中文摘要：

【目的】为了阐明乳酸乳球菌乳酸亚种KLDS4.0325的生理及代谢机制,并对其重要功能基因进行挖掘,我们对菌株KLDS4.0325的全基因组序列进行测定和基因组图谱的绘制,并利用生物软件和数据库完成对序列的注释及相关功能性分析。【方法】在菌株序列完成测序、组装和注释后,根据序列信息进行全基因组图谱的绘制,并对菌株的蛋白质水解系统、氨基酸来源的风味形成途径和B-族维生素合成途径进行了比较基因组分析,并对细菌素合成基因组和冷应激蛋白基因进行了预测。【结果】菌株KLDS4.0325基因组全长2589250 bp,G＋C含量为35.4%,共预测出2662个开放阅读框,其中1310个具有潜在的生物学功能。菌株可以有效的对细胞外蛋白质进行有效的水解,具有潜在的降低苦味肽以及产生一系列能够抑制血管紧张素转化酶活性的活性肽。在转氨途径方面,菌株KLDS4.0325具有较为完成的酶系统,可以催化相关氨基酸转化为风味物质。在菌株KLDS4.0325的基因组中,我们发现了较多编码糖转运、代谢以及L-乳酸合成的基因。关于叶酸和核黄素合成途径的编码基因在菌株KLDS4.0325的基因组中也较为完整。此外,我们在菌株KLDS4.0325的基因组中预测出了一个关于乳球菌素的基因簇和两个冷应激蛋白Csp D和csp E的编码基因。【结论】这些编码菌株显著特性基因的存在为菌株KLDS4.0325能够进行工业发酵提供了理论基础,并为其进一步研究提供了方向。

英文摘要：

[ Objective] Aim to study the physiology and functionally important genes of Lactobacillus lactis KLDS4. 0325. [Methods] We sequenced the complete genome of L. lactis KLDS4.0325, drew the genomic map, and performed functional annotation and analysis in metabolism and probiotic. [ Results] L. lactis KLDS4. 0325 contains a chromosome of 2589261 bp, GC content is 35.4% , with 2662 predicted ORFs, of which 1310 are functionally classified. L. lactis KLDS4. 0325 can carry out hydrolysis of extracellular proteins effectively, has the potential to degrade bitter peptides and produce a series of peptides of inhibiting angiotensin converting enzyme. L. lactis KLDS4. 0325 has complete enzyme system for transamination pathway, which can catalyze relevant amino acids to flavor compounds. More key enzyme-coding genes involved in transport and metabolizing of sugars, and L-lactic acid synthesis, are exist in L. lactis KLDS4. 0325 genome. L. lactis KLDS4. 0325 has a set of more complete encoding genes in the biosynthetic pathways of folate and riboflavin. In addition, gene cluster for Lactococcin and 2 cold stress protein （cspD and cspE ） were identified. [ Conclusion] The presence of these genes encoding desirable traits provides the theoretical basis for the strain in industrial fermentation, and relevant further research.