【摘要】 采用常压室温等离子体诱变贝莱斯芽孢杆菌(Bacillus velezensis)CY30菌株。菌株的致死率强度结果表明,在电源功率为100 W,处理距离2 mm,工作气流量10 L/min时,等离子体对CY30菌株诱变最优处理时间为50 s。通过显微镜检初筛诱变菌株,并利用摇瓶发酵结合芽孢数测定和杀菌活性评价进行复筛,建立完整的诱变筛选体系。通过斜面镜检初筛、摇瓶三轮复筛,获得摇瓶液芽孢数122.3亿/mL,杀菌活性75.58%,且遗传稳定的突变菌株CY30-314。突变株发酵水平较出发菌株芽孢数提高25.3%,杀菌活性提高15.6%,发酵周期缩短了2 h。更多还原

【Abstract】 Atmospheric and room temperature plasma(ARTP) was used to mutate Bacillus velezensis CY30 for improving the production of spores and fungicidal activity. The most optimal condition for the ARTP mutagenesis was working flow rate at 10 L/min, treating distance of 2 mm and electrical power of 100 W. The mutants were selected based on microscopic morphology of the colonies, the spore counts and antifungal activity of the cultures from shake-flask fermentation. A mutant with code of CY30-314 was obtained through 3 rounds of microscopic checking of the slants and shake-flask fermentation. The spore counts of the mutant in shake-flask fermentation was 12.23 billion spores/m L, and the corresponding cultures inhibited the growth of fungus for 75.58%. The mutant also showed genetic stability. The mutant produced 25.3% more spores in shake-flask fermentation which resulted in the increase of antifungal activity at 15.6%. The duration of the mutant was shorted for 2 h.更多还原