Psychrotrophic flora of raw milk: resistance to several common disinfectants.


The psychrotrophic bacterial flora of milk was examined after aseptic hand milking. A total of 409 strains were tentatively characterized and classified into 17 groups by a reduced set of tests and cluster analysis. Lipolytic organisms (53.7% exceeded proteolytic organisms (29.6%), and a reported predominance of oxidase-positive organisms (54.5%) was not found. Gram-negatives were mainly Enterobacteriaceae, Flavobacterium, Acinetobacter and Pseudomonas. In the Gram-positive groups Micrococcaceae were the most abundant (44.4%) followed by coryneforms (16.3%). Only two of seven commonly used disinfectants acted differently with Gram-positive and Gram-negative organisms (P less than 0.01), although in general Gram-positives were more resistant than Gram-negatives.

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@article{Surez1991PsychrotrophicFO, title={Psychrotrophic flora of raw milk: resistance to several common disinfectants.}, author={Benny Su{\'a}rez and Carlos M. Ferreir{\'o}s}, journal={The Journal of dairy research}, year={1991}, volume={58 1}, pages={127-36} }