The distribution of active beta-glucosidase producing microbial communities in composting

Cellulose degradation is an important part of global carbon cycle in composting process, and β-Glucosidases complete the final step of cellulose hydrolysis by converting cellobiose to glucose. This work analyzes the succession of β-glucosidase-producing microbial communities that persists throughout composting, evaluates their metabolic activities and community advantage during the various phases of composting. Fungal and bacterial β-glucosidase genes belonging to glycoside hydrolase families GH1 and GH3 amplified from DNA and gene abundance levels were analyzed. The major reservoirs of β-glucosidase genes were the fungal phylum Ascomycota and the bacterial phyla Firmicutes, Actinobacteria, Proteobacteria and Deinococcus Thermus. Combined with the analysis of the cellulose degradation rate and the CMCase and β-glucosidase activities, showed that the bacterial GH1 family β-glucosidase genes make greater contribution in cellulose degradation at the later thermophilic stage of composting. In summary, even GH1 bacteria families β-glucosidase genes showing low abundance in DNA may be functionally important in the later of thermophilic phase in composting. The results indicate that a complex community of bacteria and fungi expresses β-glucosidases in compost. Several β-glucosidase-producing bacteria and fungi identified in this study may represent potential indicators of composting in cellulose degradation.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author