Draft Genome Sequence of Brevibacillus brevis DZQ7, a Plant Growth-Promoting Rhizobacterium with Broad-Spectrum Antimicrobial Activity.

Brevibacillus brevis DZQ7 is a plant growth-promoting rhizobacterium (PGPR) isolated from tobacco rhizosphere. Here, we report the draft genome sequence of B. brevis DZQ7. Several functional genes related to antimicrobial activity were identified in the genome.

GENOME ANNOUNCEMENT

Brevibacillus brevis (formerly Bacillus brevis), the type species of Brevibacillus, is considered a plant growth-promoting rhizobacterium (PGPR) (1–3) and organic pollutant degradation strain (4, 5). B. brevis is widespread in the soil and sediment, and it has been widely used in agriculture and environmental remediation because of its multiple potential functions (6, 7). B. brevis DZQ7 was isolated from the soil of tobacco rhizosphere in Guizhou, China. It showed broad-spectrum antimicrobial activity to pathogens of soilborne plant diseases, such as Ralstonia solanacearum, Phytophthora nicotianae, and Fusarium spp., and has been widely used in biological control of soilborne plant diseases.

Here, we report the draft genome sequence of B. brevis DZQ7. Genomic DNA was extracted and sequenced using the Illumina HiSeq 2500 platform. The whole-genome shotgun sequencing produced 1,243,319 paired-end reads with an average insert size of 500 bp (over 96-fold coverage). Another mate-paired (MP) library containing 5-kb inserts was constructed, and 5,041,325 paired-end reads (read length, 125 bp) were produced. The filtered reads were assembled by SOAPdenovo (8, 9) (http://soap.genomics.org.cn/soapdenovo.html) to generate scaffolds. All reads were used for further gap closure. Final assembly consisted of 3 scaffolds (length, ≥500 bp) with an N50 length of 6,158,809 bp, average length of 2,144,406 bp, and largest length of 6,158,809 bp. The genome sequence was annotated using the NCBI Prokaryotic Genome Automatic Annotation Pipeline (PGAAP) (http://www.ncbi.nlm.nih.gov/genome/annotation_prok/).

The genome consists of 6.43 Mb, with a G+C content of 47.42%, which is similar to those of B. brevis NBRC 100599 (47.3%) (NCBI reference sequence NC_012491), B. brevis FJAT-0809-GLX (47.3%) (GenBank accession no. AHKL00000000), and B. brevis X23 (46.8%) (GenBank accession no. AKYF00000000). A total of 5,762 coding sequences (CDS), 44 pseudogenes, 120 tRNA genes, and 29 rRNA genes were identified. As expected, many of the genes involved in the antimicrobial activity of B. brevis DZQ7 were identified in the genome, such as tyrocidine-synthetic gene, bacteriocin-synthetic gene, fusaricidin-synthetic gene, polyketide-synthetic (PKS) gene, chalcone-synthetic gene, nonribosomal peptide synthetic (NRPS) gene, and chitinase gene, and so on. In addition, B. brevis DZQ7 possesses genes with likely relevance to the degradation of organic pollutants, such as the phenylacetic acid degradation, phenylacetate degradation, and ethyl tert-butyl ether degradation genes.

The genome sequence of B. brevis DZQ7 and its curated annotation provides deeper insights into understanding the antimicrobial mechanism of B. brevis, which is critical for the development of a genetically engineered biocontrol agent. Also, it provides abundant genetic information regarding useful functions in bioremediation.

Nucleotide sequence accession numbers.

The whole-genome shotgun project of B. brevis DZQ7 has been deposited in DDBJ/ENA/GenBank under the accession number LDZV00000000. The version described in this paper is the first version, LDZV00000000.1.