中文摘要：

【目的】分离与鉴定人肠道乳酸利用菌,研究其乳酸利用的代谢特性。【方法】利用Hungate滚管技术从人粪便中分离厌氧细菌,通过形态、生化和16S r RNA基因鉴定;通过体外发酵技术研究乳酸代谢,并且与乳酸产生菌共培养,研究二者之间交互饲喂。【结果】验证了乳酸可作为代谢中间产物被人肠道混合菌群利用;分离到一株乳酸利用菌,在24 h内消耗乳酸超过50 mmol/L,经鉴定为韦荣氏球菌,并将其形成乙酸和丙酸。当和肠球菌共培养时,可以有效地减缓乳酸的积累。【结论】本株乳酸利用菌可以作为潜在的益生菌,和乳酸菌一起调节人肠道的乳酸动态平衡。

英文摘要：

[Objective] To isolate and identify lactate-utilizing bacteria from human gut, and investigate thier metabolic traits of lactate. [Methods] We used Hungate roll tube technique to isolate anaerobic bacteria with lactate as substrate, and then identified the strain based on morphologies, biochemical reaction and 16 S r RNA gene. Then, in vitro fermentation system was used to assess the metabolic traits of lactate and its cross-feeding with lactic acid bacteria. [Results] We verified that lactate was generally utilized by human microflora. We obtained a lactate-utilizing bacterium, belonging to Veillonella, that efficiently consumed more than 50 mmol/L lactate within 24 h, and mainly generated acetate and propionate. Furthermore, it ameliorated the lactate accumulation when co-cultured with lactic acid bacteria Enterococcus. [Conclusion] Our results suggest that this strain could be used as potential probiotics with lactic acid bacteria to cooperate the dynamics of lactate in the hind gut.