基于16SrDNA的醋酸菌筛选及其发酵特性

醋酸菌是影响纯种液态酿醋效率的关键因素。为获得高质量浓度醋酸生产菌,本研究将常规筛选方法与分子生物学技术相结合进行优良醋酸菌的筛选。采用高质量浓度酒精和醋酸培养基富集,挑取醋酸菌膜初步分离目的菌;借助生理生化特征与16S rDNA保守序列分析方法鉴定并获得一株产酸高的巴氏醋酸杆菌JST-S(Acetobacter pasteurianus JST-S,BJST-S);在与沪酿1.01(Acetobacter pasteurianus HN 1.01)进行发酵特性对比研究时发现,BJST-S在生长速率、产酸速率及耐醇和耐酸等方面均优于沪酿1.01;半连续发酵3批次BJST-S的产酸量维持在58.10~59.68 g/L,发酵强度维持在1.21~1.24 g/(L·h),说明该菌产酸特性稳定。研究结果可为醋酸工业化生产以及优良菌株的选育提供一定的理论参考。

Screening and Fermentation Characteristics of an Acetic Acid Bacterial Strain Based on 16S rDNA for Vinegar Production

Acetic acid bacteria are an important factor that influences the efficiency of vinegar production by pure culture liquid-state fermentation. The goal of this study was to obtain an outstanding acetic acid bacterial strain for vinegar production by routine screening combined with molecular biological techniques. The target strain was isolated from the biofilm formed in enrichment culture in the presence of high concentrations of alcohol and acetic acid. It was identified as Acetobacter pasteurianus JST-S (BJST-S) based on physiological and biochemical characteristics combined with 16S rDNA sequence analysis. Comparative analysis of fermentation characteristics indicated that the BJST-S was better than Acetobacter pasteurianus CICC 20001 in term of growth rate, acid production rate, alcohol resistance and acid resistance. The concentration of acetic acid was maintained in the range of 58.10–59.68 g/L and the fermentation strength in the range of 1.21–1.24 g/(L·h) in three batches of semi-continuous fermentation, implicating that the fermentation characteristics of BJST-S were stable. Our findings in this work may provide a valuable reference for strain breeding for the improvement of industrial vinegar production.