Draft Genome Sequence of Methylobacterium sp. ME121, Isolated from Soil as a Mixed Single Colony with Kaistia sp. 32K.

Methylobacterium sp. ME121 was isolated from soil as a mixed single colony with Kaistia sp. 32K, and its growth was enhanced by coculture. Here, we report the draft genome sequence of Methylobacterium sp. ME121, which may contribute to the study of the molecular mechanisms underlying this phenomenon.

GENOME ANNOUNCEMENT

It has been suggested that a majority of environmental microorganisms are still uncultured, and some of them form symbiotic relationships with other organisms. For example, Symbiobacterium thermophilum was reported as a symbiotic bacterium requiring support of the associated Geobacillus stearothermophilus for growth (1). The genomic information of such symbiotic bacteria could be of use for studying the molecular mechanisms underlying microbial symbiosis (2).

Methylobacterium sp. ME121 was isolated from soil as a mixed single colony with Kaistia sp. 32K during our screening of l-glucose-utilizing microorganisms (3), and its growth was enhanced by coculture. It was expected that genomic analysis of this bacterium would provide novel information on coculture-dependent growth enhancement. Methylobacterium sp. ME121 appeared to be most closely related to M. radiotolerans based on the 16S rRNA gene sequence identity.

The draft genome sequence of Methylobacterium sp. ME121 is 7,096,979 bp in total length and comprises 197 large contigs (>500 bp) and was obtained with the Roche GS Junior and assembled using the GS de novo assembler version 2.7. Automatic annotation was performed using the Microbial Genome Annotation Pipeline (4), which predicted a total of 6,676 protein-coding genes. The product names of the predicted protein-coding genes were revised manually. tRNA detection was performed using the tRNA scan software (5), which predicted a total of 56 tRNAs.

Methylobacterium species generally live on plant surfaces and assimilate methanol emitted by plants. The genome sequences of M. aquaticum and M. radiotolerans were analyzed, and the genes involved in methylotrophy were identified (6, 7). The annotation of the draft genome sequence shows that Methylobacterium sp. ME121 has some genes that encode putative methanol/ethanol family PQQ-dependent dehydrogenases involved in methylotrophy. Some unknown factor (e.g., methanol) provided by the coculture may contribute to increase the growth of Methylobacterium sp. ME121. Future study will identify such a factor, and it would serve to clarify the molecular mechanisms of coculture-dependent growth enhancement.

Nucleotide sequence accession numbers.

The draft genome sequence of Methylobacterium sp. ME121 was deposited at DDBJ/EMBL/GenBank under the accession number BBUX00000000. The version described in this paper is the first version, BBUX00000000.1.