芒草木质素含量对里氏木霉产木质纤维素酶的影响

Effects of lignin on Trichoderma reesei producing cellulase and xylanase in Miscanthus substrates

[目的]研究芒草木质素含量对里氏木霉产木质纤维素酶的影响。[方法]选择了2组木质素含量差异显著（p〈0．01，n=3）、纤维素和半纤维素含量相近的芒草材料作底物来培养3株里氏木霉（野生型QM6a、突变型QM9414和RutC30），对诱导产生的木质纤维素酶的酶活和降解木质纤维素的效率进行分析。[结果]在第1组中，Mfl40木质素含量比Msa02低36％（P〈0．01，／Z=3），其诱导3株菌生产的木质纤维素酶体积比酶活高于Msa02组1．2～1．8倍（P〈0．05或者P〈0．01，n=3）；在第Ⅱ组中，Mfl37木质素含量比Mlu13低48％（P〈0．01，n=3），其生产的木质纤维素酶体积比酶活高于Mlu13材料1．2—3．3倍（p〈0．05或者P〈0．01，n=3）。[结论]芒草细胞壁中木质素含量对里氏木霉产木质纤维素酶量有显著负影响。

[ Objective ] The influence of lignin on Trichoderma reesei producing cellulase and xylanase in Miscanthus sub- strates. [ Methods] Two pairs of Miscanthus were selected with distinct lignin levels, and their biomass residues were incubated with three Trichoderma reesei strains （Wild type： QM6a; Mutants： QM9414 and RutC30） for cellulase and xylanase produc- tion. [ Results] The Mfl40 sample at Pair I showed a lower lignin level than that of Msa02 by 36% at p 〈 0.01 level （ n = 3 ）, but it resulted in three Trichoderma reesei strains producing much higher holocellulase （ cellulase and xylanase） activities 1.2 - 1.8 at p 〈0.05 and p 〈0.01 levels（n --3） respectively,compared with the Msa02. Meanwhile,the Mf137 in the Pair II ,also exhibited much higher holocellulase activities by 1.2 - 3.3 at p 〈 0.05 and p 〈 0.01 levels（ n = 3 ） respectively than those of Mlul3 sample, due to its relatively lower lignin level by 48%. [ Conclusion] The cellulase and xylanase productions released by three Trichoderma reesei strains were negatively affected by lignin levels of Miscanthus.