茶叶籽乳杆菌的分离鉴定及其发酵作用特性研究

为阐明茶叶籽水浆发酵微生物种类及其在发酵过程中的作用特性,对发酵5βh的茶叶籽水浆发酵液进行微生物分离与提纯,从中分离纯化出1株菌株。经形态观察、16βS rDNA及pheS基因测序与比对、系统发育树的构建与分析,确定该菌株为植物乳杆菌（Lactobacillus plantarum ssp. Plantarum）;命名该菌株为茶叶籽乳杆菌（Lactobacillus plantarum ssp. plantarum JJZ21）,菌种保藏号为CCTCC M 2016471。在茶叶籽水浆发酵过程中,发酵液中茶叶籽乳杆菌的数量在5βh之后逐渐快速增加,至12~15βh之间达到最大值,之后又逐渐降低,至22βh后,逐渐趋于稳定。伴随茶叶籽乳杆菌数量的增加,发酵液中的干物质含量、可溶性糖含量、可溶性蛋白含量及其pH均明显下降,呈极显著（P<0.01）负相关性。茶叶籽乳杆菌通过消耗发酵液中的可溶性糖及可溶性蛋白等物质,向发酵液中分泌乳酸等酸性有机物,导致发酵液pH逐渐降低,为发酵液中的油脂体上浮以及茶叶籽水浆发酵分层现象发生奠定了基础。

Studies on the Identification and Isolation of Lactobacillus plantarum ssp. plantarum JJZ21 and Its Fermentation Properties

To clarify the fermentation properties of microorganisms in fermentation layering of tea-seed-water-milk (TSWM), identification and isolation of microorganism in 5βh fermented TSWM were conducted. Based on morphological observation, 16βS rDNA, pheS gene sequencing and comparison, and phylogenetic tree analysis, a bacterial strain isolated from the fermented TSWM was identified as a strain of Lactobacillus plantarum ssp. Plantarum and named as L. plantarum ssp. Plantarum JJZ21 (LPJJZ21). Its culture preservation number was CCTCC M 2016471. In the fermentation process of TSWM, the total number of LPJJZ21 was increased rapidly after 5βh, peaked at 12βh to 15βh, then gradually reduced until 22βh, finally stayed stable after 22βh. Accompanied by the increasing of LPJJZ21, the dry matter, soluble sugar, soluble protein contents and pH decreased significantly, with highly significant (P<0.01) and negative correlation. Through consuming the soluble protein, soluble sugar and other substances in fermented TSWM, JJZ21 secreted acidic organic matter (such as lactate acid and so on), leading to the gradual decrease of pH in fermented TSWM, which were the prerequisite for the floating up of fat bodies in fermented TSWM and fermentation layering of TSWM.