酸奶生产菌株的诱变选育

Mutation Screening of Bacillus in Yogurt Manufacture

通过诱变选育高产酸力菌株;首先采用紫外线和亚硝基胍对乳酸菌进行单因素诱变,确定紫外线照射剂量为150s,并得到一株产酸力为57.85°T的菌株,比原菌株产酸力提高了3.05%;NTG的诱变剂量是0.3mg/mL,处理时间为60min,得到产酸力为58.02°T的菌株,较出发菌株提高了6.52%。接着以紫外线和NTG对高产酸菌株进行了2轮复合诱变,最终得到产酸力达83.66°T的诱变株,较出发菌株产酸力提高了30.64%。

To obtain a high acid- produced of strain by mutation; UV and NTG were used to mutate HET- S. Firstly, HET- S was exposed in ultraviolet 150s, obtained a new strain The acid - produced ability of the new strain could reach 57.85°T, increased 3.05% than that of the original strain .When HEF - S was disposed with 0.3mg/mL NTG, 60min, a new strain which ability of acidproduced could reach 58.02°T, was obtained, increased 6.52% than before. Then, we disposed the new strain with UV ＋ NTG for two times, obtained a new strain HETI - S - U - N which acid- produced could reach 83.66°T, increased 30.64% than before.