高产纤维分解酶康氏木霉诱变选育与发酵条件优化

Mutagenesis Breeding and Fermentation Condition Optimization of High Yield Fiber Decomposition Enzyme of Trichoderma koningii

本试验旨在研究高产纤维分解酶康氏木霉诱变选育与发酵条件优化。通过对康氏木霉诱变选育(紫外、硫酸二乙酯、紫外-硫酸二乙酯复合诱变),获得产纤维分解酶高的突变菌,并对其产酶发酵条件和水解秸秆能力进行研究。结果表明:康氏木霉原菌经紫外、硫酸二乙酯、紫外-硫酸二乙酯复合诱变筛选出了1株突变菌康氏木霉UH-1;与原菌相比,突变菌木聚糖酶活性提高了42.7%,纤维素酶活性提高了78.5%。康氏木霉UH-1最适固态发酵产酶条件为玉米秸秆∶麸皮为7∶3、硫酸铵浓度2%、接种量1.1 mL、培养基含水量67%、发酵时间84 h、磷酸二氢钾浓度1%。在此条件下滤纸酶活性达到0.86 U/g,纤维素酶活性达到99.81 U/g,木聚糖酶活性达到1 150.32 U/g;而康氏木霉原菌滤纸酶活性为0.23 U/g,纤维素酶活性为46.38 U/g,木聚糖酶活性为677.86 U/g。本研究表明,紫外-硫酸二乙酯复合诱变可有效对康氏木霉进行诱变育种,改善其产酶能力和秸秆水解能力。

This experiment was conducted to study the mutagenesis breeding and optimal fermentation condition optimization of high yield fiber decomposition enzyme of Trichoderma koningii. High cellulose decomposition enzyme of mutant strain was obtained through the mutagenesis breeding( ultraviolet,diethyl sulfate and ultraviolet-diethyl sulfate compound mutagenesis) of Trichoderma koningii,and the fermentation conditions of enzyme production and the hydrolysis ability of strawwere studied. The results showed that a mutant strain of Trichoderma koningii UH-1 was selected through ultraviolet,diethyl sulfate and ultraviolet-diethyl sulfate compound mutagenesis of the original strain of Trichoderma koningii;compared with the original strain,the xylanase activity increased by 42.7% and the cellulase activity increased by 78.5% in mutant strain. The optimization of fermentation condition were corn stalk to bran was 7 to 3,ammonium sulphate concentration was 2%,inoculation quantity was 1.1 mL,culture medium moisture was 67%,fermentation time was 84 h,potassium dihydrogen phosphate concentration was 1%. In this condition, the filter paper enzyme activity reached0.86 U/g,cellulase activity reached 99. 81 U/g,xylanase activity reached 1 150. 32 U/g;however,in the original strain of Trichoderma koningii,the filter paper enzyme activity was 0. 23 U/g,the cellulase activity was 46.38 U/g,the xylanase activity was 677.86 U/g. This study showed that the mutagenesis of ultravioletdiethyl sulfuric acid is effective in mutagenesis breeding of Trichoderma koningii,thus to improve enzyme producing ability and strawhydrolysis capacity.