^(60)Coγ射线对不同细胞形态出芽短梗霉的辐射诱变效应

INDUCED MUTATIONS OF DIFFERENT STATES OF AUREOBASIDIUM PULLULANS BY RADIATION OF (60)Coγ RAY

使用^(60)Coγ射线辐照诱变的方法处理出芽短梗霉AureobasidiumPullulansAP92菌株的原生质体、菌丝体片段、分生孢子悬液，经初筛、复筛与对突变株的遗传稳定性研究，发现采用原生质体进行诱变，所获突变株的正突变率、单株产多糖的提高幅度、正突变株的产多糖遗传稳定性均明显高于菌丝体与分生孢子。比较出发菌株AP92与经原生质体诱变获得的正突变株A81的性能，有如下明显改善：产多糖能力从16．35g／L提高到29．69g／L，糖转化率从32．7％升到61．4％，残糖从13．269／L降到3．06g／L，而发酵周期则可缩短约24小时。结果证明，对原生质体进行^(60)Coγ射线诱变，是优化出芽短梗霉菌种的有效途径。

The protoplasts. mycelium fragments and spores of Aureobasidiumpullulans strain AP92 were treated by radiation of,60Coy ray respectively It wasfound that the positive mutation rate and increase of yield of Pul. and stability ofyield of mutant strains obtained from the protoplast mutagenesis were much moresuperior than those obtained from the mycelium fragment and spore mutagenesis. Themutant strain A81 from protoplast mutagenesis was compared with the initial stainAP92. The results showed that the yield of Pul. was increased to 29.6g / L form16.35g / L, the conversion rate of sugar was increased to 61.4% from 32.7% and theresidual sugar was decreased t0 3.06g / L from 13.26g / L So that the fermentationPeriod was shortened by about 24 hours. It showed that induced mutation fromProtoplasts by,60Coγ ray was an effective means of gaining excellent mutant strains ofAureobasidium pullulans.'