Study On The Production And Enzymatic Characteristics Of Pectinase By Thermophilic Actinomycete FBKL 4.01

Pectinase is a kind of enzyme system that can decompose pectin.It is a multi-component compound enzyme,which is widely used in food,medicine,environment and other fields.At present,the research on pectinase properties is mainly focused on normal or moderate temperature conditions,and there are few reports on pectinase properties under high temperature conditions.This study is based on a high temperature actinomycetes that produces pectinase screened from a high temperature maotai-fragrance daqu,and discusses the optimum conditions of producing enzyme and the enzymatic characteristics of pectinase.It provides some theoretical reference for the development of microbial heat-resistant pectinase resources.The specific research results are as follows:1.A strain of high-temperature actinomycete FBKL 4.013（Laceyella sacchan）was selected from a brewery in Guizhou province as the research object.The optimum growth temperature of the strain was50℃in ISP2 medium,which was gram positive and could liquefy gelatin,hydrolyze starch,coagulate milk and peptone.Can use starch,cellulose and other sugar sources and ammonium sulfate,glutamic acid,tyrosine and other organic or inorganic nitrogen sources;2.The best enzyme production conditions of strain FBKL 4.013（Laceyella sacchan）.Nitrogen source:organic and inorganic nitrogen3.sources are yeast powder and ammonium sulfate respectively,and the best ratio combination is 1%yeast powder and 2%ammonium sulfate;Carbon source:soluble starch,the optimal supplemental amount is 8%;Inducers were orange peel powder.Optimal temperature for enzyme production:50℃;Optimal liquid volume:40 mL/250 mL;Optimal dose:10%;The maximum pectinase activity reached 2565.43 U/mL,which was 3.79 times higher than that before optimization.3.Preliminary study on the crude enzyme properties of pectinase produced by strain FBKL 4.013（Laceyella sacchan）.Optimum reaction temperature:70℃;The optimal pH value of pectinase:pH=5;Thermal stability:the maximum residual enzyme activity was obtained at 60℃for 120 min.The effect of metal ions:Na⁺promoted the most obvious,Fe²⁺inhibited the most obvious.The reaction kinetics parameters of pectinase production by actinomycete were studied by Lineweaver-Burk double reciprocal plotting method.The regression equation of the standard curve was Y=15.7884 X+1.8596,R²=0.9984,and the maximum reaction speed was V_m=0.53 mg·（mL·h）^-1.Mi constant K_m=8.40 mg/mL;The preliminary results showed that the enzyme might have good thermal stability.