Study On Mechanism Of Degradation In Lignin-cellulose And Morphological Development Of White-rot Fungi

White rot fungi is a kind of main wood decay fungi. It secretes many kinds of enzymes, such as lignin degrading enzymes, cellulose degrading enzymes and hemi cellulose degrading enzymes. The influence of lignin and cellulose digestion on the morphological development of white rot fungi was investigated in the study.By adding laccase activity inducing and inhibiting factors to the sawdust-based substrates, the article tried to find a probably relationship between the fruitbody development and lignocellulose digestion of white rot fungi.On the other hand, the article compared the lignocellulose degrading enzymes and lignin-cellulose digestion of two kinds of white rot fungus during the entire stage of cultivating, and investigated the biochemical roles of lignin-cellulose digestion and the representative enzymes involved in degradation of lignin and cellulose in association to the fruit-body formation of the basidiomycete.The results suggest that 0.5mmol/L copper,2mmol/L copper,3mmol/L copper and 0.2mmol/L manganese ions,0.84mmol/L manganese ions,3.36mmol/L manganese ions can stimulate the laccase activity of white rot fungi P.ostreatus BP2 , faster the degradation of lignin and induce the primordia development and fruit body initiation. It also shows that 2mmol/L EDTA and 8mmol/L EDTA can not inhibit fruit body development apparently, for the probably reason that 2mmol/L EDTA and 8mmol/L EDTA can not effectly inhibit the activity of lignin-degrading enzyme and lignin-digestion of the white rot fungi.The changes of the representative enzymes of lignin and cellulose degradation during the stage of vegetative growth seemed to be no different between monokaryon and dicaryo P.ostreatus. In the process of fruiting body initiation, the laccase activity of dicaryo P.ostreatus decreased, and then increased during the formation of fruit body and mushroom, whereas the activity of the laccase detected in the monokaryon P.ostreatus declines. The activities of cellulose degrading enzymes were observed to be gradually increased approaching the level of laccase activity in the stage of primordial formation in dicaryo P. ostreatus, while in the case of monokaryon P. ostreatus the situation was totally different.In this thesis, the article for the first time, explained and studied the relationship between the lignocellulose degradation and morphological development. It suggests that stimulating the activity of laccase and lignin degradation can stimulate primordial formation of white rot fungi. The article also explored the difference of lignin digestion and laccase activity between dicaryo and monokaryon P. ostreatus, which was of great academic and practical significance. It shows that morphological development is very important to lignin degradation and lignin degraded enzyme during the growth of white rot fungi.