title: Application of bacteriophages to reduce biofilms formed by hydrogen sulfide producing bacteria on surfaces in a rendering plant.
abstract: Hydrogen sulfide producing bacteria (SPB) in raw animal by-products are likely to grow and form biofilms in the rendering processing environments, resulting in the release of harmful hydrogen sulfide (H2S) gas. The objective of this study was to reduce SPB biofilms formed on different surfaces typically found in rendering plants by applying a bacteriophage cocktail. Using a 96-well microplate method, we determined that 3 SPB strains of Citrobacter freundii and Hafnia alvei are strong biofilm formers. Application of 9 bacteriophages (10(7) PFU/mL) from families of Siphoviridae and Myoviridae resulted in a 33%-70% reduction of biofilm formation by each SPB strain. On stainless steel and plastic templates, phage treatment (10(8) PFU/mL) reduced the attached cells of a mixed SPB culture (no biofilm) by 2.3 and 2.7 log CFU/cm(2) within 6 h at 30 °C, respectively, as compared with 2 and 1.5 log CFU/cm(2) reductions of SPB biofilms within 6 h at 30 °C. Phage treatment was also applied to indigenous SPB biofilms formed on the environmental surface, stainless steel, high-density polyethylene plastic, and rubber templates in a rendering plant. With phage treatment (10(9) PFU/mL), SPB biofilms were reduced by 0.7-1.4, 0.3-0.6, and 0.2-0.6 log CFU/cm(2) in spring, summer, and fall trials, respectively. Our study demonstrated that bacteriophages could effectively reduce the selected SPB strains either attached to or in formed biofilms on various surfaces and could to some extent reduce the indigenous SPB biofilms on the surfaces in the rendering environment.
authors.affiliation: a Department of Biological Sciences, Clemson University, 222 Life Science Facility, Clemson, SC 29634, USA.
authors.forename: Chao
authors.initials: C
authors.lastname: Gong
authors.affiliation: b Department of Food, Nutrition and Packaging Sciences, Clemson University, 228A Life Science Facility, Clemson, SC 29634, USA.
authors.forename: Xiuping
authors.initials: X
authors.lastname: Jiang
mesh_terms: D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D001435:Bacteriophages; D018441:Biofilms; D006862:Hydrogen Sulfide / Q000378:metabolism*; D017900:Myoviridae; D017906:Siphoviridae; D013193:Stainless Steel
chemical_list: D013193:Stainless Steel; D006862:Hydrogen Sulfide
keywords: bacteriophage; bactéries productrices de sulfure d’hydrogène; bactériophage; biofilm; hydrogen sulfide producing bacteria; rendering plant; usine d’équarrissage