Impacts of Season and Large Scale Storage on California Bovine Milk Bacterial Communities

We set out to investigate the microbial composition of conventional milk collected during different seasons and to determine the effects of the built-environment within a dairy processing facility on the composition of those milks. The bacterial diversity in raw milk was determined for 991 tanker trucks of raw milk received at two dairy processing facilities in California during three different times of year (spring, summer, and fall). The microbial composition of milk was also identified as it was being prepared for the production of cheese and included samples collected at 8 different sampling points in duplicate at 4 to 5 h intervals over a 21 h period in both spring and late summer. Microbial communities in the milks and milk fractions were characterized by Illumina MiSeq sequencing of the 16S rRNA V4 region.