The technology addresses a persistent and underappreciated problem in livestock production. Rice husk, an abundant by-product of rice milling, is widely used as poultry bedding because it is cheap, lightweight, and absorbs moisture well. But during storage and use, bedding accumulates organic matter, fecal residues, and moisture that support microbial growth. Contaminated bedding can act as a long-term environmental reservoir for foodborne pathogens, facilitating transmission between production cycles and throughout the poultry supply chain. Conventional sanitation relies on chemical disinfectants such as quaternary ammonium compounds, aldehyde-based treatments, and oxidizing agents, yet these often penetrate bulk biomass poorly, work unevenly in porous substrates, and lose effectiveness under high organic loading, while raising concerns about residues, worker exposure, and environmental impact.

The new system, described in the journal Cleaner Engineering and Technology, is a trailer-mounted, mobile processing platform designed for continuous on-site operation. Its core components include an insulated sanitization chamber, a screw-assisted biomass transport mechanism that lifts and cascades rice husk particles through the treatment zone, an LPG-fueled gas burner generating hot air at 350 to 400 degrees Celsius, a hot-air mixing chamber, forced-air and recirculation blowers, and a cyclone dust separation unit. The screw-assisted cascading design is central to the system’s performance: by continuously lifting and redistributing particles, it repeatedly exposes fresh surfaces to the heated airflow, minimizing localized cold spots and thermal dead zones within the porous biomass bed.

A key engineering innovation is the airflow recirculation architecture. Rather than exhausting heated air after a single pass, the system captures hot air exiting the chamber, passes it through cyclone separators to remove suspended dust, and redirects it back into the heating circuit. This recirculation loop achieved an efficiency of approximately 86.7 percent, substantially improving thermal retention, stabilizing chamber temperature under transient loading, and reducing fuel consumption. Under steady-state conditions, the sanitization chamber held temperatures of roughly 115 to 125 degrees Celsius while rice husk exited at 95 to 100 degrees Celsius, with chamber temperature variation held to about plus or minus 2.1 degrees Celsius.

Residence time proved to be a critical operating variable. By tuning screw rotational frequency between 50 and 60 hertz, the researchers achieved residence times of 15 to 17 minutes, which they identified as the optimal window balancing microbial inactivation against throughput. At these settings the system processed 2.0 to 2.5 tonnes of rice husk per hour with thermal utilization efficiency peaking near 87.6 percent. Shorter residence times below 10 minutes risked ineffective sanitization, while longer exposures reduced productivity without meaningful gains. Statistical analysis confirmed that both temperature and residence time significantly influenced microbial reduction, with their interaction significant at p less than 0.01.

The microbiological validation was unusually rigorous for an industrial study. Throughout three years of routine monitoring, approximately 67 samples per month were collected from production lots of about 15 tonnes each, and formal annual validations compared 50 samples before treatment with 50 after. All analyses were performed at an ISO/IEC 17025-accredited laboratory, using selective enrichment, culture on Xylose Lysine Deoxycholate agar, and confirmatory identification by MALDI-TOF mass spectrometry. Under optimized conditions, contamination frequency fell from 16 percent to 4 percent, an estimated 75 percent reduction in positive detections. In controlled laboratory experiments, log reductions of total bacterial count reached 6.2 to 6.4 log CFU per gram at 120 to 125 degrees Celsius, corresponding to inactivation efficiencies above 99.999 percent, and Salmonella was not detected under any tested condition.

Perhaps the most instructive finding concerned moisture. Feedstock water content emerged as a dominant constraint on performance, contributing an estimated 18.6 percent of the relative influence on lethality. At moisture levels of 8 to 11 percent, the system achieved log reductions of about 6.3, but at 18 to 20 percent moisture the reduction fell to roughly 2.7 log, a level the authors classified as ineffective. The explanation is thermodynamic: water evaporation consumes latent heat, diverting thermal energy away from microbial destruction and buffering the biomass temperature. Field validation during rainy conditions confirmed the pattern, with positive detections rising to 9 percent at high moisture and 14 percent when high moisture was combined with shortened residence time. The researchers argue that industrial thermal sanitization must therefore be governed by integrated heat-and-moisture frameworks rather than temperature-only criteria, and they recommend real-time moisture sensing and adaptive residence-time control as future upgrades.

The economics are compelling. Total treatment cost was estimated at 0.0083 US dollars per kilogram of rice husk, compared with 0.014 to 0.021 dollars for conventional centralized chemical sterilization, an operating cost reduction of roughly 40 to 60 percent and a benefit-cost ratio of 4.6. LPG consumption averaged 8.3 kilograms per tonne of treated biomass, translating to a fuel cost of about 0.0052 dollars per kilogram. The savings arose from multiple vectors: complete elimination of disinfectant procurement, which alone accounted for 38.4 percent of total savings; removal of dedicated chemical storage warehouses; simplified single-stage logistics replacing multi-stage transport to centralized facilities; and reduced transportation emissions from on-site processing. Over three years, cumulative savings exceeded 0.30 million US dollars, averaging about 100,000 dollars annually.

From a sustainability standpoint, the system embodies cleaner production and circular economy principles. By using thermal energy as the sole sanitizing agent, it removes chemical residues from bedding that might otherwise accumulate in soils when spent litter is applied as fertilizer, and it eliminates occupational exposure to formaldehyde and related compounds. The life-cycle analysis, conducted through a life-cycle thinking approach rather than a formal ISO 14040/14044 assessment, attributed 34.8 percent of sustainability benefits to chemical elimination, 26.5 percent to biomass reuse and valorization, and 11.6 percent to avoided transportation. The technology effectively upcycles a low-value agricultural residue into a standardized sanitary product, closing a resource loop that links rice milling, poultry farming, and eventual nutrient recycling through spent bedding.

The authors are careful to note limitations. The microbiological outcomes reflect the tested operating conditions and should not be read as evidence of complete pathogen elimination under all field scenarios, and the sustainability percentages are relative indicators rather than quantified greenhouse gas reductions. Future work will pursue a full cradle-to-grave life cycle assessment, quantitative microbial inactivation modeling using D-value and z-value kinetics, computational fluid dynamics optimization of the reactor, and predictive process control. Still, the demonstrated combination of scale, reliability, and economics marks a significant step. A system that processes nearly 8,000 tonnes of abrasive, silica-rich biomass over three years with greater than 95 percent availability shows that continuous thermal sanitization has moved beyond the pilot stage, offering poultry producers a practical blueprint for biosecurity that is simultaneously cleaner, cheaper, and more circular than the chemical status quo.

Subject of Research: Industrial-scale continuous thermal sanitization of rice husk bedding for chemical-free poultry biosecurity

Article Title: Industrial-scale continuous thermal sanitization of rice husk bedding for cleaner poultry production: Resource valorization, biosecurity improvement, and sustainability assessment

Article References: Sangpradit, K., Thoetrattanakiat, S., Sookyoo, W., Intarasuk, A., & Samseemoung, G. (2026). Industrial-scale continuous thermal sanitization of rice husk bedding for cleaner poultry production: Resource valorization, biosecurity improvement, and sustainability assessment. Cleaner Engineering and Technology, 34, Article 101304. https://doi.org/10.1016/j.clet.2026.101304

Image Credits: AI Generated

DOI: 10.1016/j.clet.2026.101304

Keywords: rice husk, poultry bedding, thermal sanitization, biosecurity, cleaner production, circular economy, pathogen inactivation, agricultural waste valorization, hot-air heating, Salmonella, LPG energy efficiency, sustainable livestock production

Antimicrobial resistance, commonly abbreviated as AMR, occurs when bacteria, viruses or other microorganisms evolve the ability to withstand treatments such as antibiotics that would normally kill them or stop their growth. In aquaculture, the farming of fish, crustaceans, molluscs and other aquatic organisms, the emergence of resistant pathogens is a particular concern because intensive production systems can create conditions in which disease spreads rapidly and antimicrobials are used to control outbreaks. When resistant organisms develop in aquatic environments, they can move through water, food chains and human contact, complicating treatment of infections in animals and people alike. Responsible antimicrobial use, coupled with strong biosecurity measures that prevent disease from entering or spreading within farms, is therefore regarded internationally as a cornerstone of sustainable aquatic food production.

Mississippi State University brings a long institutional history to this role. As a land-grant university with leading expertise in fisheries and aquaculture, veterinary medicine and international food security, it has worked with FAO on antimicrobial use and antimicrobial resistance, aquaculture biosecurity and aquatic animal health. The renewal of the reference centre designation signals that the organization’s reviewers judged the university’s contributions during the first designation period to have met the standards expected of a centre that provides authoritative scientific advice to FAO and its member nations. The agreement positions the university to continue supplying the technical competencies needed to strengthen capacity development efforts worldwide.

University President Mark E. Keenum said he looks forward to the institution continuing this important work under the renewed agreement. According to Keenum, the renewal means the university will continue to provide the scientific expertise and technical competencies needed to strengthen capacity development efforts that support FAO’s work in promoting the responsible use of antimicrobials in aquaculture and reducing the risks associated with antimicrobial resistance. He added that Mississippi State will also continue to support FAO’s efforts to advance responsible aquaculture practices and strengthen aquaculture biosecurity worldwide, framing the partnership as an extension of the university’s land-grant mission into the international arena.

The renewal was marked in person at FAO headquarters in Rome, where Mississippi State Provost and Executive Vice President David Shaw and other university leaders met with officials on September 22 as part of a broader agri-food systems conference. The discussions focused on building more resilient food systems, a theme that has grown in urgency as aquatic foods supply an increasing share of animal protein for a growing global population while facing mounting pressures from disease, environmental change and intensifying production. The Rome meeting provided an opportunity to align the centre’s next five-year work programme with FAO’s strategic priorities on antimicrobial resistance and biosecure aquaculture.

Shaw emphasized the interconnected nature of the challenges the centre addresses. He noted that issues related to food security, animal health, environmental stewardship and human well-being are often deeply intertwined, even when institutions attempt to address them separately, and that aquatic food systems provide a particularly compelling example of those connections. In his view, the university’s experience in aquaculture, veterinary medicine and international food-security initiatives has repeatedly reinforced why collaborative, multidisciplinary approaches are essential. Addressing antimicrobial resistance, he said, requires scientists, veterinarians, producers, policymakers, regulators, environmental specialists and public health experts to work together across disciplines and sectors rather than in isolation.

Shaw also argued that universities carry a responsibility that goes beyond generating knowledge. As a land-grant institution, Mississippi State believes strongly that universities must connect expertise across disciplines and translate that knowledge into practical solutions for producers and communities. He described antimicrobial resistance as a reminder that complex challenges demand integrated approaches, and he identified a central lesson that the partnership with FAO highlights: the most effective response to disease is often prevention. That principle, in which biosecurity and good husbandry reduce the need for antimicrobial treatment in the first place, sits at the heart of the reference centre’s technical philosophy.

Stephen Reichley, who heads the FAO Reference Centre and serves as associate director of the Global Center for Aquatic Health and Food Security, said the redesignation recognizes the university’s continuing contributions at the intersection of aquatic animal health, antimicrobial stewardship, aquaculture biosecurity, food security and One Health. The One Health framework, which treats human, animal and environmental health as inseparable, has become the dominant lens through which international agencies approach antimicrobial resistance, since resistant organisms and the genes that confer resistance can circulate among people, livestock, wildlife, water and soil. Reichley noted that the work also reinforces the university’s role in supporting both the United States aquaculture sector and international efforts to build sustainable, biosecure aquatic food systems.

Reichley described the five-year redesignation as a reflection of FAO’s continued confidence in Mississippi State and, more importantly, as another opportunity to put the university’s expertise to work on challenges that affect producers and food systems around the world. By connecting research, diagnostics, education and extension, he said, the centre can help prevent aquatic animal disease, promote responsible antimicrobial use and strengthen aquaculture biosecurity from Mississippi to the global level. That combination of laboratory science, field diagnostics and outreach is characteristic of the land-grant model, in which discoveries move from research settings into the hands of farmers, veterinarians and regulators who can apply them.

The measurable record of the first designation period underlines the scale of that contribution. Between 2022 and the renewal, Mississippi State reported 47 scientific papers on antimicrobial resistance and aquatic biosecurity to FAO, along with 139 presentations and more than 30 research projects that advanced understanding of AMR in aquatic environments and improved aquaculture biosecurity practices. Those outputs fed directly into FAO’s mission of providing authoritative advice to its member nations, informing guidance on how farms can reduce disease risk through stocking density management, water quality control, vaccination, diagnostic surveillance and other preventive measures that limit the need for antimicrobials. With the agreement now extended through October 2031, the centre is positioned to build on that foundation at a moment when demand for aquatic protein is rising and the global fight against antimicrobial resistance has never been more consequential. Ongoing workshops and events connected to the centre’s work are listed through the Global Center for Aquatic Health and Food Security, offering producers, researchers and policymakers continuing avenues to engage with the science of biosecure, responsible aquaculture.

Subject of Research: Renewal of an FAO reference centre designation for research on antimicrobial resistance and biosecurity in aquaculture

Article Title: FAO renews university's designation as Reference Centre on Antimicrobial Resistance and Aquaculture Biosecurity

Article References: FAO renews university's designation as Reference Centre on Antimicrobial Resistance and Aquaculture Biosecurity. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: antimicrobial resistance, aquaculture, biosecurity, FAO, Mississippi State University, aquatic animal health, One Health, food security, antimicrobial stewardship, global center for aquatic health and food security, sustainable aquaculture, fish health