高效选择性降解稻草木质素的菌株及其产酶特性的研究

Screening of White Rot Fungi with Strong Degradation of Straw Lignin and Their Enzyme Production

采用变色圈试验和木质素降解试验,对19株木材腐朽菌对稻草生物降解能力进行定性及定量筛选,获得了毛革盖菌(Coriolus hirsutus)、东方栓菌(Trametes orientalis)、彩绒革盖菌S2(Coriolus versicolor)和白干酪菌(Tyromyces albidus)4株高效降解稻草木质素的菌株。在15 d的培养中,各菌株对稻草木质素的降解率分别为36.71%、33.59%、22.46%和21.90%。在基础培养基发酵培养中,4菌株的漆酶活性分别在8 d和14 d达到峰值,其中白干酪菌的漆酶活性最高,为147.73 U/L,毛革盖菌、东方栓菌和彩绒革盖菌S2的漆酶活性最高分别为113.00,133.65,122.65 U/L;4菌株的木质素过氧化物酶和锰过氧化物酶的酶活性均不高,可能与缺少必要的诱导剂有关。4菌株的胞外蛋白含量和菌丝重增加变化曲线基本一致,只是峰值略有提前。4株不同来源的彩绒革盖菌在木质素降解能力上存在一定的差异,这与菌株的地域差异和菌株的多次转接有直接的关系。

The method of coloring zone and lignin degradation experiment was designed to screen high efficient fungal strains from the 19 test fungi. At last Coriolus hirsutus, Trametes orientalis, Coriolus versicolor S2 and Tyromyces albidus were found to have a strong lignin degrading efficiency. They are 36.71%, 33.59%, 22.46% and 21.90% respectively after 15 days of degradation test. During fermentation in basic media, the laccase enzyme activities of the four strains reach a peak on the 8th and 14th days. The enzyme activity of Tyromyces albidus is the highest （147.73 U/L）, while the other three strains are 113.00, 133.65 and 122.65 U/L respectively; the enzyme activities of their Lip and Mnp are not high, and it may be due to lack of inducers. The varying curves of extracellular proteins and mycelial weight are generally similar to those of their enzyme activities, with a little earlier peak. The four strains of Coriolus versicolor are different in straw degradation efficiency, and it may be due to their different ori- gins or more subcultures.