不同固体发酵培养基下三种白腐真菌分泌的木质纤维素酶活性

Lignocellulolytic enzyme activities of three white rot fungi under different solid-state fermentation media

本研究选取众所周知的典型白腐真菌树舌灵芝Ganoderma applanatum、毛栓孔菌Trametes hirsuta和木蹄层孔菌Fomes fomentarius作为研究对象,对其利用木质纤维生物质进行发酵及添加有机营养、无机盐、金属离子、表面活性剂等进行了探索,期间以测定漆酶、滤纸纤维素酶、木聚糖酶活性表征3种菌株对木质纤维生物质的预处理能力,为确定白腐真菌菌株及单环境因子而达到高效预处理木质纤维生物质提高生物转化效率的目的奠定了重要的理论基础。结果显示,3种菌株分泌的木质纤维素酶在10周内基本都呈现先上升后下降的趋势,且酶活都较高,均可作为木质纤维生物质预处理的备选菌株。相比于针叶树(落叶松)基质,阔叶树(白桦)基质更适宜于3种菌株生长及分泌木质纤维素酶。各环境因子中,Cu2+的添加可提高漆酶活性,表面活性剂对于3种酶活的诱导作用均十分显著。

The capabilities of pretreating lignocellulose of three typical white rot fungi,G.applanatum,T.hirsuta,and F.fomentarius,under solid-state fermentation were assessed,and activities of the laccase,filter paper cellulase,and xylanase were determined.In addition,influences of environmental factors such as organic nutrition,inorganic salts,metallic ions,and surfactants on degradation of lignocellulose were also explored.This study aims at providing basis for confirming the effects and efficiency of white rot fungal strains and environmental factors on pretreatment and bioconversion of lignocellulose biomass.The results demonstrated that the lignocellulolytic enzymes secreted by the three strains exhibited a trend of rise at first and then declining within 10 weeks.The enzymatic activities were significantly high,and the enzymes could be used as alternatives for pretreatment of lignocellulose biomass.By contrast with coniferous(Larix sp.)substrate,broad-leaved(Betula sp.)substrate was more suitable for the fungal growth and secretion of lignocellulolytic enzymes.Addition of Cu2+can improve laccase activity.Surfactants have a significant induction effect on the activities of three enzymes.