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ARS Home » Midwest Area » Wooster, Ohio » Application Technology Research » Research » Research Project #444194

Research Project: Biological Approaches to Mitigate Biofilm-Associated Food Safety Risks in Indoor Leafy Greens Production

Location: Application Technology Research

Project Number: 5082-21000-001-074-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Sep 1, 2023
End Date: Aug 31, 2027

1. Characterize Salmonella and Listeria monocytogenes biofilms in commercial NFT (Nutrient Flow Technology) and DWC (Deep Water Culture) leafy green indoor production systems. 2. Evaluate the influence of algae on establishment of Salmonella and Listeria monocytogenes on leafy green crops and environmental surfaces. 3. Establishment of bioremediation procedures and alternative approaches to co-mitigation of biofilms and environmental algal mats in leafy green indoor production systems. 4. Development of risk communication materials describing biofilm and algae management best practices in commercial NFT and DWC leafy green indoor production systems.

We will characterize Salmonella and Listeria monocytogenes biofilms, when grown in monoculture or in association with native algae. For this we will use commercial hydroponic NFT and DWC surfaces at laboratory scale, and in commercial production systems in BSL-2 indoor greenhouse facilities. Biofilm growth and structure will be evaluated using drop plate and standard crystal violet staining methods, and biofilm structure and composition will be visualized by fluorescent in situ hybridization. Novel bacterial strains with biocontrol properties, bacterial feeding nematodes, and commercially available enzymatic products will be screened for their biocidal effect against the pathogens and to assess single-pathogen or pathogen-algae biofilm removal. Control and mitigation programs that will include standard operating procedures for the prevention of contamination and establishment of biofilms and educational materials to raise awareness of food risks associated with algae will be developed.