诱变筛选VC二步发酵高产菌

Mutation of Mingle Strains in the Fermentation of 2-keto-L-Gulonic acid--Precursor of VC

研究了亚硝基胍(NTG)的诱变剂量、处理时间对VC二步发酵菌系存活率的影响,NTG的诱变剂量为25—200mg/L,处理时间为10—30min范围内,随着诱变剂量增加和时间的延长,VC二步发酵菌的存活率不断下降。利用细菌存活率为55%的诱变条件,经摇瓶发酵复筛,获得高产诱变菌系LZ-1003,其转化率较出发菌系WS-02提高4%,经传代实验证明,其遗传性状较稳定,4代平均转化率可达86.5%。

The affects of the concentration and working time of NTG on the living rate of mingle strains in the fermentation of 2-keto-L-gulonic acid--precursor of VC was investigated. When the concentration of NTG was 25-200 mg/L and working time was 10-30 min, the living rate of LZ-1003 was decraeased with addition of the conditions of the living rate of LZ-1003 was 55%, LZ-1003 was obtained from above potential strains.The convertion rate was increased by 4% compared with that of strain WS-02.Its genetic quality was proved stable by experiments.The average convertion rate of four generations was 86.5%.