Pseudooceanicola endophyticus sp. nov., a novel endophytic bacterium isolated from bark Aegiceras corniculatum

A Gram-stain-negative, aerobic, short-rod-shaped bacterium, designated strain CBS1P-1^T, was isolated from a surface-sterilized bark of Aegiceras corniculatum. Growth of strain CBS1P-1^T was observed with between 0 and 12.0 % (w/v) NaCl (optimally with 5.0 %) and at between pH 6.0-9.0. It grew at temperatures between 25-37 °C (optimum, 30 °C). Chemotaxonomic analysis showed that ubiquinone-10 was the respiratory quinone. The lipids comprised diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid, an unidentified phospholipid and an unidentified aminolipid. The major fatty acids of strain CBS1P-1^T were C_18 : 1  ω7c, C_16 : 0 and C_19 : 0 cyclo ω8c. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain CBS1P-1^T was most related to Pseudooceanicola antarcticus CGMCC 1.12662^T with a sequence similarity of 96.5 %. The average nucleotide identity and digital DNA-DNA hybridization values between strain CBS1P-1^T and P. antarcticus 1.12662^T were 77.5 and 21.1 %, respectively. The G+C content of the genomic DNA was 67.3 mol%. Based on phylogenetic, chemotaxonomic and phenotypic data, strain CBS1P-1^T is considered to represent a novel species of the genus Pseudooceanicola, for which the name Pseudooceanicola endophyticus is proposed. The type strain is CBS1P-1^T (=KCTC 62836^T=CGMCC 1.13743^T).

Pseudooceanicola algae sp. nov., isolated from the marine macroalga Fucus spiralis, shows genomic and physiological adaptations for an algae-associated lifestyle

The genus Pseudooceanicola from the alphaproteobacterial Roseobacter group currently includes ten validated species. We herein describe strain Lw-13eT, the first Pseudooceanicola species from marine macroalgae, isolated from the brown alga Fucus spiralis abundant at European and North American coasts. Physiological and pangenome analyses of Lw-13eT showed corresponding adaptive features. Adaptations to the tidal environment include a broad salinity tolerance, degradation of macroalgae-derived substrates (mannitol, mannose, proline), and resistance to several antibiotics and heavy metals. Notably, Lw-13eT can degrade oligomeric alginate via PL15 alginate lyase encoded in a polysaccharide utilization locus (PUL), rarely described for roseobacters to date. Plasmid localization of the PUL strengthens the importance of mobile genetic elements for evolutionary adaptations within the Roseobacter group. PL15 homologs were primarily detected in marine plant-associated metagenomes from coastal environments but not in the open ocean, corroborating its adaptive role in algae-rich habitats. Exceptional is the tolerance of Lw-13eT against the broad-spectrum antibiotic tropodithietic acid, produced by Phaeobacter spp. co-occurring in coastal habitats. Furthermore, Lw-13eT exhibits features resembling terrestrial plant-bacteria associations, i.e. biosynthesis of siderophores, terpenes and volatiles, which may contribute to mutual bacteria-algae interactions. Closest described relative of Lw-13eT is Pseudopuniceibacterium sediminis CY03T with 98.4% 16S rRNA gene sequence similarity. However, protein sequence-based core genome phylogeny and average nucleotide identity indicate affiliation of Lw-13eT with the genus Pseudooceanicola. Based on phylogenetic, physiological and (chemo)taxonomic distinctions, we propose strain Lw-13eT (=DSM 29013T=LMG 30557T) as a novel species with the name Pseudooceanicola algae.

Pseudooceanicola aestuarii sp. nov., isolated from the Jiulong River Estuary in PR China

A novel Gram-stain-negative, rod-shaped, aerobic, oxidase-positive and catalase-positive bacterium of the genus Pseudooceanicola, designated strain E2-1^T, was isolated from surface water of Jiulong River Estuary, PR China. Cells of strain E2-1^T grew in medium containing 0.5-12 % NaCl (w/v; optimum, 2-4 %), at 15-45 °C (optimum, 28-33 °C) and at pH 7.0-9.0 (optimum, pH 7.0-8.0). Comparative analyses of the 16S rRNA gene sequence revealed that strain E2-1^T had the highest similarity to Pseudooceanicola nitratireducens JLT1210^T (97.3 %) and Pseudooceanicola batsensis HTCC2597^T (97.1 %), and had less than 97.0 % 16S rRNA gene sequence similarity to other type strains within the genus Pseudooceanicola. The DNA G+C content of strain E2-1^T was 65.7 mol%. The average nucleotide identity and digital DNA-DNA hybridization relatedness values between E2-1^T and related type strains were 75.0 and 20.1 % with P. nitratireducens JLT1210^T and 75.6 and 20.4 % with P. batsensis HTCC2597^T, respectively. The sole isoprenoid quinone was Q-10; the predominant polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, three unidentified phospholipids and six unidentified lipids; the major cellular fatty acids were C_16 : 0 (17.5 %), C_19 : 0 cyclo ω8c (22.7 %) and summed feature 8 (C_18 : 1  ω7c/C_18 : 1  ω6c; 10.1 %). According to the phylogenetic and genotypic results, strain E2-1^T represents a novel species in the genus Pseudooceanicola, for which the name Pseudooceanicola aestuarii sp. nov. is proposed. The type strain is E2-1^T (=MCCC 1K03742^T=KCTC 72107^T).

Pelagovum pacificum gen. nov., sp. nov., a novel member of the family Rhodobacteraceae isolated from surface seawater of the Mariana Trench

A Gram-stain-negative, aerobic, ovoid-rod-shaped bacterium, designated strain SM1903^T, was isolated from surface seawater of the Mariana Trench. The strain grew at 15-37 °C (optimum, 35 °C) and with 1-15 % (optimum, 4 %) NaCl. It hydrolysed aesculin but did not reduce nitrate to nitrite and hydrolyse Tween 80. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain SM1903^T formed a separate lineage within the family Rhodobacteraceae, sharing the highest 16S rRNA gene sequence similarity with type strains of Pseudooceanicola antarcticus (95.7 %) and Roseisalinus antarcticus (95.7 %). In phylogenetic trees based on single-copy OCs and whole proteins sequences, strain SM1903^T fell within a sub-cluster encompassed by Oceanicola granulosus, Roseisalinus antarcticus and Histidinibacterium lentulum and formed a branch adjacent to Oceanicola granulosus. The major cellular fatty acids were summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c), C_16 : 0 and 11-methyl-C_18 : 1  ω7c. The polar lipids mainly comprised phosphatidylglycerol, phosphatidylcholine, one unidentified lipid, one unidentified aminolipid, and one unidentified glycolipid. The solo respiratory quinone was ubiquinone-10. The genomic DNA G+C content of strain SM1903^T was 66.0 mol%. Based on the results of phenotypic, chemotaxonomic, and phylogenetic characterization for strain SM1903^T, it is considered to represent a novel species of a novel genus in the family Rhodobacteraceae, for which the name Pelagovum pacificum gen. nov., sp. nov. is proposed. The type strain is SM1903^T (=MCCC 1K03608^T=KCTC 72046^T).

Pseudooceanicola pacificus sp. nov., isolated from deep-sea sediment of the Pacific Ocean

A Gram-strain-negative, rod-shaped, aerobic bacterium, designated 216_PA32_1^T, was isolated from deep-sea sediment of the Pacific Ocean. Cells of strain 216_PA32_1^T were non-motile, oxidase-positive and catalase-negative. The strain could grow at temperatures of 10-45 °C (optimum, 32-35 °C), at pH 5.0-10.0 (optimum, 6.0-7.0) and at salinities of 0-10% (optimum, 2-8%). The principal fatty acid (>10 %) was summed feature 8 (C_18:1 ω6c/ω7c). The sole respiratory quinone was Q10 (100 %). The polar lipids included phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, phosphatidylmonomethylethanolamine, two unidentified phospholipids and five unidentified aminolipids. The G+C content of the chromosomal DNA was 66.3 mol%. According to the 16S rRNA gene similarity, strain 216_PA32_1^T showed the highest sequence similarity to Pseudooceanicola nitratireducens JLT 1210^T (97.3 %), followed by Pseudooceanicola nanhaiensis SS011B1-20^T (97.1 %). Phylogenetic trees indicated that strain 216_PA32_1^T clustered with strain P. nanhaiensis SS011B1-20^T. The average nucleotide identity and the DNA-DNA hybridization values between strain 216_PA32_1^T and all species of the genus Pseudooceanicola were below 79.5 and 20.6%, respectively. A combination of the phylogenetic, phenotypic, chemotaxonomic and genomic evidence demonstrated that strain 216_PA32_1^T represents a novel species of the genus Pseudooceanicola, for which the name Pseudooceanicola pacificus sp. nov. is proposed. The type strain is 216_PA32_1^T (=MCCC 1A14128^T=KCTC 72688^T).

Microbial community succession and its correlation with reactor performance in a sponge membrane bioreactor coupled with fiber-bundle anoxic bio-filter for treating saline mariculture wastewater

The application of MBR in high saline wastewater treatment is mainly constrained by poor nitrogen removal and severe membrane fouling caused by high salinity stress. A novel carriers-enhanced MBR system was successfully developed for treating saline mariculture wastewater, which showed efficient TN removal (93.2%) and fouling control. High-throughput sequencing revealed the enhancement mechanism of bio-carriers under high saline condition. Bio-carriers substantially improved the community structure, representatively, nitrifiers abundance (Nitrosomonas, Nitrospira) increased from 2.18% to 9.57%, abundance of denitrifiers (Sulfurimonas, Thermogutta, etc.) also rose from 3.81% to 14.82%. Thereby, the nitrogen removal process was enhanced. Noteworthy, ammonia oxidizer (Nitrosomonas, 8.26%) was the absolute dominant nitrifiers compared with nitrite oxidizer (Nitrospira, 1.13%). This supported the finding of shortcut nitrification-denitrification process in hybrid system. Moreover, a series of biomacromolecule degraders (Lutibacterium, Cycloclasticus, etc.) were detected in bio-carriers, which could account for the mitigation of membrane fouling as result of EPS and SMP degradation.

Pseudooceanicola onchidii sp. nov., isolated from a marine invertebrate from the South China Sea

A novel bacterial strain, XY-99^T, was isolated from the epidermis of a marine invertebrate of the genus Onchidium from seawater of the South China Sea. The cells of the strain were aerobic, Gram-stain-negative, non-motile, and oval-shaped (0.8-1.0 µm wide and 1.0-1.5 µm long) without a flagellum. The strain grew at temperatures of 15-37 °C (optimum, 35-37 °C), at pH 5.5-9.5 (optimum 7.5), and at NaCl concentrations of 0-12.0 % (w/v) (optimum 1.5-3.0 %). The major fatty acids (>10 %) were summed feature 8 (comprising C_18 : 1ω7c and/or C_18 : 1ω6c), C_16 : 0 and 11-methyl C_18 : 1ω7c. The predominant polar lipid was diphosphatidylglycerol. The respiratory quinone was Q-10. The closet phylogenetic neighbours were Pseudooceanicola flagellatus DY470^T and Pseudooceanicola nitratireducens JLT1210^T, showing 97.5 and 97.3 % of 16 s rRNA gene sequence similarity. The genome size of XY-99^T was 3 673 499 bp, with 64.5 % DNA G+C content. The average nucleotide identity and digital DNA-DNA hybridization values between XY-99^T and Pseudooceanicola flagellatus DY470^T were 72.8 and 14.0 %, respectively, while they were 79.3 and 22.3 % between XY-99^T and Pseudooceanicola nitratireducens JLT1210^T. Characterization based on phylogenetic, phenotypic, chemotaxonomic and genomic evidence demonstrated that XY-99^T represents a novel species of the genus Pseudooceanicola, for which the name Pseudooceanicola onchidii sp. nov. is proposed. The type strain is XY-99^T (=KCTC 72211^T=MCCC 1K03607^T).

Pseudooceanicola lipolyticus sp. nov., a marine alphaproteobacterium, reclassification of Oceanicola flagellatus as Pseudooceanicola flagellatus comb. nov. and emended description of the genus Pseudooceanicola

A Gram-stain-negative, rod-shaped bacterium, designated 157^T, was isolated from seawater collected from the Philippine Sea. Cells of strain 157^T grew in medium containing 0.5-10.0 % NaCl (w/v, optimum 3 %), at pH 6.0-8.5 (optimum 7.0) and at 15-40 °C (optimum 30 °C). Tweens 20, 40 and 80 as well as urea were hydrolysed. The 16S rRNA gene sequence of strain 157^T had a high sequence similarity with respect to Pseudooceanicola marinus AZO-C^T (97.2 %), and exhibited less than 97.0 % sequence similarity to other type strains of the species with validly published names. Phylogenetic analyses revealed that strain 157^T fell within a cluster comprising the Pseudooceanicola species and formed a coherent clade with P. marinus AZO-C^T and Pseudooceanicola antarcticus Ar-45^T. Strain 157^T exhibited average nucleotide identity values of 74.5 and 74.9 % to P. marinus LMG 23705^T and P. antarcticus Ar-45^T, respectively. In silico DNA-DNA hybridization analysis revealed that strain 157^T shared 20.2 % DNA relatedness with P. marinus LMG 23705^T and 20.6 % with P. antarcticus Ar-45^T, respectively. The sole isoprenoid quinone was ubiquinone 10. The major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C19 : 0 cyclo ω8c, C16 : 0 2-OH and C16 : 0. The major polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid and one unidentified glycolipid. The DNA G+C content was 64.6 mol%. According to the phylogenetic, chemotaxonomic and phenotypic data, it represents a novel species of the genus Pseudooceanicola, for which the name Pseudooceanicolalipolyticus is proposed. The type strain is 157^T (=KCTC 52654^T=MCCC 1K03317^T). In addition, the description of the genus Pseudooceanicola is emended and Oceanicola flagellatus is reclassified as Pseudooceanicola flagellatus comb. nov., with the type strain DY470^T (=CGMCC 1.12664^T=LMG 27871^T) proposed.

Psychromarinibacter halotolerans gen. nov., sp. nov., isolated from seawater of the Yellow Sea

A Gram-stain-negative, strictly aerobic, motile, non-gliding, oxidase-positive, catalase-positive, rod-shaped bacterium, designated strain YBW34T, was isolated from seawater from the bottom of the Yellow Sea at station H12 (-73m in depth). Growth occurred at 10-45 °C (optimum 28 °C), in the presence of 1-12 % NaCl (w/v, optimum 4 %) and at pH 6.0-8.0 (optimum pH 7.0). The major fatty acids (>10 %) were C18 : 1 ω7c and C16 : 0. The major polar lipids comprised phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and three unidentified aminolipids. The major respiratory quinone was ubiquinone-10 (Q-10). The DNA G+C content of strain YBW34T was 64.2 mol%. The most closely related species was Tropicimonas isoalkanivorans JCM 14837T with 95.8 % sequence similarity in Alphaproteobacteria. It showed 16S rRNA gene sequence similarities of 93.03-95.49, 93.03-95.49 and 95.31-95.32 % to species of genera Rhodovulum, Lutimaribacter and Oceanicola, respectively. Nevertheless, strain YBW34T formed a distinct lineage in the trees which did not join the genera mentioned above in the phylogenetic dendrogram based on 16S rRNA gene sequences. The phenotypic, chemotaxonomic and phylogenetic data indicated that strain YBW34T represents a novel genus and species, for which the name Psychromarinibacter halotolerans gen. nov., sp. nov. is proposed. The type strain is YBW34T (=JCM 31462T=KCTC 52366T=MCCC 1K03203T).

Lacimonas salitolerans gen. nov., sp. nov., isolated from surface water of a saline lake

A Gram-stain-negative bacterium, strain TS-T30T, was isolated from a saline lake (Lake Tuosu) in Qaidam basin, Qinghai province, China, and its taxonomic position was determined by using a polyphasic approach. Cells were non-spore-forming rods, non-motile, 0.8–1.4 μm wide and 1.9–4.0 μm long. Strain TS-T30T was strictly heterotrophic and aerobic. Catalase- and oxidase-positive. Growth was observed in the presence of 0.5–11.0 % (w/v) NaCl (optimum 3.0 %), and at 10–35 °C (optimum 25 °C) and pH 6.5–10.0 (optimum pH 8.5). Strain TS-T30T contained C18 : 1ω7c as the only predominant fatty acid. The major respiratory quinone was Q-10. The DNA G+C content was 62 mol% (T m). Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T30T formed a distinct lineage that was independent of other most closely related genera: Lutimaribacter (95.2–95.9 % 16S rRNA gene sequence similarities), Poseidonocella (95.4 %), Ruegeria (92.8–94.9 %), Marivita (93.6–94.9 %), Seohaeicola (94.7 %), Sediminimonas (94.7 %), Shimia (93.9–94.7 %), Oceanicola (92.6–94.5 %) and Roseicyclus (94.5 %). The major polar lipids were phosphatidylglycerol, one unidentified phospholipid and an unknown aminolipid; phosphatidylcholine was not detected. These data demonstrated that strain TS-T30T represents a novel species of a new genus in the family Rhodobacteraceae, for which the name Lacimonas salitolerans gen. nov., sp. nov. is proposed. The type strain of the type species is TS-T30T ( = CGMCC 1.12477T = NBRC 110969T).