RT Journal Article SR Electronic(1) A1 Appleby, J. C. A1 Knowles, E. A1 Mcallister, R. C. A. A1 Pearson, J. A1 White, T.YR 1947 T1 The Production of Tyrothricin by Submerged Culture of Bacillus brevis in Synthetic Media JF Microbiology, VO 1 IS 2 SP 145 OP 157 DO https://doi.org/10.1099/00221287-1-2-145 PB Microbiology Society, SN 1465-2080, AB SUMMARY: Synthetic media containing ammonium succinate as the sole source of nitrogen permit Bacillus brevis to grow and form tyrothricin in aerated submerged culture. The yield of the antibiotic is almost doubled by adding a complex of B-vitamins to the medium, the effect being due specifically to the presence of biotin. Urea can be used as an alternative but less satisfactory source of nitrogen, but ammonium succinate cannot be replaced by ammonium salts of a number of other organic acids. The process can be operated successfully on a large scale. Normally, B. brevis will grow, but will not produce tyrothricin, in submerged culture in the presence of complex nitrogen sources. An exception to this has been observed, but metabolic investigations show distinct differences in the behaviour of the organism (in submerged culture) in synthetic and in peptone media., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-1-2-145