Malolactic fermentation is far more than an acid adjustment. As lactic acid bacteria consume malic acid, they also release a cascade of metabolic byproducts that shape a wine’s aroma, mouthfeel, and stability. Diacetyl contributes buttery notes, esters modulate fruit expression, and the bacteria’s enzymatic machinery can either enhance or strip away desirable volatile compounds. The choice of which bacterium performs this transformation is therefore one of the most consequential decisions a winemaker makes, and the industry’s reliance on a narrow genetic pool has long struck researchers as both a limitation and an opportunity.

The research team, led by Carla Vargas-Luna of the Pontificia Universidad Católica de Chile, focused on two indigenous strains: Levilactobacillus brevis BCV-46 and Levilactobacillus brevis C18, both isolated from Chilean grapes. They compared these against a commercial Lactiplantibacillus plantarum strain, a species that has emerged in recent years as the leading alternative to Oenococcus oeni. The experiments were conducted at microvinification scale, using four-liter fermentations of Chardonnay must, with each bacterial strain co-inoculated alongside Saccharomyces cerevisiae, the yeast responsible for the primary alcoholic fermentation. This co-inoculation strategy, in which yeast and bacteria are introduced together rather than sequentially, is gaining favor because it shortens production schedules and reduces the risk of spontaneous bacterial growth between fermentations.

A central concern in any such experiment is whether the bacteria will interfere with the yeast’s work. Alcoholic fermentation depends on Saccharomyces cerevisiae converting sugars to ethanol efficiently and completely, and some lactic acid bacteria produce compounds that inhibit yeast metabolism. The researchers found encouraging news on this front: co-inoculation did not impair alcoholic fermentation in any of the treatments. The yeast completed its task regardless of which bacterial companion was present, confirming that these native strains are compatible with standard winemaking yeast at the timing and conditions tested.

The malolactic conversion itself, however, proved more uneven. Only partial malolactic fermentation occurred across the trials, and the degree of malic acid degradation varied substantially by strain. The commercial Lactiplantibacillus plantarum achieved the highest level of malic acid breakdown, demonstrating why it has become the benchmark alternative starter. Among the native strains, Levilactobacillus brevis BCV-46 outperformed its compatriot C18 in acid conversion. The incomplete fermentation suggests that these strains, while viable, may require further optimization of inoculation timing, cell density, or nutritional conditions to fully complete the acid conversion in white wines, which are generally a harsher environment for lactic acid bacteria than reds due to lower pH, higher acidity, and fewer nutrients.

Despite the partial conversion, the chemical differences among the wines were measurable and meaningful. The researchers documented variations in chemical composition across the treatments, though all wines remained within acceptable enological limits, meaning none of the bacterial interventions pushed the wines outside the ranges considered sound and stable for commercial production. This is a nontrivial finding, because lactic acid bacteria can consume residual sugars, produce acetic acid, or alter pH in ways that compromise wine integrity. The native strains passed this basic quality threshold, establishing their fundamental suitability for further development.

The safety dimension of the study produced the sharpest contrast between the two native isolates. Biogenic amines, including histamine, tyramine, and putrescine, are nitrogen-containing compounds that some lactic acid bacteria generate by decarboxylating amino acids. At elevated concentrations, these amines can trigger headaches, flushing, and blood pressure changes in sensitive individuals, and histamine in particular is regulated in some markets. Using molecular screening, the researchers searched for the amino acid decarboxylase genes that confer the ability to produce these compounds. The genes were detected only in L. brevis C18, and correspondingly, wines fermented with that strain showed higher concentrations of tyramine and putrescine. The other strains, including BCV-46 and the commercial L. plantarum, did not carry the decarboxylase genes and did not elevate these amines.

This single genetic distinction transforms the practical outlook for the two native strains. BCV-46 emerges as a candidate worth pursuing: it degraded malic acid respectably, left the wine chemically sound, and carried no detectable amine-producing potential. C18, by contrast, would require careful evaluation before any commercial use, since its amine production represents a genuine food safety consideration. The finding underscores a principle that wine microbiologists have emphasized repeatedly: safety and quality traits are strain-dependent rather than species-dependent, and each candidate starter must be individually characterized before deployment.

Perhaps the most appealing results came from the sensory analysis. The wines produced with different bacterial strains developed significantly different sensory profiles, and the selected native strains enhanced floral, fruity, and creamy attributes in the Chardonnay. These are precisely the aromatic dimensions that white wine consumers prize, and the fact that indigenous Latin American strains could amplify them hints at a strategy for producing wines with a genuine sense of place. Regional microbial biodiversity, long dismissed as a source of unpredictable spoilage, may instead be a reservoir of distinctive flavor signatures that commercial starter cultures cannot replicate.

The broader significance of the work lies in its demonstration that the next generation of malolactic starter cultures may come from vineyards far removed from the traditional wine heartlands of Europe. As climate change alters growing conditions and winemakers worldwide seek to differentiate their products, native bacterial strains offer a dual advantage: adaptation to local conditions and the potential for unique sensory contributions. The Chilean and Mexican research groups behind this study have shown that careful screening, combining fermentation performance testing, chemical analysis, sensory evaluation, and genetic safety checks, can identify which native strains deserve investment and which should be left in the vineyard. For now, the commercial Lactiplantibacillus plantarum still leads in acid conversion, but the native BCV-46 strain has staked its claim as a safe, flavor-enhancing alternative, and the race to domesticate Latin America’s wine microbiome has only begun.

Subject of Research: Non-Oenococcus lactic acid bacteria as malolactic fermentation starters in Chardonnay wine

Article Title: Latin-American non-Oenococcus lactic acid bacteria in Chardonnay wine: effects on chemical composition, sensory profile, and biogenic amine production

Article References: Vargas-Luna, C., Franco, W., Arvizu-Medrano, S., Cortés-Herrera, C., Redondo-Solano, M., Barboza-Vargas, N., Godoy-Olivares, L., & Miranda-Castilleja, D. (2026). Latin-American non-Oenococcus lactic acid bacteria in Chardonnay wine: effects on chemical composition, sensory profile, and biogenic amine production. Food Science and Biotechnology. https://doi.org/10.1007/s10068-026-02330-6

Image Credits: AI Generated

DOI: 10.1007/s10068-026-02330-6

Keywords: malolactic fermentation, Chardonnay, lactic acid bacteria, Lactiplantibacillus plantarum, Levilactobacillus brevis, biogenic amines, wine microbiology, co-inoculation, Saccharomyces cerevisiae, sensory profile, food safety, Latin America

The research team, led by Ivan Dudaš of the University of Novi Sad and Åbo Akademi University, tested five cyanobacterial strains alongside five fungal strains, both individually and in every possible cyanobacteria–fungi combination, on quartz sand tailings over a 90-day incubation period. The cyanobacteria included species from the genera Nostoc, Trichormus, Tolypothrix, and two strains of Chroococcidiopsis, while the fungal panel comprised Penicillium oxalicum, Purpureocillium lilacinum, Aspergillus clavatus, Penicillium brasilianum, and Talaromyces wortmannii. This systematic screening of all 25 pairings is what gives the study its unusual power: rather than assuming that mixing microbes is always beneficial, the researchers could measure exactly how each combination performed.

Biocrusts are natural features of arid and semi-arid ecosystems worldwide, where cyanobacteria, lichens, mosses, and fungi colonize the top millimeters of soil and hold it together. In natural settings, these crusts form slowly over years or decades. The concept behind induced biocrusts is to jump-start the process by seeding suitable substrates with pioneer organisms. Cyanobacteria are the classic choice because many filamentous species glide through sediment, excrete sticky exopolysaccharides, and even contribute to carbonate precipitation. But the authors of the new study argue that the fungal side of the partnership has been largely overlooked, even though fungi in natural biocrusts weave hyphal networks that enmesh sand grains and can supply nutrients and moisture to their photosynthetic partners.

To evaluate success, the team deployed a battery of physical and biochemical measurements. Scanning electron microscopy revealed whether the microbes had actually colonized the tailings and bound sediment particles together. Chlorophyll-a content served as a proxy for cyanobacterial biomass, while exopolysaccharide production—measured in both loosely bound and tightly bound fractions—indicated how much glue-like material the community was generating. The researchers also assessed fungal abundance, the thickness of the induced crust, water drop penetration time as a measure of surface water repellency, and sediment penetration resistance as an indicator of mechanical stability.

The results showed that pairing mattered enormously. Certain combinations produced striking synergies that far exceeded anything achieved by cyanobacteria alone. The pairing of Tolypothrix sp. with Penicillium oxalicum delivered substantial boosts in chlorophyll-a, exopolysaccharides, and water repellency, while Trichormus sp. combined with Purpureocillium lilacinum produced thicker induced crusts along with a modest increase in sediment stability. Scanning electron micrographs confirmed that in these successful combinations, the microbes had effectively colonized the sand and were binding particles through EPS-mediated stabilization, with fungal filaments and cyanobacterial filaments visibly entangling the quartz grains.

Just as revealing were the failures. Some pairings had little effect at all, and others actively harmed crust development. Tolypothrix sp. combined with either Penicillium brasilianum or Talaromyces wortmannii caused significant reductions in key indicators, demonstrating that incompatibility between strains can undermine the entire enterprise. The authors emphasize that the benefits of co-inoculation depend strongly on the compatibility of the specific microorganisms involved—a caution for anyone hoping to simply throw a microbial cocktail at a degraded landscape and expect improvement.

Correlation analysis added a layer of nuance that complicates any simple recipe for crust engineering. Chlorophyll-a and the loosely bound EPS fraction were positively correlated with each other and with water repellency, suggesting that photosynthetic biomass and polysaccharide glue reinforce one another and help the surface shed or repel water. Yet crust thickness told a different story: it was negatively correlated with water repellency, chlorophyll-a, and penetration resistance. In other words, thicker crusts were not automatically stronger or more photosynthetically active, and different functional traits of the induced biocrusts responded in contrasting ways. This decoupling means that restoration practitioners may need to decide which property matters most for a given site—surface sealing, mechanical resistance, or biomass accumulation—and select their microbial partners accordingly.

The implications extend well beyond a single laboratory experiment. Quartz sand tailings are generated in enormous quantities by mining and mineral processing operations around the world, and their fine, unconsolidated particles are prone to becoming airborne dust or washing into waterways. Conventional stabilization approaches often rely on physical barriers, chemical binders, or imported topsoil, all of which can be costly and environmentally problematic. An induced biocrust strategy, by contrast, works with living organisms that self-assemble, self-repair, and potentially begin the long process of building genuine soil, complete with organic matter and nutrient cycling. If tailored consortia can be matched to specific tailings chemistries and climates, rehabilitation could shift from heavy engineering toward ecological restoration.

The study also contributes to a broader scientific conversation about microbial interactions in extreme environments. Cyanobacteria–fungi partnerships echo the ancient symbioses that produced lichens, and understanding the rules that govern which pairings succeed could illuminate how early life colonized barren substrates on Earth—and perhaps how life might be established on other planets with regolith surfaces. The finding that compatibility, not mere co-presence, drives synergy suggests that the metabolic exchange between the partners—potentially involving carbon compounds, growth factors, and moisture retention—is finely tuned and species-specific. Mapping those exchanges is a likely next step for the field.

For now, the message of the research is one of cautious optimism. Co-inoculation of compatible cyanobacteria and fungi can markedly enhance induced biocrust formation and stabilize degraded mine tailings, offering what the authors describe as an effective biocrust-facilitated strategy for rehabilitating degraded substrates. But the same experiments show that the wrong pairing can stall or reverse progress. The era of microbial landscaping—seeding damaged landscapes with designer communities of photosynthetic and fungal pioneers—is coming into focus, and its success will depend on the kind of patient, systematic compatibility testing this study exemplifies. The desert’s own engineers, it turns out, work best in carefully chosen teams.

Subject of Research: Induced biocrust formation on mine tailings through cyanobacteria–fungi co-inoculation

Article Title: Co-inoculation of Cyanobacteria and Fungi Promotes Induced Biocrust Formation and Stabilization of Quartz Sand Tailings

Article References: Dudaš, I., Dulić, T., Čapelja, E., Nystrand, M., Palanački Malešević, T., Österholm, P., Svirčev, Z., & Meriluoto, J. (2026). Co-inoculation of Cyanobacteria and Fungi Promotes Induced Biocrust Formation and Stabilization of Quartz Sand Tailings. Microbial Ecology. https://doi.org/10.1007/s00248-026-02887-z

Image Credits: AI Generated

DOI: 10.1007/s00248-026-02887-z

Keywords: biocrusts, cyanobacteria, fungi, mine tailings, exopolysaccharides, microbial consortia, ecosystem restoration, soil stabilization, microbial ecology, erosion control, Co-inoculation, Promotes

The research team, led by Zixu Chen and Pei Wang of the Institute of Hydrobiology at the Chinese Academy of Sciences, together with colleagues from the Institute of Karst Geology and other Chinese institutions, set out to test whether biological soil crusts, the living skins of cyanobacteria, algae, mosses, fungi and bacteria that blanket soil surfaces in the world’s drylands, could be deliberately induced on degraded karst soils. These crusts are celebrated among ecologists as ecosystem engineers: their filamentous networks and sticky extracellular polymeric substances bind soil particles, curb erosion, fix atmospheric carbon through photosynthesis, and pump bioavailable nitrogen into the ground via biological nitrogen fixation. But in karst terrain, with its shallow regolith, high calcium carbonate content and relentless hydrological instability, natural crust development stalls almost completely.

The experiment combined controlled laboratory work in Wuhan with a field trial at the Maocun Experimental Base in Guilin, part of the UNESCO-affiliated International Research Center on Karst. The team isolated two native algal strains from local degraded sites: one belonging to the genus Geminocystis, and a filamentous, nitrogen-fixing cyanobacterium identified as Leptolyngbya. The dominant local moss, Homomallium incurvatum, was surface-sterilized and propagated on half-strength Murashige and Skoog medium before inoculation. Four treatments were compared under both indoor and field conditions: an untreated control, algae alone, moss alone, and a combined moss–algae co-inoculation, with soil samples taken at 0, 30, 60 and 90 days to track the full cascade of chemical and biological change.

The headline result was unambiguous: co-inoculation outperformed every single-organism treatment across virtually every measured variable. Chlorophyll a, the standard proxy for photosynthetic biomass, climbed dramatically in the mixed treatment. Indoors, the co-inoculated soils reached 6.5 micrograms per square centimeter by day 90, nearly ten times the level of untreated controls and well above either moss-only or algae-only plots. Outdoors the same ranking held, with co-inoculation reaching 4.49 micrograms per square centimeter, a 74 percent increase over the control. Field photographs told the same visual story: control plots stayed dry, cracked and gray, while co-inoculated plots developed dense, vibrant green moss cover, more extensive than in moss-only treatments.

Underneath the green surface, the chemistry of the soil was changing just as fast. By day 90, nitrate concentrations in indoor co-inoculated plots had reached 11.68 milligrams per kilogram, roughly five times the control level, while ammonium rose by about 126 percent indoors and 188 percent in the field. Nitrite followed the same pattern, increasing nearly fivefold. Total and organic carbon climbed by roughly 61 to 162 percent in the mixed treatment compared with bare soil. The authors attribute this carbon gain to photosynthetic fixation by the developing crust and the incorporation of crust biomass and excreted polymers into stable soil organic matter pools—effectively the first stages of new soil formation on ground that had been functionally sterile.

Enzyme activity measurements provided the mechanistic bridge between these pools. Urease, which drives organic nitrogen mineralization, rose by 41 percent indoors and 43 percent in the field under co-inoculation, closely matching the concurrent surge in ammonium and nitrate. Sucrase, an indicator of carbon-cycling intensity, increased by about 39 percent, and alkaline phosphatase by around 21 to 24 percent, signaling heightened microbial demand for phosphorus in these naturally phosphorus-poor soils. The coordinated rise of all three enzymes pointed to a re-coupling of the carbon, nitrogen and phosphorus cycles—precisely the decoupling that earlier work has identified as the hallmark of dysfunction in degraded drylands.

Fluorescence spectroscopy of dissolved organic matter added a subtler layer of evidence. Using excitation–emission matrix analysis and parallel factor modeling, the team identified two humic-like and two protein-like fluorescent components in the soil solutions. Inoculated treatments showed elevated biological and freshness indices, indicating that the dissolved organic pool was increasingly dominated by fresh, microbially produced, labile compounds, while rising humification indices in moss and co-inoculation plots hinted at the earliest stages of stable humus formation. In other words, the crusts were not merely adding organic matter; they were shifting its composition toward forms that feed soil food webs and, eventually, lock carbon into the ground.

The microbial community itself underwent a striking succession. Photosynthetic communities began dominated by unicellular Synechococcales, typical of nutrient-starved early successional states, and shifted within ninety days toward filamentous, nitrogen-fixing Nostocales and Leptolyngbyales, the very taxa that confer structural stability to mature biocrusts. Fungal richness more than doubled, with saprotrophic Ascomycota becoming dominant and FUNGuild-based functional predictions showing increased decomposition activity alongside declining pathotrophs. Bacterial functional profiling through FAPROTAX revealed enrichment of nitrate reduction, nitrate respiration, nitrite ammonification and complex carbon degradation pathways such as cellulolysis and ligninolysis. Together these shifts describe the assembly of an integrated decomposer-fixer network where only a fragmented microbial web had existed before.

The practical implications are considerable. Unlike conventional restoration approaches such as spraying exogenous soil, which demand heavy machinery and repeated inputs, moss–algae co-inoculation relies on locally collected, self-regenerating biological material that progressively builds soil structure and fertility with minimal intervention. The authors caution that their trial covered only ninety days at a single site under relatively stable weather, so the resilience of these young crusts to droughts, frosts and other climatic extremes during the fragile establishment window remains untested. Still, within a single season the technique demonstrably accelerated nutrient accumulation, enzyme activation, organic matter humification and microbial reorganization—a positive feedback loop linking surface stabilization, carbon input and nutrient cycling. For the millions of hectares of degraded karst in China and around the world, deliberately cultivated living crusts may offer one of the fastest, cheapest and most self-sustaining paths back to functional soil.

Subject of Research: Induced composite biological soil crusts for early-stage restoration of karst rocky desertification soils

Article Title: Construction of composite biological soil crusts accelerates early-stage soil restoration in karst rocky desertification areas

Article References: Chen, Z., Li, T., He, X., Yang, H., Huang, F., Cao, J., Wang, P., & Wang, G. (2026). Construction of composite biological soil crusts accelerates early-stage soil restoration in karst rocky desertification areas. Environmental Earth Sciences, 85(15), Article 400. https://doi.org/10.1007/s12665-026-13121-x

Image Credits: AI Generated

DOI: 10.1007/s12665-026-13121-x

Keywords: karst rocky desertification, biological soil crusts, moss, algae, co-inoculation, soil restoration, carbon-nitrogen coupling, cyanobacteria, soil enzymes, dissolved organic matter, microbial communities, ecological engineering