凉州熏醋酿造中高产乙偶姻醋酸菌菌株筛选及其发酵条件优化  

Isolation of Acetic Acid Bacterium with High Acetoin-Producing Ability from Aerobic Solid-Fermentation Culture of Liangzhou Fumigated Vinegar and Optimization of Its Fermentation Conditions

作　　者：赵洪源[1] 贠建民[1] 邵晓庆[1] 齐丹[1] 

机构地区：[1]甘肃农业大学食品科学与工程学院,甘肃兰州730070

出　　处：《食品科学》2015年第15期98-104,共7页Food Science

基　　金：国家自然科学基金地区科学基金项目(31360405)

摘　　要：四甲基吡嗪是传统发酵食品中重要风味物质,而乙偶姻(acetoin,ACT)是其生物合成前体。本实验从凉州熏醋醋醅中分离出了200株产酸菌株,利用Voges-Proskauer(V-P)显色反应法初筛得到了28株产乙偶姻的菌株,用火焰离子化检测器结合气相色谱(gas chromatograph-flame ionization detector,GC-FID)法复筛得到了一株高产乙偶姻的菌株C92,经生理生化和16S rRNA鉴定为巴氏醋酸杆菌(Acetobacter pasteurianus)。在单因素试验基础上使用Design-Expert设计响应面优化试验,得到最佳发酵条件为培养温度31.31℃、接种量8.27%、pH 6.55、摇床转速209 r/min,此条件下乙偶姻产量最大,达到19.04 g/L,比原始发酵产量高35.8%,证明C92菌株是一株在食醋酿造过程中具有潜在应用价值的菌株。Acetoin （ACT） is the precursor of tetramethylpyrazine, a popular food flavor found in different traditional fermented foods. In our present study, we isolated approximately 200 pure cultures by forming transparent zone on GYC agar medium, and obtained 28 ACT-producing strains from these isolates by Voges-Proskauer （V-P） colorimetric assay and gas chromatograph with flame ionization detector （GC-FID）. Based on ACT level, C92 strain with the highest yield was selected for further analysis. It was identified as Acetobacter pasteurianus by physiological and biochemical characteristics and 16S rRNA gene sequence similarity. We examined ACT level of C92 strain under different conditions and found that the optimal culture conditions that provided maximum ACT yield of 19.04 g/L were 31.31 ℃, pH 6.55, shaking at 209 r/min, 48 h and inoculum size of 8.27%, representing a 35.8% increase compared to that before optimization. Therefore, C92 has a promising potential in the production of vinegar.

关 键 词：凉州熏醋 巴氏醋酸杆菌 乙偶姻 响应面优化 

分 类 号：TS264.2[轻工技术与工程—发酵工程]