title: Effects of Homologous Expression of 1,4-Benzoquinone Reductase and Homogentisate 1,2-Dioxygenase Genes on Wood Decay in Hyper-Lignin-Degrading Fungus Phanerochaete sordida YK-624.
abstract: We investigated the function of 1,4-benzoquinone reductase (BQR)- and homogentisate 1,2-dioxygenase (HGD)-like genes in wood degradation by Phanerochaete sordida YK-624, which exhibits high ligninolytic activity and selectivity. We determined homologous expression in the genomic and cDNA sequences of BQR- and HGD-like genes in P. sordida YK-624 (PsBQR and PsHGD). Both genes shared high homology (≥90 % amino acid sequence similarity) with the corresponding genes in Phanerochaete chrysosporium. These genes were co-transformed with a reporter gene into an uracil auxotrophic mutant of P. sordida YK-624. The PsBQR and PsHGD co-transformants exhibited lower holocellulolytic activity and higher ligninolytic selectivity than the control transformants. In liquid culture with vanillin, both co-transformants significantly accelerated vanillin degradation. Thus, we suggest that the rapid metabolism of low-molecular weight lignin fragments, due to the homologous expression of BQR- and HGD-like genes, affects quinone redox cycling to produce hydroxyl radicals, thereby decreasing holocellulose degradation and increasing ligninolytic selectivity.
authors.affiliation: Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Mori
authors.affiliation: Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.
authors.forename: Genki
authors.initials: G
authors.lastname: Koyama
authors.affiliation: Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.|Research Institute of Green Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.|Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kawagishi
authors.affiliation: Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan. hirai.hirofumi@shizuoka.ac.jp.|Research Institute of Green Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan. hirai.hirofumi@shizuoka.ac.jp.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hirai
mesh_terms: D001547:Benzaldehydes / Q000378:metabolism; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D050560:Homogentisate 1,2-Dioxygenase / Q000235:genetics* / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D020075:Phanerochaete / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D011808:Quinone Reductases / Q000235:genetics* / Q000378:metabolism; D014170:Transformation, Genetic; D014934:Wood / Q000378:metabolism / Q000382:microbiology
chemical_list: D001547:Benzaldehydes; D005656:Fungal Proteins; D008031:Lignin; C100058:vanillin; D050560:Homogentisate 1,2-Dioxygenase; C100348:1,4-benzoquinone reductase; D011808:Quinone Reductases