一株人消化道中韦荣氏球菌的分离、鉴定及其代谢特性研究

【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。

Isolation, identification and metabolism of a Veillonella strain in human gut

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 16S rRNA 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.