东北酸菜中20个乳杆菌新种的多相分类和发酵特性研究

As a traditional fermented food, pickle is rich in lactic acid bacteria (LAB). In recent years, researchers have separated and characterized nineteen novel LAB species from pickle (ten isolated from Korean pickle, six isolated from Japanese pickle, one isolated from northeast pickle of China by Japanese, two from Taiwan pickle of China) and one novel LAB subspecies (isolated from Japanese pickle).How many novel LAB species do there exist in Chinese traditional pickles? This question has not been answered in previous studies. We have isolated 25 novel LAB species from northeast pickle of China. Currently, 5 novel species have already been identified and published, and another 20 novel species within the genus Lactobacillus have not been systematically studied. This project will characterize ten novel LAB species isolated from northeast pickle of China based upon polyphasic approach, evaluate their fermentation characteristic and analyze whole genome sequence of excellent species. This has the following meaning: First, to enlarge our knowledge on the species diversity of pickle LAB and improve the taxonomic system of LAB; Second, to achieve starter strains selection and compatibility based upon fermentation performance of the new species; third, to fully develop the metabolic potential of lactic acid bacteria by using genomic information.

作为一种传统发酵食品，酸泡菜中富含乳酸菌。近些年来，研究人员从酸泡菜（主要是韩国和日本的酸泡菜）中分离和鉴定了19个乳酸菌新种（10个从韩国泡菜中分离，6个从日本泡菜中分离，1个由日本人从我国东北酸菜中分离，2个从我国台湾泡菜中分离）和1个乳酸菌新亚种（从日本泡菜中分离）。而我国传统酸泡菜中存在哪些乳酸菌新种？以往的研究并没有给出充分的回答。申请人领导的研究小组从我国东北酸菜中分离和鉴定了25个乳酸菌新种，并对其中5个新种进行了多相分类和发表，另外20个新种（乳杆菌）尚未进行系统研究。本项目针对这20个乳酸菌新种进行多相分类和发酵特性研究，并对优良菌种进行全基因组测序分析。这具有如下意义：①扩大对酸泡菜中乳酸菌物种多样性的认识，完善乳酸菌分类系统；②依据新种的发酵性能，可以实现发酵剂菌种的选择与配伍；③利用基因组信息，可以充分开发乳酸菌的代谢潜力。

采用16S rDNA序列分析、多位点序列分析（pheS、rpoA和dnaK）、ANI（平均核苷酸相似性）分析、API50CH糖发酵实验和脂肪酸甲酯分析（FAME）等方法对前期研究中发现的乳酸菌新种进行了多相分类，确定了它们的分类学地位。鉴定了29个乳酸菌新种。这些新种是分类学上的新种，其科学意义在于：扩大了对酸泡菜这一生态系统中乳酸菌物种多样性的认识，并丰富和完善了乳酸菌的分类系统，同时也为完善整个微生物自然分类系统做出了贡献。筛选了5个发酵性能优良的菌种。这些优良菌种的应用前景在于：可以为发酵剂和益生菌的开发提供宝贵的菌种资源；充实我国的东北酸菜乳酸菌资源库，为从中选择特定的乳酸菌菌株来发酵制作东北酸菜，并用于改善东北酸菜品质贮备菌株资源；依据新种的发酵性能，可以实现发酵剂菌种的选择与配伍。为促进东北酸菜用乳酸菌发酵剂产业的形成与发展以及实现东北酸菜的现代工业化生产奠定基础。