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García-Roldán A, de la Haba RR, Sánchez-Porro C, Ventosa A. 'Altruistic' cooperation among the prokaryotic community of Atlantic salterns assessed by metagenomics. Microbiol Res 2024; 288:127869. [PMID: 39154602 DOI: 10.1016/j.micres.2024.127869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 07/25/2024] [Accepted: 08/05/2024] [Indexed: 08/20/2024]
Abstract
Hypersaline environments are extreme habitats with a limited prokaryotic diversity, mainly restricted to halophilic or halotolerant archaeal and bacterial taxa adapted to highly saline conditions. This study attempts to analyze the taxonomic and functional diversity of the prokaryotes that inhabit a solar saltern located at the Atlantic Coast, in Isla Cristina (Huelva, Southwest Spain), and the influence of salinity on the diversity and metabolic potential of these prokaryotic communities, as well as the interactions and cooperation among the individuals within that community. Brine samples were obtained from different saltern ponds, with a salinity range between 19.5 % and 39 % (w/v). Total prokaryotic DNA was sequenced using the Illumina shotgun metagenomic strategy and the raw sequence data were analyzed using supercomputing services following the MetaWRAP and SqueezeMeta protocols. The most abundant phyla at moderate salinities (19.5-22 % [w/v]) were Methanobacteriota (formerly "Euryarchaeota"), Pseudomonadota and Bacteroidota, followed by Balneolota and Actinomycetota and Uroviricota in smaller proportions, while at high salinities (36-39 % [w/v]) the most abundant phylum was Methanobacteriota, followed by Bacteroidota. The most abundant genera at intermediate salinities were Halorubrum and the bacterial genus Spiribacter, while the haloarchaeal genera Halorubrum, Halonotius, and Haloquadratum were the main representatives at high salinities. A total of 65 MAGs were reconstructed from the metagenomic datasets and different functions and pathways were identified in them, allowing to find key taxa in the prokaryotic community able to synthesize and supply essential compounds, such as biotin, and precursors of other bioactive molecules, like β-carotene, and bacterioruberin, to other dwellers in this habitat, lacking the required enzymatic machinery to produce them. This work shed light on the ecology of aquatic hypersaline environments, such as the Atlantic Coast salterns, and on the dynamics and factors affecting the microbial populations under such extreme conditions.
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Affiliation(s)
- Alicia García-Roldán
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla 41012, Spain
| | - Rafael R de la Haba
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla 41012, Spain
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla 41012, Spain
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla 41012, Spain.
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Galisteo C, de la Haba RR, Ventosa A, Sánchez-Porro C. The Hypersaline Soils of the Odiel Saltmarshes Natural Area as a Source for Uncovering a New Taxon: Pseudidiomarina terrestris sp. nov. Microorganisms 2024; 12:375. [PMID: 38399779 PMCID: PMC10893183 DOI: 10.3390/microorganisms12020375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
The hypersaline soils of the Odiel Saltmarshes Natural Area are an extreme environment with high levels of some heavy metals; however, it is a relevant source of prokaryotic diversity that we aim to explore. In this study, six strains related to the halophilic genus Pseudidiomarina were isolated from this habitat. The phylogenetic study based on the 16S rRNA gene sequence and the fingerprinting analysis suggested that they constituted a single new species within the genus Pseudidiomarina. Comparative genomic analysis based on the OGRIs indices and the phylogeny inferred from the core genome were performed considering all the members of the family Idiomarinaceae. Additionally, a completed phenotypic characterization, as well as the fatty acid profile, were also carried out. Due to the characteristics of the habitat, genomic functions related to salinity and high heavy metal concentrations were studied, along with the global metabolism of the six isolates. Last, the ecological distribution of the isolates was studied in different hypersaline environments by genome recruitment. To sum up, the six strains constitute a new species within the genus Pseudidiomarina, for which the name Pseudidiomarina terrestris sp. nov. is proposed. The low abundance in all the studied hypersaline habitats indicates that it belongs to the rare biosphere in these habitats. In silico genome functional analysis suggests the presence of heavy metal transporters and pathways for nitrate reduction and nitrogen assimilation in low availability, among other metabolic traits.
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Affiliation(s)
| | | | | | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain; (C.G.); (R.R.d.l.H.); (A.V.)
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Zhang TT, Liu D, Zhang XY, Wang JC, Du ZJ. Spiribacter salilacus sp. nov., a novel moderately halophilic bacterium isolated from a saline lake in China. Arch Microbiol 2023; 205:166. [PMID: 37014519 DOI: 10.1007/s00203-023-03511-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/19/2023] [Accepted: 03/22/2023] [Indexed: 04/05/2023]
Abstract
A Gram-staining-negative, non-motile, rod-shaped or curved rod-shaped, moderately halophilic bacterium, designated C176T, was isolated from Yuncheng Salt Lake in Shanxi Province, P.R. China. The optimal temperature, salinity and pH for growth of strain C176T was 37 °C, 6% (w/v) NaCl and 7.5. Phylogenetic analysis using 16S rRNA gene sequences indicated strain C176T has the highest similarity with Spiribacter salinus LMG 27464 T (97.7%), following by the S. halobius E85T (97.6%), S. curvatus DSM 28542 T (97.2%), S. roseus CECT 9117 T (97.0%) and S. vilamensis DSM 21056 T (96.9%). The ANI and dDDH values between strain C176T and S. salinus LMG 27464 T were 69.8 and 17.7%, respectively. The DNA G + C content of genome for strain C176T was 54.1%. Summed feature 8 (C18:1 ω7c and/or C18:1 ω6c) and C16:0 were detected as its major fatty acids, with content of 38.7 and 28.6% respectively, while Q-8 was the predominant ubiquinone. The major polar lipids of strain C176T contained phospholipid, phosphatidylglycerol and phosphoglycolipid. In accordance with results of polyphasic taxonomy, strain C176T is considered as a novel species of the genus Spiribacter, for which the name Spiribacter salilacus sp. nov. is proposed. The type strain is C176T (= MCCC 1H00417T = KCTC 72692 T).
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Affiliation(s)
- Tong-Tong Zhang
- SDU-ANU Joint Science College, Shandong University, Weihai, 264209, Shandong, China
| | - Dun Liu
- SDU-ANU Joint Science College, Shandong University, Weihai, 264209, Shandong, China
| | - Xiao-Yu Zhang
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, Guangdong, China
| | - Jia-Cheng Wang
- University of Chinese Academy of Sciences, Beijing, 10049, China
| | - Zong-Jun Du
- Marine College, Shandong University, Weihai, 264209, Shandong, China.
- Weihai Research Institute of Industrial Technology, Shandong University, Weihai, 264209, Shandong, China.
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Galisteo C, de la Haba RR, Sánchez-Porro C, Ventosa A. Biotin pathway in novel Fodinibius salsisoli sp. nov., isolated from hypersaline soils and reclassification of the genus Aliifodinibius as Fodinibius. Front Microbiol 2023; 13:1101464. [PMID: 36777031 PMCID: PMC9909488 DOI: 10.3389/fmicb.2022.1101464] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/22/2022] [Indexed: 01/27/2023] Open
Abstract
Hypersaline soils are extreme environments that have received little attention until the last few years. Their halophilic prokaryotic population seems to be more diverse than those of well-known aquatic systems. Among those inhabitants, representatives of the family Balneolaceae (phylum Balneolota) have been described to be abundant, but very few members have been isolated and characterized to date. This family comprises the genera Aliifodinibius and Fodinibius along with four others. A novel strain, designated 1BSP15-2V2T, has been isolated from hypersaline soils located in the Odiel Saltmarshes Natural Area (Southwest Spain), which appears to represent a new species related to the genus Aliifodinibius. However, comparative genomic analyses of members of the family Balneolaceae have revealed that the genera Aliifodinibius and Fodinibius belong to a single genus, hence we propose the reclassification of the species of the genus Aliifodinibius into the genus Fodinibius, which was first described. The novel strain is thus described as Fodinibius salsisoli sp. nov., with 1BSP15-2V2T (=CCM 9117T = CECT 30246T) as the designated type strain. This species and other closely related ones show abundant genomic recruitment within 80-90% identity range when searched against several hypersaline soil metagenomic databases investigated. This might suggest that there are still uncultured, yet abundant closely related representatives to this family present in these environments. In-depth in-silico analysis of the metabolism of Fodinibius showed that the biotin biosynthesis pathway was present in the genomes of strain 1BSP15-2V2T and other species of the family Balneolaceae, which could entail major implications in their community role providing this vitamin to other organisms that depend on an exogenous source of this nutrient.
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León MJ, Galisteo C, Ventosa A, Sánchez-Porro C. Spiribacter aquaticus Leon et al. 2017 is a later heterotypic synonym of Spiribacter roseus Leon et al. 2016. Reclassification of Halopeptonella vilamensis Menes et al. 2016 as Spiribacter vilamensis comb. nov. Int J Syst Evol Microbiol 2020; 70:2873-2878. [DOI: 10.1099/ijsem.0.004113] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A comparative taxonomic study of
Spiribacter
and
Halopeptonella
species was carried out using a phylogenomic approach based on comparison of the core genome, orthologous average nucleotide identity (OrthoANIu), Genome-to-Genome Distance Calculator (GGDC) and average amino acid identity (AAI). Phylogenomic analysis based on 976 core translated gene sequences obtained from their genomes showed that
Spiribacter aquaticus
SP30T,
S. curvatus
UAH-SP71T,
S. roseus
SSL50T,
S. salinus
M19-40T and
Halopeptonella vilamensis
DSM 21056T formed a robust cluster, clearly separated from the remaining species of closely related taxa. AAI between
H. vilamensis
DSM 21056T and the species of the genus
Spiribacter
was ≥73.1 %, confirming that all these species belong to the same single genus. On the other hand,
S. roseus
SSL50T and
S. aquaticus
SP30T showed percentages of OrthoANIu and digital DNA–DNA hybridization of 98.4 % and 85.3 %, respectively, while these values among those strains and the type strains of the other species of
Spiribacter
and
H. vilamensis
DSM 21056T were ≤80.8 and 67.8 %, respectively. Overall, these data show that
S. roseus
SSL50T and
S. aquaticus
SP30T constitute a single species and thus that
S. aquaticus
SP30T should be considered as a later, heterotypic synonym of
S. roseus
SSL50T based on the rules for priority of names. We propose an emended description of
S. roseus
, including the features of
S. aquaticus
. We also propose the reclassification of
H. vilamensis
as Spiribacter vilamensis comb. nov.
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Affiliation(s)
- María José León
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Cristina Galisteo
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
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Haloglomus irregulare gen. nov., sp. nov., a New Halophilic Archaeon Isolated from a Marine Saltern. Microorganisms 2020; 8:microorganisms8020206. [PMID: 32024278 PMCID: PMC7074781 DOI: 10.3390/microorganisms8020206] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 11/17/2022] Open
Abstract
A halophilic archaeal strain, designated F16-60T, was isolated from Isla Cristina marine saltern in Huelva, Spain. Cells were pleomorphic, irregular, non-motile, and Gram-stain-negative. It produced red-pigmented colonies on agar plates. Strain F16-60T was extremely halophilic (optimum at 30% (w/v) NaCl) and neutrophilic (optimum pH 7.5). Phylogenetic tree reconstructions based on 16S rRNA and rpoB´ gene sequences revealed that strain F16-60T was distinct from species of the related genera Natronomonas, Halomarina, and Halomicrobium, of the order Halobacteriales. The polar lipids are phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS), and one glycolipid chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1). The DNA G+C content is 68.0 mol%. The taxonomic study, based on a combination of phylogenetic, genomic, chemotaxonomic, and phenotypic analyses, suggest that strain F16-60T (= CECT 9635T = JCM 33318T), represents a novel species of a new genus within the family Haloarculaceae and the order Halobacteriales, for which the name Haloglomus irregulare gen. nov., sp. nov. is proposed. Metagenomic fragment recruitment analysis revealed the worldwide distribution of members of this genus and suggested the existence of other closely related species to be isolated.
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Selivanova EA, Poshvina DV, Khlopko YA, Gogoleva NE, Plotnikov AO. Diversity of Prokaryotes in Planktonic Communities of Saline Sol-Iletsk lakes (Orenburg Oblast, Russia). Microbiology (Reading) 2018. [DOI: 10.1134/s0026261718040161] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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León MJ, Hoffmann T, Sánchez-Porro C, Heider J, Ventosa A, Bremer E. Compatible Solute Synthesis and Import by the Moderate Halophile Spiribacter salinus: Physiology and Genomics. Front Microbiol 2018; 9:108. [PMID: 29497403 PMCID: PMC5818414 DOI: 10.3389/fmicb.2018.00108] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/17/2018] [Indexed: 11/13/2022] Open
Abstract
Members of the genus Spiribacter are found worldwide and are abundant in ecosystems possessing intermediate salinities between seawater and saturated salt concentrations. Spiribacter salinus M19-40 is the type species of this genus and its first cultivated representative. In the habitats of S. salinus M19-40, high salinity is a key determinant for growth and we therefore focused on the cellular adjustment strategy to this persistent environmental challenge. We coupled these experimental studies to the in silico mining of the genome sequence of this moderate halophile with respect to systems allowing this bacterium to control its potassium and sodium pools, and its ability to import and synthesize compatible solutes. S. salinus M19-40 produces enhanced levels of the compatible solute ectoine, both under optimal and growth-challenging salt concentrations, but the genes encoding the corresponding biosynthetic enzymes are not organized in a canonical ectABC operon. Instead, they are scrambled (ectAC; ectB) and are physically separated from each other on the S. salinus M19-40 genome. Genomes of many phylogenetically related bacteria also exhibit a non-canonical organization of the ect genes. S. salinus M19-40 also synthesizes trehalose, but this compatible solute seems to make only a minor contribution to the cytoplasmic solute pool under osmotic stress conditions. However, its cellular levels increase substantially in stationary phase cells grown under optimal salt concentrations. In silico genome mining revealed that S. salinus M19-40 possesses different types of uptake systems for compatible solutes. Among the set of compatible solutes tested in an osmostress protection growth assay, glycine betaine and arsenobetaine were the most effective. Transport studies with radiolabeled glycine betaine showed that S. salinus M19-40 increases the pool size of this osmolyte in a fashion that is sensitively tied to the prevalent salinity of the growth medium. It was amassed in salt-stressed cells in unmodified form and suppressed the synthesis of ectoine. In conclusion, the data presented here allow us to derive a genome-scale picture of the cellular adjustment strategy of a species that represents an environmentally abundant group of ecophysiologically important halophilic microorganisms.
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Affiliation(s)
- María J León
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Tamara Hoffmann
- Laboratory for Microbiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Johann Heider
- Laboratory for Microbiology, Department of Biology, Philipps University of Marburg, Marburg, Germany.,LOEWE-Center for Synthetic Microbiology, Philipps University of Marburg, Marburg, Germany
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Erhard Bremer
- Laboratory for Microbiology, Department of Biology, Philipps University of Marburg, Marburg, Germany.,LOEWE-Center for Synthetic Microbiology, Philipps University of Marburg, Marburg, Germany
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León MJ, Aldeguer-Riquelme B, Antón J, Sánchez-Porro C, Ventosa A. Spiribacter aquaticus sp. nov., a novel member of the genus Spiribacter isolated from a saltern. Int J Syst Evol Microbiol 2017; 67:2947-2952. [PMID: 28820120 DOI: 10.1099/ijsem.0.002053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A moderately halophilic bacterium, designated strain SP30T, was isolated from a solar saltern located in Santa Pola, Alicante, on the East coast of Spain. It was a Gram-stain-negative, strictly aerobic bacterium, able to grow in 7.5-25 % (w/v) NaCl and optimally in 12.5 % (w/v) NaCl. Phylogenetic analyses, based on 16S rRNA gene sequences, showed that the novel isolate is a member of the genus Spiribacter, with the most closely related species being Spiribacter roseus SSL50T (99.9 % sequence similarity) and Spiribacter curvatus UAH-SP71T (99.4 % sequence similarity). The 16S rRNA gene sequence similarity with the type species Spiribacter salinus M19-40T was 96.6 %. The DNA-DNA relatedness value between strain SP30T and S. roseus SSL50T and S. curvatus UAH-SP71T was 40 and 55 %, respectively; these values are lower than the 70 % threshold accepted for species delineation. The major fatty acids were C16:0, C18 : 1ω7c, C19 : 0 cyclo ω8c and C12 : 0. Similarly to other species of the genus Spiribacter, strain SP30Twas observed as curved rods and spiral cells. Metabolic versatility was reduced to the utilization of a few organic compounds as the sole carbon and energy sources, as with other members of Spiribacter. However, it differed in terms of colony pigmentation (brownish-yellow instead of pink) and in having a higher growth rate. Based on these data and on the phenotypic, genotypic and chemotaxonomic characterization, we propose the classification of strain SP30T as a novel species within the genus Spiribacter, with the name Spiribacter aquaticus sp. nov. The type strain is SP30T (=CECT 9238T=LMG 30005T).
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Affiliation(s)
- María José León
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Borja Aldeguer-Riquelme
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Josefa Antón
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
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León MJ, Sánchez-Porro C, Ventosa A. Marinobacter aquaticus sp. nov., a moderately halophilic bacterium from a solar saltern. Int J Syst Evol Microbiol 2017; 67:2622-2627. [DOI: 10.1099/ijsem.0.001984] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- María José León
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
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López-Hermoso C, de la Haba RR, Sánchez-Porro C, Papke RT, Ventosa A. Assessment of MultiLocus Sequence Analysis As a Valuable Tool for the Classification of the Genus Salinivibrio. Front Microbiol 2017; 8:1107. [PMID: 28690592 PMCID: PMC5479898 DOI: 10.3389/fmicb.2017.01107] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/31/2017] [Indexed: 01/15/2023] Open
Abstract
The genus Salinivibrio includes obligatory halophilic bacteria and is commonly isolated from hypersaline habitats and salted food products. They grow optimally between 7.5 and 10% salts and are facultative anaerobes. Currently, this genus comprises four species, one of them, S. costicola, with three subspecies. In this study we isolated and characterized an additional 70 strains from solar salterns located in different locations. Comparative 16S rRNA gene sequence analysis identified these strains as belonging to the genus Salinivibrio but could not differentiate strains into species-like groups. To achieve finer phylogenetic resolution, we carried out a MultiLocus Sequence Analysis (MLSA) of the new isolates and the type strains of the species of Salinivibrio based on the individual as well as concatenated sequences of four housekeeping genes: gyrB, recA, rpoA, and rpoD. The strains formed four clearly differentiated species-like clusters called phylogroups. All of the known type and subspecies strains were associated with one of these clusters except S. sharmensis. One phylogroup had no previously described species coupled to it. Further DNA–DNA hybridization (DDH) experiments with selected representative strains from these phylogroups permitted us to validate the MLSA study, correlating the species level defined by the DDH (70%) with a 97% cut-off for the concatenated MLSA gene sequences. Based on these criteria, the novel strains forming phylogroup 1 could constitute a new species while strains constructing the other three phylogroups are members of previously recognized Salinivibrio species. S. costicola subsp. vallismortis co-occurs with S. proteolyticus in phylogroup 4, and separately from other S. costicola strains, indicating its need for reclassification. On the other hand, genome fingerprinting analysis showed that the environmental strains do not form clonal populations and did not cluster according to their site of cultivation. In future studies regarding the classification and identification of new Salinivibrio strains we recommend the following strategy: (i) initial partial sequencing of the 16S rRNA gene for genus-level identification; (ii) sequencing and concatenation of the four before mentioned housekeeping genes for species-level discrimination; (iii) DDH experiments, only required when the concatenated MLSA similarity values among a new isolate and other Salinivibrio strains are above the 97% cut-off.
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Affiliation(s)
- Clara López-Hermoso
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of SevillaSevilla, Spain
| | - Rafael R de la Haba
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of SevillaSevilla, Spain
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of SevillaSevilla, Spain
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, StorrsCT, United States
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of SevillaSevilla, Spain
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