Decay Of Metaborates-treated Wood By Wood-rotting Fungi

Wood rotting fungi is important factor to the wood decay in the nature, and also is the main reasonto shortening the service life of wood. Metaborats treatment is one of methods to improving wood decayresistance nowadays. Isolation and identification of wood-rotting fungi was performed usingmorphology and molecular biology method in this paper. In order to explore the lignocellulosedegradation mechanism of wood rotting fungi, lignocellulose enzymes and the ability to wood decaywere determined from the wood-rotting fungi. Meanwhile, wood was treated with boric acid and threekinds of metal salts (Calcium chloride, Copper sulfate, Zinc sulfate) using two-step method in this paper.And leachability and decay resistance of metaborates-treated wood were investigated in order to offermeaningful information of expanding the application range of boron in wood preservation and woodpreservation research. The major results are as follow:(1) Five kinds of wood-rotting fungi were identified in this paper, namely Fusarium oxysporum,Trametes hirsute, Fusarium proliferatum, Schizophyllum commune and Pycnoporus sanguineus. Speciesand activities of ligcellulases among the five kinds of wood-rotting fungi were quite difference.(2) The wood decay results indicated T. hirsute had the strongest wood-decay ability, and causedQuercus mongolica69.16%mass loss, Tectona grandis31.03%mass loss. The P. sanguineus couldcause Q. mongolica41.37%mass loss, and Cunninghamia lanceolata14.08%mass loss. However, therest of the three kinds of fungi only caused less than3%mass losses. The result of leaching testindicated that the boron retention increased by20%~30%in wood treated with metaborates.(3) Wood decay test showed waterlogging produced around the metaborates-treated wood in petridish so that hypha of wood-rotting fungi cannot grow on the wood. Hence, the experimental resultsindicated that it is effective to enhance the leaching resistance of boron by two-step method. But it waseasy to produce waterlogging around the treated wood, which had an impact on the mechanicalproperties and practicability of wood.