六种白腐菌预处理对毛白杨木材酶水解效果的影响

通过化学分析和酶水解试验，研究了不同的白腐菌对毛白杨的预处理效果及不同组分的降解对酶水解的影响。毛白杨木片经6种白腐菌预处理30d后，各组分都发生了降解，其中半纤维素的损失最为显著，Trametes ochracea C6888引起半纤维素降解率高达47.19%，其次是纤维素和酸不溶木素的降解。在后续酶水解过程中，6种白腐菌处理后的样品显示出不同的水解模式，菌株Trametes ochracea C6888、T. pubescens C7571和T. versicolor C6915预处理效果最为显著，还原糖得率在整个酶水解过程中一直高于对照，其中T. ochracea C6888在水解96h后还原糖得率达到15.93%，比未处理样品提高了25%。分析酸不溶木素降解率及半纤维素降解率与还原糖得率的关系发现，不同菌株在作用同一种基质时，预处理效果差异显著，木质素和半纤维素的脱除都会影响木质纤维素的酶水解。

Effects of pretreatment by six species of white rot fungi on enzymatic hydrolysis of Populus tomentosa wood

The pretreatment efficiency of different fungi and the effects of different components on enzymatic hydrolysis were investigated through chemical analysis and enzymatic hydrolysis experiments. Chemical components of Populus tomentosa were all degraded after pretreatment by six species of white rot fungi for 30 days. Hemicellulose loss was found to be the most significant, and 47.19% of the loss was caused by Trametes ochracea C6888. The losses of cellulose and acid insoluble lignin were less than those of hemicellulose. The samples treated by six species of white rot fungi displayed different patterns in the subsequent enzymatic hydrolysis. Reducing sugar yields were higher in the samples treated by Trametes ochracea C6888, T. pubescens C7571 and T. versicolor C6915 during the whole of the hydrolysis periods. 15.93% of reducing sugar yield was achieved by T. ochracea C6888 in 96h, increasing by 25% as compared with the untreated sample. The relationships between the loss of acid insoluble lignin and the yield of reducing sugar, and hemicellulose loss and reducing sugar yield were investigated. It was found that different fungi varied greatly during pretreatment with the same substrate, and the losses of lignin and hemicellulose could influence on the enzymatic hydrolysis of lignocellulose.