Draft Genome Sequence of Bacteroides reticulotermitis Strain JCM 10512T, Isolated from the Gut of a Termite.

Here we report the draft genome sequence of Bacteroides reticulotermitis strain JCM 10512(T), a xylanolytic and cellulolytic bacterium isolated from the gut of a wood-feeding termite. The genome information will facilitate the study of this strain for biomass degradation and adaptation to the gut environment.

GENOME ANNOUNCEMENT

The gut of wood-feeding termites harbors a complex microbial community, which plays crucial roles in lignocellulose degradation and metabolisms of the host termites (1). Although the majority of the gut bacteria are very difficult to cultivate, molecular studies without cultivation have shown the great diversity of termite gut bacteria, and members of the order Bacteroidales are among the major constituents in the gut microbial community (2). Strain Rs-03T (available from the Japan Collection of Microorganisms as JCM 10512T) was isolated from the gut of the wood-feeding subterranean termite Reticulitermes speratus and designated a novel species, Bacteroides reticulotermitis (3). B. reticulotermitis strain JCM 10512T is obligately anaerobic, and the cells of this strain are nonpigmented, nonmotile, non-spore forming, Gram-negative staining, and rod shaped. This strain ferments xylan, carboxymethylcellulose, and starch (3).

The genome of B. reticulotermitis strain JCM 10512T was sequenced using the Ion Torrent PGM system and Newbler version 2.8 (Roche). A total of 564,185 reads were assembled into 97 contigs with an N50 length of 137,557 bp and the largest length of 270,264 bp. This assembly resulted in a draft genome sequence of 5,365,278 bp with 22.1× redundancy and a G+C content of 43.3%. Totals of 4,841 protein-coding genes and 64 RNA coding sequences were detected after manual inspection of the annotations using the RAST server (4).

RAST annotation and the following analyses with the CAZy database (5) revealed 108 predicted genes for xylanolytic and cellulolytic enzymes in the genome sequence of B. reticulotermitis JCM 10512T. There were various genes encoding xylanases homologous to those in the glycoside hydrolase 5 (GH5), -10, -30, -43, -95, and -98 families in the CAZy database; genes encoding the α- and β-xylosidases of GH31, -39, -43, and -97; genes encoding cellulases of GH9; and genes encoding α- and β-glucosidases of GH3 and -97. In addition, the genome had several genes encoding α-1,6-mannanase, β-mannosidase, and arabinofuranosidase. Furthermore, the genome had a starch utilization system locus (susRABCDEF) similar to that of Bacteroides thetaiotaomicron. The genes susC, susD, susE, and susF are involved in starch binding, susA and susB are involved in starch catabolism, and susR is involved in regulation of this gene locus as a transcription factor (6, 7). These results support the hypothesis that B. reticulotermitis JCM 10512T utilizes soluble and insoluble polysaccharides, and this ability seems to be advantageous for inhabiting the gut of the termite.

Nucleotide sequence accession numbers.

The genome sequence of Bacteroides reticulotermitis strain JCM 10512T has been deposited in DDBJ/EMBL/Genbank under the accession numbers BAIV01000001 through BAIV01000097.