16S rRNA Identification of Microorganisms and Direct Detection of Functional Genes in Waste Material Generated by an In-Vessel Rotating Compost System

rRNA genes. Characterization of each clone was performed by DNA sequencing. Results: 16S rRNA identification of bacterial isolates showed the phylum Firmicutes with the highest numbers of species, 42%. Lower frequencies of Actinobacteria (26%), Proteobacteria (24%), and Bacteroidetes (8%) were detected. Clone libraries of eubacteria 16S rRNA genes showed the Firmicutes comprising 86% of the sequences while Proteobacteria accounted for 14%. Molds were not culturable from the samples neither any mold ITS sequences were detected in clone libraries. Direct DNA extraction and PCR detection showed that β-glucosidase genes had the highest frequency of all functional genes. Conclusions: The RCS produced finished material with a vigorous heterotrophic bacterial community. However, the absence of mold and other bacterial phyla might indicate that the material produced is not degraded enough to be classified as mature compost and needed further processing. Most of the β-glucosidase sequences were related to members of the phyla Actinobacteria and Firmicutes while amoA genes were related to Nitrosomonas sp.