γ射线对斜卧青霉的诱变筛选及产酶条件优化

以斜卧青霉(Penicillium decumbens)A10为出发菌株,经450 Gy60Coγ射线诱变处理,选育出1株纤维素酶高产菌株A50,对其产纤维素酶的液态发酵条件进行研究优化,确定了所试因素的最佳组合,即主碳源浓度为5%,其中麸皮与玉米秸秆比例为1∶1,辅加碳源为0.1%的葡萄糖,辅加氮源为0.2%的磷酸氢二铵,Tween-80添加量为0.1%,培养基初始pH为5.0,300ml三角瓶的装液量为30ml、接种量10%、培养温度为32℃、摇床转速200r/min。发酵至60h时,纤维素酶活和滤纸酶活均达到最高,分别为27.28和1.98IU/ml,较出发菌株A10分别提高了33.2%和45.59%。

MUTANT STRAIN SCREENING BY ~(60)Co γ-RAYS IRRADIATION AND ITS CELLULASE ENZYME PRODUCE CONDITION

A mutant strain A50 with high cellulase activity was induced and isolated by using ~(60)Co γ-rays irradiation from the initial Penicillium decumbens A10.The optimum fermentation conditions of A50 were investigated through orthogonal designing experiment,the major carbon resource 5%,the ratio between wheat bran and corn straw 1∶1,the concentration of glucose as supplemental carbon 0.1%,the concentration of(NH_4)_2HPO_4 as supplemental nitrogen resource 0.2%,the initial pH of liquid medium 5.0,the inoculated amount for fermentation 10% and the concentration of Tween-80 0.1%,30ml initial media filled in the 300ml flask with culture condition of 32℃and 200r/min.Under the optimum conditions mentioned above,the highest activities of cellulase and filter paper enzyme were 27.28 and 1.98IU/ml at 60h fermentation,respectively,which was 33.2% and 45.59% higher than those of the initial strain.