The Role of Glycosides Formation on the Degradation of Lignin by Wood-Rotting Fungi.

糖苷形成对木材腐烂真菌降解木质素的作用。

基本信息

批准号：
62560179
负责人：
KONDO Ryuichiro
金额：
$ 1.09万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

In order to clarify the role of carbohydrates components on the biodegradation of lignin in wood, the transformation of lignin model compounds and DHP lignin was studied. The results are as follows;(1)(1) The rate of the consumption of the starting lignin model compounds (4-ethylsyringylglycerol- -syringyl ether, veratryl alcohol, vanillyl alcohol and veratrum aldehyde) by wood-rotting fungi (Phanerochaete chrysosporium, Coriolus versicolor and Tyromyces palustris) dependedon the kind of carbohydrate media. The order of the rate of the modelcompounds consumption was, polysaccharide medium(xylan, holocellulose) disaccharide medium (cellobiose ) monosaccharide medium (glucose,xylose).(2) In the polysaccharide and the disaccharide medium, model compounds were transformed into their glycosides by the transglycosy-lation of glycosidase induced by carbohydrates with wood-rotting fungi. In the xylan and birch holocellulose medium, veratryl alcohol was transformed into veratryl -D-xyloside during the early phase of cultivation. In the cellobiose medium, vanillyl alcohol and veratryl alcohol were biotransformed into vanillyl -D-glucoside and veratryl -D-glucoside, respectively.(3) The toxicity of lignin model compounds against fungus was reduced by the formation of their glycosides. The polymerization of phenolic model compounds by laccaseor lignin peroxidase was reduced by the formation of their glycosides.(4) DNP lignin-glucoside was synthesized by an enzymatic method. Incubation of DHP lignin-glucoside with lignin peroxidase / H_2O_2 resulted in partial depolymerization, although treatment of DHP ligninwith them caused polymerization.

为了阐明碳水化合物成分对木材中木质素生物降解的作用，对木质素模型化合物和DHP木质素的转化进行了研究。结果如下：(1)(1)木腐真菌(Phanerochaete chrysosporium、Phanerochaete chrysosporium、云芝 (Coriolus versicolor) 和沼泽酪霉菌 (Tyromyces palustris) 取决于碳水化合物培养基的类型。模型化合物消耗率的顺序为：多糖介质（木聚糖、全纤维素）二糖介质（纤维二糖）单糖介质（葡萄糖、木糖）。（2）在多糖和二糖介质中，模型化合物通过以下方式转化为其糖苷：碳水化合物与木材腐烂真菌诱导的糖苷酶的转糖基化。在木聚糖和桦木全纤维素培养基中，藜芦醇在培养早期转化为藜芦基-D-木糖苷。在纤维二糖培养基中，香草醇和藜芦醇分别生物转化为香草基-D-葡萄糖苷和藜芦基-D-葡萄糖苷。(3)木质素模型化合物通过其苷的形成降低了对真菌的毒性。漆酶或木质素过氧化物酶对酚类模型化合物的聚合反应通过其糖苷的形成而被还原。(4)采用酶法合成了DNP木质素葡萄糖苷。 DHP木质素-葡萄糖苷与木质素过氧化物酶/H_2O_2的孵育导致部分解聚，尽管用它们处理DHP木质素引起聚合。