^(60)Co-γ射线诱变选育弱后酸化乳酸菌株

Selection of Weak Post-acidification Mutation of Lactobacillus by Treatment of ^(60)Co

选择剂量为60、80、100 kR的60Co-γ射线对保加利亚乳杆菌G4进行诱变处理,根据突变株的生长情况及产酸特性筛选出G4-1、G4-2、G4-3三株弱后酸化乳酸菌。此3株突变菌在酸奶的贮藏试验中表现出良好的弱后酸化特性,在4℃和10℃下贮藏25 d,酸奶的pH值变化很小。

Lactobacillus bulgaricus G4 was mutagenized by ^60 Co -γ ray at the dose of 60, 80 and 100 kR. According to the growth and characteristics of the mutant, G4 - 1, G4 - 2 and G4 - 3 with weak post - acidification were selected. These three mutant strains showed good character of weak post - acidification in yogurt storage tests, the yogurt had little changes in pH - value when it was stored at 4℃or 10 ℃ for 25 days.