Effects Of Functional Inoculum On Lignocellulose Degradation And Microbial Diversity During Composting

High-temperature composting is a widely used way for handling of manures. Lignocellulose in agricultural wastes is difficult to be biodegraded due to its complex component, which leads low quality of compost. Inoculum can improve the type and structure of original microorganisms of composting. Most study of the inoculating agent field prefer to the affect. However, fewer on the degradation of lignocellulose and microbial communities metabolic. In the research screening microbial agent physico-chemical properties, lignocellulolytic enzymes activities, biodegradation process of lignocellulose and microbial communities metabolic and diversity were revealed. To provide theoretical basis for revealing the mechanism of lignocellulose degradation during the composting process.1Three bacterial strains had been screened from soil, straw and cattle manure by various screening criterions which had capacity and potential of ligocellulose degradation, temperature-rising and deodorization. According to the morphological, cultural feature, physiological and biochemical features and16Sr DNA sequencing, the three bacterial strains were identified as Bacillus sp. X9、Bacillus sp. LI and Bacillus sp. L8.2The effects on physicochemical properties and maturation of the compost.The result indicated that:the inoculated compost was characterized by reaching the thermophilic phase on the third day and keeping high temperature (>45℃) phase for20days; The pH value was during7.8～9.0in the two composts, the pH value of inocula compost was lower than natural compost; Water content showed the trend of decrease, as42%、48%. The result of germination index indicated the GI value more than50%of the two compost, inocula compost reach50%on day22and natural compost on day31. C/N value showed a downward trend in two composts, which down to under20on31d during inocula compost and on46day during natural compost; The content of total C showed a downward trend; The content of total N showed a small upward trend; The ratio of NH4+-N/NO3--N was lower than0.16on day31in the microbiological inocula compost which could be used as a maturity mark.3The result of enzymatic activities analysis in compost showed that after adding inoculant, the lignocellulolytic enzymes activities was higher than that of natural compost in each stage; in inoculated compost the highest activities for sodium carboxymethyl cellulose (CMCase), filter paper enzyme and hemicellulase was1120U/L,268U/L and1681U/L respectively,959U/L,209U/L and1459U/L higher than those in natural compost; The peak activities for laccase enzyme occurred on day16(4666U/L) and day31(3666U/L) and occurred one time on day18in natural compost.The number of lignocellulolytic microorganisms were higher than natural compost each period.The peak number of the lignin-degrading microorganisms occurred on day12and day31which was similar as the laccase enzyme activity.5The effects of inocula on lignocellulose degradation and microbial communities metabolic profiles during cattle manure compost process were studied using Biolog method mainly in order to promote lignocellulose degradation and understand the microbial community diversity of metabolic functions. The analysis on average well color development showed that the cell metabolic capacity were increased by the inocula at thermophilic stage of the compost. The analysis on Shannon index, Simpson index and McIntosh index showed that the microbial diversity were increased significantly by the inocula in the early stage of the compost. The results of PCA indicated that the metabolic capability on amphiphile, polymers, amino acids and amides carbon substrates of microorganisms in compost were enhanced by the inocula, which results in the efficient degradation of organic substance.