pH对粪肠球菌高产双乙酰的影响  

Effect of pH on high-level diacetyl production of Enterococcus faecalis

作　　者：郑遂[1,2] 康欢[1,2] 赵蕊[1,2] 杨丽杰[1,2] 霍贵成[1,2] 

机构地区：[1]乳品科学教育部重点实验室,哈尔滨150030 [2]东北农业大学食品学院,哈尔滨150030

出　　处：《东北农业大学学报》2013年第2期7-11,共5页Journal of Northeast Agricultural University

基　　金：教育部长江学者和创新团队发展计划(IRT0959)

摘　　要：将分离自内蒙古农家酸马奶(Koumiss)的粪肠球菌KLDS 4.1004经NTG诱变获得诱变株KLDS 4.1003,后者的LDH、DR酶活力下降,且ALD酶失活。对两者进行8个pH点条件下的酶活、生长情况与代谢物测定,确定KLDS 4.1003在pH 6.5、7.0时双乙酰产量最高。在6个时间点分别检测两个pH点的菌数与双乙酰产量变化,发现发酵16 h两项指标均最高,最终确定最高产双乙酰条件为pH 7.0、16 h,最大产量为1.29 g.L-1。结果表明,诱变株KLDS 4.1003产双乙酰性能优良,可进一步开发成产香型益生发酵剂菌种。A mutant strain KLDS 4.1003 was obtained via NTG from an Enterococcus faecalis KLDS 4.1004 which is separated from the Koumiss of Inner Mongolia. The activities of enzyme LDH and DR in KLDS 4.1003 decreased, while that of ALD was inactivated. The enzyme activities, growth statuses and metabolites of KLDS 4.1003 and KLDS 4.1004 at eight pH were determined. The yield of diacetyl in KLDS 4.1003 was the highest at pH 6.5 and 7.0, especially fermenting for 16 h. Therefore, the optimal condition of diacetyl production was at pH 7.0 for 16 h, and the highest yield was 1.29 g. L-1. The results showed that, for mutant strain KLDS 4.1003, the ability to produce diacetyl was excellent, and hence, it would be developed to an probiotic starters.

关 键 词：粪肠球菌 PH 双乙酰 乙偶姻 酶活 生长情况 

分 类 号：R378.99[医药卫生—病原生物学]