Human Growth Hormone ELISA Kit

The composting ecosystem is a suitable source for the discovery of novel microorganisms and secondary metabolites. Cellulose degradation is an important part of the global carbon cycle, and beta-glucosidases complete the final step of cellulose hydrolysis by converting cellobiose to glucose. This work analyzes the succession of beta-glucosidase-producing microbial communities that persist throughout cattle manure - rice straw composting, and evaluates their metabolic activities and community advantage during the various phases of composting. Fungal and bacterial beta-glucosidase genes belonging to glycoside hydrolase families 1 and 3 (GH1 and GH3) amplified from DNA were classified and gene abundance levels were analyzed. The major reservoirs of beta-glucosidase genes were the fungal phylum Ascomycota and the bacterial phyla Firmicutes, Actinobacteria, Proteobacteria, and Deinococcus-Thermus. This indicates that a diverse microbial community utilizes cellobiose. The succession of dominant bacteria was also detected during composting. Firmicutes was the dominant bacteria in the thermophilic phase of composting; there was a shift to Actinomycetes in the maturing stage. Proteobacteria accounted for the highest proportions during the heating and thermophilic phases of composting. By contrast, the fungal phylum Ascomycota was a minor microbial community constituent in thermophilic phase of composting. Combined with the analysis of the temperature, cellulose degradation rate and the carboxymethyl cellulase and beta-glucosidase activities showed that the bacterial GH1 family beta-glucosidase genes make greater contribution in cellulose degradation at the later thermophilic stage of composting. In summary, even GH1 bacteria families beta-glucosidase genes showing low abundance in DNA may be functionally important in the later thermophilic phase of composting. The results indicate that a complex community of bacteria and fungi expresses beta-glucosidases in compost. Several beta-glucosidase-producing bacteria and fungi identified in this study may represent potential indicators of composting in cellulose degradation.

The present study reports the isolation and analysis of two novel GH1 beta-glucosidases from the alkalophilic fungus Stachybotrys microspora, using PCR and Nested-PCR. Three major gene fragments were obtained by PCR: the first two are very similar and constitute a novel gene, which was named Smbgl1A, and the third PCR fragment is part of a different gene, named Smbgl1B. The truncated gene sequences were completely filled using the recent partial whole genome sequencing data of S. microspora (data not yet published). Moreover, we investigated the relative effects of glucose in comparison to cellulose rather than evaluate their absolute effects. In fact, RT-PCR analysis showed that while Smbgl1A was expressed when the fungus was grown in the presence of cellulose but not when grown with glucose, Smbgl1B was equally expressed under both conditions. The putative catalytic residues and the conserved glycone binding sites were identified. Zymogram analysis showed the intracellular production of beta-glucosidases in S. microspora. The predicted secondary structure exhibited a classical (beta/alpha)8 barrel fold, showing that both SmBGL1A and SmBGL1B belong to the GH1 family. Phylogenetic studies showed that SmBGL1A and SmBGL1B belong to the same branch as beta-glucosidases from Stachybotrys chlorohalonata and Stachybotrys chartarum. However, SmBGL1A and SmBGL1B form two distinct clades.