褐腐真菌产生的低分子化合物对纤维素的解聚作用研究

糙皮侧耳（Pleurotusostreatus）、密粘褶菌（Gloeophyllumtrabeum）、洁丽香菇（Lentinuslepideus）等8株褐腐菌在滤纸上进行固体培养时，在培养初期，纤维素的聚合度均呈现大幅度下降，但不表现失重。培养过程中也未能检测出滤纸酶活力，只有少量内切葡聚糖酶活力。而且这8株菌都具有络合Fd3+和产生羟基自由基·OH的能力。由降解和解聚能力最强的密粘语菌的胞外酶液在SephadexLH-20上分离得到一可络合Fe3+的低分子多肽组分，它与H2O2具有协同降解纤维素的作用，其机制与Fenton's试剂作用相似。Fe2+与H2O2反应生成的·OH可使纤维素氧化断裂，使之成为短小纤维，从而大幅度降低聚合度。

DEPOLYMERIZATION OF CELLULOSE BY LOW MOLECULAR WEIGHT COMPOUNDS FROM BROWN-ROT FUNGI

Eight strains incuding Pleurotus ostreatus, Gloeophyllum trabeum and Lentinus lepideus were selected for degradation of filter paper.In initial incubation,fungal degradation of cellulose was characterized by the rapid decrease of polymerization and little weight loss of cellulose. Besides that, the filter.paper activities were not detected . All the tested strains had Fe3+-chelating ability and produced hydroxyl radical. Extracellular compounds of Gloeophllum trabeum were partially purified on Sephadex LH-20 and a fraction with low molecular weight was obtained. This fiaction could oxidize Cellulose and break it into short fibrils which resulted in the great reduction of cellulose polymerization degree.