Adhesion and Biofilm Production by Wine Isolates of<i>Brettanomyces bruxellensis</i>

Dye retention assays were used to investigate the adhesion and biofilm-forming ability of geographically diverse isolates of <i>Brettanomyces bruxellensis</i>. Thirty-eight of 40 isolates showed a significant ability to adhere to a surface at a low sugar concentration within 6 hours. Fifteen of a subset of 36 strains showed some level of biofilm formation, with eight of those strains appearing to form an extensive biofilm under assay conditions. Biofilm formation and adherence increased for the <i>Brettanomyces</i> isolates with increasing pH of the medium. The ability of various cleaning agents to remove the biofilm formed by an isolate from Thailand was assessed. Most agents tested showed some reduction in adherence and biofilm production by <i>Brettanomyces</i>, but a commercial preparation of caustic soda was most effective. Of the eight strains with the most extensive biofilm formation, one was an isolate from Thailand, one from New Zealand, two from California, one from Chile, one from France, and two from Malta. Thus, biofilm-forming capacity is broadly distributed geographically.