Screening And Analysis Of Fermentation Conditions Of Strain With Hyper-producing Of Laccase

Laccase is a kind of polyphenol oxidase which is combination with a plurality of copper ions. It has broad application prospects in lignin degradation, pulping and bleaching in papermaking industrytextile industry, dyeing industry, degradation of toxic substancesand food industry.By guaiacol discoloration circle method and qualitative determination method of enzyme activity, one strain FA-J1 which has relatively high enzyme activity.By ITS rDNA appraisal, strains belonged to Trametes.Explored liquid fermentation impact factors of the the strains FA-J1, carbon sources for glucose and nitrogen sources for ammonium sulfate are the most suitable for enzyme producing of strain FA-J1; initial pH of 4.5, fermentation temperature of 28℃ and the liquid volume in 60mL/250mL erlenmeyer flask are the most suitable for enzyme producing of strain FA-J1; Add 0.1 mmoL/LCu2+ is beneficial for enzyme producing of strains FA-J1.Explored solid-state fermentation impact factors of strains FA-J1, the results showed that the ratio of 6:4 as miscanthus:bran is most suitable for enzyme production; moisture content of 70%,initial pH of 6.5 and fermentation temperature of 28℃ are the most suitable for enzyme production of strain FA-J1; Add 0.15mmoL/L Cu2+ is beneficial for solid-state fermentation enzyme production of strains FA-J1.The preparation of the strain FA-J1 protoplasts, respectively, UV and diethyl sulfate (DES) mutagenesis were used on protoplasts. A mutant strain U V-56 which was gains by UV mutagenesis increased enzyme activity by 56% and a mutant strain D52 which was gains by diethyl sulfate mutagenesis increased enzyme activity by 45%. BY RAPD analysis, it was found that the original strain and mutation strain had differences in specific amplification.