一株新的毛螺旋菌Lachnospiraceae bacterium BTY6的分离与鉴定

Isolation and Identification of a new Lachnospiraceae bacterium BTY6

摘要:

窖泥微生物对浓香型白酒的品质、风味起着重要作用. 本研究从25年窖龄的成熟窖池中，分离得到54株功能微生物，并对其中一株新的产丁酸菌株BTY6进行了多相分类学研究. 该菌株为严格厌氧，革兰氏阳性，无芽孢形成，菌体呈短杆状. 该菌株可以利用的碳源有α-D-葡萄糖，蔗糖，麦芽糖，D-果糖，D-纤维二糖，α-D-乳糖，D-半乳糖，L-乳酸，等等. 该菌株主要的脂肪酸为C16 : 0 (54.85%)，C16 : 0 N alcohol (9.61%)，C17 : 0 10-methyl (7.06%) 和C18 : 0 (4.71%). 菌株BTY6的G+C (mol%)含量为48.52%. 16S rRNA基因序列显示，BTY6与GenBank数据库中一株未培养毛螺旋菌（uncultured Firmicutes bacterium; HBG_A4R5-4; DQ837628）有最高的的序列相似性（99.8%），但与所有可培养模式菌株相似性均低于93%. 经形态学、生理生化特征和系统发育分析，该菌可能为毛螺旋菌科的一个新属.

Abstract:

Microbes in pit mud play an important role on the quality and flavor of Chinese Luzhou-flavor liquor. Here, 54 bacterial strains were isolated from the pit mud of a 25 year-old fermentation pit, and a new butyrate-producing bacterium BTY6 was identified by polyphasic taxonomical method. Strain BTY6 is a strictly anaerobic, Gram-stain-positive, non-spore-forming，and short rod bacterium. Strain BTY6 has positive reactions for α-D-glucose, sucrose, maltose, D-fructose, D-cellobiose, α-D-lactose, D-galactose, L-lactic Acid, and so on. The major cellular fatty acids were C16 : 0 (54.85%),C16 : 0 N alcohol (9.61%), C17 : 0 10-methyl (7.06%) and C18 : 0 (4.71%). The genomic DNA G+C content of strain BTY6 was 48.52mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BTY6 was most closely related to an uncultured Firmicutes bacterium HBG_A4R5-4 ( DQ837628 ) of the family Lachnospiraceae with 99.8% sequence similarity, but only had less than 93% sequence similarity with all cultured type species. Based on morphological observation, physiological and biochemical tests and phylogenetic analysis, strain BTY6 should represent a previously unknown subline within the family Lachnospiraceae.