混合发酵对纤维素酶和淀粉酶活性的影响

The effect of mixed fermentation on cellulase and amylase activities

采用混合培养法 ,研究了假丝酵母对黑曲霉和烟曲霉固态发酵中纤维素酶及淀粉酶活性的影响。结果表明 :1接入少量假丝酵母混合培养 ,可明显提高黑曲霉和烟曲霉纤维素酶系中滤纸酶、羧甲基纤维素酶、微晶纤维素酶及淀粉酶的活性。混合培养时 ,黑曲霉发酵产物中上述 4种酶的峰值酶活较黑曲霉单独培养时分别提高 36 .1% ,11.1% ,16 .2 %及 4 1.8% ;烟曲霉分别提高 2 4 .9% ,5 2 .8% ,4 0 .8%及 16 3.5 %。 2混合培养时 ,在黑曲霉和烟曲霉中 ,除黑曲霉的滤纸酶和淀粉酶外 ,其余纤维素酶和淀粉酶的产酶高峰期较单纯培养提前 2 4 h出现 ,接入酵母菌加快了发酵进程 ,使发酵周期缩短。 3接入酵母菌后 ,黑曲霉和烟曲霉固态发酵产物中细胞外可溶性蛋白质峰值含量 ,较无酵母菌接入时分别提高 34.8%和 4 1% ;且细胞外可溶性蛋白质含量随发酵时间的变化趋势与纤维素酶及淀粉酶的活性变化趋势吻合 ,揭示了混合培养时纤维素酶及淀粉酶活性提高是酶蛋白合成与分泌量增加的结果。 4酵母菌利用了固态发酵中水解形成的纤维二糖等小分子还原糖 ,解除了纤维二糖对纤维素酶和淀粉酶合成的反馈阻遏 ,提高了发酵产物的酶活性。

The effect of Candida on cellulase and amylase activities of Aspergillus niger and Aspergillus fumigatus in soild fermentation was studied by mixed culture.The result showed:① FPA,cmcase,avicelase in cellulase system of Aspergillus niger and amylase activities increased obviously by mixed culture.In Aspergillus niger,the peak values of the four kinds of enzyme activities in mixed culture increased by 36.1% ,11.1%,16.2% and 41.8% respectively over those of sole culture;In Aspergillus fumigatus ,they increased by 24.9%,52.8%,40.8% and 163.5%.② In Aspergillus fumigatus and Aspergillus niger ,the peak values of other cellulases and amylases activities in mixed culture were 24 h earlier than those of sole culture,excepting FPA and amylase of Aspergillus niger .Mixed culture accelerated fermentation process and shortened fermentation period.③ The maximal content of extracellular protein of Aspergillus niger and Aspergillus fumigatus in mixed culture increased respectively by 34.8% and 41%;extracellular protein and cellulase and amylase activities changing were identical with fermentation time,which indicated that an increase in enzyme activities was the result of enzyme forming and exudation.④ Candida could use dextrose and cellobiose produced in soild fermentation so that it breaked off feedback repression of glucose and cellobiose versus cellulase and amylse synthics,and enhanced enzyme activity of fermentation substance.