Bacterial biofilm as a possible source of contamination in the microbrewery environment

Abstract In this study, possible sources of bacterial contamination on surfaces were identified in an Italian microbrewery. A high degree of microbial diversity was detected, which suggests very little selective pressure on these environments from cleaning agents and disinfectants, or from the presence of beer. Lactobacillus brevis , Lactobacillus lindneri , and Pediococcus pentosaceus isolates that were able to grow in beer were detected on the surfaces, among other potential beer-spoiling species. Most of the isolates showed a strong ability to form biofilms on both polystyrene and on stainless steel, and the mature biofilms on stainless steel were insufficiently inactivated by peracetic acid-based sanitiser.