紫外线与亚硝基胍复合诱变选育高效降解亚硝酸盐乳酸菌

Screening of high quality nitrite degrading Lactobacillus by UV/NTG mutage-nesis

中文关键词:  诱变  亚硝基胍  紫外线  亚硝酸盐  乳酸菌

英文关键词:mutagenesis  nitrosoguanidine  UV  nitrite  Lactobacillus

中文摘要:

      目的 通过诱变方法获得高效降解亚硝酸盐的优良乳酸菌应用于降低腌制品中的亚硝酸盐。方法 以前期实验筛选获得的降解亚硝酸盐性能较强乳酸菌D2作为初始诱变菌株, 采用紫外线和亚硝基胍复合诱变, 选育高效降解亚硝酸盐的乳酸菌。结果 经15 W紫外线和0.5 mg/mL亚硝基胍三轮复合诱变得到一株优良乳酸菌, 该菌株24 h降解亚硝酸盐(200 mg/L)降解率为91.4%, 较初始菌株提高了12.7%; 以亚硝酸钠为底物, 其产亚硝酸盐还原酶的比活力为7.7 mmol/L, 较诱变前提高42.9%; 连续传代培养后降解亚硝酸盐能力和产亚硝酸盐还原酶活力性能稳定。结论 通过紫外线和亚硝基胍复合诱变, 获得一株遗传稳定性良好的高效降解亚硝酸盐的菌株。

英文摘要:

      Objective To obtain efficient nitrite degrading lactic acid bacteria by mutagenesis. Methods With the strain D2 isolated in the preliminary work as the original strain, the UV/NTG mutagenesis were used to prepare for screening. Results After mutagenesis with 15 W UV and 0.5 mg/mL nitrosoguanidine for three times, the new strain obtained degradated 91.4% nitrite (200 mg/L) after cultivation for 24 h, increasing by 12.7% compared with the original. With sodium nitrite as the substrate, the activity of nitrite reductase enzyme reached 7.7 mmol/L, increasing by 42.9%. The ability of nitrite degradation and the activity of nitrite reductase were stable after several generations. Conclusion A high quality nitrite degrading strain stable genetic char-acteristics was obtained via UV/NTG mutagenesis.