几株半知菌对马尾松落叶的分解——木质纤维素酶的活性动力学

应用固体发酵方法,研究Alternaria sp., Penicillium sp., Cephalosporium sp., Tricherderma sp., Pestalotiopsis sp.和Aspergillus fumigatus 6种土壤半知菌降解马尾松凋落叶片过程中产生的漆酶(Laccase)、木质素过氧化物酶 (LiP)、锰过氧化物酶 (MnP)、羧甲基纤维素酶 (CMCase) 和滤纸糖酶 (FPA)的动力学曲线,以及各种酶活性与底物降解的关系.结果表明:Pestalotiopsis sp. 能够产生相对较高的漆酶活性和引起底物的总有机物质(TOM)质量损失最大;Alternaria sp. 产生的MnP酶活性最高;Pestalotiopsis sp. 产生的CMCase和FPA酶活性也为最高.试验中6种菌前期的降解速率依赖于CMCase 和 FPA酶活性的高低,后期则由木质素酶和纤维素酶协同作用来决定.依据6种菌的酶生产动力学曲线、TOM 质量损失和降解速率,可将其划分为2种功能类型:功能群Ⅰ为纤维素分解菌,包括Alternaria sp., Penicillium sp., Cephalosporium sp.和Tricherderma sp. 4种;功能群Ⅱ为木质纤维素分解菌,包括 Pestalotiopsis sp.和Aspergillus fumigatus 2种.试验中也发现:Pestalotiopsis sp.产生漆酶的活性较高,同时是一株比较有效降解木质纤维素底物的菌种.

Decomposition of Pinus massoniana Needle Driven by Deuteromycetes——Dynamics of Lignocellulolytic Enzymes

In the study,the dynamics of lignolytic and cellulolytic enzymes,viz.laccase,lignin peroxidase(LiP),manganese peroxidase(MnP),carboxymethylcellulase(CMCase)and filter paper activity(FPA)secreted by six soil_inhabiting deuteromycetes,were investigated systematically during the decomposition of Pinus massoniana needle litter in solid state fermentation(SSF).The six deuteromycetes exhibited varied profiles of enzymes secretion and caused different loss in TOM and decomposing rate.Pestalotiopsis sp.produced the highest laccase activity and caused the highest loss in TOM;Alternaria sp.produced the highest MnP activity;the highest CMCase and FPA activities were detected in strain Pestalotiopsis sp.The process of decomposition was closely correlated to the changes of enzyme activities.The early_stage decomposition primarily depended on activities of cellulolytic enzymes.While later_stage decomposition depended on the lignolytic enzymes,which acted synergistically with cellulase.According to these results,fungi could be divided into two functional groups:group 1 were cellulose decomposers,including Alternaria sp.,Penicillium sp.,Cephalosporium sp.and Tricherderma sp.,group 2 were decomposers of lignocellulose,including Pestalotia sp.and Aspergillus fumigatus.Meanwhile,we find Pestalotiopsis sp.could produce an appreciable high level of laccase.