Abstract:

Because different wood-rot fungi have different physiological properties, and they can produce different enzymes with different activity, different wood-rot fungi degrade different compositions of wood with different velocities, and the middle materials degraded by different wood-rot fungi are different. In order to offer a applicating basic theory study to biopulping with david poplar wood, and offer a related study to microbial conversions of lignin to useful chemicals, biobleaching, enzymes treatment preventing from becoming yellow of mechanical pulping, wasted water control, microbial pretreatment of cellulose sugaring by enzymes, and decrease environment pollution in paper industry and make full use of lignin resources, this study selected Phellius igniarius and other 5 wood-rot fungi with higher wood degrading ability living on broad leaf trees, i.e. Funalia gallica, Lenzites tricolor, Polyporellus brumalis, Pseudotrametes gibbosa, Pycnoporus sanguineus, tested their degrading ability to david poplar wood lignin, measured the lignin content change of david poplar wood after a period of time degraded by 6 wood-rot fungi, which is the first study on the biodegradation mechanism of lignin by wood white-rot fungi. Under sterile conditions, the standard david poplar wood samples were put plate media of 6 species white-rot fungi and degraded by them. After 40 d, 60 d, 80 d and 120 d, the rotted wood samples were taken out respectively and the mycelium on the wood samples were brushed off. Then the lignin contents of primitive wood sample and rotted wood samples were measured. Results showed the lignin degrading ability of 6 species of wood white-rot fungi is different, it is Pycnoporus sanguineus, Pseudotrametes gibbbosa, Polyporellus brumalis, Lenzites tricolor, Funalia gallica and Phellius igniarius in turn. If considering the degraded extent of cellulose, Polyporellus brumalis is the better wood white-rot fungi with higher ability of degrading lignin and lower ability of degrading cellulose.

Key words: Wood white-rot fungi, Lignin, Degrading ability