Optimizing The Culturing Conditions Of B7 And F4 Strains For Producing Ligninolytic Enzyme And Analysis Of Characteristics

Lignin is a class of substances constitute with polymer of aromatic alcohols,found in wood-based organizations,a major role is through formation of intertwined with Net to hardening cell wall.Lignin is mainly located between the cellulose fibers,as a role of resistance.In woody plants,the lignin 25%,is the world's second most abundant organic compounds after cellulose.With the rise of awareness the problem of resources crisis,such as environmental pollution,and the renewable of the natural polymer,human pay more and more attention to biodegradable nature.Waste and the resources renewable,are the major issues of contemporary economic and social development,as well as the new requirements to the contemporary science and technology.Lignin degradation,conversion and use are related to clean production of today's pulp and paper industry,and the Sound processing of toxic phenolic compounds and bioremediation of environmental pollution,lignin-degrading strains are mainly fungi,bacteria and actinomycetes,white-rot fungi are the most studied species,the lignin degradation process are the real oxidation process,phenol oxidase is one of the key enzyme.Their role in natural lignin re-use should not be underestimated.In nature,White-rot fungi are the most effective lignin degradation microbial,the decomposition of lignin rely largely on the process of lignin degradation enzymes achieve during the its growth and metabolism,since the late 80's of 20th century,many aspects of the study against the white-rot fungi in the degradation of pollutants,production of lignin-degrading enzyme characteristics,optimization of fermentation conditions and biological characteristics of the molecular level are carry on both at home and abroad,but just a narrow range of white-rot fungi are used,enzyme production capacity and a amount of enzyme production are limited.The research of bacteria and Actinomycete bacteria on lignin degradation are rare,it is significance to research and development of new bacteria or actinomycetes to degrade lignin,and can rich strains resources.In this paper,bacteria strains B7,B8,B9 and fungal strains F2,F3,F4,F5,F7,F8,F10, F12 were screened form a corn straw surface,all have the Capacity of produce lignin-degrading enzyme.after screened I choise B7 and F4 strains for advanced reseach,and optimized the lignin-degrading enzyme production conditions of F4 and B7 strains with Orthogonal test.inhance the production of lignin-degrading enzyme and studied the physical and chemical properties of lignin-degrading enzyme.1.optimized the condition for Ligninolytic enzymes productionEstablished at the experimental conditions obtained:the best culture conditions of F4 strain producing ligninolytic enzymes as follow:carbon source for starch 2g/l,ammonium nitrogen for the tartaric acid 1g/l,the best pH was 4.5.Under these conditions the laccase activity reached up to 3827.1u / L,Lignin peroxidase activity of 8602.2U/l.The best culture conditions of B7 strain producing lignin-degrading enzyme producing as follow:carbon source is maltose 2g/l.tartaric acid ammonium nitrogen for the 1.2g/l.Optimum pH of 4.5. Under these conditions the laccase activity reached up to 210.6U/l.,Lignin peroxidase activity of 8602.2U/l.The induced For B7 strain produce lignin-degrading enzyme have show that Inducer have an impact on lignin-degrading enzyme production.xylidine have a best induced,under the conditions at 0.01mM xylidine,the laccase activity can be of 2222.2U/l. Lignin peroxidase activity of 8602.2U/l.2.Enzymatic propertiesCrude enzyme obtained from the fermentation liquid,obtained purified laccase and lignin peroxidase after purified.The optimal pH is 4 of laccase from enzyme study,low concentrations of copper ions have a promotion on the laccase activity,high concentration inhibitory the laccase activity.Laccase has good temperature tolerance,between the 5-65℃,there no significant changes in laccase activity.The optimum pH is 2.5 of Lignin peroxidase,low concentrations of iron ions have an promotion on the Lignin peroxidase activity,high concentration inhibitory the Lignin peroxidase activity.3.ligninolytic enzymes production capacity compared of F4 and B7 strainsThe ability of F4 strain producing ligninolytic enzymes is high then B7,and easy culture, F4 strain con production a mount of lignin-degrading enzyme even without inducer.but B7 strain producing ligninolytic enzymes has a shorter incubation time also has certain advantages,shorten the fermentation time in industrial production ligninolytic enzymes,improve the fermentation efficiency.