Draft genome sequence and comparative genomic analysis of Halomonas salifodinae strain A2 isolated from the Zapotitlán Salinas Valley, Puebla, Mexico.

Abstract

In this study, we report the draft genome sequence of strain A2. The genome size was 3.8 Mbp, the GC content was 67.4%, and it was predicted to contain 3520 protein-coding genes, 62 tRNA genes, 8 rRNA genes, and 4 snRNA genes. Phylogenetic analysis of the 16S rRNA gene in different databases suggests that strain A2 belongs to Halomonas salifodinae. Also, Multilocus Sequence Typing analysis confirms that A2 is closely related to H. salifodinae. Phylogenomic of the core genes and comparative genomic analysis using the Average Nucleotide Identity, digital DNA-DNA Hybridization, Average Amino acid Identity, the Percentage of Conserved Proteins values indicators, and the Genome Taxonomy Database indicates that strain A2 is identified as H. salifodinae and suggest that this species has a closer phylogenetic relationship with the genus Bisbaumannia than with Halomonas. The pangenomic analysis of A2 against 100 reference genomes of described Halomonas and another related genus shows 136,122 genes that comprise the pangenome with 317 core genes, 3457 shell genes, 132,332 accessory genome genes, and 691 unique genes. A2 has 261 signature genes that it shares only with Bisbaumannia and Halomonas salifodinae. For strain A2 we found 29 genes for secretion systems, 23 genes for Na⁺ and K⁺ ion transport, 6 Biosynthetic Gene Clusters groups, a total of 12 genomic islands, an 8.2 kb gene prophage region, 15 regions associated with CRISPR and one CAS-TypeIF cas gene cluster region, 12 genes of biotechnological importance, 38 unique genes essential for adaptability and biotechnological relevance, as well as, 35 genes for the synthesis of compatible solutes. Comparative genomics analysis shows that strain A2 has multiple unique genetic features that could be useful for biotechnological applications. The result of this study places the species Halomonas salifodinae in a very close relationship with the genus Bisbaumannia than with Halomonas, so its reclassification to the genus Bisbaumannia is proposed for future validation.