Streptomyces baarnensis strain SW‘lwas the most efficient strain in vitamin 2-; reduction. The effects of different concentrations of oatmeal extract. some e‘- ':nmenta| factors i.e. incubation period, initial pH, temperature and shaking rate : ‘r‘erent levels were studied to obtain the maximum yield of vitamin Bu:- production re 'esults of the present study revealed that the maximum yield of vitamin Bi :'::..ction by Streptomyces baarnensis strain SW1was reached under submerged :. t..re conditions in modified fermentation medium containing 15 g L“ of the most table raw material (oatmeal extract) with initial pH value 7' and temperature "so at 32 "C after 6 days on a rotary shaker at 200 rpm. being 8". 08pg ml".The .T‘ty of S. baarnensis SW1 dried mycelium as natural source of vitamin 012 was szsdied , the obtained results in vivo revealed that vitamin Beg derived from the dried vcelium is available .