降胆固醇优良菌株的筛选及其胆盐水解酶特性研究

对已证实具有降胆固醇能力并能产生胆盐水解酶（BSH）的3株乳酸菌进一步筛选,综合模拟人工胃肠液的耐受性、疏水性能力和去结合胆盐能力三个指标,筛选出一株具有优良的降胆固醇综合性能的潜力菌株,并对其产生的BSH的部分特性进行研究。结果表明,屎肠球菌90-1作为降胆固醇潜力菌株其综合性能较好,其所产的BSH最适反应pH为6.0,最适反应温度为37℃,最适底物浓度为7mmol/L,最适三磷酸腺苷二钠（ATP）浓度为2.5mg/mL。 

Screening of excellent strains for cholesterol-lowing and studies on characteristics of bile salt hydrolase

Three strains of lactic acid bacteria with cholesterol removal ability and bile salt hydrolase (BSH) producing activity were further filtered, using the standard which was included three indexes of the tolerance to simulated artificial gastric juice, hydrophobic capability and deconjugation of sodium taurocholate. A potential strain of lactic acid bacteria with comprehensive performance and excellent cholesterol -lowering ability was filtered out, and partial BSH characteristics was studied. The result indicated that Enterococcus faecium 90-1 could be potential cholesterol-lowering strain for further research with good comprehensive performance. The optimum reaction pH of BSH was 6.0, the optimum reaction temperature was 37℃ , the optimum substrate concentration was 7mmol/L, and the optimum ATP concentration was 2.5mg/mL.