Analysis of gut bacterial diversity and exploration of cellulose-degrading bacteria in xylophagous insects

Department of Biology, Kyung Hee University, Seoul 130-701, Republic of Korea(Received May 15, 2015; Accepted June 2, 2015)ABSTRACT: In this study, gut bacterial communities in xylophagous insects were analyzed using the pyrosequencing of 16S rRNA genes for their potential biotechnological applications in lignocelluloses degradation. The result showed that operational taxonomic units (OTUs), species richness and diversity index were higher in the hindgut than in the midgut of all insect samples analyzed. The dominant phyla or classes were Firmicutes (54.0%), Bacteroidetes (14.5%), γ-Proteobacteria (12.3%) in all xylophagous insects except for Rhinotermitidae . The principal coordinates analysis (PCoA) showed that the bacterial community structure mostly clustered according to phylogeny of hosts rather than their habitats. In our study, the two carboxymethyl cellulose (CMC)-degrading isolates which sho wed the highest enzyme activity were most closely related to Bacillus toyonensis BCT-7112