激光复合诱变选育叶酸高产菌

Screening Folic Acid High-yield Strains by Laser Compound Mutagenesis

利用高效液相色谱测定发酵液中叶酸含量,比较产朊假丝酵母(Candida utilis)、异常汉逊酵母(Han-senula anomala)和枯草芽孢杆菌(Bacillus subtilis)产叶酸能力的高低,从而确定生产叶酸的最佳菌种。出发菌株经紫外照射诱变后,再采用激光复合诱变方式进行进一步的筛选,并对其传代稳定性进行研究,以期进一步获得稳产高产叶酸产生菌突变株。结果表明产朊假丝酵母产叶酸量最高。紫外照射3 min得到的Y1.4菌株产叶酸量与原始菌株相比,产量提高了33.8%。激光—紫外复合诱变后筛选出4株产量较高的菌株,其中以Y2.12产量最高。Y2.12产叶酸量与原始菌株相比,提高了65.8%。经传代培养分析,Y2.12诱变株的产量稳定。该结果表明,激光复合诱变是获得高产叶酸的有效途径。

The yield of folic acid was tested by HPLC. The optimal folic acid high-yield strain was chosen by comparing the yield of folic acid from Candida utilis, Hansenula anomala and Bacillus subtilis. The folie acid-producing strain was screened by UV and laser compound mutation, and the hereditary stability from generation to generation was studied. The results showed that the optimal folie acid high-yield strain was Candida utilis. The mutant Y1.4 with higher yield of folie acid was obtained after UV induction for 3 minutes, and the yield of folic acid was 33.8 % higher than that of the original strain. The umtant Y2. 12 with the highest yield of folic acid among four mutants was obtained by compound laser-inducing the mutation of Y1.4, the yield of folie acid was 65.8 % higher than that of the original strain. Y2.12 had good hereditary stability after several generations. The results showed that compound laser-inducing was an effective way for screening folic acid high-yield strains.