Microwave mutagenesis of high-producing rennet strain from Bacillus subtilis

摘要

In order to acquire a high-producing rennet strain from Bacillus, different microwave irradiation intensities and durations were tested. The effect of microwave irradiation power and time were studied and the microwave mutagenesis parameters were optimized. The results indicated that the best conditions for microwave mutagenesis that produced better performed mutant strains were 450 W, 4 min. Under these conditions a viable strain with high-producing rennet (Strain No.: BsB1.1) was achieved whose genetic stability is good and rennet activity reaches 516.12 U/g which has increased by 29.0% compared with the original strain in the experiment.