Study On The Screening,Identification And Enzymatic Characterization Of Cellulase-Producing Fungi

This study was divided into three Formalization Breeding Swine Farms in Guangxi Province(Yuan Feng,Kang Jiarong,Qichang)for feces and feed sampling.After isolation and purification,27 strains with relatively large hydrolysate ring were obtained,and 4 kinds of enzyme-producing better strains named z1-1,slr-1,Ml-1,z1-2 was found by screening,screening fermentation production of enzyme tests,the ability of z1-1 to produce enzymes was the strongest.The molecular biology and morphological identification of the four strains were carried out,and the genetic evolutionary tree was established by blast online comparison of sequencing results,and the four strains were identified as genus Penicillium,genus of Fusarium,Aspergillus and Penicillium.In this paper,the enzyme activity characteristics of z1-1 were studied by considering the safety of bio-production and the ability of producing enzyme.The conditions of solid fermentation of z1-1 strain were studied,and the best conditions for the solid fermentation of the strain were:8:2 proportion of soybean meal and Bran after 3NaOH treatment,material water ratio 1:2,and incubate at 28 ? for 84 h.At the same time,the enzymatic activity produced by z1-1 Strain was studied by FPA method and CMC method,and the most suitable enzymatic reaction conditions were obtained:the optimum conditions for enzymatic reaction of FPA are at temperature of 50 ? and pH 5.0;CMC enzymatic activity are at temperature 50 ? and pH 4.6,Both Fe2+ and Mn2+ are Activator of cellulase produced by z1-1 by investigating the effect of metal ions on its enzymatic activity,which has a strong promotive effect on enzymatic reaction,in which Fe2+ promotes the two kinds of enzymatic reaction,while Cu2+ is the inhibitor of z1-1 producing cellulase,and the inhibition of enzymatic reaction is strong,and the inhibitory effect of Cu2+ on two kinds of enzymatic reaction is most significant.Finally,the enzymatic stability of z1-1 strains producing under different temperature and ph was studied,and the PFA and CMC enzymatic activity of z1-1 were found to be acidic enzymes and conserved at a certain temperature.Finally,the safety of z1-1 strains was considered,in mice as the medium,a certain amount of z1-1 fermented enzyme suspension was poured into the mice,and the normal saline was compared.After 15 days of feeding,no mice died,the survival rate was 100%,and the daily activities were not abnormal,no adverse reactions were observed.There was no significant difference in body weight between each stage and normal saline group(P>0.05).It shows that z1-1 has no toxic effect on mice,and its biological safety is good.In this study,Cellulase-producing fungi were screened from swine's feed and feces.Through two rounds of screening,enzymatic characteristics and fungus biological safety test,A fungi with high cellulase activity was discovered,named z1-1.It is expected to be used as feed additive in the actual industry to promote the decomposition and digestion of cellulose in animals,improve the degradation rate of cellulose in animal faeces,promote the degradation and recycling of animal feces,This study also provides sufficient theoretical basis for the development and utilization of wheat bran and soybean meal.