保宁醋醋曲中产多糖乳酸菌的筛选及其代谢产物分析

Screening of Polysaccharide-producing Lactic Acid Bacteria in Baoning Vinegar Koji and Analysis of Its Metabolites

摘要:

保宁醋因其复杂微生物体系和酿造工艺而形成独特风味，其风味物质和营养成分主要由各种功能性微生物发酵生成，其中乳酸菌是非常关键的一类菌株，其对保宁醋的风味和营养物质的形成具有重要作用。本研究以稀释涂布平板法从保宁醋醋曲中分离得到12株乳酸菌，通过定性试验、产酸率、耐酸试验和胞外多糖测定等实验，得到一株产多糖量为191.98 mg/L、产酸率为1.62%的乳酸菌L7，鉴定为发酵乳酸杆菌(Lactobacillus femertum)，其发酵液中3-羟基-2-丁酮和乙酸相对含量较高，分别为36.22%、45.76%，HPLC检测到乳酸、乙酸，含量分别为66.56 mg/100 mL和104.08 mg/100 mL，这表明L7将有利于提高食醋酸度以及川芎嗪含量。产多糖乳酸菌在食醋发酵过程中的具有重要作用，而此次所得乳酸杆菌对保宁醋生产和发酵工艺改良具有指导意义。

Abstract:

Baoning vinegar had a unique flavor due to the complex microbial system and unique brewing process. The flavor substances and nutrients were mainly produced by fermentation of various functional microorganisms. Lactobacillus was one of the most important strains, which played an important role in the formation of flavors and nutrients in Baoning vinegar. In this study, 12 strains of lactic acid bacteria were isolated from Baoning vinegar koji by dilution separation methods. Lactobacillus L7 was obtained with an acid-producing rate of 1.62% and polysaccharide yield of 191.98 mg/L, and was identified as Lactobacillusfemertum. . HPLC analysis showed that the contents of 3-hydroxy-2-butanone and acetic acid in fermentation broth were 36.22% and 45.76% respectively, and the contents of lactic acid and acetic acid were 66.56 mg/100 mL and 104.08 mg/100 mL, respectively. These results suggested that the strain L7 would be beneficial to improve the vinegar acidity and ligustrazine content. Consequently, the polysaccharide-producing lactic acid bacteria played an important role in the vinegar fermentation process, and the Lactobacillus obtained in this study had significance for improving the fermentation process and production of Baoning vinegar.