啤酒污染菌的鉴定及其细胞膜脂肪酸的组成分析

Identification of beer-spoilage bacterium and analysis of its membrane fatty acids composition

从纯生啤酒中富集分离得到11株啤酒污染菌。对这11株菌进行16S rRNA同源性分析和系统发育树构建。结果表明:11株菌均属于乳酸杆菌,分属于植物乳杆菌(Lactobacillus plantarum)、类布氏乳杆菌(Lactobacillus parabuchneri)和乳酸短杆菌(Lactobacillus brevis)3个种。进一步对11株菌的膜脂肪酸组成进行分析,其脂肪酸组成变化规律与16S rRNA进化分布高度一致。将BN01、BN02和BN03号菌接种到不同程度啤酒环境胁迫的培养基中,发现随着啤酒成分增加,菌的膜不饱和直链脂肪酸和链长18和20碳的脂肪酸含量增加。该研究结果不仅对啤酒污染菌进行了分类鉴定,而且阐述了基于膜脂肪酸调控的污染菌膜对啤酒环境胁迫的耐受机制。

A total of 11 strains of beer-spoilage bacteria were isolated from draft beer. The homology of 16S rRNA was analyzed and phylogenetic tree was structured for these 11 beer-spoilage bacteria. These 11 beer-spoilage bacteria were all classified into Lactobacillus genus, including Lactobacillus plantarum, Lactobacillus parabuchneri and Lactobacillus brevis. Variation of beer-spoilage bacteria membrane lipid composition was consistent with the result of 16S rRNA. The contents of straight chain unsaturated fatty acids and C18 and C20 fatty acids of BN01, BN02 and BN03 were increased with increase of beer content. These results not only classified and identified beer-spoilage bac- teria but also expound tolerance mechanism of beer environmental stress based on regulation of fatty acids of beer bac- teria membrane.