Draft Genome Sequence of Geobacillus sp. Strain FW23, Isolated from a Formation Water Sample

Abstract

The thermophilic Geobacillus sp. strain FW23 was isolated from the Mehsana oil wells in Gujrat, India, during a screening for oil-degrading bacteria. Here, we report the draft genome sequence of Geobacillus sp. FW23, which may help reveal the genomic differences between this strain and the earlier reported species of the genus Geobacillus.

GENOME ANNOUNCEMENT

High temperature and pressure make oil reservoirs an extreme environment that supports the growth of novel organisms which may possess unique biotechnological potential, such as production of thermostable enzymes. Investigation of diversity and functional analysis of microorganisms associated with oil reservoirs will provide assistance for the use of microorganisms as bioremediation agents in oil spills, which are a major source of environmental pollution (1).

FW23, a Gram-positive rod-shaped bacterial isolate with optimum growth at 60°C, was identified as a putative novel species of the genus Geobacillus based on 16S rRNA gene sequencing. The culture is deposited at the Microbial Culture Collection (MCC) (Pune, India) with the accession number MCC2339. Whole-genome sequencing was performed to enhance detailed understanding of the genome organization of this isolate and predict the presence of certain unprecedented genes involved in major pathways. Genomic DNA was isolated using a GenElute Bacterial DNA isolation kit (Sigma, USA). Whole-genome sequencing of Geobacillus sp. strain FW23 was performed using 316 chip and 200-bp chemistry on the Ion Torrent PGM platform (Life Technologies). Sequencing of the library generated 2,464,863 reads with an average read length of 228 bp. A total of 564 Mb of data were sequenced, with 485 Mb of data with a quality value above 20. Reads were assembled using MIRA assembler version 4.0.5. The coverage was 93.08×, and 227 contigs were generated. The length of the largest contig was 182,724 bp (N₅₀, 39,806).

The genome was annotated using the RAST server (2), the KEGG database (3), GeneMark (4, 5), and Signal P4.1 (6). We predicted 3,844 coding sequences (CDS), 443 subsystems, 135 RNAs, and 204 signal peptides. A total of 127 unique genes associated with a subsystem in Geobacillus sp. FW23 were found when we performed a comparison with the nearest phylogenetic neighbor, Geobacillus kaustophilus HTA426.

Genes encoding several enzymes involved in oil degradation and utilization were detected using annotation studies. Metabolic pathways involved in the degradation of aromatic and aliphatic compounds such as toluene, xylene, naphthalene, dichlorobenzene, bromobenzene, dichloroethylene, and trichloroethylene were detected. In oil reservoirs, organic acids such as acetate have been found to be abundant and are commonly detected and recognized as important components for bacterial survival (7). In FW23, genes encoding acetate kinase, butyrate kinase, and formate dehydrogenase were found, and genes for the fatty acid metabolism pathway were also found. FW23 also has genes that encode methylmalonyl-coenzyme A (CoA) mutase. Ammonia, which is the primary nitrogen source in oil reservoirs (8), may be utilized by a specific ammonia transporter and assimilated via glutamate dehydrogenase or the glutamine synthetase pathway. Genes for sulfur metabolism proteins, such as alkanesulfonate monooxygenase, alkanesulfonate ABC transporter ATP-binding protein, and flavin mononucleotide (FMN) reductase, were present. Genes involved in copper tolerance and translocation, as well as arsenate reduction, were present. Genes involved in utilization of carbohydrate and amino acid synthesis, such as a gene for dihydropyriminidase, were detected. Information available from the whole-genome sequence enabled us to describe the metabolic profile of the strain and has revealed the metabolic potential of FW23 for oil degradation and the production of industrially important biomolecules such as thermostable enzymes.

Nucleotide sequence accession numbers.

This whole-genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number JGCJ00000000. The version described in this paper is version JGCJ01000000.