International Committee on Systematics of Prokaryotes Subcommittee on the taxonomy of Halobacteriaceae and Subcommittee on the taxonomy of Halomonadaceae: minutes of the joint open meeting, 31 July 2014, Montreal, Canada

Larsenimonas suaedae sp. nov., a moderately halophilic, endophytic bacterium isolated from the halophyte Suaeda salsa

A moderately halophilic, Gram-stain-negative, non-endospore-forming endophytic bacterium designated strain ST307T was isolated from the euhalophyte Suaeda salsa in Dongying, China. Strain ST307T was aerobic, rod-shaped, motile and orange-yellow-pigmented. The organism grew at NaCl concentrations of 0.6-20 % (w/v) (optimum 5-6 %, w/v), at temperatures of 5-45 °C (optimum 35 °C) and at pH 5-9 (optimum pH 7-8). It accumulated poly-β-hydroxybutyric acid and produced exopolysaccharides. The major fatty acids were C18 : 1ω7c/C18 : 1ω6c, C16 : 0 and C16 : 1ω7c/C16 : 1ω6c. The predominant lipoquinone was ubiquinone Q-9. The polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, a glycoaminolipid and a phosphoglycoaminolipid. The DNA G+C content was 60.5 mol%. Phylogenetic analyses of 16S rRNA gene sequences and concatenated atpA, rpoD and secA gene sequences revealed that the strain represents a member of the genus Larsenimonas. The closest related type strain was Larsenimonas salina M1-18T. Mean DNA-DNA relatedness values between strain ST307T and the related species L. salina M1-18T, Chromohalobacter beijerinckii DSM 7218T, C. canadensis DSM 6769T, C. israelensis DSM 6768T, C. marismortui CGMCC 1.2321T, C. nigrandesensis DSM 14323T, C. salexigens DSM 3043T and C. sarecensis DSM 15547T were 15±2-45±1 %. On the basis of phenotypic, chemotaxonomic and molecular features, strain ST307T clearly represents a novel species of the genus Larsenimonas. The name Larsenimonassuaedae sp. nov. is proposed, with ST307T (=CGMCC 1.8902T=DSM 22428T) as the type strain.

Draft genome sequence of the extremely halophilic archaeon Haladaptatus cibarius type strain D43(T) isolated from fermented seafood

An extremely halophilic archaeon, Haladaptatus cibarius D43^T, was isolated from traditional Korean salt-rich fermented seafood. Strain D43^T shows the highest 16S rRNA gene sequence similarity (98.7 %) with Haladaptatus litoreus RO1-28^T, is Gram-negative staining, motile, and extremely halophilic. Despite potential industrial applications of extremely halophilic archaea, their genome characteristics remain obscure. Here, we describe the whole genome sequence and annotated features of strain D43^T. The 3,926,724 bp genome includes 4,092 protein-coding and 57 RNA genes (including 6 rRNA and 49 tRNA genes) with an average G + C content of 57.76 %.

Horizontal gene transfer, dispersal and haloarchaeal speciation

The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria.