Activities of laccase produced by a strains Penicillium simplicissimum induced by chemical agentia and UV radiation

Penicillium simplicissimum was cultured and preserved on the potato dextrose agar（PDA）medium.PDA-RBBR（Remazal Brilliant Blue R）medium was used for the screening of the strains,which is able to produce enzymes.After the mutation process in Penicillium simplicissimum induced by chemical reagent and ultraviolet radiation,a high laccase-producing strains Penicillium simplicissimum was obtained.When 5 m L diethyl sulfate（2%）was mixed along with 5 m L spore suspension for 30 min,chemical mutagenesis reached its best condition.And the optimum conditions of UV mutagenesis were that spore suspension was irradiated for 4 min under 15 W UV lamp at a distance of 30 cm.The highest activity of C5E4 strains was 4.80 U/g over 18%higher than the maximum laccase activity of original microorganism.Five generations of the mutant strains were cultured,and the laccase activity of the strains was measured.The result showed that C5E4 strains can product laccase of the five subcultures stably.