爱尔兰帚霉产低温纤维素酶的酶学性质和发酵工艺

Characterization and optimal fermentation conditions of cold-adapted cellulase produced by Scopulariopsis hibernica

本文旨在对爱尔兰帚霉E71702M菌株产低温纤维素酶的酶学性质进行初步研究,并获得其最优发酵条件,为低温纤维素酶开发利用提供参考。通过单因素试验确定温度、pH及金属离子对纤维素酶活力的影响;以Plackett-Burman试验设计从8个培养条件中筛选出影响产酶的3个主要因素,即麸皮含量、装瓶量和起始pH;运用Box-Behnken试验设计及响应面分析法确定这3个主要因素的最优发酵条件。对酶学性质的初步研究表明,该酶最适pH为3.0,最适反应温度为30℃,在0℃时残余酶活力为最适反应温度时的56.3%。响应面分析得到最优发酵条件为:麸皮含量8.79g/L、装瓶量40.93m L、初始pH 4.01。通过优化,纤维素酶活力由0.6338IU/m L提高到1.7386IU/m L,提高了174%。

Characterization of cold-ad and optimum conditions of cellulase apted cellu production ase produced by scopuloriopsis hibernico E71702M was analyzed prelimina were obtained by response surface methodology. The effect of temperature, and metal ions on cellulase activity was determined by single factor test. The important factors influencing cellulase product rliy, pH ion, as identified by a two-level Plackett-Burman design with eight variables, were wheat bran content, liquid volume, and initial pH The Box-Benhnken design and response surface analysis were adopted to further investigate the mutual interactions betweenthese variables and to obtain their optimal values that bring maximum cellulase activity. The research results of cold-adapted cellulase characterization revealed that the optimum pH was 3.0 and the reaction temperature was 30℃. The remaining cellulase activity at 0℃ still reached 56.3% as compared with that at optimal reaction temperature. The optimal conditions of the maximal cellulase activity were indicated as follows： wheat bran content, 8.79g/L; liquid volume, 40.93mL; initial pH value, 4.02. Under the conditions, cellulase activity was increased by 174%, ranging from 0.6338 to 1.73861U/mL.