Extremeophiles and Extreme Environments

Genome Sequence And Methylome Of The Extremely Halophilic Bacterium Salinibacter Ruber Strain M31T Isolated From A Crystallizer Pond In Mallorca, Spain

By Keith Cowing

Status Report

Environmental Microbiology

November 30, 2025

Filed under Archaea, Balearic Islands, Environmental Microbiology, extremophile, genomics, halophilic, microbiology, Proteome, Salinibacter ruber

Genome Sequence And Methylome Of The Extremely Halophilic Bacterium Salinibacter Ruber Strain M31T Isolated From A Crystallizer Pond In Mallorca, Spain — Maximum likelihood phylogenetic trees of the S. ruber M31T-predicted proteins with an archaeal evolutionary history potentially acquired by horizontal gene transfer: (A) sodium-dependent transporter (XGX02982.1); (B) MFS transporter (XGX01653.1); and (C) ABC transporter ATP-binding protein (XGX02353.1). The organism names are followed by the PID of the sequence from NCBI. The S. ruber M31T sequences group with the archaeal sequences (orange) instead of bacterial (blue) or eukaryotic (green) ones. — Environmental Microbiology

Salinibacter ruber strain M31T, an extremely halophilic bacterium, was isolated from a saltern crystallizer pond in Spain. Single-molecule real-time sequencing revealed a 3.6-Mbp genome with a single 3.55-Mbp circular chromosome and a 35.5-kbp plasmid. The highly acidic proteome includes a total of 2,962 proteins, some of which are archaeal-like.

Besides an elevated intracellular concentration of KCl for osmotic balance, it also possesses rhodopsins for phototrophic energy production and displays a high degree of genome plasticity (4).

The gram-negative Salinibacter ruber strain M31T was isolated from a saltern crystallizer pond in Mallorca, Balearic Islands, Spain (GPS: 39.3499° N, 3.0110° E) on September 1999 and was a gift from the American Type Culture Collection (1). Salinibacter ruber M31T cultures were grown in ATCC 2402 medium (5). High-molecular weight genomic DNA was prepared by lysis and extraction with phenol:chloroform, followed by ethanol precipitation as described earlier (6).

Genome sequence and methylome of the extremely halophilic bacterium Salinibacter ruber strain M31T isolated from a crystallizer pond in Mallorca, Spain Environmental Microbiology via PubMed
Genome sequence and methylome of the extremely halophilic bacterium Salinibacter ruber strain M31T isolated from a crystallizer pond in Mallorca, Spain, Environmental Microbiology (open access)

Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

Follow on Twitter