VITAMIN REQUIREMENTS OF THE GENUS PROPIONIBACTERIUM

Abstract

25 cultures of propionic bacteria, representing 9 different spp. were grown on a basal synthetic medium with the addition of B vitamins. By using large inoculum repeated transfers could be made. All the cultures required pan-tothenic acid, and all but three, biotin. Thiamine and PABA stimulated growth in some cases, but were not essential. This group of organisms has a great capacity to adapt, and grow in the absence of particular growth factors. Past failure to cultivate certain strains successfully on synthetic media may have been due to the small inoculum used, in which there was an insufficient number of "adapted" organisms.