Utilization of lactose and production of corrinoids in selected strains of propionic acid bacteria in cheese-whey and casein media.

Comparative studies were carried out with 23 strains (14 species) of propionibacteria in two media-cheese-whey and casein. The degree of lactose fementation and the efficiency of the corrinoids synthesis were studied. Lactose fermentation showed great differences even within one species (e.g. 13.3% and 66.1% for various strains of P. shermanii). The differences were particularly sharp in casein medium (0% or 100%). The highest capacity for utilizing cheese-whey lactose (70--80%) was found in two strains of P. shermanii and P. petersonii and P. arabinosum. No definite correlation, however, was found either in the cheese-whey or in the casein medium, between the capability of lactose fermentation and the efficiency of the corrinoids. As the most technologically effective strains have been recognized P. shermanii 1, P. shermanii 566 and P. petersonii J.