干酪乳杆菌12A碳源代谢的比较基因组学分析

【目的】在基因组学水平上,对干酪乳杆菌的碳源代谢特性及调控机制进行研究。【方法】基于BioCyc和MetaCyc数据库,利用Pathway Tools对菌株12A及7株已公布全基因序列的干酪乳杆菌进行全基因组水平的碳源代谢比较分析。【结果】全基因组比较分析结果显示,干酪乳杆菌12A可以将9种糖转运到细胞内代谢利用;可以将多种寡糖和多糖在细胞外水解成半乳糖和葡萄糖;干酪乳杆菌12A可经异型乳酸发酵或混合酸发酵途径生成乙醇及其副产物。【结论】干酪乳杆菌12A可以代谢多种类型碳源,底物选择范围宽泛,而且可以作为工业乙醇发酵的特定菌株;利用比较基因组学方法建立基因结构与细菌代谢能力的联系是可靠的。

Comparative genomics analysis of carbon metabolism of Lactobacillus casei 12A

[Objective] The aim of this study was to describe carbon metabolic characteristics and regulation mechanisms of Lactobacillus casei strain at the genome-level. [Methods] Pathway Tools, based on BioCyc and MetaCyc database, was used for genome-wide level of carbon metabolism comparative analysis of 12A and other 7 L. casei strains published complete genome sequences. [Results] Nine sugars could be transferred and metabolized by L. casei 12A inside cells. Various oligosaccharides and polysaccharides could be hydrolyzed into galactose and glucose by strain 12A outside cells. In particular, strain 12A could generate ethanol and its by-products through heterolactic fermentation and mixed acid fermentation pathways. [Conclusion] L. casei 12A can metabolize multiple types of carbohydrate, thus the choice of its fermentation substrates is broad. And strain 12A can be used as a specific strain for industrial ethanol production. In addition, it is reliable that comparative genomics is used for analyzing and establishing relationship between genetic structure and bacterial metabolic capability.