The Comparison For The Capacity Of Laccase Production In Various Types Of Edible Fungi And The Characterization Of Laccase

In the research,Through flat colour analysis,compared the capacity of laccase production in various types of edible fungi.It can be roughly divided 15 kinds of of edible fungi with production capacity laccase into three categories.One category is higher production capacity laccase-strains including Pleurotus pulmonarius,Pleurotus ostreatus,and so on.Their analysis of flat have dark blue-green edge,in-dicated that a higher laccase activity;the second category is laccase production capacity is not high strains including Flammuling velutipes Cart.Sing, Pleurotus cornucopiea and so on.In their analysis of flat,it shows light blue-green,indicated that a laccase exists,but the activity is not high.The third is no production capacity laccase strains including Stropharia rugoso-annulata.Hypsizigus marmoreus.Agrocybe chaxinggu,Grifola Frondosa.In their analysis of flat,it has no blue-green edge,showed no laccase.Meanwhile an isolate of Pleurotus eryngii(Fengjie NO-1)with high laccase activity was screened out by enzyme activity determination based on ABTS.Futher studies on the optimization of cultural conditions for enzyme production purification,characterization and decolor ability analysis were carried out with this strain.The maximal enzyme activity of 10.85 U·mL^-1was obtained under the optimal cultural conditions with 1.0%annitol,1.5%yeast extract,0.3% KH₂PO₄ and 0.15%MgSO₄·7H₂O at 25℃140 rpm for 8 d.The enzyme is stable below 60℃and in the pH range of 4.5-6.0.The optimum pH and temperature for oxidation of ABTS were 4.5 and 65℃,respectively.The km value is 0.335 mmol·L^-1and Vmax is 0.795 umol·L^-1·min^-1with ABTS as the substrate.The reaction time is 4-5 min.Under different substrate,ABTS displayed maximum oxygenation capability,Guaiacol,Hydroquinone,catechol take second place,Ferulic acid have no oxygenation capability.Sodium azide is the most efficient inhibitor,which can restrain laccase activity completely at 0.5 mmol·L^-1.The laccase could decolor triphenylmethane (malachite green stain,crystal violet).And from the research,The laccase decoloring malachite green stain is better than crystal violet.Moreover,adding ABTS into the system could impove its discoloring ability.This study analyzed and compared the capacity of production laccase in different types of edible fungus,selected the highest laccase activity strain.It has positive significance on the further development of laccase resources,provide the basis for genetic improvement for the edible fungi species,It also lay a good foundation for laccase industrial production and application.