【摘要】 从神农架金丝猴的粪便中分离出1株益生菌株dlt7a,经鉴定为粪肠球菌。为进一步提高发酵液中dlt7a的活菌数量,对菌株dlt7a的发酵工艺进行优化。通过单因素水平试验,确定dlt7a的最佳培养条件为装液量20%（50mL/250mL）,接种量2%,培养基初始pH 6.5。设计Plackett-Burman（PB）试验和响应面试验,找出发酵培养基中影响dlt7a活菌数的主要成分是蔗糖、鱼粉和KH₂PO₄,并优化3种重要成分的含量,确定最优发酵培养基配方为:蔗糖2.55%,鱼粉2.63%,豆粕2.5%,酵母膏0.4%,CaCO₃ 1.0%,KCl 0.1%,MgSO₄·7H₂O 0.1%,KH₂PO₄ 0.014%。在此条件下培养dlt7a菌株,活菌数可达58.83×108cfu/mL,比优化前提高了46.53%。更多还原

【Abstract】 A probiotic strain dlt7 awas isolated from feces of the Shennongjia golden snub-nosed monkey and was identified as Enterococcus faecalis.In order to improve the viable count of dlt7 ain the fermentation broth,the fermentation technology of dlt7 awas optimized.The optimal culture condition with 20%（50mL/250mL）loading volume,2%inoculation amount,and initial pH of 6.5,was obtained by single-factor-experiment.In the study,Plackett-Burman experiment and response surface experiment were designed to identify the main nutrients affecting the viable count of dlt7 ain the fermentation broth and to optimize the content of the three main nutrients including sucrose,fish meal and KH₂PO₄.The optimum nutrients in the media consisted of 2.55% sucrose,2.63%fish meal,2.5% soya bean,0.4% yeast extract,1.0% CaCO₃,0.1% KCl,0.1% MgSO₄·7H2O and 0.014% KH₂PO₄.E.faecalis dlt7 awere then cultured by the optimized fermentation medium and condition,and the viable count reached 58.83×108cfu/mL,which was 46.53% higher than that not optimized.更多还原