屎肠球菌R40产胆盐水解酶发酵动力学及底物特异性分析  

Fermentation kinetic and substrate specificity of bile saline hydrolase produced by Enterococcus faecium R40

作　　者：雷霜江 吕青遥 王文杰 杨浩 孙博瑞 武雪梅 焦士蓉 LEI Shuangjiang;LV Qingyao;WANG Wenjie;YANG Hao;SUN Borui;WU Xuemei;JIAO Shirong(College of Food and Bioengineering,Xihua University,Chengdu 610039,China)

机构地区：[1]西华大学食品与生物工程学院,四川成都610039

出　　处：《中国酿造》2021年第11期144-148,共5页China Brewing

基　　金：2019学科开放课题“食品生物技术”平台下项目(DC1900010109)。

摘　　要：该研究以产胆盐水解酶的屎肠球菌(Enterococcus faecium)R40为研究对象,模拟人体胆盐条件,对其发酵动力学进行分析。采用Logistic、Luedeking-Piret、Luedeking方程描述屎肠球菌R40发酵过程中菌体生长、产物生成、底物消耗的内在关系,并比较不同胆盐条件对屎肠球菌R40生长和降胆固醇能力的影响,判断其产生的胆盐水解酶是否存在底物特异性。结果表明,拟合模型的相关系数R2均>0.9,效果良好,模型预测值与试验测量值的误差均<10%,说明可以通过建立发酵动力学模型对屎肠球菌R40产酶情况进行预测和描述。胆盐的添加有利于屎肠球菌R40发挥降胆固醇作用,使菌株R40提前4 h进入对数生长期,且提高了菌株R40的生物量。不同胆盐对菌株R40生长的影响存在差异性,甘氨酸脱氧胆盐虽能提高生物量,但未缩短适应期。牛磺酸胆盐和甘氨酸胆盐缩短了菌株R40的适应期,但对生物量并无显著影响,说明菌株R40产的胆盐水解酶具有一定的底物特异性。In this study,using bile salt hydrolase-producing Enterococcus faecium R40 as the research object,the conditions of human bile salt were simulated,and its fermentation kinetics was analyzed.The internal relationship among cell growth,product production and substrate consumption during the fermentation of E.faecium R40 was described using Logistic,Luedeking-Piret and Luedeking equations,and the effects of different bile salt conditions on the growth and cholesterol-lowering ability of E.faecium R40 were compared to determine whether the bile salt hydrolase produced by E.faecium R40 had substrate specificity.The results showed that the correlation coefficients R2 of the fitting models were more than 0.9,the effects were good,and the error between the predicted value of the model and the measured value of the test was less than 10%,indicating that the enzyme production of E.faecium R40 could be predicted and described by establishing fermentation kinetic model.The addition of bile salt was beneficial to the cholesterol-lowering effect of E.faecium R40,made the strain R40 enter the logarithmic growth phase 4 h in advance,and increased the biomass of strain R40.The effects of different bile salts on strain R40 growth were different.Glycine deoxybile salt could increase the biomass,but did not shorten the adaptation period.Taurine bile salt and glycine bile salt shortened the adaptation period of strain R40,but had no significant effect on biomass,indicating that the bile salt hydrolase produced by strain R40 had certain substrate specificity.

关 键 词：屎肠球菌 胆盐水解酶 发酵动力学 底物特异性 

分 类 号：Q93-31[生物学—微生物学]