Ruegeria marisflavi sp. nov. and Ruegeria aquimaris sp. nov., isolated from seawater of the Yellow Sea.

Two novel Gram-stain-negative, aerobic, non-motile and rod-shaped bacteria, designated as WL0004T and XHP0148T, were isolated from seawater samples collected from the coastal areas of Nantong and Lianyungang, PR China, respectively. Both strains were found to grow at 10-42 °C (optimum, 37 °C) and with 2.0-5.0 % (w/v) NaCl (optimum, 3.0 %). Strain WL0004T grew at pH 6.0-9.0 (optimum, pH 7.0-8.0), while XHP0148T grew at pH 6.0-10.0 (optimum, pH 7.0-8.0). The major cellular fatty acids (>10 %) of both strains included summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c). In addition, strain WL0004T contained 11-methyl C18 : 1 ω7c and strain XHP0148T contained C12 : 0 3-OH. The respiratory quinone of both strains was ubiquinone-10. The G+C content of genomic DNA of strains WL0004T and XHP0148T were 62.5 and 63.0 mol%, respectively. Strains WL0004T and XHP0148T showed the highest 16S rRNA gene sequence similarity to Ruegeria pomeroyi DSS-3T (99.4 and 99.0 %, respectively), and the 16S rRNA gene-based phylogenetic analysis indicated that the two strains were closely related to members of the genus Ruegeria. The average nucleotide identity and digital DNA-DNA hybridization values among the two strains and type strains of the genus Ruegeria were all below 95 and 70 %, respectively, and the phylogenetic tree reconstructed from the bac120 gene set indicated that the two strains are distinct from each other and the members of the genus Ruegeria. Based on this phenotypic and genotypic characterization, strains WL0004T (=MCCC 1K07523T=JCM 35565T=GDMCC 1.3083T) and XHP0148T (=MCCC 1K07543T=JCM 35569T=GDMCC 1.3089T) should be recognized as representing two novel species of the genus Ruegeria and the names Ruegeria marisflavi sp. nov. and Ruegeria aquimaris sp. nov. are proposed, respectively.

Marixanthotalea marina gen. nov., sp. nov., a bacterium in the family Flavobacteriaceae isolated from seawater.

A Gram-stain-negative, yellow-pigmented, non-motile, rod-shaped, catalase-positive, strictly aerobic marine bacterium, designated XHP0103T, was isolated from seawater collected from the southern Yellow Sea, PR China (34° 45' 53″ N 119° 25' 30″ E). Strain XHP0103T grew optimally at 28 °C, pH 7.5 and in 1.0-3.0 % (w/v) sea salt. MK-6 was the major respiratory quinone. The major cellular fatty acids (>10%) were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The polar lipid profile contained phosphatidylethanolamine, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. Results of 16S rRNA gene sequence analysis indicated that strain XHP0103T displayed highest sequence similarity to Aestuariibaculum marinum IP7T (94.1 %). However, the phylogenetic trees based on 16S rRNA gene sequences suggested that strain XHP0103T clustered with Tamlana crocina HST1-43T (93.4 % sequence similarity) and Aestuariivivens insulae AH-MY3T (93.5 %). Genome sequencing revealed that strain XHP0103T comprised 3 134 388 bp with 2770 protein-coding genes, and the DNA G+C content was 35.5 %. The average nucleotide identity and digital DNA-DNA hybridization values between strain XHP0103T and T. crocina HST1-43T were 73.6 and 17.3 %, respectively. Based on phylogenetic, phenotypic, genomic and chemotaxonomic evidence, strain XHP0103T represents a novel genus in the family Flavobacteriaceae, for which the name Marixanthotalea marina gen. nov., sp. nov. is proposed. The type strain is XHP0103T (=MCCC 1K06060T=JCM 34682T).

Description of Limnobaculum eriocheiris sp. nov., an intestinal bacterium of Eriocheir sinensis, and reclassification of the genera Jinshanibacter and Insectihabitans as Limnobaculum.

A Gram-stain-negative, aerobic, non-motile and rod-shaped strain, designated LJY008T, was isolated from the intestinal of Eriocheir sinensis in Pukou base of Jiangsu Institute of Freshwater Fisheries. Strain LJY008T could grow at 4-37 â„ƒ (optimum, 30 â„ƒ), pH 6.0-8.0 (optimum, pH 7.0), and with 1.0-6.0% NaCl (w/v; optimum, 1.0%). Strain LJY008T shared highest 16S rRNA gene sequence similarity with Jinshanibacter zhutongyuii CF-458T (99.3%), followed by J. allomyrinae BWR-B9T (99.2%), Insectihabitans xujianqingii CF-1111T (97.3%), and Limnobaculum parvum HYN0051T (96.7%). The major polar lipids include phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The only respiratory quinone was Q8, and the main fatty acids (> 10%) were C16:0, summed feature 3 (C16:1ω7c/C16:1ω6c), summed feature 8 (C18:1ω7c), and C14:0. The genome-based phylogenies showed that strain LJY008T was closely associated with members of the genus Jinshanibacter, Insectihabitans, and Limnobaculum. The average nucleotide identities and average amino acid identities (AAI) among strain LJY008T and closely related neighbours were all below 95%, and the digital DNA-DNA hybridization values among them were all below 36%. The genomic DNA G + C content of strain LJY008T was 46.1%. Based on the phenotypic, phylogenetic, biochemical and chemotaxonomic analysis, strain LJY008T represents a novel species of the genus Limnobaculum, for which the name Limnobaculum eriocheiris sp. nov. is proposed. The type strain is LJY008T (= JCM 34675T = GDMCC 1.2436T = MCCC 1K06016T). In addition, the genera Jinshanibacter and Insectihabitans were reclassified as Limnobaculum, because there was no significant genome-scale divergence or diagnosable difference on phenotypic and chemotaxonomic traits, such as strains of Jinshanibacter and Insectihabitans sharing AAI values of 93.88-94.96%.

Paracoccus marinaquae sp. nov., isolated from coastal water of the Yellow Sea.

A Gram-stain-negative, non-motile and coccoid bacterial strain, designated XHP0099T, was isolated from the coastal water of the Yellow Sea, China. Growth occurred at 20-37 â„ƒ (optimum, 28 â„ƒ), pH 5.0-9.0 (optimum, pH 7.0-8.0), and with 0-7.0% NaCl (optimum, 2.0-3.0%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain XHP0099T was related to members of the genus Paracoccus and shared the highest sequence similarity with "P. siganidrum" M26 (98.2%), followed by P. alkanivorans 4-2 T (97.6%) and P. alkenifer DSM 11593 T (97.4%). The average nucleotide identity, amino acid identity, and digital DNA-DNA hybridization values of strain XHP0099T against related members in the genus Paracoccus were below the cut-off points proposed for the delineation of a novel species. The major cellular fatty acids (> 10%) were summed feature 8 (C18:1 ω7c/C18:1 ω6c), and C18:0. The major isoprenoid quinone was Q-10 and the polar lipids contained diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), aminolipid (AL) and unidentified polar lipids (L). The G + C content of the genomic DNA of strain XHP0099T was 66.0%. Genomic analysis suggested that strain XHP0099T harbored gene clusters for formaldehyde and the XoxF-type methanol oxidation and type 1 Calvin cycle, which could confer the methylotrophy pathway. Based on the phenotypic, phylogenetic, biochemical and chemotaxonomic analysis, strain XHP0099T represents a novel species of the genus Paracoccus, for which the name Paracoccus marinaquae sp. nov. is proposed. The type strain is XHP0099T (= JCM 34661 T = GDMCC 1.2414 T = MCCC 1K05846T).

Description of Nocardioides jiangsuensis sp. nov., and Proposal for Reclassification of the Genus Marmoricola as Nocardioides.

A Gram-staining-positive, non-motile, aerobic, spherical actinobacterium, designated WL0053T, was isolated from the coastal sediment of Nantong City, Jiangsu Province, China. The 16S rRNA gene sequence of strain WL0053T exhibited the highest similarities to Nocardioides mesophilus MSL-22T (98.0%), N. massiliensis GD12T (97.8%), Marmoricola bigeumensis MSL-05T (97.6%), and N. jensenii DSM 20641T (97.3%). The polyphasic taxonomic approach was used for the identification of strain WL0053T. This strain formed white, round, and smooth colonies and grew in the presence of 0-18% (w/v) NaCl (optimum, 0-4.0%), at pH 6.0-9.0 (optimum, pH 7.0) and at 20-37 °C (optimum, 28 °C). The main cellular fatty acids comprised of C17:1 ω8c, C18:1 ω9c, and iso-C16:0. The genomic DNA G + C content was 71.9%. The predominant quinone was MK-8(H4), and the major polar lipid consisted of phosphatidylcholine, glycolipid, phosphatidylethanolamine, and two unidentified phospholipids. Phylogenetic trees of 16S rRNA gene and bac120 gene set indicted that strain WL0053T was closely related to the species N. iriomotensis and N. mesophilus, while these two species clustered in a separate clade together with M. caldifontis YIM 730233T in the bac120 tree. Combined with the analysis of average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH), it can be considered that the strain WL0053T is a new member of the genus Nocardioides and is proposed to be named as Nocardioides jiangsuensis sp. nov.. The type strain is WL0053T (=MCCC 1K05897T=JCM 34671T=GDMCC 4.192T). Furthermore, based on the fact that the genera Nocardioides and Marmoricola both appeared polyphyletic with no significant difference on phenotypic and chemotaxonomic traits, we proposed to reclassify the genus Marmoricola as Nocardioides.

Characterization of Marinilongibacter aquaticus gen. nov., sp. nov., a unique marine bacterium harboring four CRISPR-Cas systems in the phylum Bacteroidota.

A novel bacterium, designated YYF0007T, was isolated from an agar-degrading co-culture. The strain was found harboring four CRISPR-Cas systems of two classes in the chromosome and subsequently subjected to a study on polyphasic taxonomy. Pairwise analyses of the 16S rRNA gene sequences indicated that strain YYF0007T had highest 16S rRNA gene sequence similarity (92.2%) to Jiulongibacter sediminis JN-14-9T. The phylogenomic trees based on the 16S rRNA gene and 269 single-copy orthologous gene clusters (OCs) indicated that strain YYF0007T should be recognized as a novel genus of the family Spirosomaceae. The cells were Gramstain-negative, nonmotile, strictly aerobic, and straight long rods with no flagellum. Optimum growth occurred at 28°C and pH 7.0 with the presence of NaCl concentration 1.0-3.0% (w/v). The strain showed oxidase and catalase activities. The major fatty acids were C16:1ω5c, iso-C15:0 and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The predominant isoprenoid quinone was MK-7. The complete genome size was 4.64 Mb with a DNA G + C content of 44.4%. Further typing of CRISPR-Cas systems in the family Spirosomaceae and the phylum Bacteroidota indicated that it was remarkable for strain YYF0007T featured by such a set of CRISPR-Cas systems. This trait highlights the applications of strain YYF-0007T in studies on the evolutionary dynamics and bacterial autoimmunity of CRISPR-Cas system as a potential model. The name Marinilongibacter aquaticus gen. nov., sp. nov. is proposed, and the type strain is YYF0007T (= MCCC 1K06017T = GDMCC 1.2428T = JCM 34683T).

Aestuariicella albida sp. nov., isolated from surface water of the Yellow Sea, and proposal of the genus Aestuariicella as a member of the family Cellvibrionaceae.

A Gram-stain-negative, non-motile and aerobic bacterium, designated HHU G3-2T, was isolated from surface water of the Yellow Sea, PR China. Strain HHU G3-2T was positive for oxidase activity and negative for catalase. Optimal growth occurred at 28 °C (range, 20-37 °C), pH 7.0 (range, pH 6.0-9.0) and in the presence of 2-5 % (w/v) NaCl (range, 1-7%). Phylogenetic analysis based on 16S rRNA gene sequences and 120 ubiquitous single-copy protein-coding genes indicated that strain HHU G3-2T formed a distinct phylogenetic lineage with Aestuariicella hydrocarbonica JCM 30134T, sharing a 16S rRNA gene sequence similarity of 98.05%. Average nucleotide identity and digital DNA-DNA hybridization values between strain HHU G3-2T and A. hydrocarbonica JCM 30134T were 75.74 and 17.80%, respectively, which were below the threshold values of 95-96 and 70 %, respectively. The DNA G+C content of the genomic DNA was 51.17 mol%. The major fatty acids (>10 %) were C17 : 1 ω8c (19.8 %), summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c; 15.9 %), summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c; 13.8 %) and C17 : 0 (10.3 %). The predominant isoprenoid quinone was ubiquinone-8. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Based on the polyphasic taxonomic data, strain HHU G3-2T represents a novel species of the genus Aestuariicella, for which the name Aestuariicella albida sp. nov. is proposed. The type strain is HHU G3-2T (=MCCC 1K04224T=JCM 34652T=GDMCC 1.2418T=CGMCC 1.17397T). In addition, we proposed the genus Aestuariicella as a member of the family Cellvibrionaceae.

Sphingopyxis jiangsuensis sp. nov. Isolated From the Surface Water of the Yellow Sea.

A novel bacterium, designated strain XHP0097T, was isolated from the surface water of the Yellow Sea, China. The cells were Gram-stain-negative, aerobic, rod-shaped, yellow-colored, and non-motile on 2216E agar. Optimal growth of strain XHP0097T occurs at 28 °C and pH 7.0 with the presence of NaCl concentration 2% (w/v). According to the analysis of comparative 16S rRNA gene sequence, strain XHP0097T showed the highest 16S rRNA gene sequence similarity with Sphingopyxis panaciterrulae KCTC 22112T (98.2%). Phylogenetic analysis based on 16S rRNA gene sequences as well as on 120 ubiquitous single-copy protein-coding genes supported that strain XHP0097T formed a distinct phyletic lineage as a new species within the genus Sphingopyxis. Strain XHP0097T showed an average nucleotide identity value and a digital DNA-DNA hybridization (dDDH) of 79.1-81.7% and 21.9-24.4% to the members of the genus Sphingopyxis, respectively. According to genome sequence, the DNA G + C content of XHP0097T was 64.8%. The major fatty acids (>10%) were C16:0 (17.5%), summed feature 3 (C16:1ω7c and/or C16:1ω6c) (15.1%), and summed feature 8 (C18:1ω7c and/or C18:1ω6c) (19.2%). The major polar lipids of strain XHP0097T were phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), and sphingoglycolipid (SGL). Q-10 was the predominant respiratory quinone. Characteristics of physiological and biochemical, phylogenetic, and chemotaxonomic analysis demonstrated the isolate XHP0097T represents a novel species of the genus Sphingopyxis, for which the name Sphingopyxis jiangsuensis sp. nov. is proposed. The type strain is XHP0097T (=MCCC 1K05845T = GDMCC 1.2415T = JCM 34678T).

Actirhodobacter atriluteus gen. nov., sp. nov., isolated from the surface water of the Yellow Sea.

A Gram-stain-negative, aerobic, orange-pigmented bacterial strain, designated HHU K3-1 T, was isolated from the surface water of the Yellow Sea. The strain was observed to grow on 2216E agar medium, and growth occurred at pH 6.0-8.0 (optimum 7.0), 28-37 °C (optimum 28 °C), and in the presence of 0.5-5% (w/v) NaCl (optimum 1-3%). The major fatty acids (> 10%) were summed feature 3 (C16:1ω6c/C16:1ω7c), C17:1ω6c and summed feature 8 (C18:1ω6c/C18:1ω7c). Strain HHU K3-1 T was found to contain ubiquinone-10 as the predominant quinone and the major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG) and sphingoglycolipid (SGL). The 16S rRNA gene sequence analysis indicated that strain HHU K3-1 T shared highest similarities with Pelagerythrobacter marensis KCTC 22370 T (97.7%) and Qipengyuania oceanensis MCCC 1A09965T (96.9%). However, a phylogenetic tree based on 288 orthologous clusters (OCs) indicated that HHU K3-1 T was close related to Parapontixanthobacter aurantiacus MCCC 1A09962T. The pairwise AAI and evolutionary distance between HHU K3-1 T and Parapontixanthobacter aurantiacus MCCC 1A09962T are 67.1% and 0.43, respectively, which meet the recently proposed standard to differentiate genera in the family Erythrobacteraceae. On the basis of the result obtained by the polyphasic taxonomic study, strain HHU K3-1 T can be considered to represent a novel genus in the family Erythrobacteraceae, for which the name Actirhodobacter atriluteus gen. nov., sp. nov. is proposed. The type strain is HHU K3-1 T (= MCCC 1K04225T = KCTC 72834 T = CGMCC 1.17395 T).

Description of Salinimonas profundi sp. nov., a deep-sea bacterium harboring a transposon Tn6333.

A Gram-staining-negative bacterium, strain HHU 13199T, was isolated from a marine sediment sample collected from South China Sea (119°19.896'E, 19°41.569'N) at a depth of 2918 m. The 16S rRNA gene sequence analysis indicated that strain HHU 13199T represents a member of the genus Salinimonas with the highest sequence similarity (99.8%) to the type strain S. iocasae KX18D6T. However, the average nucleotide identity values and digital DNA-DNA hybridization between strain HHU 13199T and closely related members of the genus Salinimonas were all below the cut-off level (95-96 % and 70%, respectively) for species delineation. This strain grew with sea salt of 0.5-18% (w/v) (optimum, 2-5%), but no growth observed when using NaCl instead. The major fatty acids are C16:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c), and summed feature 8 (C18:1ω7c and/or C18:1ω6c). The predominant isoprenoid quinone is ubiquinone-8. The polar lipids mainly consist of phosphatidylethanolamine, and phosphatidylglycerol. Genomic characterization revealed that strain HHU 13199T harbors a distinct type I-F CRISPR-Cas system and plenty of genes associated with heavy metal resistance, including a transposon (Tn6333) conferring mercury resistance. In addition, a phylogenetic tree based on the bac120 core genes suggested that the genus Salinimonas should be a subclade within Alteromonas. On the basis of the phenotypic, phylogenetic and chemotaxonomic characterizations, strain HHU 13199T represents a novel species of the genus Salinimonas, for which the name Salinimonas profundi sp. nov. is proposed. The type strain is HHU 13199T (= KCTC 72837T = MCCC 1K04127T).