[Function of nitric oxide in initiating production of lignin degrading peroxidases by Phanerochaete chrysosporium].

Objective: By analyzing the function and mechanism of nitric oxide in initiating producing lignin peroxidases by phanerochaete chrysosporium, we studied the regulation mechanism triggering the secondary metabolism of white-rot fungi.

Methods: Mutant (pcR5305) and wild-type (pc530) strains of phanerochaete chrysosporium were respectively cultured under both the conditions of nitrogen limitation and nitrogen sufficiency. To compare their lignin peroxidases (LiP)-production and nitric oxide(NO)-production kinetics and their different influences on producing LiP after the NO donor Sodium Nitroprusside (SNP) and scavenger cPTIO were respectively added to the nitrogen limitation or sufficiency culture medium to show the function and mechanism of nitric oxide in initiating production of lignin peroxidases by white-rot fungi.

[Carbon-nitrogen regulation of a laccase-producing mutant of Phanerochaete chrysosporium resisting carbon and nitrogen nutritional repression].

Objective: Comparing the effects of different carbon-nitrogen nutrition and their consumption on laccase production, we studied the ecophysiological characteristics of Phanerochaete chrysosporium resisting nutritional repression, and the carbon-nitrogen physiological regulation mechanism of the white-rot fungi.

Methods: The mutant and the wild-type strains were respectively cultured under the conditions of: carbon and nitrogen limitation, carbon limitation and nitrogen sufficiency, carbon sufficiency and nitrogen limitation, carbon and nitrogen sufficiency, to compare their laccase-production kinetics, cell growth and glucose and ammonia nitrogen consumption to show the characteristics and the regulation pathway of carbon-nitrogen nutrition on laccase production.

Results: The wild-type strain produced 0.

[Breeding and characterization of laccase-producing Phanerochaete chrysosporium mutant resistant to nutritional repression].

Objective: To screen Phanerochaete chrysosporium mutants resisting nutritional repression and to characterize laccase produced by the mutants.

Methods: We used repeated UV mutagenesis and screened the mutant strains by using the guaiacol nitrogen sufficient differential medium. We characterized enzymes production mechanism of the nutritional regulation through comparing the differences of cell growth and enzyme-production kinetics under different nutritional conditions; We validated production of laccase by Phanerochaete chrysosporium through measurements of the heat treatment, removal of manganese ion and addition of the catalase.