紫外线与亚硝酸钠复合诱变选育L-组氨酸产生菌

以1株谷氨酸棒杆菌(Corynebacterium glutamicum)S_6作为出发菌株,利用亚硝酸钠(NaNO_2)、紫外线(UV)进行诱变,通过实验证明亚硝酸钠诱变时间在180 s后致死率达到80%,紫外线在照射30 s后致死率达到80%。诱变后的突变菌株经6-巯基嘌呤结构类似物的抗性平板筛选,最终筛得3株菌,Y_1产L-组氨酸量达到331 mg/L,比出发菌株S_6高了5.08%,Z_2产L-组氨酸量达到325 mg/L,比出发菌株S_6高了1.9%,F_6产L-组氨酸量达到330 mg/L,比出发菌株S_6高了7.14%。结果显示,经紫外线与亚硝酸钠复合诱变后的菌株F_6产L-组氨酸的产量最高,比亚硝酸钠诱变后的菌株产L-组氨酸量提高2.06%,比紫外线诱变后的菌株产L-组氨酸量提高5.24%。

Breeding of L-Histidine Producing Bacterium by Composite Mutation with UV and NaNO2

Corynebacterium glutamicum S_6 was taken as starting strain and mutated by NaNO_2 and UV for breeding L- histidine producer.The lethality of the strain up to 80% was proved through experiment 180 s after mutated with NaNO_2,and up to 80% 30 s after UV radiation.After the mutation,the mutated strain was screened on 6-mercaptopu- fine(6-MP)analogue resistance plate and consequently got three mutant strains,the L-histidine output of Y_1 was 331 mg/L,5.08% higher than S_6;that of Z_2 was 325 mg/L,1.9% higher than S_6;and that of F_6 was 330 mg/L,7.14% higher than S_6.The results showed that after composite mutation with UV and NaNO_2 the output of L-histidine of strain F_6 was the highest,2.06% higher than strain mutated with NaNO_2,and 5.24% higher than strain mutated with UV.