Improvement of ligninolytic properties by recombinant expression of glyoxal oxidase gene in hyper lignin-degrading fungus Phanerochaete sordida YK-624

Abstract

Glyoxal oxidase (GLOX) is a source of the extracellular H₂O₂ required for the oxidation reactions catalyzed by the ligninolytic peroxidases. In the present study, the GLOX-encoding gene (glx) of Phanerochaete chrysosporium was cloned, and bee2 promoter of P. sordida YK-624 was used to drive the expression of glx. The expression plasmid was transformed into a P. sordida YK-624 uracil auxotrophic mutant (strain UV-64), and 16 clones were obtained as GLOX-introducing transformants. These transformants showed higher GLOX activities than wild-type P. sordida YK-624 and control transformants harboring marker plasmid. RT-PCR analysis indicated that the increased GLOX activity was associated with elevated recombinant glx expression. Moreover, these transformants showed higher ligninolytic activity than control transformants. These results suggest that the ligninolytic properties of white-rot fungi can be improved by recombinant expression of glx.

Graphical Abstract

Ligninolytic properties of hyper lignin-degrading fungus Phanerochaete sordida YK-624 were improved by the recombinant expression of GLOX gene.

Keywords:

• Phanerochaete sordida YK-624
• lignin degradation
• glyoxal oxidase
• molecular breeding

Funding

This work was partially supported by Grants-in-Aid for Scientific Research (A) [grant number 21248023], [grant number 24248030] from the Ministry of Education, Culture, Sports, Science and Technology of Japan.