Breed Strain Of High Laccase Activity Pleurotus Erygii With UV-irradiation Protoplast Technique And Studies Of Its Fermentative Condition

Pleurotus erygii belongs to Basidio mycotina, Hymenomycetes, Homobasidiomycetidae, Agaricales, Pleurotaceae, Pleurotus.Fungus is plump and nutritious.It can slow down blood pressure and blood grease. There are several kinds of enzymes produced by Pleurotus erygii, for example laccase, peroxide, Aryl-alcohol oxidase etc. Laccase is a kind of enzyme containing 4 copper ions(Ⅱ) outside much phenol oxidize enzyme belongs to the covelline albumen family and universally exists in white-rot bacterium. The ability of Pleurotus erygii in degrading lignin is related with its laccase activity. C Mu? oz etc.( C Mu?oz, F Guillén, A T Martínez,1997) purified two kinds of laccase isoenzymes of Pleurotus erygii :laccaseⅠand laccaseⅡ.Both are monomer protein, the content of carbohydrate is 7% and 1% respectively, molecular mass ( SDS-PAGE) is 65 kDa and 61 kDa respectively, pI volue is 4.1 and 4.2 respectively. Guillen F etc. also discovered that laccase is active in the culture medium of Pleurotus erygii. Laccase was drawn from these mushroom of Agaricus bisporus, Pleurotus sapidus , Agrocy becylindracea , Lentinula edodes, Pleutotus pulmonarius, which activity are lower than that of Pleurotus erygii. Protoplast technology is important to edible mushroom breeding. In 1972 , Dutch De Vessels split pleat bacterium protoplasm body by lyase for the first time.The protoplast of Agaricus bisporus and straw mushroom were split soon. After 1980, the protoplast split of edible bacterium was reported in large quantities .In this paper, with UV-irradiation and protoplast technique,the mutants were screened whose laccase activity was increased .I studied the best fermentative procedure conditions of the mutant that were cultivated in submerged culture medium,and studied the partial biological character of its laccase. The results showed that the best conditions of Pleurotus erygii protoplast separation and regeneration were to use the strains after cultivated in submerged culture medium for four days, while the mycelia co-treated with 1.5% lywallzyme, at 30℃,for 2.5 hours, and the production rate of protoplast reached to 2.90×107 个/mL ,and the regeneration frequencies reached to 0.18% on hyperosmotic medium containing 0.6mol/L mannitol.