中性蛋白酶B．S．HD401生产菌激光选育

本文报道了从花生地土壤分离到一株分泌中性蛋白酶的枯草芽孢杆菌，经纯铜蒸汽激光诱变，选育到一株高产菌株ＨＤ４０１，产酶提高幅度高达７２．７％。诱变过程说明，菌体存活率和正变率以及激光波长、孢子体生理状态有一定的相关性。Ｂ．Ｓ．ＨＤ４０１经多次传代，产酶性状稳定，通过正交试验对培养基进行优化，在２升罐中酶活达８５２０ｕ／ｍｌ。

Mutagenesis and Selection of Neutral-proteinase-producing Strains of Bacillus Subtilis HD401 by Laser Irradiating

The mutant strain B.S.HD401 was selected from a neutral-proteinase-producing strain Bacillus subtilis spores irradiated by copper vapor laser.Its perent strain was screened from peanut-grown soil.Its enzymatic activity was increaed by 72.7%.The experimental results showed that survial percentage and percentage of positive mutants had relation with laser wavelength and spores'physiological condition.The high capacity of B.S.HD401 for producing neutral proteinase remained stable after many generation of subculturing.By orthogonal tests of culture medium,its enzymatic activity could raise to 8520u/ml in 2L fermentor.