产亚硝酸盐还原酶低温乳酸菌的筛选鉴定及发酵特性

Isolation and characterization of psychrotrophic lactic acid bacteria producing nitrite reductase

为有效控制酸菜中的亚硝酸盐含量,降低食品安全风险,加快我国酸菜产业的现代化生产,本研究利用溴甲酚绿指示剂法对从黑龙江省哈尔滨地区采集的8份自然发酵的酸菜样品进行筛菌,共分离低温乳酸菌17株。经亚硝酸盐降解能力的评估,获得5株具有较强降解亚硝酸能力的低温乳酸菌,通过测定菌株亚硝酸盐酶活力获得了1株高产亚硝酸还原酶的低温乳酸菌R11,该菌在含125 mg/L NaNO2的MRS培养基中诱导48h,亚硝酸盐还原酶活力为68.4U/mL。菌株R11经形态学、生理生化特征、16SrDNA序列和构建系统发育树等方法分析,鉴定该菌株为冷明串珠菌(Leuconostoc gelidum),命名为Leuconostoc gelidum R11。发酵特性的初步研究结果表明,该菌具有良好的低温生长性能和产酸能力。因此,L.gelidum R11是1株产亚硝酸盐还原酶、发酵性能优良的具有巨大应用潜力的酸菜低温发酵菌株。

In order to effectively eliminate the nitrite content in sauerkraut ,reduce food safety risks and accelerate the development of sauerkraut industry ,in this study ,seventeen strains of lactic acid bacteria were isolated from eight sauerkraut samples collected from Harbin ,Chi‐na .By assessing the nitrite‐degradation ability and the nitrite reductase activity ,strain R11 with a high yield of nitrite reductase was selected .When the bacteria cultivated in MRS broth containing NaNO2 （125 mg/L） ,Nitrite reductase activity reached 68 .4 U/mL .The strain was identified as Leuconostoc gelidum by morphology ,physiology and 16S rRNA analysis ,named Leuconostoc gelidum R11 .The fermentation characteristics indicate that the strain R11 is of great potential as starter culture in sauerkraut production .