Mitsuzo Kuno

Culture Conditions for the Production of Alkaline Protease from n-Paraffins by a Kabicidin Resistant Mutant No. 5–128B

A novel process for the microbial production of alkaline protease on an industrial scale was successfully established by using a kabicidin resistant mutant, No. 5–128B, derived from Fusarium sp. S–19–5. The most suitable carbon source for producing alkaline protease was n-paraffins (C10~C14) and the effective nitrogen source was dried-yeast cells containing no nucleic acid, the optimum concentrations being 12.5% (w/v) and 7.0% (w/v), respectively. The optimal temperature and initial pH for protease production were 24°C and 6.0, respectively. Under the optimal conditions using a shaker flask mutant No. 5–128B produced 41000 PU/ml of alkaline protease, which corresponded to about 10 times the amount produced by the parent strain. The relation between the high ability to produce alkaline protease and the resistance to kabicidin, a polyene antibiotic, is discussed.