Dataset Information

Comparative Genomics and Phylogenomic Analysis of the Genus Salinivibrio.

ABSTRACT: In the genomic era phylogenetic relationship among prokaryotes can be inferred from the core orthologous genes (OGs) or proteins in order to elucidate their evolutionary history and current taxonomy should benefits of that. The genus Salinivibrio belongs to the family Vibrionaceae and currently includes only five halophilic species, in spite the fact that new strains are very frequently isolated from hypersaline environments. Species belonging to this genus have undergone several reclassifications and, moreover, there are many strains of Salinivibrio with available genomes which have not been affiliated to the existing species or have been wrongly designated. Therefore, a phylogenetic study using the available genomic information is necessary to clarify the relationships of existing strains within this genus and to review their taxonomic affiliation. For that purpose, we have also sequenced the first complete genome of a Salinivibrio species, Salinivibrio kushneri AL184T, which was employed as a reference to order the contigs of the draft genomes of the type strains of the current species of this genus, as well as to perform a comparative analysis with all the other available Salinivibrio sp. genomes. The genome of S. kushneri AL184T was assembled in two circular chromosomes (with sizes of 2.84 Mb and 0.60 Mb, respectively), as typically occurs in members of the family Vibrionaceae, with nine complete ribosomal operons, which might explain the fast growing rate of salinivibrios cultured under laboratory conditions. Synteny analysis among the type strains of the genus revealed a high level of genomic conservation in both chromosomes, which allow us to hypothesize a slow speciation process or homogenization events taking place in this group of microorganisms to be tested experimentally in the future. Phylogenomic and orthologous average nucleotide identity (OrthoANI)/average amino acid identity (AAI) analyses also evidenced the elevated level of genetic relatedness within members of this genus and allowed to group all the Salinivibrio strains with available genomes in seven separated species. Genome-scale attribute study of the salinivibrios identified traits related to polar flagellum, facultatively anaerobic growth and osmotic response, in accordance to the phenotypic features described for species of this genus.

SUBMITTER: de la Haba RR

PROVIDER: S-EPMC6749099 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Comparative Genomics and Phylogenomic Analysis of the Genus Salinivibrio.

de la Haba Rafael R RR López-Hermoso Clara C Sánchez-Porro Cristina C Konstantinidis Konstantinos T KT Ventosa Antonio A

Frontiers in microbiology 20190911

In the genomic era phylogenetic relationship among prokaryotes can be inferred from the core orthologous genes (OGs) or proteins in order to elucidate their evolutionary history and current taxonomy should benefits of that. The genus Salinivibrio belongs to the family Vibrionaceae and currently includes only five halophilic species, in spite the fact that new strains are very frequently isolated from hypersaline environments. Species belonging to this genus have undergone several r ...[more]

PMID: 31572321

Similar Datasets

Project description:Riboswitches are cis-regulatory elements that regulate the expression of genes involved in biosynthesis or transport of a ligand that binds to them. Among the nearly 40 classes of riboswitches discovered so far, three are known to regulate the concentration of biologically encoded amino acids glycine, lysine, and glutamine. While some comparative genomics studies of riboswitches focusing on their gross distribution across different bacterial taxa have been carried out recently, systematic functional annotation and analysis of lysine riboswitches and the genes they regulate are still lacking. We analyzed 2785 complete bacterial genome sequences to systematically identify 468 lysine riboswitches (not counting hits from multiple strains of the same species) and obtain a detailed phylogenomic map of gene-specific lysine riboswitch distribution across diverse prokaryotic phyla. We find that lysine riboswitches are most abundant in Firmicutes and Gammaproteobacteria where they are found upstream to both biosynthesis and/or transporter genes. They are relatively rare in all other prokaryotic phyla where if present they are primarily found upstream to operons containing many lysine biosynthesis genes. The genome-wide study of the genetic organisation of the lysine riboswitches show considerable variation both within and across different Firmicute orders. Correlating the location of a riboswitch with its genomic context and its phylogenetic relationship with other evolutionarily related riboswitch carrying species, enables identification and annotation of many lysine biosynthesis, transporter and catabolic genes. It also reveals previously unknown patterns of lysine riboswitch distribution and gene/operon regulation and allows us to draw inferences about the possible point of origin of lysine riboswitches. Additionally, evidence of horizontal transfer of riboswitches was found between Firmicutes and Actinobacteria. Our analysis provides a useful resource that will lead to a better understanding of the evolution of these regulatory elements and prove to be beneficial for exploiting riboswitches for developing targeted therapies.

Project description: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.

Dataset Information

Comparative Genomics and Phylogenomic Analysis of the Genus Salinivibrio.

Publications

Comparative Genomics and Phylogenomic Analysis of the Genus <i>Salinivibrio</i>.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets