Abstract
Roseovarius sp. A-2 is a heterotrophic iodide (I-)-oxidizing bacterium isolated from iodide-rich natural gas brine water in Chiba, Japan. This strain oxidizes iodide to molecular iodine (I2) by means of an extracellular multicopper oxidase. Here we report the draft genome sequence of strain A-2. The draft genome contained 46 tRNA genes, 1 copy of a 16S-23S-5S rRNA operon, and 4,514 protein coding DNA sequences, of which 1,207 (27%) were hypothetical proteins. The genome contained a gene encoding IoxA, a multicopper oxidase previously found to catalyze the oxidation of iodide in Iodidimonas sp. Q-1. This draft genome provides detailed insights into the metabolism and potential application of Roseovarius sp. A-2.
Keywords: Roseovarius sp. A-2, draft genome, iodide oxidation, IoxA.
Introduction
Roseovarius sp. A-2 is a heterotrophic iodide (I-)-oxidizing bacterium, and was isolated from natural gas brine water in Chiba, Japan, which contained very high concentration (0.7 mM) of iodide 1. Based on 16S rRNA gene sequence analysis, iodide-oxidizing bacteria are divided into two distinct groups within the class Alphaproteobacteria. One of the groups is most closely related to Roseovarius tolerans and Roseovarius mucosus with sequence similarities of 94 to 98%. The other group is closely related to the genera Rhodothalassium and Kordiimonas, and the newly proposed Iodidimonas gen. nov 2. Shiroyama et al. 3 recently characterized an iodide-oxidizing enzyme of Roseovarius sp. A-2. It was an extracellular protein, and had significant oxidizing activities not only for iodide but also for p-phenylenediamine and hydroquinone. Tandem mass spectrometric analysis of this enzyme revealed that it is homologous to IoxA, a multicopper oxidase previously found as a component of iodide-oxidizing enzyme of Iodidimonas sp. Q-1 4. IoxA is a novel type of bacterial multicopper oxidase, and expected to be used as an enzyme-based antimicrobial system due to its strong molecular iodine (I2)-producing activity 5. We have generated a draft genome sequence of Roseovarius sp. A-2 to better understand the metabolism of this strain and to provide insights into future practical applications of iodide-oxidizing bacteria, in general.
Roseovarius sp. A-2 was grown in Marine Broth 2216 (Becton Dickinson, Sparks, MD) and DNA was extracted using a DNeasy Blood and Tissue kit (Qiagen, Hilden, Germany). Whole-genome sequencing was performed using paired-end sequencing on an Illumina MiSeq. The sequencer produced 300-bp paired-end reads that were obtained from 550-bp inserts. The quality of the reads was checked using FastQC 6. PhiX contaminations 7 were removed using bbduk 8, and the PhiX free reads were trimmed using Trimmomatic 9. The reads were assembled using SPAdes version 3.9.0 10. After the removal of low-coverage contigs, the resulting assembly contains 126 contigs consisting of 4,584,578 bp, with a G+C content of 62.8 %. The genome size and G+C content for strain A-2 were within the range of those for other Roseovarius spp. including R. tolerans (3.7 Mb and 63.9%), R. mucosus (4.2 Mb and 61.9%), and R. indicus (5.5 Mb and 64.8%) 11-13. Genome annotation was performed using Prokka v1.11, which is a pipeline comprising several bioinformatic tools 14. Briefly, Aragorn 15 detected 46 tRNA genes, Barrnap predicted 1 copy of a 16S-23S-5S rRNA operon, and Prodigal 16 identified 4,514 protein coding DNA sequences (CDS), of which 400 contained signal peptides identified using SignalP 17. Of the 4,514 proteins, 1,207 were hypothetical proteins of unknown function, 2,491 were annotated by UniProtKB 18, 621 by Pfam 19, 255 by NCBI's CDD (Conserved Domain Database) 20, and 21 by HAMAP 21.
The genome contained four multicopper oxidase genes. Among these, one was closely related to ioxA, which was previously found to be involved in iodide oxidation in Iodidimonas sp. Q-1 4. A key gene encoding phosphofructokinase (pfk) for glycolysis was not detected, but a complete set of genes for the TCA cycle and pentose phosphate pathway were predicted. The inability to grow on glucose has been observed commonly in Roseovarius spp., and this was probably due to lack of pfk 22, 23. Genes involved in starch, sucrose, and galactose metabolism were also absent. The genome contained nitrate reductase (nar), but not nitrite reductase (nir) or nitrogenase (nif) genes. The genome did not contain the photosynthetic gene cluster (puf, bch, and crt genes), which has been found in Iodidimonas sp. Q-1 24 and other Roseovarius spp. 11, 12. There were no autotrophic CO2 fixation pathway genes such as rbc genes. The genome contained at least 39 genes coding for cytochrome c. Nearly complete sets of genes for the flagellar system (flg, fli, and mot), type II secretion system (gsp), type IV secretion system (virB), general secretion system (sec), and twin-arginine translocation pathway (tat) were identified. A wide variety of ABC transporters, including those involved in sulfate, tungstate, molybdate, zinc, iron(III), phosphate, phosphonate, taurine, spermidine, putrescine, glycine betaine, sorbitol/mannitol, glycerol, sn-glycerol 3-phosphate, and urea transport were identified. Various proteins involved in aerobic metabolism, such as NADH dehydrogenase (nuo), succinate dehydrogenases (sdh and frd), cytochrome-c oxidase (cbb3-type and quinol oxidase), catalase-peroxidase (katG), and superoxide dismutase (sodB) were identified. These results suggest that Roseovarius sp. A-2 is an aerobic heterotrophic iodide (I-)-oxidizing bacterium, and that it is well adapted to brine water environments.
Nucleotide sequence accession numbers
This whole genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number BDIY00000000. The version described in this paper is the first version, BDIY01000000, which consists of sequences BDIY01000001 to BDIY01000126.
Table 1.
Genome features of Roseovarius sp. A-2.
| Genome size | 4.58 Mb |
|---|---|
| GC content | 62.8% |
| Number of contigs | 126 |
| Total contig size | 4,584,578 bp |
| Largest contig | 670,842 bp |
| N50 | 160,967 |
| L50 | 8 |
| Protein encoding genes | 4,514 |
| tRNAs | 46 |
| rRNA | 1 |
Acknowledgments
This work was supported financially by Directorate-General of Higher Education, the Ministry of Research, Technology and Higher Education, Indonesia awarded to Tri Yuliana. This work was supported in part by research funding from Yamagata Prefecture and Tsuruoka City.
References
- 1.Amachi S, Muramatsu Y, Akiyama Y, Miyazaki K, Yoshiki S, Hanada S, Kamagata Y, Ban-nai T, Shinoyama H, Fujii T. Isolation of iodide-oxidizing bacteria from iodide-rich natural gas brines and seawaters. Microbial Ecol. 2005;49:547–557. doi: 10.1007/s00248-004-0056-0. [DOI] [PubMed] [Google Scholar]
- 2.Iino T, Ohkuma M, Kamagata Y, Amachi S. Iodidimonas muriae gen. nov, sp. nov, an aerobic iodide-oxidizing bacterium isolated from brine of a natural gas and iodine recovery facility, and proposals of Iodidimonadaceae fam. nov, Iodidimonadales ord. nov, Emcibacteraceae fam. nov. and Emcibacterales ord. nov, Int J Syst Evol Microbiol. 2016;66:5016–5022. doi: 10.1099/ijsem.0.001462. [DOI] [PubMed] [Google Scholar]
- 3.Shiroyama K, Kawasaki Y, Unno Y, Amachi S. A putative multicopper oxidase, IoxA, is involved in iodide oxidation by Roseovarious sp. strain A-2. Biosci Biotechnol Biochem. 2015;79:1898–1905. doi: 10.1080/09168451.2015.1052767. [DOI] [PubMed] [Google Scholar]
- 4.Suzuki M, Eda Y, Ohsawa S, Kanesaki Y, Yoshikawa H, Tanaka K, Muramatsu Y, Yoshikawa J, Sato I, Fujii T, Amachi S. Iodide oxidation by a novel multicopper oxidase from the Alphaproteobacterium strain Q-1. Appl Environ Microbiol. 2012;78:3941–3949. doi: 10.1128/AEM.00084-12. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Yuliana T, Ebihara K, Suzuki M, Shimonaka C, Amachi S. A novel enzyme-based antimicrobial system comprising iodide and a multicopper oxidase isolated from Alphaproteobacterium strain Q-1. Appl Microbiol Biotechnol. 2015;99:10011–10018. doi: 10.1007/s00253-015-6862-0. [DOI] [PubMed] [Google Scholar]
- 6.FastQC: A quality control tool for high throughput sequence data. http://www.bioinformatics.babraham.ac.uk/projects/fastqc/
- 7.Huntemann M, Ivanova N, Kyrpides NC, Pati A. Large-scale contamination of microbial isolate genomes by Illumina PhiX control. Stand Genomic Sci. 2015;10:18. doi: 10.1186/1944-3277-10-18. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.BBMap short read aligner, and other bioinformatics tools. https://sourceforge.net/projects/bbmap/
- 9.Bolger AM, Lohse M, Usadel B. Trimmomatic: a flexible trimmer for Illumina sequence data. Bioinformatics. 2014;30:2114–2120. doi: 10.1093/bioinformatics/btu170. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Bankevich A, Nurk S, Antipov D, Gurevich AA, Dvorkin M, Kulikov AS, Lesin VM, Nikolenko SI, Pham S, Prjibelski AD, Pyshkin AV, Sirotkin AV, Vyahhi N, Tesler G, Alekseyev MA, Pevzner PA. SPAdes: a new genome assembly algorithm and its applications to single-cell sequencing. J Comput Biol. 2012;19:455–477. doi: 10.1089/cmb.2012.0021. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Voget S, Bruns H, Wagner-Döbler I, Schulz S, Daniel R. Draft genome sequence of Roseovarius tolerans EL-164, a producer of N-acylated alanine methyl esters and N-acylhomoserine lactones. Genome Announcements. 2015;3:e01096–15. doi: 10.1128/genomeA.01096-15. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Riedel T, Spring S, Fiebig A, Scheuner C, Petersen J, Göker M, Klenk H-P. Genome sequence of the Roseovarius mucosus type strain (DSM 17069T), a bacteriochlorophyll a-containing representative of the marine Roseobacter group isolated from the dinoflagellate Alexiandrium ostenfeldii. Stand Genomic Sci. 2015;10:17. doi: 10.1186/1944-3277-10-17. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Rosana ARR, Orata FD, Xu Y, Simkus DN, Bramucci AR, Boucher Y, Case RJ. Draft genome sequences of seven strains isolated from a polymicrobial culture of coccolith-bearing (C-type) Emiliania huxleyi M217. Genome Announcements. 2016;4:e00673–16. doi: 10.1128/genomeA.00673-16. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Seemann T. Prokka: rapid prokaryotic genome annotation. Bioinformatics. 2014;30:2068–2069. doi: 10.1093/bioinformatics/btu153. [DOI] [PubMed] [Google Scholar]
- 15.Laslett D, Canback B. ARAGORN, a program to detect tRNA genes and tmRNA genes in nucleotide sequences. Nucleic Acids Res. 2004;32:11–16. doi: 10.1093/nar/gkh152. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Hyatt D, Chen G-L, Locascio PF, Land ML, Larimer FW, Hauser LJ. Prodigal: prokaryotic gene recognition and translation initiation site identification. BMC Bioinformatics. 2010;11:119. doi: 10.1186/1471-2105-11-119. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Petersen TN, Brunak S, von Heijne G, Nielsen H. SignalP 4.0: discriminating signal peptides from transmembrane regions. Nat Methods. 2011;8:785–786. doi: 10.1038/nmeth.1701. [DOI] [PubMed] [Google Scholar]
- 18.UniProt Consortium. Activities at the universal protein resource (UniProt) Nucleic Acids Res. 2014;42:D191–D198. doi: 10.1093/nar/gkt1140. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Finn RD, Coggill P, Eberhardt RY, Eddy SR, Mistry J, Mitchell AL, Potter SC, Punta M, Qureshi M, Sangrador-Vegas A, Salazar GA, Tate J, Bateman A. The Pfam protein families database: towards a more sustainable future. Nucleic Acids Res. 2016;44:D279–D285. doi: 10.1093/nar/gkv1344. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Marchler-Bauer A, Derbyshire MK, Gonzales NR, Lu S, Chitsaz F, Geer LY, Geer RC, He J, Gwadz M, Hurwitz DI, Lanczycki CJ, Lu F, Marchler GH, Song JS, Thanki N, Wang Z, Yamashita RA, Zhang D, Zheng C, Bryant SH. CDD: NCBI's conserved domain database. Nucleic Acids Res. 2015;43:D222–D226. doi: 10.1093/nar/gku1221. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Lima T, Auchincloss AH, Coudert E, Keller G, Michoud K, Rivoire C, Bulliard V, de Castro E, Lachaize C, Baratin D, Phan I, Bougueleret L, Bairoch A. Hamap: a database of completely sequenced microbial proteome sets and manually curated microbial protein families in UniProtKB/Swiss-Prot. Nucleic Acids Res. 2009;37:D471–D478. doi: 10.1093/nar/gkn661. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Labrenz M, Collins MD, Lawson PA, Tindall BJ, Schumann P, Hirsch P. Roseovarius tolerans gen. nov, sp. nov, a budding bacterium with variable bacteriochlorophyll a production from hypersaline Ekho Lake. Int J System Bacteriol. 1999;49:137–147. doi: 10.1099/00207713-49-1-137. [DOI] [PubMed] [Google Scholar]
- 23.Biebl H, Allgaier M, Lünsdorf H, Pukall R, Tindall BJ, Wagner-Döbler I. Roseovarius mucosus sp. nov, a member of the Roseobacter clade with trace amounts of bacteriochlorophyll a. Int J System Evol Microbiol. 2005;55:2377–2383. doi: 10.1099/ijs.0.63832-0. [DOI] [PubMed] [Google Scholar]
- 24.Ehara A, Suzuki H, Kanesaki Y, Yoshikawa H, Amachi H. Draft genome sequence of strain Q-1, an iodide-oxidizing Alphaproteobacterium isolated from natural gas brine water. Genome Announcements. 2014;2:e00659–14. doi: 10.1128/genomeA.00659-14. [DOI] [PMC free article] [PubMed] [Google Scholar]
