Construction Of Cellulose-degrading Compound Microbial Inoculum And Degradation Efficiency

Cellulose,as the most abundant organic biomass,is widely concerned about its resource transformation.Researching its scientific and rational utilization methods can not only realize the recycling of energy,but also obtain high value-added products.At present,the main utilization methods of vegetal cellulose are mostly physical comminution or chemical incineration,resulting in waste of resources and causing many adverse effects on the environment.In this study,microorganisms with cellulose degradation ability were screened from the existing strains in the laboratory,and a compound inoculum was successfully constructed,which has positive significance for the biodegradation and utilization of cellulose and environmental protection.In this paper,Aspergillus niger,Trichoderma viride,and Bacillus licheniformis with cellulose degradation ability were screened by Congo red staining assay and FPA enzyme activity assay.After fully considering the symbiotic and complementary factors between the strains,the complex inoculum were successfully constructed.It was proved that cellulase activity of compound inoculum group was higher than that of single strain,and FPA enzyme activity could reach 3.65 U/mL.Through the single factor test,the optimum conditions for enzyme production were as follows: temperature,initial p H,salinity,shaking speed,and inoculum size.The optimal enzyme production conditions were as follows: temperature 32?,initial pH=8.0,salinity 1%,shaker speed 160 rpm,inoculation amount 1%.Orthogonal test method was used to optimize the ratio of strains of the compound inoculum.The optimum ratio was Aspergillus niger: Trichoderma viride: Bacillus licheniformis = 3:3:2,and the maximum FPA activity was 7.01 U/mL is 1.9 times before optimization.The straw of three different crops of rice,corn and wheat was selected as the substrate.The changes of the contents of different straw components before and after degradation were studied using the paradigm-washing method,and the degradation efficiency of the different microbial bacterium was determined.This study has broadened the channels for the utilization of agricultural waste straw cellulose and has a positive impact on the industrialization of cellulose degradation.