Maricoccus atlantica gen. nov. sp. nov., isolated from deep sea sediment of the Atlantic Ocean

Genome Sequence of the Euphotic Hawaiian Gammaproteobacterium HetDA_MAG_MS8, in the Order Nevskiales, Family Oceanococcaceae, Genus Oceanococcus

We present a metagenome-assembled genome (MAG), HetDA_MAG_MS8, that was determined to be unique via relative evolutionary divergence (RED) scores and average nucleotide identity (ANI) values. HetDA_MAG_MS8 is in the order Nevskiales, genus Oceanococcus, and was assembled from a heterocytous cyanobiont enrichment from the Hawaii Ocean Time Series. HetDA_MAG_MS8 is predicted to be a facultative, aerobic, anoxygenic photolithoheterotroph that has the potential for sulfide oxidation and dimethylsulfoniopropionate (DMSP) synthesis.

Genomic Comparison, Phylogeny and Taxonomic Reevaluation of the Ectothiorhodospiraceae and Description of Halorhodospiraceae fam. nov. and Halochlorospira gen. nov

The Ectothiorhodospiraceae family represents purple sulfur bacteria of the Gammaproteobacteria found primarily in alkaline soda lakes of moderate to extremely high salinity. The main microscopically visible characteristic separating them from the Chromatiaceae is the excretion of the intermediate elemental sulfur formed during oxidation of sulfide prior to complete oxidation to sulfate rather than storing it in the periplasm. We present a comparative study of 38 genomes of all species of phototrophic Ectothiorhodospiraceae. We also include a comparison with those chemotrophic bacteria that have been assigned to the family previously and critically reevaluate this assignment. The data demonstrate the separation of Halorhodospira species in a major phylogenetic branch distant from other Ectothiorhodospiraceae and support their separation into a new family, for which the name Halorhodospiraceae fam. nov. is proposed. In addition, the green-colored, bacteriochlorophyll-containing species Halorhodospira halochloris and Halorhodospira abdelmalekii were transferred to the new genus Halochlorospira gen. nov. of this family. The data also enable classification of several so far unclassified isolates and support the separation of Ectothiorhodospira shaposhnikovii and Ect. vacuolata as well as Ect. mobilis and Ect. marismortui as distinct species.

Microbes mediating the sulfur cycle in the Atlantic Ocean and their link to chemolithoautotrophy

Only about 10%-30% of the organic matter produced in the epipelagic layers reaches the dark ocean. Under these limiting conditions, reduced inorganic substrates might be used as an energy source to fuel prokaryotic chemoautotrophic and/or mixotrophic activity. The aprA gene encodes the alpha subunit of the adenosine-5'-phosphosulfate (APS) reductase, present in sulfate-reducing (SRP) and sulfur-oxidizing prokaryotes (SOP). The sulfur-oxidizing pathway can be coupled to inorganic carbon fixation via the Calvin-Benson-Bassham cycle. The abundances of aprA and cbbM, encoding RuBisCO form II (the key CO2 fixing enzyme), were determined over the entire water column along a latitudinal transect in the Atlantic from 64°N to 50°S covering six oceanic provinces. The abundance of aprA and cbbM genes significantly increased with depth reaching the highest abundances in meso- and upper bathypelagic layers. The contribution of cells containing these genes also increased from mesotrophic towards oligotrophic provinces, suggesting that under nutrient limiting conditions alternative energy sources are advantageous. However, the aprA/cbbM ratios indicated that only a fraction of the SOP is associated with inorganic carbon fixation. The aprA harbouring prokaryotic community was dominated by Pelagibacterales in surface and mesopelagic waters, while Candidatus Thioglobus, Chromatiales and the Deltaproteobacterium_SCGC dominated the bathypelagic realm. Noticeably, the contribution of the SRP to the prokaryotic community harbouring aprA gene was low, suggesting a major utilization of inorganic sulfur compounds either as an energy source (occasionally coupled with inorganic carbon fixation) or in biosynthesis pathways.

Salifodinibacter halophilus gen. nov., sp. nov., a halophilic gammaproteobacterium in the family Salinisphaeraceae isolated from a salt mine in the Colombian Andes

Two morphologically similar halophilic strains, named USBA 874 and USBA 960^T, were isolated from water and sediment samples collected from the Zipaquirá salt mine in the Colombian Andes. Both isolates had non-spore-forming, Gram-stain-negative and motile cells that grew aerobically. The strains grew optimally at 30 °C, pH 7.0 and with 25 % NaCl (w/v). The isolates showed almost identical 16S rRNA gene sequences (99.0 % similarity). The predominant quinones of USBA-960^T were Q-8, Q-7 and Q-9. The major cellular fatty acids were C_19 : 0 cyclo ω8c, C_18 : 0 and C_16 : 0. According to 16S rRNA gene sequencing, the closest phylogenetic relatives are Salinisphaera species (similarity between 93.6 and 92.3 %), Abyssibacter profundi OUC007^T (88.6 %) and Oceanococcus atlanticus 22II-S10r2^T (88.7 %). In addition, the result of genome blast distance phylogeny analysis between strains USBA 874 and USBA 960^T, Salinisphaera halophila (YIM 95161^T), Salinisphaera shabanensis (E1L3A^T), Salinisphaera orenii (MK-B5^T) and Salinisphaera japonica (YTM-1^T) was 18.5 %. Other in silico species delineation analyses also showed low identity such as ANIb and ANIm values (<69.0 and <84.0 % respectively), TETRA (<0.81) and AAI values (<0.67). Genome sequencing of USBA 960^T revealed a genome size of 2.47 Mbp and a G+C content of 59.71 mol%. Phylogenetic analysis of strains USBA 874 and USBA 960^T indicated that they formed a different lineage within the family Salinisphaeraceae. Based on phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA-DNA relatedness values, along with identity at whole genome level, it can be concluded that strains USBA 960^T and USBA 874 represent a novel genus of the family Salinisphaeraceae and the name Salifodinibacter halophilus gen. nov., sp. nov. is proposed. The type strain is USBA 960^T (CMPUJ U095^T=CECT 30006^T).

Stenotrophobium rhamnosiphilum gen. nov., sp. nov., isolated from a glacier, proposal of Steroidobacteraceae fam. nov. in Nevskiales and emended description of the family Nevskiaceae

A Gram-stain-negative strain, designated GT1R17^T, was isolated from an ervoconite sample collected from Gawalong glacier in the Tibet Autonomous Region, PR China. Strain GT1R17^T was catalase- and oxidase-positive, and grew optimally at 20-25°C and pH 7.0. The highest level of 16S rRNA gene sequence similarities were found to members of the genera Nevskia(92.27-93.15 %) and Hydrocarboniphaga(91.92-92.96 %). Phylogenetic analyses based on 16S rRNA gene sequences and genomic data revealed that the strain GT1R17^T belonged to the family Nevskiaceae, but could not be assigned to any known genera. The genomic DNA G+C content was 54.4 mol%. The major fatty acids were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), summed feature 8 (C18 : 1 ω7c and/or C18 : 1ω6c), C16 : 0, iso-C16 : 0 and summed feature 2 (C14 : 0 3OH and/or iso-C16 : 1 I). The polar lipids were phosphatidylglycerol, phosphatidylethanolamine and one unidentified lipid. The ubiquinone was Q-8. On the basis of the phenotypic, chemotaxonomic, genotypic and phylogenetic data, a novel species of a new genus,Stenotrophobiumrhamnosiphilum gen. nov., sp. nov. within the family Nevskiaceae, is proposed, with GT1R17^T (=CGMCC 1.16137^T=NBRC 113346^T) as the type strain. In addition, phylogenetic analyses revealed that Steroidobacter and Povalibacter formed an independent clade in the order Nevskiales and were away from the families Nevskiaceae, Algiphilaceae and Salinisphaeraceae. Therefore, we propose to remove Steroidobacter and Povalibacter from the family Nevskiaceae and propose a new family Steroidobacteraceae in the order Nevskiales.

List of new names and new combinations previously effectively, but not validly, published

The purpose of this announcement is to effect the valid publication of the following effectively published new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof, or an electronic copy of the published paper to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries. It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in the nomenclature of prokaryotes. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.

Roseivivax atlanticus sp. nov., isolated from surface seawater of the Atlantic Ocean

A taxonomic study was carried out on strain 22II-S10s(T), which was isolated from the surface seawater of the Atlantic Ocean. The bacterium was found to be Gram-negative, oxidase and catalase positive, rod shaped and motile by subpolar flagella. The isolate was capable of gelatine hydrolysis but unable to reduce nitrate to nitrite or degrade Tween 80 or aesculin. Growth was observed at salinities of 0.5-18 % (optimum, 2-12 %), at pH of 3-10 (optimum, 7) and at temperatures of 10-41 °C (optimum 28 °C). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II-S10s(T) belongs to the genus Roseivivax, with highest sequence similarity to Roseivivax halodurans JCM 10272(T) (97.2 %), followed by Roseivivax isoporae LMG 25204(T) (97.0 %); other species of genus Roseivivax shared 95.2-96.7 % sequence similarity. The DNA-DNA hybridization estimate values between strain 22II-S10s(T) and the two type strains (R. halodurans JCM 10272(T) and R. isoporae LMG 25204(T)) were 22.00 and 21.40 %. The principal fatty acids were identified as Summed Feature 8 (C18:1 ω7c/ω6c) (67.4 %), C18:0 (7.2 %), C19:0 cyclo ω8c (7.1 %), C18:1 ω7c 11-methyl (6.8 %) and C16:0 (5.9 %). The respiratory quinone was determined to be Q-10 (100 %). Phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an aminolipid, a glycolipid and three phospholipids were present. The G+C content of the chromosomal DNA was determined to be 67.5 mol%. The combined genotypic and phenotypic data show that strain 22II-S10s(T) represents a novel species within the genus Roseivivax, for which the name Roseivivax atlanticus sp. nov. is proposed, with the type strain 22II-S10s(T) (= MCCC 1A09150(T) = LMG 27156(T)).