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

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.