长双歧杆菌F16菌株胆盐水解酶基因的鉴定及产酶条件优化  

Identification of bile salt hydrolyase gene and optimization of enzymeproducing conditions of Bifidobacterium longum F16

作　　者：惠明[1,2] 冯诗诗 田青 胡军[3] HUI Ming;FENG Shishi;TIAN Qing;HU Jun(School of Biological Engineering,Henan University of Technology,Zhengzhou 450001,China;Henan ProvincialEngineering Laboratory of Preservation and Breeding of Industrial Microbial Strains,Zhengzhou 450001,China;Basic Medical College,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]河南工业大学生物工程学院,河南郑州450001 [2]工业微生物菌种保藏与选育河南省工程实验室,河南郑州450001 [3]郑州大学基础医学院,河南郑州450001

出　　处：《浙江工业大学学报》2022年第3期349-354,共6页Journal of Zhejiang University of Technology

基　　金：中国工程科技发展战略河南研究院战略咨询研究项目(2020HENZT13)。

摘　　要：在前期益生性实验过程中,驯化后的长双歧杆菌F16菌株具有显著的降胆固醇作用,对人体健康具有重要意义。为探讨其降解机制,实验测定了其产胆盐水解酶(Bile salt hydrolase,BSH)能力并鉴定了胆盐水解酶基因。为提高F16菌株的降胆固醇效果,在单因素实验的基础上,利用Box-Behnken中心组合原理设计3因素3水平响应面实验,以葡萄糖质量浓度、蛋白胨质量浓度和接种量为自变量,BSH活性OD_(570)为响应值,确定了F16菌株产BSH的优化发酵条件:葡萄糖质量浓度为10.05 g/L、蛋白胨质量浓度为15 g/L、接种量为1.05%(OD_(600)为1),既定条件下BSH活性OD_(570)可达到0.896,酶活可达到优化前的1.8倍。对F16菌株降解胆固醇的降解率进行了测定,优化后在48 h内的胆固醇降解率可达到72.6%,约为优化前的1.6倍。实验结果表明F16菌株的益生性能在食品、保健和医药等领域具有潜在的应用前景。The domesticated Bifidobacterium longum F16 strain was found to have significant cholesterol reduction during early probiotic tests and is of great significance to human health.In order to explore the mechanism of cholesterol degradation,using Oxford cup method and ninhydrin reaction,we found that F16 can produce the bile salt hydrolase(BSH).According to the sequence of the strains,we identified the related the bile salt hydrolase gene.In order to improve the fermentation activity of BSH produced by Bifidobacterium longum F16,the medium composition and inoculation quantity of F16 were optimized.Firstly,the main components in fermentation medium were selected through single factor experiments.Then,the concentration of glucose and peptone were optimized through response surface analysis.Finally,the effects of inoculation quantity of F16 on the enzyme activity was investigated.The result showed that under glucose mass concentration 10.05 g/L,peptone 30 g/L,concentration 15 g/L,1.05%(OD_(600) for 1),OD_(570) can reach 0.896 and enzyme activity 1.8 times before optimization.The degradation rate of F16 cholesterol was determined,optimized within 48 h to 72.6%,about 1.6 times before optimization.After the fermentation conditions of BSH in F16,the activity and the degradation rate of cholesterol are significantly improved,indicating that Bifidobacterium longum F16 after optimized fermentation conditions has better cholesterol reduction effect and has potential applications in the fields of food,health care and medicine.

关 键 词：长双歧杆菌 胆固醇降解 胆盐水解酶 响应面法 

分 类 号：TS201.3[轻工技术与工程—食品科学]