Cultural Conditions for Protein Production by Bacillus brevis No. 47

Influence of the components of fermentation medium upon protein production by Bacillus brevis No. 47 was investigated. Bacterial growth was highly stimulated with yeast extract or meat extract without any appreciable increase in protein accumulation. But, both growth and protein production was enhanced with increasing amount of polypepton, a commercial product of peptone. Mg ion and potassium phosphate appeared to have important roles in protein production. Higher concentrations of Mg ion stimulated growth, but prevented protein excretion. An optimal pH for protein production was about 8. Factor(s) stimulating protein production in polypepton were fractionated by Sephadex G-25. Such an activity was detected in a fraction consisting of peptide(s) with molecular weight of 2 ~ 3000. Based on the time course of protein production and growth curve, it was suggested that protein accumulation is not the result of cellular autolysis.