复合诱变选育高产3-羟基丁酮枯草芽孢杆菌

选育高产3-羟基丁酮枯草芽孢杆菌,将一株枯草芽孢杆菌YD-1作为出发菌株,通过紫外线、硫酸二乙酯反复诱变处理,选取每一轮发酵3-羟基丁酮产量最高的菌株进入下一轮诱变。结果表明,菌株的复合诱变条件是在照射距离为25 cm时紫外诱变30 s后再经10%的硫酸二乙酯诱变处理30 min,然后进行有利突变株的筛选,通过初筛、复筛和遗传稳定性试验,获得1株遗传性状稳定的3-羟基丁酮高产菌,其产量高达19.02 g/L,比诱变前提高了50.95%,其遗传物质经RAPD分析,与出发菌株YD-1相比有较大差异。得到的枯草芽孢杆菌新菌株3-羟基丁酮产量高而残糖量低。

Selection of High Acetoin-Producing Strain of Bacillus Subtilis by Composit Mutation

The aim of this study was to breed new strains which have higher production of acetoin.With a Bacillus subtilis as the original strain,and under mutation by ultraviolet（UV） and diethyl sulfate（DES）,we use the highest acetoin-producing Strain of Bacillus subtilis in each mutationtreatmen as the original strain in the next mutation.The compound mutation condition of YD-1 strain was that after the starting strain was mutated by ultraviolet for 30 s at the distance of 25 cm,it was mutated by 10% diethyl sulfate for 30 min,then the available mutant was screened and a High acetoin-producing Strain of Bacillus subtilis with stable genetic characters was obtained through the primary screening,secondary screening and the genetic stability experiment.The acetoin production was 19.02 g/L,which was 50.95% higher than the starting strain.The genetic substances of two stains were different through RAPD analysis.A new Bacillus subtilis with high acetoin production and low residual sugar was obtained.