Microbial communities in dairy processing environment floor drains are dominated by product-associated bacteria and yeasts

The composition of microbial communities in FDs in general and the influence of the dairy environment -, product- or water derived communities on FD communities were investigated. Drain water (DW) and drain biofilm (DB) samples were taken from three different locations in an Austrian cheese producing facility, producing different fresh and soft cheeses using pasteurised milk. All samples (n=6) were sequenced via 16S rRNA gene pyrosequencing and via cloning and Sanger sequencing of 18S rRNA genes. Product-associated bacterial (e.g. Lactobacillus kefiranofaciens, Streptococcus thermophilus) and eukaryotic (e.g. Debaryomyces hensenii, Saccharomyces unisporus) communities played a dominat role in both, DW and DB. Halotolerant, drain water phylotypes (e.g. Psychrilyobacter atlanticus, Cobetia marina) have been identified as high abundant phylotypes as well as Spelobia bifrons-like phylotpes (insects) and alveolates (Pseudocohnilembus persalinus). Interestingly the insects’ and alveolates’ DNA could only be found in the DB in the ripening room. No serious foodborne pathogens such as Listeria monocytogenes could be detected. However potential food spoilage bacteria (Pseudomonas) and one low abundant diarrhea causing (Arcobacter) bacterial phylotype could be found.