Metagenomic Analysis of Microbial Community Affiliated with Termitarium Reveals High Lignocellulolytic Potential

Termitarium (nest of termites) is a rich source of microbial populations whose resources remain untapped to date. Using the metagenomic sequencing approach, we generated 38 GB sequences comprising 808,386 contigs (896 MB) with a maximum contig size of 470 kb. The taxonomic profile obtained by BLAST against the NCBI NR database and annotation by MEGAN showed that the termitarium microbial community was dominated by Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes. Functional annotation using the CAZY database revealed a huge diversity of glycosyl hydrolase genes from 104 families, some of which appeared to be part of polysaccharide utilization systems (PUL). Strikingly, Actinobacteria was the main contributor of the cellulolytic and hemicellulolytic GHs. Genes involving in lignin degradation were also abundantly identified in this metagenome. Comparative analysis of COG profiles of termitarium with those of other lignocellulolytic microbial communities showed a distant clustering pattern resulting from the dietary differences in carbohydrate compositions. Altogether, this study revealed that termitarium hosts a unique microbial community, which can efficiently degrade lignocelluloses.