Studies on the screening of highly producing strains of F. yellowsea of low temperature alkaline protease

In screening high producer of low temperature alkaline protease, F. yellowsea YS 9412 130 is chosen as original strain, which is treated repeatedly with various mutagens(NTG、DEM、UV and Microwave). The mutant YS 9412 130 SW 1 104 with high and stable yield of alkaline protease is selected after repeated natural selection. The alkaline protease activity of this mutant is in the 16 fold of the original strain, reaching 2 320U/ml (assayed 20℃). The mutant has marked with Ref r、Str r、Amp r 、Met - and Lys -.The result shows that there are no significant differences between the cells of the mutant and the original strain.