Australian samples using PCA on FTIR spectra and their first derivatives. Idrizi’s team in North Macedonia reported 96 to 100 percent classification accuracy with supervised self-organizing maps, and, notably, twelve samples collected three years after the initial sampling were correctly grouped with their corresponding urban parks, suggesting the spectral fingerprints are stable over time. Newland’s mock casework study in Perth achieved 100 percent classification accuracy when matching a simulated suspect-recovered soil sample to the crime scene using PCA-LDA. Chauhan’s team in India reported 99.35 percent discriminating power for surface samples through visual analysis and 100 percent accuracy for sub-surface samples with LDA models. Sangwan’s group in Haryana reported 100 percent accuracy for surface samples and 98.85 percent for sub-surface samples, with blind samples classified correctly in most cases.

But the picture is not uniformly rosy. De Caritat’s provenancing study across North Canberra found that FTIR alone achieved only 26.6 percent average accuracy in predicting the origins of blind samples under a simultaneous multivariate approach, though combining FTIR with magnetic susceptibility raised accuracy to 61.3 percent and precision to 80.7 percent under a sequential approach. Two studies, one in Turkey near the Ömerli Dam and one in Brazil’s Curitiba region, concluded that FTIR did not provide sufficient information for discrimination on its own. Several groups recommended pairing FTIR with complementary techniques such as X-ray diffraction, X-ray fluorescence, or laser-induced breakdown spectroscopy. The review observes that discrimination accuracy improved when the locations in question were more varied, spanning sand, clay, and loam across short and long geographic distances, and that well-developed databases are expected to improve prediction accuracy further.

The review’s authors close with a call that reads like a roadmap for the field’s next decade: a standardized and consensus approach to sampling, preprocessing, and data collection would accelerate comparisons across laboratories worldwide. They envision an interlaboratory study in which all participants follow a specified procedure and compile results into a searchable, GPS-mapped database, allowing broad conclusions about any sample set and clarifying whether surface and sub-surface soils can be differentiated in a given region. The standard FTIR recording range was most frequently 4,000 to 400 wavenumbers at 4 wavenumber resolution with 64 scans run in triplicate, and the authors suggest these settings as a baseline. If that consensus emerges, the humble dirt on a suspect’s shoes could become one of forensic science’s most powerful and objective witnesses, capable of placing a person at a specific patch of earth with a confidence that no visual inspection could ever match.

Subject of Research: FTIR spectroscopic analysis of soil in forensic science

Article Title: FTIR spectroscopic analysis of soil in forensic science

Article References: Force, J., & Elkins, K. M. (2025). FTIR spectroscopic analysis of soil in forensic science. Frontiers in Analytical Science, 5, Article 1716867. https://doi.org/10.3389/frans.2025.1716867

Image Credits: AI Generated

DOI: 10.3389/frans.2025.1716867

Keywords: FTIR, spectroscopic, analysis, soil, forensic, science, scientific research

Biosurfactants are amphiphilic molecules, meaning they possess both water-loving and water-fearing regions, and this dual nature allows them to dramatically reduce surface and interfacial tension between immiscible liquids such as oil and water. Unlike their petroleum-derived synthetic counterparts, biosurfactants are biodegradable, exhibit low toxicity, and maintain high surface activity across a range of industrial conditions. These properties make them attractive for applications spanning environmental remediation of oil spills, enhanced petroleum recovery, food preservation, pharmaceutical formulations, and cosmetic products. The most extensively studied and commercialized classes are lipopeptides like surfactin, produced by Bacillus species, and glycolipids like rhamnolipids, produced by Pseudomonas species. However, the search for novel biosurfactant producers has increasingly turned toward lactic acid bacteria, a group generally recognized as safe (GRAS) and widely employed in food fermentation.

Lactobacillus species are particularly compelling candidates because they are already embedded in human food systems, carry a long history of safe use, and produce bioactive metabolites with both antimicrobial and surface-active properties. Prior research has shown that biosurfactants from Lactobacillus can inhibit pathogens, preserve foods, and support probiotic preparations. The biosynthetic machinery behind these molecules typically involves non-ribosomal peptide synthetases, which are large multidomain enzymes that assemble peptide structures without the ribosomal translation machinery. These NRPS systems contain conserved catalytic domains, including adenylation (A), condensation (C), and peptidyl carrier protein (PCP) domains, each responsible for specific steps in substrate recognition, activation, and peptide elongation. What makes the current study distinctive is its focus on whether the adenylation domain alone, without the full NRPS assembly line, could still contribute meaningfully to biosurfactant production.

To answer this question, the research team first turned to comparative bioinformatics. They retrieved the NRPS protein sequence from Bacillus velezensis FZB42, a well-characterized commercial biosurfactant producer with extensively studied NRPS domains, and used it as a query against the NCBI non-redundant protein database. The most significant hit was a non-ribosomal peptide synthetase from Lactococcus lactis subsp. lactis KF147, with 99% query coverage, a BLAST score of 1,052, and an E-value of 0.0, indicating a highly significant alignment despite only moderate sequence identity of approximately 26%. This combination of high coverage and low E-value strongly suggested functional relatedness between the NRPS systems of these taxonomically distant bacteria. Further BLASTp analysis using the Lactococcus sequence as query revealed homologous proteins across multiple Lactobacillus species, including hybrid NRPS-polyketide synthase proteins and adenylate-forming enzymes.

Domain architecture analysis using InterProScan confirmed the presence of conserved functional modules across the analyzed sequences. The team identified the NRPS domain (IPR010060), the PCP domain (IPR009081), and the PKS domain (IPR020806), confirming the hybrid modular nature of these proteins. The condensation domain (IPR001242), responsible for peptide bond formation between activated amino acid substrates, appeared at multiple positions. Critically, the adenylation AMP-binding domain (IPR000873) and the amino acid adenylation domain (IPR010071) were highly conserved across all analyzed strains, underscoring their central role in substrate recognition and activation. The AMP-binding C-terminal domain (IPR025110) was also detected, providing structural stability to the adenylation modules. Notably, the number and organization of these domains varied considerably between strains. Lactobacillus helveticus MTCC 5463 and L. helveticus DPC 4571 each carried two conserved domains, representing a relatively streamlined biosynthetic organization. In contrast, Lactococcus lactis subsp. lactis KF147 harbored seven conserved domains, suggesting a more complex biosynthetic architecture and potentially greater catalytic capacity.

With the bioinformatic foundation in place, the researchers moved to the laboratory. They extracted genomic DNA from L. helveticus MTCC 5463 and used gene-specific primers to amplify the AMP-binding domain by polymerase chain reaction. The resulting fragment, approximately 353 base pairs in length, was directionally cloned into the pET-28a expression vector using XhoI and EcoRI restriction enzymes. Successful cloning was verified through restriction digestion analysis, which released an insert fragment of the expected size in positive clones. The recombinant plasmid was then transformed into Escherichia coli BL21(DE3) for heterologous protein expression. Induction with isopropyl 2-D-1-thiogalactopyranoside (IPTG) at concentrations ranging from 0.2 to 1.0 mM, followed by time-course analysis from 1 to 7 hours, revealed a clear recombinant protein band at approximately 14 kilodaltons on SDS-polyacrylamide gel electrophoresis. Expression intensity increased progressively with both inducer concentration and induction time, reaching maximum accumulation between 5 and 7 hours post-induction.

The recombinant biosurfactant was then extracted from the E. coli culture using chloroform:methanol solvent systems. The researchers tested two ratios, 1:1 and 2:1, and found that the 2:1 ratio produced significantly more visible precipitation, with the greatest accumulation observed at the 5-hour extraction time point. This enhanced recovery is attributed to the higher chloroform content, which improves solubilization of lipid-rich amphiphilic molecules. To rule out the possibility that the observed activity originated from endogenous E. coli membrane lipids, the team conducted a critical empty-vector control experiment. An E. coli BL21(DE3) strain carrying the empty pET-28a vector was processed under identical conditions, and the resulting extract showed no measurable emulsification activity against any of the tested oils and no detectable bands on thin-layer chromatography. This control definitively linked the biosurfactant phenotype to the recombinant AMP-binding domain construct rather than host-derived lipids.

Functional evaluation of the extracted biosurfactant revealed impressive emulsification performance across multiple substrates. Using the emulsification index (E24) assay, which measures the percentage of emulsified layer height relative to total liquid column height after 24 hours, the recombinant product achieved approximately 75% to 82% emulsification against petrol and diesel oil, maintaining stability for a full week with minimal variation. Against mustard oil, the performance was even more striking, reaching 88% to 95%, far exceeding the 10% to 12% achieved by rhamnolipid and the 30% to 38% achieved by surfactin under the same conditions. For refined oil, the recombinant biosurfactant delivered 65% to 75% emulsification at 24 hours, sustaining approximately 65% to 70% even after one week, while rhamnolipid showed only 4% to 6% and surfactin showed moderate activity of 46% to 50%. These results demonstrate that the recombinant glycolipopeptide consistently outperformed both benchmark biosurfactants across hydrocarbon and vegetable oil substrates.

Analytical characterization provided detailed structural insights into the recombinant molecule. Thin-layer chromatography using iodine vapor revealed a yellow-brown spot with an Rf value of 0.80, indicating a relatively non-polar lipid-rich compound, while anisaldehyde staining produced a spot at Rf 0.75, consistent with glycolipid or lipopeptide chemistry. Fourier-transform infrared spectroscopy identified key functional groups: a broad band at 3,325 cm⁻¹ corresponding to hydrogen-bonded O-H and N-H stretching from carbohydrate and protein moieties, aliphatic C-H stretching at 2,916 cm⁻¹ confirming long hydrocarbon chains, a band at 1,649 cm⁻¹ assigned to amide I (C=O stretching) indicating peptide bonds, and C-O stretching at 1,021 cm⁻¹ pointing to carbohydrate or ester linkages. Together, these spectral features are characteristic of a glycolipopeptide structure containing lipid, peptide, and carbohydrate components.

Gas chromatography-mass spectrometry profiling further confirmed the hydrophobic lipid architecture of the biosurfactant. The most abundant compound identified was 9-octadecenamide, accounting for 20.50% of the total relative area, followed by significant amounts of C16 and C18 long-chain fatty acid derivatives and amides. These hydrophobic moieties form the structural basis for surface tension reduction, emulsification, and micelle formation. Nuclear magnetic resonance spectroscopy, conducted on a Bruker Avance NEO spectrometer at 400 MHz, provided complementary evidence. Proton NMR revealed strong signals at δ 1.23 to 1.58 ppm from methylene protons of long-chain fatty acyl groups, glyceryl and carbohydrate-associated signals at δ 3.72 ppm, and a broad singlet at δ 7.3 ppm assigned to exchangeable amide N-H protons, confirming peptide-associated functionalities. Carbon-13 NMR showed resonances at δ 18 ppm for terminal methyl carbons of branched-chain fatty acids, δ 66 and 76 ppm for O-CH₂ and CH-O carbons of glycerol or carbohydrate moieties, δ 56 and 58 ppm for alpha-methine carbons of amino acid residues, and carbonyl carbons at δ 173 to 175 ppm for amide or ester linkages. Collectively, the spectroscopic data confirm a multicomponent amphiphilic glycolipopeptide structure. The authors note that while the isolated adenylation domain alone is unlikely to catalyze complete glycolipopeptide biosynthesis, it may influence production indirectly through interactions with endogenous metabolic pathways in the E. coli host, and they plan future transcriptomic, proteomic, and metabolomic investigations to elucidate the precise molecular mechanism underlying this observation.

Subject of Research: Biosurfactant production mediated by the NRPS adenylation domain of Lactobacillus helveticus MTCC 5463

Article Title: In silico and experimental characterization of NRPS adenylation domain-mediated biosurfactant production in Lactobacillus helveticus MTCC 5463

Article References: Kumari, M., Pandey, K., Mehtab, S., & Singhal, B. (2026). In silico and experimental characterization of NRPS adenylation domain-mediated biosurfactant production in Lactobacillus helveticus MTCC 5463. Frontiers in Bacteriology, 5, Article 1895576. https://doi.org/10.3389/fbrio.2026.1895576

Image Credits: AI Generated

DOI: 10.3389/fbrio.2026.1895576

Keywords: biosurfactant, Lactobacillus helveticus, NRPS, adenylation domain, glycolipopeptide, emulsification, probiotics, non-ribosomal peptide synthetase, heterologous expression, FTIR, GC-MS, NMR

The research team, led by Luthfi and colleagues, fabricated composites containing five different volume fractions of sago pith waste, from 20 to 40 percent, in a commercial orthophthalic unsaturated polyester resin identified as SHCP 3315, cured with 1.5 weight percent methyl ethyl ketone peroxide hardener. Before any mixing began, the raw waste collected from facilities in Lhokseumawe had to be cleaned. The material was washed repeatedly in plain water, stirred and squeezed to strip away residual soil and sand, then sun-dried for five to seven days. Moisture content was verified with a gravimetric oven method at 60 degrees Celsius, and only batches drying below 2 percent moisture were accepted. During drying, the pith gradually shifted from white to light brown, a visual signature of moisture loss and natural oxidation.

Because dried sago pith tends to clump into soft agglomerates that could seed weak spots in a finished panel, the team sieved the material through a 20-mesh screen, capping particle size at roughly 0.841 millimeters. Notably, they skipped the glycerol plasticization used in earlier sago-waste studies, deliberately choosing a simpler and cheaper route. The apparent density of the sieved particles was estimated at 1.4286 grams per cubic centimeter using a simple ethanol displacement calculation, a value the authors candidly flag as an estimate rather than a validated true density, since no calibrated pycnometer or degassing was employed. That honesty matters, because the same number feeds into the theoretical density and porosity calculations that frame the entire mechanical analysis.

The composites themselves were mixed by hand, homogenized with a motorized mixer, and cast into 300 by 300 by 10 millimeter molds lined with aluminum foil, curing at room temperature for at least 24 hours. Three formulations, at 20, 30, and 40 percent sago pith waste, served most physical and thermal tests, while intermediate compositions at 25 and 35 percent were fabricated specifically to sharpen the mechanical trend analysis. Density measurements told the first part of the story: experimental density fell steadily from 1.08435 grams per cubic centimeter at 20 percent filler to 1.00232 at 40 percent, while estimated porosity climbed from 8.86 percent to 19.78 percent. In other words, more sago means a lighter panel, but also one riddled with more internal voids, as the resin increasingly struggles to wet and penetrate the growing mass of particles.

Flexural performance followed the same downward slope. In modified three-point bending tests on 200 by 15 by 10 millimeter specimens over a 160 millimeter span, average bending strength dropped from 3.87 kilograms-force per square millimeter for the 20 percent composite to 2.92 for the 40 percent version, and the maximum bending moment fell from 1.611 to 1.219 kilograms-force meters. A one-way analysis of variance confirmed these differences were statistically significant, with F values of 20.68 for moment and 19.06 for stress and p-values in the millionths. Strain at failure, intriguingly, showed a rising trend with more filler, from 1.19 to 1.35 percent, but the ANOVA returned p equal to 0.265, so the authors correctly decline to claim that sago content meaningfully changes how far the material bends before it breaks.

Scanning electron microscopy of the fractured surfaces explains why the strength falls. Micrographs of the 20 percent composite revealed residual sago starch granules roughly 20 to 30 micrometers across, cracked polyester matrix, and irregular voids with torn edges. Clean particle pull-out and interfacial gaps pointed to weak adhesion between the untreated lignocellulosic filler and the resin, meaning stress is not transferred efficiently across the interface. To separate failure damage from manufacturing defects, the team also imaged carefully cut, unfractured cross-sections, where voids appeared smoother and near-spherical, the classic fingerprint of air bubbles entrapped during mixing and molding. The 40 percent composite showed all of these features in greater abundance, consistent with its highest porosity, and the authors conclude that interfacial optimization, such as surface treatment of the particles, is the clearest path to better performance.

Fourier transform infrared spectroscopy added the chemical dimension. Using potassium bromide pellets, the team found all composites dominated by the polyester’s ester carbonyl stretch near 1730 inverse centimeters, with a broad hydroxyl band around 3533 to 3539 inverse centimeters growing more pronounced as sago content rose, reflecting the cellulose, hemicellulose, and absorbed water carried in with the biomass. Crucially, no new absorption bands unique to the composites appeared, indicating that sago pith and polyester interact primarily through physical rather than covalent chemical bonding. That chemical aloofness at the interface dovetails neatly with the pull-out features seen under the electron microscope.

Thermal analysis rounded out the picture. Differential scanning calorimetry showed the glass transition temperature sliding from 58 degrees Celsius at 20 percent sago to 54 at 30 percent and 50 at 40 percent, a shift the authors attribute to changes in crosslink density, interfacial region volume, and free volume when bio-filler particles enter the network. Because cured unsaturated polyester is a crosslinked thermoset, the broad high-temperature endotherms, which shifted from 165 to 200 degrees Celsius and grew in enthalpy from 3.74 to 5.86 joules per gram, reflect relaxation and thermally activated transitions rather than any true melting. Thermogravimetric analysis under nitrogen revealed multi-stage degradation: negligible moisture loss below 150 degrees Celsius, a 4 to 6 percent stage linked to hemicellulose decomposition up to 330 degrees, and a massive degradation stage between 331 and 490 degrees where more than 80 percent of the mass vanished. Final residues at 600 degrees Celsius ranged from 6.57 to 7.44 percent, with the 40 percent composite retaining the most, likely carbonaceous char from lignin plus natural mineral ash, though the authors caution the trend is not systematic.

Taken together, the study delivers a sober but genuinely useful verdict: sago pith waste can indeed be incorporated into unsaturated polyester as a renewable, nearly free filler, lightening the material while leaving the resin’s chemistry intact, but rising filler content drags in porosity and interfacial defects that erode bending strength. The authors frame the work as the integrating chapter of a broader program that previously examined tensile, acoustic, and thermal-conductivity behavior separately, and they point squarely at future work on particle-size optimization, improved processing, and surface chemical modification of the waste as the levers that could turn an agricultural liability into panels for insulation, construction, and other value-added uses. For Indonesia’s sago mills, the residue currently rotting behind the factory may be one sieve, one mixer, and one better interface away from a second life.

Subject of Research: Characterization of sago pith waste-filled unsaturated polyester composites

Article Title: The analysis of sago pith waste – unsaturated polyester composites by mechanical, SEM, FTIR, DSC, and TGA tests

Article References: Luthfi, Azhar, Jagodang, H., Riyadhsyah, T., Rihayat, T., & Setiawan, A. (2026). The analysis of sago pith waste – unsaturated polyester composites by mechanical, SEM, FTIR, DSC, and TGA tests. Environmental Challenges, 25, Article 101681. https://doi.org/10.1016/j.envc.2026.101681

Image Credits: AI Generated

DOI: 10.1016/j.envc.2026.101681

Keywords: sago pith waste, unsaturated polyester resin, natural fiber composites, flexural strength, porosity, FTIR, DSC, TGA, SEM, biomass waste utilization, Indonesia, thermal degradation

The motivation behind the research sits at the intersection of agriculture and green chemistry. Plant-derived extracts are increasingly investigated as sources of environmentally compatible compounds that could replace synthetic chemicals in agricultural applications, from crop protection to soil amendments. Nettle is an attractive candidate because it is widely available, grows readily in Ethiopia, and is known to contain a diverse array of secondary metabolites. Yet the value of any plant extract depends heavily on how efficiently those compounds are recovered, and the authors note that information on optimized extraction of Ethiopian Urtica dioica leaves has remained limited. Without that information, any downstream application would rest on guesswork rather than on a characterized, reproducible process.

The extraction method at the heart of the study is the Soxhlet technique, a workhorse of natural products chemistry that has been in use for well over a century. In a Soxhlet apparatus, a solvent is repeatedly cycled through the plant material: solvent vapor rises, condenses, drips onto a thimble holding the powdered leaves, and once the siphon fills, the solvent carrying dissolved compounds drains back into the boiling flask. Each cycle exposes the plant matrix to fresh solvent, which is why Soxhlet extraction is prized for its thoroughness. But the same thoroughness comes with sensitivity to conditions. Too much heat can degrade thermolabile compounds or drive off volatile ones; too little time leaves valuable chemistry locked in the plant tissue; and the solid-to-solvent ratio governs how much material the solvent can dissolve before it approaches saturation.

Rather than testing conditions one variable at a time, the team employed response surface methodology, or RSM, a statistical framework that treats an industrial or laboratory process as a mathematical surface whose height, in this case the extraction yield, depends on the settings of several input variables. Within RSM, the researchers used a central composite design, a specific experimental layout that efficiently samples the corners, faces, and center of the experimental space. The design allowed them to vary three factors simultaneously: extraction temperature across a range of 50 to 70 degrees Celsius, extraction time from 3 to 5 hours, and the solid-to-solvent ratio from 0.125 to 0.1875 grams per milliliter. By fitting a quadratic model to the resulting yield data, they could capture not only the individual effect of each factor but also the interactions between them, which one-variable-at-a-time experiments would miss entirely.

The statistical quality of the fitted model proved strong. The quadratic model was highly significant, with a p-value below 0.0001, indicating that the relationship between the process variables and extraction yield was unlikely to be a statistical accident. Equally important, the lack-of-fit test came back non-significant, with a p-value of 0.0749. In the language of experimental design, a significant lack of fit would signal that the quadratic equation was missing genuine structure in the data, whereas a non-significant result means the model adequately describes the response surface across the tested range. That combination, a significant model with an insignificant lack of fit, is exactly what an experimenter hopes to see before trusting the model to make predictions outside the exact conditions that were physically tested.

With the validated model in hand, the researchers turned to numerical optimization to find the point on the response surface where yield is maximized. The optimum landed at an extraction temperature of 64.62 degrees Celsius, an extraction time of just 3.01 hours, and a solid-to-solvent ratio of 0.139 grams per milliliter. Under those conditions, the model predicted an extraction yield of 0.330 percent by weight. Several features of that optimum are noteworthy. The predicted best temperature sits comfortably inside the tested range rather than at an extreme, suggesting a genuine interior maximum where the benefits of increased solubility and diffusion are balanced against the risks of thermal degradation. The optimal time of roughly three hours, at the low end of the tested window, hints that most of the extractable material is recovered early and that extended extraction adds little, a finding with real implications for energy consumption and throughput if the process is ever scaled up.

Optimization alone, however, says nothing about what is actually in the extract, so the team complemented the yield study with a preliminary chemical characterization using two complementary techniques. Fourier-transform infrared spectroscopy, or FTIR, probes the vibrational signatures of chemical bonds, allowing researchers to identify the functional groups present in a sample, such as hydroxyl groups characteristic of phenols and flavonoids, carbonyl groups found in many plant metabolites, and the carbon-hydrogen frameworks of lipids and waxes. Thin-layer chromatography, or TLC, takes a different approach, separating the extract’s constituents as they migrate at different speeds across a coated plate, revealing how many distinct chemical fractions the extract contains. Together, the two methods provided preliminary evidence of diverse functional groups and multiple chromatographic fractions in the nettle leaf extract, confirming that the optimized process recovers chemically rich material rather than a narrow, uninteresting fraction.

The significance of the work extends beyond the specific numbers. For researchers working with plant extracts as candidates for agricultural or pharmaceutical use, the study demonstrates a disciplined pipeline: define the process variables, model their combined effects statistically, validate the model, optimize it, and only then characterize the product. That sequence matters because an unoptimized extraction can bias the chemical profile of an extract, enriching some compounds while leaving others behind, which in turn makes biological testing difficult to reproduce. By establishing an optimized laboratory-scale extraction condition and a preliminary chemical profile for Ethiopian Urtica dioica leaves, the authors have created a reproducible baseline that other laboratories can adopt, compare against, and refine.

There are also broader implications for how underutilized plants are developed as resources. Ethiopia’s nettle populations have long been part of local knowledge, but transforming that traditional resource into a standardized product requires exactly the kind of quantitative process engineering this study provides. The modest yield of 0.330 percent by weight may sound small, but for many plant secondary metabolites such figures are typical, and the value lies in the identity and activity of the extracted compounds rather than in bulk mass. The open-access publication, funded without external support and carried out with chemicals and instruments provided by Bahir Dar University, also illustrates how well-equipped institutions in the Global South can contribute rigorous, citable process chemistry to the global natural products literature.

As with any preliminary characterization, the authors are careful about scope. FTIR and TLC establish the presence of diverse chemistry but do not identify individual compounds, a task that would require more powerful tools such as high-performance liquid chromatography coupled with mass spectrometry. The study likewise does not test the extract’s biological activity in agricultural settings, which remains the logical next step now that a consistent extraction protocol exists. Still, the work captures something of a quiet revolution in natural products research: the stinging nettle, a plant most people avoid touching, is being handled with the same statistical rigor that governs petrochemical refineries and pharmaceutical manufacturing. In the hands of chemical engineers armed with central composite designs and response surfaces, even a common weed becomes a process to be understood, optimized, and, perhaps one day, deployed in service of more sustainable agriculture.

Subject of Research: Optimization of Soxhlet extraction of Urtica dioica leaf extract using response surface methodology

Article Title: Optimization of Soxhlet extraction conditions and preliminary phytochemical characterization of Urtica dioica leaf extract using response surface methodology

Article References: Getahun, S. A., Abera, W. G., Enyew, T. W., & Aklilu, H. A. (2026). Optimization of Soxhlet extraction conditions and preliminary phytochemical characterization of Urtica dioica leaf extract using response surface methodology. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10102-x

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10102-x

Keywords: Urtica dioica, stinging nettle, Soxhlet extraction, response surface methodology, central composite design, extraction optimization, phytochemical characterization, FTIR, thin-layer chromatography, natural products, plant extracts, Bahir Dar University

The experimental design is deceptively simple but methodologically deliberate. Stage 1 held ghee at 60 to 70 degrees Celsius for 30 minutes in a water bath, mimicking warm storage and culinary preheat. Stage 2 ramped the sample from 220 to 340 degrees Celsius in 20-degree steps, each held for five minutes, under flowing nitrogen to suppress oxidative side reactions. Stage 3 dropped the sample directly into a muffle furnace set to a nominal 500 degrees Celsius for just 90 seconds, a condition meant to model the pyrolytic shock of a cooking flare-up rather than ordinary frying. The authors are candid about a key caveat here: no thermocouple sat at the sample, and a 50-gram liquid charge cannot reach furnace temperature in 90 seconds, so the reported set point is an upper bound on what the ghee actually experienced. Five independent replicates were run for each stage and each temperature step, giving the statistical backbone for the comparisons that followed.

At the gentle end of the scale, the chemistry was quiet but measurable. Infrared spectroscopy of the residue showed a broadening O-H stretch and a growing carbonyl feature, the fingerprints of ester hydrolysis, the slow cleavage of the fat’s triglyceride bonds by water. Titration confirmed it: free fatty acid content rose from 0.42 percent to 0.71 percent over the 30-minute hold, a statistically significant increase, while free glycerol, released from the same broken esters, accumulated to 0.18 percent of sample mass. Crucially, no volatile carbonyls escaped at this temperature. Glycerol was liberated but not yet dehydrated, meaning the fat was ageing without yet becoming a source of airborne toxins. The team notes this mirrors the mild hydrolytic ageing documented in butter during warm storage, and that the two-step cascade they propose, hydrolysis first and dehydration later, remains plausible but unproven because the stages used separate aliquots of ghee.

The intermediate stage is where the story turns toxic. As the temperature climbed through the 280 to 320 degrees Celsius window, acrolein, a pungent, irritating aldehyde flagged by food scientists and air-quality regulators alike, surged to a maximum of 112.6 micrograms per gram of ghee at 300 degrees Celsius, accounting for 64.2 percent of all carbonyls detected by derivatisation and high-performance liquid chromatography. Above 300 degrees the acrolein yield fell, consistent with the molecule itself breaking apart into smaller fragments. The peak sits squarely inside the 280 to 340 degrees Celsius window known for catalytic glycerol dehydration, and the glycerol backbone of triglycerides, not the fatty-acid chains, is the established precursor. In other words, the glycerol freed during low-temperature hydrolysis becomes the feedstock for acrolein once the ghee approaches its smoke point, a two-act mechanism the data support circumstantially if not yet causally.

Stage 3 delivered the study’s most tantalising puzzle. Within a minute of insertion into the hot furnace, the headspace flooded with volatile fragments, and proton-transfer-reaction time-of-flight mass spectrometry caught a base peak at nominal mass-to-charge ratio 27 that rose between 45 and 60 seconds and decayed to background by about 180 seconds, with a 1/e decay time of 90 to 140 seconds. The signal matched none of the carbonyl reference standards. The team systematically eliminated the obvious candidates: vinyl alcohol, ketene and propene would all appear at different masses in proton-transfer ionisation, and the absence of any protonated parent at mass 43 rules out ketene and propene outright. The falling intensity across masses 27, 28 and 29 suggests hard, electron-impact-like fragmentation rather than soft proton transfer. Definitive identification would have required exact-mass measurement to distinguish the C2H3+ ion at 27.0229 from other formulas, but the raw high-resolution data files were not retained and cannot be recovered. The researchers therefore report an unassigned transient ion, an unusually honest label in a field where over-claiming is common.

Conventional bag sampling told a complementary story. Tedlar-bag gas chromatography-mass spectrometry of the Stage 3 headspace detected acrolein at 245 micrograms per gram, along with benzene, toluene, 1,3-butadiene and 2-methylfuran, a roster of light aromatics and dienes consistent with radical cracking of fatty-acid chains above 400 degrees Celsius. Notably, the transient mass-27 ion was absent from the bag samples, consistent with a lifetime shorter than the storage interval, exactly the class of short-lived reactive species that conventional cooking-emission studies, which typically operate at 150 to 250 degrees Celsius and rely on bag capture, have never catalogued. Mass-balance accounting showed progressive loss of material through the stages, with the lowest recovery at Stage 3, the missing fraction inferred to be non-condensable gases such as hydrogen, methane and carbon monoxide that the protocol did not capture.

The most unexpected experiment came last. The team injected 100 millilitres of pyrolysis gas into a 2.5-litre humid chamber held at 25 degrees Celsius and 65 percent relative humidity, alongside blank and nitrogen-injection controls, and watched what happened to the water. Gravimetric uptake on desiccant cartridges reached 1.3 milligrams after 30 minutes in the pyrolysis condition, against 0.3 milligrams for the blank and 0.4 for the nitrogen control, a difference that held up statistically against the blank and was marginal against the nitrogen control. Raman spectroscopy of the chamber’s O-H stretching envelope told the same story from a different angle: under pyrolysis gas the envelope maximum shifted 4 to 7 wavenumbers toward lower frequency, and roughly 8 percentage points of intensity migrated from the higher-frequency sub-band to the lower-frequency one, a redistribution consistent with oxygenated organic species hydrogen-bonding to water.

The authors are careful, almost to a fault, about what this chamber result does and does not mean. The Raman envelope peaks near 3400 wavenumbers, the signature of condensed water, not the two narrow gas-phase stretches near 3657 and 3756, so the signal reflects an integrated chamber water response dominated by condensed films and droplets rather than resolved gas-phase clusters. The 100-millilitre injection is a 4 percent by-volume perturbation, several orders of magnitude above ambient cooking-VOC mixing ratios, and with only three replicates per condition the design detects only large effects. The team explicitly frames the experiment as a laboratory feasibility observation carrying no atmospheric inference. Still, the coincidence of gravimetric uptake, spectral shift and sub-band redistribution is a genuine first: no prior study has tested whether high-temperature lipid pyrolysis products perturb a water-vapour hydrogen-bonding network at all, and the answer, provisionally, is that they do something measurable.

The practical implications reach from the stovetop to the atmosphere. Cooking is a newly recognised heavyweight in urban air chemistry, accounting for up to 20 percent of anthropogenic volatile organic compound emissions in some PTR-MS field studies, with cooking organic aerosol emission factors spanning 0.1 to 6 grams per kilogram of food. In domestic cooking, where temperatures rarely exceed 250 degrees Celsius, the study suggests the acrolein window opens as ghee nears its smoke point, reinforcing long-standing concerns about overheating clarified butter. The Stage 3 regime applies only to flare-ups, oil fires and industrial high-heat frying, but it is precisely there that short-lived reactive species, the kind no bag sample can catch, are released. The authors lay out a clear roadmap: a continuous temperature ramp tracking free fatty acid, glycerol and acrolein simultaneously to confirm the hydrolysis-dehydration cascade; high-resolution mass spectrometry with isotope-pattern resolution to finally name the mass-27 ion; and chamber experiments at parts-per-billion mixing ratios with condensed water controlled, ideally in vessels above 100 litres with cryogenic trapping. Until then, the humble jar of ghee carries a chemical secret that only extreme heat, and now careful instrumentation, can reveal.

Subject of Research: Thermal degradation chemistry of cow ghee from hydrolysis to pyrolysis and its pyrolysis products' interaction with water vapour

Article Title: Thermal decomposition of cow ghee by multi-stage heating and preliminary study of interactions of pyrolysis products with water vapour

Article References: Dorepalli, N. R., Prasad, M. S. V. K. V., & Pappoppula, S. (2026). Thermal decomposition of cow ghee by multi-stage heating and preliminary study of interactions of pyrolysis products with water vapour. Discover Chemistry, 3(1), Article 564. https://doi.org/10.1007/s44371-026-01008-6

Image Credits: AI Generated

DOI: 10.1007/s44371-026-01008-6

Keywords: cow ghee, acrolein, pyrolysis, glycerol dehydration, PTR-ToF-MS, FTIR, HPLC-DNPH, cooking emissions, indoor air quality, water vapour, Raman spectroscopy, free fatty acids

The motivation behind the work is stark. Decades of intensive fertilizer and pesticide use have degraded soil structure, depleted organic matter, and undermined the biological activity that underpins long-term productivity. Microbial exopolysaccharides have attracted attention as a gentler alternative because of the multiple roles they can play in the soil environment. These long-chain carbohydrates help bacteria adhere to surfaces and form biofilms, but in the wider soil system they can improve water retention, stabilize soil aggregates, and modulate plant physiological responses to stress. Earlier studies have shown that EPS-producing bacteria can restrict sodium uptake in salt-stressed wheat seedlings, alleviate drought effects in sunflower and maize, and improve soil aggregation in degraded land. What has been less explored is the potential of bacteria that live as endophytes inside seeds themselves, a niche that offers a particularly intimate and protected association with the host plant.

The researchers began with a collection of 86 pearl millet seed endophytic bacteria, abbreviated PMSEB, previously isolated from surface-sterilized seeds. Screening for EPS production was carried out on two different growth media, Nutrient Agar and ATCC No. 14 medium, allowing the team to identify which strains were prolific polymer producers under laboratory conditions. Selected high-producing strains were then subjected to extraction, partial purification, and quantification of their exopolysaccharides, with carbohydrate content measured using the classical anthrone-sulfuric acid colorimetric method originally described by Dreywood in 1948. This pipeline, from raw culture to partially purified polymer, mirrors the practical steps any industrial production process would need to follow, making the study as much about process development as about discovery.

The first biological test was a seed germination bioassay using partially purified EPS applied at a concentration of 0.2 percent. The results showed a clear biostimulatory effect on early-stage wheat growth, with treated seeds germinating better and producing more vigorous seedlings than untreated controls. The team then explored dose dependence, testing EPS solutions at 0.25, 0.5, and 1 percent. The response varied with concentration, an important observation for anyone hoping to translate laboratory results into field-ready formulations, since overdosing a biostimulant can be as counterproductive as underdosing it. Three strains stood out from the pack: MPT27, PC7N47, and PC7T5, whose EPS produced significant improvements in seed germination, seedling dry weight, and vigor indices, the standard metrics used to quantify seedling quality in agricultural science.

Molecular identification revealed a taxonomically diverse trio. Strain MPT27 was identified as Atlantibacter hermannii, a member of the Enterobacteriaceae, while PC7N47 and PC7T5 were both classified as Bacillus subtilis subsp. subtilis, a species with a long and celebrated history in agricultural biotechnology. Partial 16S ribosomal RNA sequences for all three strains have been deposited in the NCBI GenBank database under accession numbers PQ182223, PQ182224, and PQ182225, providing a permanent record that other laboratories can use to obtain and verify the same organisms. The fact that two independent Bacillus isolates from the same seed source proved to be strong EPS producers underscores how common this trait may be among seed-associated beneficial bacteria.

Because yield matters as much as efficacy in any commercial context, the researchers systematically optimized EPS production for each strain. Culture conditions were tuned strain by strain, and the carbon source in the growth medium emerged as a decisive variable, with sucrose proving the most effective substrate for polymer synthesis. This kind of strain-specific optimization is a recurring theme in EPS bioprocess literature; studies on lactic acid bacteria, alkaliphilic Bacillus species, and marine isolates have all shown that medium composition, pH, and incubation parameters can swing production yields dramatically. The New Delhi team’s results confirm that there is no universal recipe, and that each promising organism requires its own tailored fermentation strategy before it can be considered a viable production platform.

Characterization of the extracted polymers revealed meaningful differences between strains, differences that could matter functionally in the field. Water absorption capacity, a key property for a compound intended to help soil retain moisture, varied among the EPS samples, as did antioxidant activity measured by the DPPH radical scavenging assay. Fourier-transform infrared spectroscopy, or FTIR, confirmed the presence of the characteristic functional groups of polysaccharides, including the broad hydroxyl stretching bands and carbon-oxygen signatures expected of carbohydrate polymers. Monosaccharide composition analysis added a structural dimension: the EPS from MPT27 and PC7N47 were heteropolysaccharides, built from more than one kind of sugar unit, whereas the polymer from PC7T5 was a homopolysaccharide composed of a single repeating sugar. Such structural distinctions often correlate with differences in rheology, solubility, and biological activity, and they give formulators a molecular handle for selecting the right polymer for a given application.

The broader significance of the study lies in its framing of EPS as a phytostimulant in their own right, decoupled from the living bacteria that make them. Applying purified or partially purified polymers avoids some of the regulatory and logistical complications of live microbial inoculants, which can be sensitive to storage conditions, compete poorly with native soil flora, or face import restrictions across borders. A stable carbohydrate formulation, by contrast, could be blended with seeds, delivered through irrigation, or combined with conventional inputs. Previous work by other groups has moved in this direction, including talc-based EPS formulations that enhanced sunflower growth under saline conditions and bioformulations combining bacterial cultures with their exopolysaccharides to improve pigeon pea productivity. The wheat results reported here extend that logic to a staple crop of global importance and to a novel source of polymers, the internal microbiome of seeds.

There are, of course, substantial steps between a germination paper assay and a farmer’s field. The experiments reported involve early-stage seedlings under controlled conditions, and the partially purified EPS preparations still contain undefined components that would need to be standardized for commercial use. Field-scale trials would need to test whether the germination and vigor benefits persist in real soils, whether the polymers interact constructively with fertilizers and pesticides already in use, and whether production costs can be brought down to levels that make economic sense for wheat growers operating on thin margins. The dose-dependent responses observed also suggest that application protocols will need careful calibration, possibly varying by soil type, climate, and crop variety.

Even so, the study offers a compelling glimpse of where agricultural biotechnology is heading. As the environmental costs of chemical-intensive farming become harder to ignore, researchers are increasingly mining the plant microbiome not just for organisms but for the molecules those organisms produce. Seed endophytes are a particularly attractive starting point because they are vertically transmitted, evolutionarily curated by the host plant, and already adapted to the crop environment. By screening 86 isolates, optimizing fermentation, and characterizing the resulting polymers down to their monosaccharide building blocks, Kamali and colleagues have demonstrated a complete discovery-to-characterization workflow for seed-derived EPS. Their three standout strains, including two Bacillus subtilis subspecies and an Atlantibacter hermannii, now join a short but growing list of microbes whose sugary secretions may help crops establish faster, cope with stress, and yield more, all while easing the chemical burden on the world’s farmland.

Subject of Research: Exopolysaccharides from pearl millet seed endophytic bacteria as phytostimulants for wheat growth

Article Title: Harnessing endophytic bacteria for enhanced wheat growth: extraction, optimization, and characterization of exopolysaccharides

Article References: Kamali, R., Grover, M., Singh, G., Kaushik, R., & Jaiswal, P. (2026). Harnessing endophytic bacteria for enhanced wheat growth: extraction, optimization, and characterization of exopolysaccharides. 3 Biotech, 16(11), Article 455. https://doi.org/10.1007/s13205-026-05074-6

Image Credits: AI Generated

DOI: 10.1007/s13205-026-05074-6

Keywords: exopolysaccharides, endophytic bacteria, wheat, pearl millet, biostimulants, Bacillus subtilis, seed germination, sustainable agriculture, FTIR, heteropolysaccharides, soil health, plant growth promotion

The work, which appeared on 5 October 2026 as volume 83, article 667 of the journal, tackles a question that has long been answered only empirically: how exactly should a PCE superplasticizer be manufactured so that the resulting concrete flows freely and hardens to maximum strength? Instead of varying one parameter at a time, the researcher applied a formal Design of Experiments strategy known as the Box–Behnken design, coupled with analysis of variance, using Design-Expert software version 11.1. Three synthesis variables were examined simultaneously: reaction temperature, the concentration of the monomer HPMA, and the monomer feeding time during free-radical copolymerization.

The choice of those three variables is not arbitrary. In free-radical copolymerization, temperature governs the kinetics of chain growth and termination, monomer concentration shapes the composition and length of the growing polymer chains, and feeding time controls how uniformly the monomers are incorporated into the final comb-like architecture. PCE molecules consist of a charged backbone carrying pendant polyether side chains, and it is this comb structure that gives the polymer its dispersing power. When cement particles are mixed with water, they tend to clump together; the adsorbed PCE molecules push the particles apart through electrostatic repulsion and, more importantly, through steric hindrance, in which the dangling side chains physically block particles from approaching one another.

To measure whether a given polymer recipe actually worked, the study used two concrete-level responses. The first was slump, the classic measure of workability in which a cone of fresh concrete is lifted away and the degree to which the mix slumps is recorded in centimeters. The second was 28-day compressive strength, the standard benchmark of how much load the hardened concrete can bear. The concrete used in the tests was produced at the C25/30 strength class with an S3–S4 slump class, and notably it incorporated fine aggregate with a methylene blue value of 2 g/kg, a parameter that indicates a certain clay content in the sand. Clay is a known enemy of PCE superplasticizers, because clay minerals can intercalate the polymer molecules and strip them out of solution before they reach the cement particles, so a moderately clay-bearing aggregate makes the optimization task more demanding and more realistic.

The statistical models that emerged from the Box–Behnken design were strikingly strong. For slump, the second-order model achieved a coefficient of determination of 0.9480, and for 28-day compressive strength the fit was even tighter at 0.9950. In practical terms, this means that nearly all of the observed variation in concrete performance could be explained by the three synthesis parameters and their interactions, leaving very little unexplained noise. Analysis of variance confirmed that the models were statistically significant for both responses, and lack-of-fit tests showed non-significant discordance, indicating that the quadratic equations adequately captured the true response surfaces rather than merely fitting the experimental points.

Within those models, two factors stood out. Reaction temperature and HPMA concentration were identified as the most influential parameters for both slump and compressive strength, with p-values below 0.01. Temperature exerted its effect through polymerization kinetics: at 40 °C, the reaction proceeded in a controlled manner that favored the formation of well-defined comb-like structures with enhanced steric hindrance, which translated directly into better dispersion of cement particles and higher slump. At higher temperatures, the polymerization became less efficient because accelerated side reactions competed with the desired chain growth, degrading the uniformity of the comb architecture and, with it, the performance of the final admixture.

The optimization procedure converged on a precise recipe: an HPMA concentration of 2.5 M, a monomer feeding time of 4.83 hours, and a reaction temperature of 40 °C. Under these conditions, the synthesized PCE delivered a slump of 14.94 cm and a 28-day compressive strength of 34.29 MPa. Those numbers are meaningful in context. A slump approaching 15 cm corresponds to a highly workable, flowing concrete that can be pumped and placed around dense reinforcement, while a compressive strength above 34 MPa comfortably exceeds the 25 MPa characteristic cylinder strength targeted by the C25/30 class, achieved even in the presence of clay-contaminated fine aggregate that would normally compromise superplasticizer efficiency.

Because a statistical optimum is only as credible as the chemistry behind it, the study also characterized the synthesized polymer with a battery of structural techniques. X-ray diffraction, Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and scanning electron microscopy were all used to confirm the structure of the PCE. Together these methods verify that the expected functional groups are present, that the copolymerization produced the intended molecular framework, and that the solid polymer exhibits the morphology associated with effective comb-type superplasticizers. The combination of structural confirmation with response-surface modeling is what the author identifies as the novel contribution of the work: a quantitative bridge linking synthesis parameters, molecular architecture, and macroscopic concrete performance.

The broader significance of the study lies in how it reframes admixture manufacturing. Superplasticizer production has traditionally relied on experience and iterative adjustment, with each new monomer combination or plant condition requiring fresh experimentation. By demonstrating that a relatively small Box–Behnken matrix can map the entire parameter space and locate the optimum with high confidence, the research offers a template that manufacturers could adapt to other monomer systems, other clay-bearing aggregates, or other performance targets. The ANOVA framework also reveals interactions between factors that one-variable-at-a-time experiments would miss entirely, such as how the benefit of a particular monomer concentration may shift depending on the reaction temperature at which it is fed.

For the construction industry, the implications are concrete in every sense. Higher slump at fixed water content means less water demand, and lower water-to-cement ratios are the single most reliable route to stronger, more durable, and lower-carbon concrete, since cement production accounts for a substantial share of global carbon dioxide emissions. A statistically optimized PCE that maintains its dispersing power even against aggregates with a measurable methylene blue value could help producers use local, clay-bearing sands that would otherwise be rejected or washed at additional cost. The study’s highlights make the practical guidance explicit: variations in synthesis parameters significantly influenced the dispersing efficiency and workability of concrete, and the findings are intended to guide the design of high-performance PCE superplasticizers for real construction applications. As infrastructure demands grow and material tolerances tighten, the message of this research is that the molecules which make concrete flow can now be engineered with the same statistical rigor that engineers apply to the structures they build.

Subject of Research: Statistical optimization of polycarboxylate ether superplasticizer synthesis for improved concrete workability and strength

Article Title: Box–Behnken optimization of polycarboxylate ether synthesis for concrete performance

Article References: Özserçe Haste, Z. (2026). Box–Behnken optimization of polycarboxylate ether synthesis for concrete performance. Polymer Bulletin, 83(12), Article 667. https://doi.org/10.1007/s00289-026-06718-6

Image Credits: AI Generated

DOI: 10.1007/s00289-026-06718-6

Keywords: polycarboxylate ether, superplasticizer, concrete, Box–Behnken design, ANOVA, free-radical copolymerization, slump, compressive strength, HPMA, methylene blue value, FTIR, XRD