Roseomonas oleicola sp. nov., isolated from an oil production mixture in Yumen Oilfield, and emended description of Roseomonas frigidaquae

Sabulicella glaciei sp. nov., Isolated from Glacier, and Reclassification of Roseomonas rubea, Roseomonas ponticola and Roseomonas oleicola as Neoroseomonas rubea comb. nov., Falsiroseomonas ponticola comb. nov. and Falsiroseomonas oleicola comb. nov

A Gram-stain-negative, short rod-shaped strain, MDT2-1-1T, was isolated from cryoconite samples collected from the Midui glacier in Tibet, China. It grew aerobically from 7 to 40 °C, within a pH range of 6.0-10.0, and in NaCl concentration of 0 to 1.0% (w/v). The pairwise 16S rRNA gene sequence similarity, average nucleotide identity and digital DNA-DNA hybridization values between strains MDT2-1-1T and Sabulicella rubraurantiaca SYSU D01096T were 99.4%, 89.7% and 38.9%, respectively. Considering the results from phylogeny, phenotypic and genotypic data, strain MDT2-1-1T (=CGMCC 1.11170T = NBRC 110485T) was suggested to represent a novel species of the genus Sabulicella, for which the name Sabulicella glaciei sp. nov. is proposed. Furthermore, based on the phylogenomic analysis, it is recommended that Roseomonas rubea, Roseomonas ponticola and Roseomonas oleicola be reclassified as Neoroseomonas rubea comb. nov., Falsiroseomonas ponticola comb. nov. and Falsiroseomonas oleicola comb. nov., respectively. Considering the illegitimate status of the genera names Pararoseomonas and Pseudoroseomonas, the species within the genera Pararoseomonas and Pseudoroseomonas should be transferred to Muricoccus and Teichococcus, respectively. Therefore, we proposed the following new combinations: Muricoccus aeriglobus comb. nov., Muricoccus aerilatus comb. nov., Muricoccus harenae comb. nov., Muricoccus nepalensis comb. nov., Muricoccus pecuniae comb. nov., Muricoccus radiodurans comb. nov., Muricoccus vinaceus comb. nov., Teichococcus aerofrigidensis comb. nov., Teichococcus aerophilus comb. nov., Teichococcus aestuarii comb. nov., Teichococcus cervicalis comb. nov., Teichococcus coralli comb. nov., Teichococcus deserti comb. nov., Teichococcus globiformis comb. nov., Teichococcus hibiscisoli comb. nov., Teichococcus musae comb. nov., Teichococcus oryzae comb. nov., Teichococcus rhizosphaerae comb. nov., Teichococcus ruber comb. nov., Teichococcus suffuscus comb. nov., Teichococcus vastitatis comb. nov., and Teichococcus wenyumeiae comb. nov.

Phototrophic Nitrogen Fixation, a Neglected Biogeochemical Process in Mine Tailings?

Biological nitrogen fixation (BNF) has important ecological significance in mine tailing by contributing to the initial accumulation of nitrogen. In addition to chemolithotrophic and heterotrophic BNF, light may also fuel BNF in oligotrophic mine tailings. However, knowledge regarding the occurrence and ecological significance of this biogeochemical process in mine tailings remains ambiguous. The current study observed phototrophic BNF in enrichment cultures established from three primary successional stages (i.e., original tailings, biological crusts, and pioneer plants) of tailings. Notably, phototrophic BNF in tailings may be more active at vegetation stages (i.e., biological crusts and pioneering plants) than in bare tailings. DNA-stable isotope probing identified Roseomonas species as potential aerobic anoxygenic phototrophs responsible for phototrophic BNF. Furthermore, metagenomic binning as well as genome mining revealed that Roseomonas spp. contained essential genes involved in nitrogen fixation, anoxygenic photosynthesis, and carbon fixation, suggesting their genetic potential to mediate phototrophic BNF. A causal inference framework equipped with the structural causal model suggested that the enrichment of putative phototrophic diazotrophic Roseomonas may contribute to an elevated total nitrogen content during primary succession in these mine tailings. Collectively, our findings suggest that phototrophic diazotrophs may play important roles in nutrient accumulation and hold the potential to facilitate ecological succession in tailings.

Shumkonia mesophila gen. nov., sp. nov., a novel representative of Shumkoniaceae fam. nov. and its potentials for extracellular polymeric substances formation and sulfur metabolism revealed by genomic analysis

A microaerophilic, mesophilic, chemoorganoheterotrophic bacterium, designated Y-P2T, was isolated from oil sludge enrichment in China. Cells of the strain were Gram-stain-negative, non-motile, non-spore-forming, rod-shaped or slightly curved with 0.8-3.0 µm in length and 0.4-0.6 µm in diameter. The strain Y-P2T grew optimally at 25 °C (range from 15 to 30 °C) and pH 7.0 (range from pH 6.0 to 7.5) without NaCl. The major cellular fatty acids were C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The main polar liquids of strain Y-P2T comprised phosphatidylethanolamine (PE) and phosphatidylglycerol (PG). The respiratory quinone was Q-10. Acetate and H2 were the fermentation products of glucose. The DNA G + C content was 66.0%. Strain Y-P2T shared the highest 16S rRNA gene sequence similarity (90.3-90.6%) with species within Oceanibaculum of family Thalassobaculaceae in Rhodospirillales. Phylogenetic analyses based on 16S rRNA gene sequences and genomes showed that strain Y-P2T formed a distinct evolutionary lineage within the order Rhodospirillales. On the basis of phenotypic, phylogenetic and phylogenomic data, we propose that strain Y-P2T represents a novel species in a novel genus, for which Shumkonia mesophila gen. nov., sp. nov., within a new family Shumkoniaceae fam. nov. The type strain is Y-P2T (= CCAM 826 T = JCM 34766 T).

Devosia ureilytica sp. nov., isolated from Kuche River in China

Two novel strains, designated XJ19-45^T and XJ19-1, were isolated from water of Kuche River in Xinjiang Uygur Autonomous Region, China. Their cells were Gram-stain-negative, aerobic and motile rods. The phylogenetic analyses based on 16S rRNA genes and genomes showed that the two isolates belonged to the genus Devosia and the closest relative was Devosia subaequoris HST3-14^T. The 16S rRNA genes sequences pairwise similarities, average nucleotide identities, digital DNA-DNA hybridizations and average amino acid identities between type strain XJ19-45^T and other relatives were all less than 98.3, 80.3, 23.6 and 85.7 %, respectively, all below the species delineation thresholds. Pan-genomic analysis indicated that the novel isolate XJ19-45^T shared 1594 core gene clusters with the 11 closely related type strains in Devosia, and the number of strain-specific clusters was 390. The major cellular fatty acids (>10 %) of the two isolates were summed feature 8, C_18 : 1 ω7c 11-methyl and C_16 : 0. Diphosphatidylglycerol, phosphatidylglycerol and glycolipids were the major polar lipids, and Q10 was the detected respiratory quinone. Based on the results of phenotypic, physiological, chemotaxonomic and genotypic characterizations, we propose that the isolates represent a novel species, for which the name Devosia ureilytica sp. nov. is proposed. The type strain is XJ19-45^T (=CGMCC 1.19388^T=KCTC 92263^T).