大曲中产3-羟基丁酮菌株的筛选及其等离子体诱变

Screening of acetoin-producing strain from Daqu and its plasma mutagenesis

从大曲中分离筛选获得1株产3-羟基丁酮的菌株G7,以葡萄糖为主要碳源,此菌株在38℃,180r/min恒温振荡培养96h,3-羟基丁酮产量达到24.30g/L.根据形态特征、生理生化特征及16SrDNA序列分析,该菌株被鉴定为甲基营养型芽胞杆菌(Bacillus methylotrophicus strain).将该菌株作为出发菌株,采用常压室温等离子体(Atmospheric and Room Temperature Plasma,简称ARTP)诱变,并进行48孔板初筛及摇瓶复筛,同时对所获菌株进行遗传稳定性分析,最后得到1株遗传性状稳定的3-羟基丁酮高产菌株G7-6,其产量可达31.65g/L,比诱变前提高了30.25%,且转化率较高,为27.31%.

An acetoin-producing bacterial strain G7 was isolated from Daqu.When it was incubated for 96 h at 38 ℃ with shaking by 180 r/min,acetoin concentration of strain G7 could reach 24.30 g/L using glucose as the carbon source.Based on morphology,physiological and biochemical characteristics as well as the 16S rDNA gene sequence,strain G7 was identified as Bacillus methylotrophicus strain.As the o-riginal strain,G7 was mutagenized by ARTP.The mutant was preliminarily screened in 48-well micro-plates and further screened in shake flask,and evaluated for genetic stability.A high acetoin-producing strain named G7-6 with stable genetic characters was obtained.The acetoin product ion was 3 1.6 5 g/L, which was 30.25% higher than the original strain G7,and the conversion of acetoin can reach 27.31%.