Effects Of Cellulase And Aspergillus Niger On The Composting Process,Quality And Fertilizer Efficiency Of Spent Mushroom Substrate

Spent mushroom substrate(SMS)is the waste culture medium of edible fungus cultivation,which contains a large number of underutilized cellulose and other macromolecular materials.In this experiment,SMS was used as raw material for composting to realize the sustainable utilization of the waste resources and to avoid the environmental pollution caused by its disposal.In this paper,whether adding cellulase and Aspergillus niger could accelerate the composting process and improve the maturity was studied,and the best adding time of them was explored.The effects of adding cellulase and Aspergillus niger in different composting stages on the evolution of physical and chemical parameters,bacterial diversities and final product qualities were studied.Cellulase,Aspergillus niger and there adding time were used as the variables in the composting test,and the group adding no enzyme and Aspergillus niger was used as the control group.Results showed that the temperature,p H value,moisture content,EC value,carbon nitrogen ratio,total carbon content,total nitrogen content,humic acid content,degree of humification,enzyme activity and GI change rate and amplitude of the four groups treated with cellulase and Aspergillus niger were higher than that of the control.The groups inoculation with Aspergillus niger showed the best composting efficiency,because that the fingus produced a lot of cellulase,protease and other biological enzymes,improved the microbial activity of composting,which made the SMS get the most adequate degradation.The most appropriate time of adding Aspergillus niger was in the late stage of composting,which improved the quality of the final composting product greatly.In terms of bacterial diversity,the additions of cellulase and Aspergillus niger,as well as there adding time have great impacts on the number of the unique OTU,especially adding them after the thermophilic period of composting.The addition of Aspergillus niger in the early stage of composting can significantly improve the abundance of the dominance phylum,while the addition of cellulase in the late stage can significantly improve the abundance of the dominance genus.The mature compost of SMS was used in the cultivation of pepper.It was found that the growths of pepper fertilized with the compost prepared by adding cellulase and Aspergillus niger were better than that of the control group and the inorganic fertilizer treated group.The plant height,stem diameter,biomass accumulation,chlorophyll content,autioxidant enzyme activities were significantly improved,the methane dicarboxylic aldehyde were significantly reduced,the growth level of pepper plant and root system was significantly improved,the photosynthesis of leaves was enhanced,the accumulation of nutrients and the root were improved.The enzyme activities of pepper root and soil were improved,indicating the stress resisting ability of pepper plant was enhanced and the condition of planting soil was improved.The results obtained in this paper has significant guide for the sustainable utilization of SMS and the solution of environmental pollution.