保加利亚乳杆菌H^+-ATPase弱化菌株的诱变选育

Mutation breeding of H^+-ATPase deficient mutant of Lactobacillus delbrueckii subsp. bulgaricus

以保加利亚乳杆菌ND06(Lactobacillus delbrueckii subsp.bulgaricus ND06)为出发菌株,利用硫酸新霉素诱变、筛选出一株H+-ATPase弱化菌株ND06-6。该菌株在MRS培养基中,37℃培养18 h时,H+-ATPase活性为0.65μmol/(mg·min),和出发菌株相比,H+-ATPase活性下降了35%。在脱脂乳培养基中培养0,4,8,12,16,20,24,36,48和72 h后,诱变菌株ND06-6的乳酸、乳糖和半乳糖的的代谢能力明显低于出发菌株。这些研究结果为弱后酸化酸奶发酵剂的开发和应用提供了理论依据。

A mutant strain was mutated from LactobaciUus delbrueckii subsp, bulgaricus ND06 and coded as ND06-6. When cultured in MILS broth for 18 h, the H＋-ATPase activity of mutant strain was 0.65 μmol/（mg.min）. Compared with the parent strain, the H＋-ATPase ac- tivity of the mutant ND06-6 decreased by 35%. After cultured in MILS broth for 72 h,metabolic capability of the lactic add, lactose and galac- tose were lower than parent strain. These results provide a theoretical basis for the development and application of the weak post-acidification yoghurt starter.