蒸汽爆破预处理和微生物发酵对玉米秸秆降解率的影响

摘要

为了提高玉米秸秆的利用效率,首先对玉米秸秆进行蒸汽爆破预处理(压力2.5 Mpa,维压200 s),然后再进行米曲霉发酵,研究物理和生物学处理对秸秆成分及相关酶活变化的影响.结果表明,蒸汽爆破使秸秆中纤维素、半纤维素和木质素的降解率分别达到8.47%、50.45%和36.65%(p<0.05).爆破预处理的秸秆再经米曲霉发酵6 d后,秸秆中纤维素和半纤维素的降解率分别为27.89%和64.80%(p<0.05),发酵秸秆中的滤纸酶、羧甲基纤维素酶、淀粉酶和蛋白酶活力分别达到335.10、1138.92、1954.20和201.99 U/g.爆破预处理后进行米曲霉发酵,对于提高玉米秸秆的降解率具有非常重要的意义.%The effects of steam explosion (2.5 MPa, 200 s) and Aspergillus oryzae fermentation on corn straw degradation were evaluated according to the changes of compositions and enzyme activities in the fermented products.The results showed that the steam explosion pre-treatment for com straw could make the degradation rates of cellose,hemicelluloses and lignin reach to 8.47％, 50.45％ and 36.65％, respectively (P＜0.05).After pretreated with steam explosion the corn straw was fermented by Aspergillus oryzae for 6 days, the contents of cellulose and hemicellulose in the fermented com straw were decreased by 27.89％ and 64.80％ respectively, compared with the original corn straw (P＜0.05).The filter paper cellulase, CMCase, amylase and protease activities in the fermented products were 335.10,1 138.92, 1954.20 and 201.99 U/g, respectively.Pre-treating with steam explosion and followed by Aspergillus oryzae fermentation seems to be a prospective method for eom straw degradation and application.