ProductÝon of B-Vitamins by Planktonic Bacteria Isolated from The Mesotrophic Lake Jasne

Studies were carried out on the occurrence of organisms producing vitamins of group B among the heterotrophic planktonic bacteria of the littoral and pelagic zone of the mesotrophic lake asne. In the littoral zone the most numerous group were bacteria producing nicotinic acid, pantothenic acid and riboflavin. In the pelagic zone the number of B-vitamins producers was much smaller, and the predominant group were strains synthesizing folic acid, biotin and thiamin. The percentage of Bvitamins producers in the pelagic zone was higher in spring than in autumn. In the littoral zone the reverse situation was stated. The majority of planktonic bacteria of both zones were able to produce 2-4 vitamins. Only a few strains synthesized only one vitamin.