Laccase Of Coprinus Comatus Degradation Of Residual Lignin Ability In Pinus Massoniana Kraft Pulp

Laccase is a copper-containing polyphenol oxidase, laccase alone can effectively oxidizephenolic-lignin structure due to its high redox potential. Fungal growth environment orphysiological state due to the different differentially expressed, can secrete a variety of paintisozymes, fungal laccase multi-gene family encodes isoenzymes to form. Currently validlaccase mediator mostly from synthetic, these mediators are expensive is not conducive to therealization of economic efficiency of enterprises; also highly toxic, polluting the environment.In this study, two different mediums induced the Coprinus comatus producing amulticomponent isozymes laccase and a single component isozymes laccase. Usingmulticomponent laccase process pinus massoniana kraft pulp with laccase-mediator system,the influence of temperature, pH, enzyme dosage, pretreatment time with LMS was studiedand the optimal enzyme pretreatment conditions was determined, in the same time, thecapacity and mechanism of multicomponent and single component isozyme laccase fromCoprinus comatus degradating lignin was respectively studied with Pinus massoniana kraftpulp. The second part of this paper, Volvacea Sing, Pholiota Nameko,Auriculariaor,Pleurotusostreatus, Pleurotus sajor-caju were used to pretreat rice straw, the small moleculesproduced by the degradation of lignin as a natural mediator replace artificial mediators,laccase-natural mediator system effect of degradation of lignin was evaluated.Pinus massoniana kraft pulp was pretreated with LMS, the optimal conditions ofpretreatment were as follows: temperature50℃, pH4.2, the enzyme dosage20IU/g, treatmenttime5h. The kappa numbers of the pulps which were pretreated with LMS which mediator isABTS, TEMPO, HBT, VIO and then extracted with alkali were reduced3.1,3.0,2.2and2.1compared with the control sample respectively. The result showed that ABTS and TEMPOwas better than HBT and VIO as mediator in LMS. Laccase from Coprinus comatus lessenedHexA content in kraft pulp. Using multicomponent isozymes laccase and single componentisoenzyme laccase pretreating KP pulp with LMS and L, different delignification effect wasobserved. No mediator involved in reaction, the multicomponent of laccase can decrease1.18%lignin content better then the single components laccase’s0.88%.When mediator participationin reaction,1.36%and1.20%lignin were degrated by multicomponent laccase and the singlecomponents, multicomponent isozymes laccase delignification effect was still better than asingle component, but the single component laccase delignification rate increased by36.4%15.3%better than that of multicomponent laccase.Laccase, Mn-peroxidase and cellulose were detected during the pretreatment (0-50day).The activity of lingin peroxidase was not detected. Volvacea Sing, Pholiota Nameko andAuriculariaor-7#were able to secret Mn-peroxidase, ostre-atus and Pleurotus secretedLaccase and Mn-peroxidase. The extraction compounded with laccase to pretreat kraft pulp and Kappa No. was dropped to25.6,26.3,27.1compared with the control’s32.9whenPholiota Nameko, Auriculariaor, Pleurotus sajor-caju respectively cultured40days,10days,20days.