乙醇脱氢酶（ADH）产酶菌株的选育

从食醋生产企业的醋醅中采集样品,以乙醇为唯一碳源,用碳酸钙透明圈平板法分离出185株菌株,然后以产酸量和耐乙醇能力为标准,瓶发酵选育出20株ADH产酶菌株；A5-2产酸量为49.85 g/L,耐乙醇能力强,A5-2的菌种形态学和16S rDNA序列分析初步鉴定为巴斯德醋酸杆菌（ Acetobacter pasteurianus）；A5-2乙醇脱氢酶酶学性质研究表明：最适作用温度和pH分别为45℃和pH 4.0,具有一定的耐热性和良好的耐酸碱性；A5-2乙醇脱氢酶粗酶制备条件为硫酸铵饱和度70%~80%,回收率84%。

Breeding of Alcohol Dehydrogenase Producing Strains

185 alcohol dehydrogenase （ ADH ） producing strains were isolated from samples collected from vinegar fermented grains in vinegar production enterprise by selective medium using ethanol as the sole carbon source, and calcium carbonate transparent circle on plate. 20 high ADH producing strains were bred under shaking-flask fermenta-tion, in which acid output and ethanol tolerance were used as standards. The acid output of A5-2 achieved 49. 85 g/L and its capacity of ethanol tolerance was strong. A5-2 was initially identified as Acetobacter pasteurianus based on its morphological characterization and 16S rDNA sequence. Study on enzyme characteristics showed that the optimal reac-tion conditions of A5-2 ADH were at 45 ℃ and pH 4. 0, and it had heat tolerance and fine tolerance against acid-base. The preparation condition of crude ADH were saturated concentration of ammonium sulfate was at 70% ~ 80%and the ADH activity recovery was at 84%.