Effects of pretreatment by six species of white rot fungi on enzymatic hydrolysis of Populus tomentosa wood
六种白腐菌预处理对毛白杨木材酶水解效果的影响

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.