Marixanthomonas ophiurae gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from a deep-sea brittle star

The early life microbiome of giant grouper (Epinephelus lanceolatus) larvae in a commercial hatchery is influenced by microorganisms in feed

Fish health, growth and disease is intricately linked to its associated microbiome. Understanding the influence, source and ultimately managing the microbiome, particularly for vulnerable early life-stages, has been identified as one of the key requirements to improving farmed fish production. One tropical fish species of aquaculture importance farmed throughout the Asia-Pacific region is the giant grouper (Epinephelus lanceolatus). Variability in the health and survival of E. lanceolatus larvae is partially dependent on exposure to and development of its early microbiome. Here, we examined the development in the microbiome of commercially reared giant grouper larvae, its surrounding environment, and that from live food sources to understand the type of bacterial species larvae are exposed to, and where some of the sources of bacteria may originate. We show that species richness and microbial diversity of the larval microbiome significantly increased in the first 4 days after hatching, with the community composition continuing to shift over the initial 10 days in the hatchery facility. The dominant larval bacterial taxa appeared to be predominantly derived from live cultured microalgae and rotifer feeds and included Marixanthomonas, Candidatus Hepatincola, Meridianimaribacter and Vibrio. In contrast, a commercial probiotic added as part of the hatchery's operating procedure failed to establish in the larvae microbiome. Microbial source tracking indicated that feed was the largest influence on the composition of the giant grouper larvae microbiome (up to 55.9%), supporting attempts to modulate fish microbiomes in commercial hatcheries through improved diets. The marked abundances of Vibrio (up to 21.7% of 16S rRNA gene copies in larvae) highlights a need for rigorous quality control of feed material.

Microbial response to a port fuel spill: Community dynamics and potential for bioremediation

Following a fuel leakage inside a Portuguese maritime port, we conducted parallel 30-day experiments using contaminated seawater and fuel, sampled five days after the incident. This study aimed to (i)survey the native microbial community response to the spilled fuel and (ii)evaluate the efficacy of bioremediation, both biostimulation and bioaugmentation with a lyophilized bacterial consortium (Rhodococcus erythropolis, Pseudomonas sp.), in accelerating hydrocarbon degradation. Metabarcoding analysis revealed a shift in microbial communities, with increased abundance of hydrocarbon-degraders (e.g. Alcanivorax, Thalassospira). Ninety-five hydrocarbonoclastic bacteria were isolated, including key groups from the enriched communities. The lyophilized bacteria added in bioaugmentation, enhanced the abundance of hydrocarbon-degraders over time and were recovered throughout time. Bioremediation treatments favoured biodegradation, achieving over 60 % removal of total petroleum hydrocarbons after 15 days, contrasting with natural attenuation where almost no TPH was removed. This work highlights the potential of bioremediation technologies to accelerate hydrocarbon-degrading activity, for oil spills inside ports.

Rasiella rasia gen. nov. sp. nov. within the family Flavobacteriaceae isolated from seawater recirculating aquaculture system

A novel bacterium designated RR4-40^T was isolated from a biofilter of seawater recirculating aquaculture system in Busan, South Korea. Cells are strictly aerobic, Gram-negative, irregular short rod, non-motile, and oxidase- and catalase-negative. Growth was observed at 15-30°C, 0.5-6% NaCl (w/v), and pH 5.0-9.5. The strain grew optimally at 28°C, 3% salinity (w/v), and pH 8.5. The phylogenetic analysis based on 16S rRNA gene sequences showed that strain RR4-40^T was most closely related to Marinirhabdus gelatinilytica NH83^T (94.16% of 16S rRNA gene similarity) and formed a cluster with genera within the family Flavobacteriaceae. The values of the average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), and average amino acid identity (AAI) between genomes of strain RR4-40^T and M. gelatinilytica NH83^T were 72.91, 18.2, and 76.84%, respectively, and the values against the strains in the other genera were lower than those. The major fatty acids were iso-C_15:0 (31.34%), iso-C_17:0 3-OH (13.65%), iso-C_16:0 3-OH (10.61%), and iso-C_15:1 G (10.38%). The polar lipids comprised phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid, aminolipid, glycolipid, and sphingolipid. The major respiratory quinone was menaquinone-6 (MK-6) and the DNA G + C content of strain RR4-40^T was 37.4 mol%. According to the polyphasic analysis, strain RR4-40^T is considered to represent a novel genus within the family Flavobacteriaceae, for which the name Rasiella rasia gen. nov, sp. nov. is proposed. The type strain is RR4-40^T (= KCTC 52650^T = MCCC 1K04210^T).

Constantimarinum furrinae gen. nov., sp. nov., a marine bacterium isolated from saline volcanic rock aquifer (lava seawater) at Jeju Island, Republic of Korea

A Gram-stain-negative, aerobic, rod-shaped (0.3-0.5 × 1.0-1.9 µm), non-motile marine bacterium designated as ALE3EI^T was isolated from a saline volcanic rock aquifer (lava sea-water) on Jeju Island, Republic of Korea. The 16S rRNA gene sequence analysis revealed that strain ALE3EI^T showed high similarity to 'Altibacter lentus' JLT2010^T (97.2%), followed by Marixanthomonas ophiurae KMM 3046^T (94.5%). Growth was observed at 10-41°C (optimum, 30°C), at pH 6.0-8.5 (optimum, pH 7.5) and at 0.5-8% (optimum, 4.0%) NaCl. The predominant cellular fatty acids were iso-C_15:0 (23.5%), iso-C_16:0 (10.2%), iso-C_16:0 3OH (10.5%), and iso-C_17:0 3OH (16.8%). The DNA G + C contents was 40.4 mol%. The major respiratory quinone was MK-6. The major polar lipids were determined to be phosphatidylethanolamine, two unidentified glycolipids, and two unidentified aminolipids. Several phenotypic characteristics such as production of acetoin, activities of arginine dihydrolase and acid phosphatase, and utilization pattern of carbon sources differentiate strain ALE3EI^T from 'A. lentus' JLT2010^T. Activities of the lipase, trypsin, α-chymotrypsin and gelatinase and utilization pattern of carbon sources differentiate strain ALE3EI^T from M. ophiurae KMM 3046^T. The genome of strain ALE3EI^T is 3.0 Mbp long and its ANI and AAI values against 'A. lentus' JLT2010^T were 76.58 and 72.76, respectively, however, AAI values against members in other genera were lower than 72%. The phylogenomic tree inferred by PhyloPhlAn clearly differentiated the strain ALE3EI^T together with strain JLT2010^T from other genera in the Falvobacteriaceae. This polyphasic taxonomic data indicates that strain ALE3EI^T should be identified as a novel species in the genus 'Altibacter', however, the name has not been validated. Therefore, the strain is classified as a novel genus and is proposed as Constantimarinum furrinae gen. nov., sp. nov. The type strain is ALE3EI^T (= KCCM 43303^T = JCM 33022^T).

Luteirhabdus pelagi gen. nov., sp. nov., a novel member of the family Flavobacteriaceae, isolated from the West Pacific Ocean

A Gram-stain-negative, aerobic, and yellow-pigmented bacterium, designated A3-108^T, was isolated from seawater of the West Pacific Ocean. Cells were non-motile and rod-shaped, with carotenoid-type pigments. Strain A3-108^T grew at pH 6.0–8.5 (optimum 6.5) and 15–40 °C (optimum 28 °C), in the presence of 0.5–10% (w/v) NaCl (optimum 1.0%). It possessed the ability to produce H₂S. Based on the 16S rRNA gene analysis, strain A3-108^T exhibited highest similarity with Aureisphaera salina A6D-50^T (90.6%). Phylogenetic analysis shown that strain A3-108^T affiliated with members of the family Flavobacteriaceae and represented an independent lineage. The principal fatty acids were iso-C_15:0, iso-C_17:0 3-OH, iso-C_15:1 G, and summed feature 3 (C_16:1ω7c and/or C_16:1ω6c). The sole isoprenoid quinone was MK-6. The major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified aminolipid and one unidentified lipid. The ANIb, in silico DDH and AAI values among the genomes of strain A3-108^T and three reference strains were 67.3–71.1%, 18.7–22.1%, and 58.8–71.4%, respectively. The G + C content was 41.0%. Distinctness of the phylogenetic position as well as differentiating chemotaxonomic and other phenotypic traits revealed that strain A3-108^T represented a novel genus and species of the family Flavobacteriaceae, for which the name Luteirhabdus pelagi gen. nov., sp. nov. is proposed (type strain, A3-108^T = CGMCC 1.18821^T = KCTC 82563^T).

Extracellular Vesicle Signatures and Post-Translational Protein Deimination in Purple Sea Urchin (Strongylocentrotus purpuratus) Coelomic Fluid-Novel Insights into Echinodermata Biology

The purple sea urchin (Strongylocentrotus purpuratus) is a marine invertebrate of the class Echinoidea that serves as an important research model for developmental biology, cell biology, and immunology, as well as for understanding regenerative responses and ageing. Peptidylarginine deiminases (PADs) are calcium-dependent enzymes that mediate post-translational protein deimination/citrullination. These alterations affect protein function and may also play roles in protein moonlighting. Extracellular vesicles (EVs) are membrane-bound vesicles that are released from cells as a means of cellular communication. Their cargo includes a range of protein and RNA molecules. EVs can be isolated from many body fluids and are therefore used as biomarkers in physiological and pathological responses. This study assessed EVs present in the coelomic fluid of the purple sea urchin (Strongylocentrotus purpuratus), and identified both total protein cargo as well as the deiminated protein cargo. Deiminated proteins in coelomic fluid EVs were compared with the total deiminated proteins identified in coelomic fluid to assess putative differences in deiminated protein targets. Functional protein network analysis for deiminated proteins revealed pathways for immune, metabolic, and gene regulatory functions within both total coelomic fluid and EVs. Key KEGG and GO pathways for total EV protein cargo furthermore showed some overlap with deimination-enriched pathways. The findings presented in this study add to current understanding of how post-translational deimination may shape immunity across the phylogeny tree, including possibly via PAD activity from microbiota symbionts. Furthermore, this study provides a platform for research on EVs as biomarkers in sea urchin models.

Marixanthomonas spongiae sp. nov., isolated from marine sponge

A novel bacterial strain, designated as HN-E44^T, was isolated from marine sponge collected from Yangpu Bay, Hainan, PR China. Strain HN-E44^T was Gram-stain-negative, non-motile, catalase-positive, oxidase-negative, rod-shaped and yellow-pigmented. Growth occurred at 4-37 °C (optimum, 28 °C), at pH 6-8 (pH 7) and in 0.5-14 % (w/v) NaCl (3-5 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain HN-E44^T formed an independent cluster with Marixanthomonas ophiurae JCM 14121^T within the family Flavobacteriaceae and had the highest sequence similarity of 93.6 % to the closest type strain M. ophiurae JCM 14121^T. The major fatty acids were iso-C_15 : 0, anteiso-C_15 : 0, iso-C_17 : 0 3-OH, summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c) and iso-C_15 : 1 G. The polar lipids comprised phosphatidylethanolamine, sphingolipid, four unidentified phospholipids, an unidentified aminophospholipid and an unidentified lipid. The respiratory quinone was identified as MK-6. The genomic DNA G+C content was determined to be 40.6 mol%. The average nucleotide identity (ANI) and average amino acid identity (AAI) values between strain HN-E44^T and closest type strain M. ophiurae JCM 14121^T were, respectively, 79.6 and 85.2 %, both of which were below thresholds for species delineation (95-96 % ANI and 95-96 % AAI), but were over thresholds for genus delineation (73.98 % ANI and 70-76 % AAI). The combined genotypic and phenotypic distinctiveness demonstrated that strain HN-E44^T could be differentiated from closely related genera. Therefore, it is proposed that strain HN-E44^T represents a novel species of the genus Marixanthomonas, for which the name Marixanthomonas spongiae sp. nov. is proposed, with the type strain HN-E44^T (=MCCC 1K03332^T=LMG 30459^T).

Comparative genomic analysis of Flavobacteriaceae: insights into carbohydrate metabolism, gliding motility and secondary metabolite biosynthesis

BACKGROUND

Members of the bacterial family Flavobacteriaceae are widely distributed in the marine environment and often found associated with algae, fish, detritus or marine invertebrates. Yet, little is known about the characteristics that drive their ubiquity in diverse ecological niches. Here, we provide an overview of functional traits common to taxonomically diverse members of the family Flavobacteriaceae from different environmental sources, with a focus on the Marine clade. We include seven newly sequenced marine sponge-derived strains that were also tested for gliding motility and antimicrobial activity.

RESULTS

Comparative genomics revealed that genome similarities appeared to be correlated to 16S rRNA gene- and genome-based phylogeny, while differences were mostly associated with nutrient acquisition, such as carbohydrate metabolism and gliding motility. The high frequency and diversity of genes encoding polymer-degrading enzymes, often arranged in polysaccharide utilization loci (PULs), support the capacity of marine Flavobacteriaceae to utilize diverse carbon sources. Homologs of gliding proteins were widespread among all studied Flavobacteriaceae in contrast to members of other phyla, highlighting the particular presence of this feature within the Bacteroidetes. Notably, not all bacteria predicted to glide formed spreading colonies. Genome mining uncovered a diverse secondary metabolite biosynthesis arsenal of Flavobacteriaceae with high prevalence of gene clusters encoding pathways for the production of antimicrobial, antioxidant and cytotoxic compounds. Antimicrobial activity tests showed, however, that the phenotype differed from the genome-derived predictions for the seven tested strains.

CONCLUSIONS

Our study elucidates the functional repertoire of marine Flavobacteriaceae and highlights the need to combine genomic and experimental data while using the appropriate stimuli to unlock their uncharted metabolic potential.

Patiriisocius marinistellae gen. nov., sp. nov., isolated from the starfish Patiria pectinifera, and reclassification of Ulvibacter marinus as a member of the genus Patiriisocius comb. nov

A marine strain, designated KK4T, was isolated from the surface of a starfish, Patiria pectinifera, which was collected from seawater off the coast of Hokkaido, Japan. Strain KK4T is a Gram-stain-negative, non-spore-forming, rod-shaped, aerobic bacterium that forms yellow-pigmented colonies. A phylogenetic relationship analysis, based on 16S rRNA gene sequences, revealed that strain KK4T was closely related to Ulvibacter marinus IMCC12008T, Ulvibacter antarcticus IMCC3101T and Ulvibacter litoralis KMM 3912T, with similarities of 96.9, 95.8 and 95.6 %, respectively, but low sequence similarities (<94 %) among other genera in the family Flavobacteriaceae . Genomic similarities between strain KK4T and the three Ulvibacter type strains based on average nucleotide identity and digital DNA–DNA hybridization values were lower than the species delineation thresholds. Moreover, phylogenetic tree based on genome sequences showed that strain KK4T was clustered with U. marinus IMCC12008T and formed a branch independent from the cluster including type species of the genera Ulvibacter , Marixanthomonas , Marinirhabdus , Aureitalea and Aequorivita . Amino acid identity values between strain KK4T/ U. marinus IMCC12008T and the neighbour type species/strains were 61.9–68.2% and 61.5–67.4 %, which were lower than the genus delineation threshold, implying the novel genus status of strain KK4T. Strain KK4T growth occurred at pH 6.0–9.0, 4–30 °C and in NaCl concentrations of 0.5–5.0 %, and optimally at pH 7.0, 25 °C and 3.0 %, respectively. Unlike Ulvibacter strains, strain KK4T could assimilate glucose, mannose, galactose and acetate. The major quinone and fatty acids were menaquinone-6 and iso-C15 : 0 (27.5 %), iso-C15 : 1 G (22.5 %) and iso-C17 : 0 3-OH (12.8 %), respectively. Based on genetic, phylogenetic and phenotypic properties, strain KK4T represents a novel species of the genus Patiriisocius, for which the name Patiriisocius marinistellae gen. nov., sp. nov. is proposed. The type strain is KK4T (=JCM 33344T=KCTC 72225T). In addition, based on the current data, Ulvibacter marinus should be reclassified as Patiriisocius marinus comb. nov.

Glutamicibacter mishrai sp. nov., isolated from the coral Favia veroni from Andaman Sea

A novel aerobic marine actinobacterium (strain S5-52^T) belonging to the genus Glutamicibacter was isolated from the coral Favia veroni sampled from the Andaman Sea, India. Cells are Gram stain positive and rod shaped. The DNA G+C content was 58.7 mol%. The major quinones were MK-8 and MK-9. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, glycolipid, trimannosyldiacylglycerol, phospholipid and dimannosylglyceride. The peptidoglycan type was A4α. Strain S5-52^T showed a maximum 16S rRNA similarity of 99.36% with Glutamicibacter halophytocola DSM 101718^T. The genome of strain S5-52^T was 3.57 Mb that contains 3274 protein coding sequences (CDS). DNA-DNA similarity and ANI values between S5-52^T and the reference strains were below 70% and 95-96%, respectively. Analysis of genomic reduction events in the evolutionary path from the LUCA (last universal common ancestor) to G. mishrai LMG 29155^T and G. halophytocola DSM 101718^T exhibit a number of genes involved in amino acid metabolism, cell wall biogenesis and replication, recombination and repair mechanism that reduced in both the species. Based on phenotypic, chemotaxonomic properties and comparative genomic studies, the strain S5-52^T is considered a novel species of the genus Glutamicibacter, for which the name Glutamicibacter mishrai sp. nov. is proposed. The type strain is S5-52^T (= KCTC 39846^T = LMG 29155^T).

Marinirhabdus gelatinilytica gen. nov., sp. nov., isolated from seawater

A Gram-stain-negative, aerobic and slightly halophilic bacterium was isolated from the South China Sea, and was subjected to characterization using a polyphasic taxonomic approach. Cells of the isolate, designated NH83T, were non-motile and rod-shaped. On the basis of 16S rRNA gene sequence analysis, strain NH83Twas closely related to members of the genera Aureisphaera (with sequence similarity of 92.9 %), Jejudonia (92.8 %), Marixanthomonas (92.6 %), Altuibacter (92.6 %), Ulvibacter (91.5-91.9 %), Gilvibacter (91.8 %) and Aequorivita (89.6-91.2 %), all of which belong to the family Flavobacteriaceae. Phylogenetic analysis indicated that it represented an independent lineage and its closest relatives belonged to the genus Marixanthomonas. The sole respiratory quinone was MK-6. The major polar lipids were phosphatidylethanolamine, two aminolipids, one aminophospholipid and one unidentified lipid. The principal fatty acids were branched fatty acids, including iso-C15 : 0, iso-C17 : 0 3-OH, iso-C16 : 0, iso-C15 : 1 G and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c). The genomic DNA G+C content was 41.0 mol%. Strain NH83T was positive for hydrolysis of aesculin, gelatin and Tween 60. Phylogenetic distinctiveness and chemotaxonomic differences, together with differential phenotypic properties, revealed that strain NH83T could be differentiated from closely related genera. Therefore, it is proposed that strain NH83T represents a novel species in a new genus, for which the name Marinirhabdus gelatinilytica gen. nov., sp. nov. (type strain NH83T=CGMCC 1.15462T=DSM 101478T) is proposed.

Tamlana sedimentorum sp. nov., isolated from shallow sand sediments of the Sea of Japan

An aerobic, Gram-stain-negative, saffron-pigmented, non-motile bacterial strain KMM 9545(T), was isolated from a marine sand sediment sample obtained from the Sea of Japan seashore and characterized in a taxonomic study using a polyphasic approach. The 16S rRNA gene sequence of strain KMM 9545(T) showed a high level of similarity to species of the genus Gaetbulibacter (95.1-96.2%), the type strains of species of the genus Tamlana (94.9-96.1%) and members of the genus Algibacter (94.8-96.1%). Phylogenetic analysis based on the 16S rRNA gene sequences positioned strain KMM 9545(T) as a distinct lineage in the cluster comprising species of the genus Tamlana. Strain KMM 9545(T) grew at temperatures between 5-36 °C and in the presence of 2-4% (w/v) NaCl. It contained MK-6 as the predominant menaquinone and iso-C(15 : 0), iso-C(15 : 1), iso-C(17 : 1) 3-OH, iso-C(15 : 0) 3-OH and iso-C(15 : 0) 2-OH as the major fatty acids. The genomic DNA G+C content was 31.3 mol%. On the basis of the phenotypic characteristics and phylogenetic distance, it can be concluded that strain KMM 9545(T) represents a novel species of the genus Tamlana, for which the name Tamlana sedimentorum sp. nov. is proposed. The type strain is KMM 9545(T) ( = NRIC 0921(T) = JCM 19808(T)).

Marinomonas fungiae sp. nov., isolated from the coral Fungia echinata from the Andaman Sea

A novel aerobic marine bacterium, strain AN44T, was isolated from the coral Fungia echinata sampled from the Andaman Sea, India. Cells were Gram-negative, motile and rod-shaped. Oxidase and catalase tests were positive. Heterotrophic growth was observed at pH 5.5–10 and at 16–42 °C, with optimum growth at pH 7–8 and 28 °C. Strain AN44T grew in the presence of 0.5–11 % (w/v) NaCl; the optimal NaCl concentration for growth was 3–5 %. The DNA G+C content was 47.8 mol%. Predominant cellular fatty acids of strain AN44T were C18 : 1ω7c, C16 : 1ω7c/C16 : 1ω6c, C16 : 0, C10 : 0 3-OH, C12 : 0, C10 : 0, C14 : 0 and C18 : 0. The sole isoprenoid ubiquinone was Q-8. The polar lipids were an unidentified phospholipid, an unidentified aminophospholipid and two unidentified glycolipids. 16S rRNA gene sequence comparisons revealed that strain AN44T clustered within the radiation of the genus Marinomonas and showed similarity of 97.9 % with Marinomonas ostreistagni UST010306-043T, 97.8 % with Marinomonas aquimarina 11SM4T, 97.1 % with Marinomonas brasilensis R-40503T and 97.0 % with Marinomonas communis 8T. However, DNA–DNA relatedness between strain AN44T and closely related type strains was well below 70 %. On the basis of the data from the present polyphasic taxonomic study, strain AN44T is considered to represent a novel species of the genus Marinomonas , for which the name Marinomonas fungiae sp. nov. is proposed. The type strain is AN44T ( = JCM 18476T = LMG 27065T).

Altuibacter lentus gen. nov., sp. nov., a novel member of family Flavobacteriaceae isolated from deep seawater of the South China Sea

A novel chemoheterotrophic, aerobic, Gram-negative, rod-shaped, yellow-pigmented, bacterial strain JLT2010(T) was isolated from deep seawater of the South China Sea. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain JLT2010(T) belongs to the family Flavobacteriaceae and is most closely related to Ulvibacter antarcticus IMCC3101(T) with 95.7 % similarity. Some phenotypic characteristics such as the absence of flexirubin-type pigments, growth at 37 °C, hydrolysis of casein differentiated strain JLT2010(T) from the genus Ulvibacter as well as other genera in the family Flavobacteriaceae. The DNA G+C content of the strain JLT2010(T) was found to be 35.7 mol% and the major respiratory quinone was found to be MK-6. On the basis of phenotypic and phylogenetic features, JLT2010(T) is classified as a novel genus and species within the family Flavobacteriaceae, for which the name Altuibacter lentus gen. nov., sp. nov. is proposed. The type strain is JLT2010(T) (=JCM 18884(T) = CGMCC 1.12167(T)).

Hwangdonia seohaensis gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from a tidal flat sediment

A Gram-staining-negative, aerobic, non-flagellated, non-gliding and rod-shaped bacterial strain, HD-3(T), was isolated from a tidal flat sediment of Hwangdo in the Yellow Sea, South Korea. Strain HD-3(T) grew optimally at pH 7.0-8.0, at 30 °C and in the presence of 2-3% (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain HD-3(T) joined the cluster comprising the type strains of Jejuia pallidilutea and Hyunsoonleella jejuensis. Strain HD-3(T) exhibited 16S rRNA gene sequence similarity values of 93.8% to each of the type strains of J. pallidilutea and Hyunsoonleella jejuensis. Strain HD-3(T) contained MK-6 as the only menaquinone and iso-C(15:0), iso-C(15:1) G, iso-C(17:0) 3-OH and iso-C(15:0) 3-OH as the major fatty acids. The polar lipid profile of strain HD-3(T), which contained phosphatidylethanolamine and one unidentified lipid as major components and one unidentified phospholipid as a significant component, differed slightly from those of the type strains of J. pallidilutea and Hyunsoonleella jejuensis. The DNA G+C content of strain HD-3(T) was 42.3 mol%. Differential phenotypic and chemotaxonomic properties and phylogenetic data of strain HD-3(T) demonstrated that this strain is distinguishable from J. pallidilutea and Hyunsoonleella jejuensis. On the basis of the data presented, strain HD-3(T) is considered to represent a novel genus and species, for which the name Hwangdonia seohaensis gen. nov., sp. nov. is proposed. The type strain is HD-3(T) ( =KCTC 32177(T) =CCUG 63246(T)).

Neiella marina gen. nov., sp. nov., isolated from the sea cucumber Apostichopus japonicus

A novel strain, designated J221(T), was isolated from the intestine of a sea cucumber, Apostichopus japonicus, collected from earthen ponds in Qingdao, China. The strain was Gram-negative, oxidase-positive, aerobic, rod-shaped and motile by means of one to several polar flagella. Growth of strain J221(T) was observed at temperatures between 10 and 40 °C with optimum growth between 25 and 28 °C. The pH range for growth was 5.0-9.0 with optimum growth at pH 7.5-8.0. The dominant fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c, 29.04 %), C16 : 0 (28.93 %) and C18 : 1ω7c (26.15 %). The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine. Diphosphatidylglycerol, an unknown aminolipid and an unknown aminophospholipid were present in moderate to minor amounts in the polar lipid profile. Strain J221(T) had Q-8 as the major respiratory quinone. The DNA G+C content of strain J221(T) was 46.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain J221(T) is a member of the Gammaproteobacteria. It formed a distinct phyletic line with less than 91 % sequence similarity to any species within previously recognized genera. On the basis of this polyphasic taxonomic study, strain J221(T) should be classified as a representative of a novel species of a new genus, for which the name Neiella marina gen. nov., sp. nov. is proposed. The type strain of Neiella marina is J221(T) ( = CGMCC 1.10130(T) = NRRL B-51319(T)).

Nonlabens marinus [corrected] sp. nov., a novel member of the Flavobacteriaceae isolated from the Pacific Ocean

Two aerobic, Gram-negative, orange pigmented and irregular rod-shaped bacteria, designated S1-05 and S1-08(T), were isolated from seawater from the Pacific Ocean. Phylogenetic analysis based on their 16S rRNA gene sequences revealed that the novel isolates could be affiliated with the genus Nonlabens of the family Flavobacteriaceae. The strains S1-05 and S1-08(T) shared 100 % pairwise sequences similarity with each other and showed less than 96.8 % similarity with the cultivated members of the genus Nonlabens. The novel isolates are phenotypically and physiologically different from strains described previously. The strains were found to be non-motile, oxidase positive, catalase positive and hydrolyzed gelatin and aesculin. The G+C contents of the DNA were determined to 41.4 and 41.7 mol% and MK-6 the predominant menaquinone. Anteiso-C15:0 and iso-C15:0 were found to be the major two cellular fatty acids. On the basis of polyphasic taxonomic studies, it was concluded that strains S1-05 and S1-08(T) represent a novel species within the genus Nonlabens, for which the name Nonlabens marina sp. nov. is proposed. The type strain of N. marina is S1-08(T) (=KCTC 23432(T) = NBRC 107738(T)).

Aureitalea marina gen. nov., sp. nov., a member of the family Flavobacteriaceae, isolated from seawater

An irregular rod-shaped, non-gliding, yellow-pigmented bacterium was isolated from seawater from the western North Pacific Ocean near Japan. The strain, designated S1-66T, was Gram-negative, obligately aerobic, heterotrophic and oxidase-positive. Growth occurred in the presence of 1–4 % NaCl, with optimum growth at 2 % NaCl. The strain grew at 15–30 °C, with optimum growth at 20–25 °C. The G+C content of genomic DNA was 48.1 mol% (HPLC). The predominant isoprenoid quinone was MK-6 and the major cellular fatty acids were iso-C15 : 0 (26.4 %), iso-C15 : 1 (20.3 %) and iso-C17 : 0 3-OH (14.2 %). Phylogenetic trees generated by using 16S rRNA gene sequences revealed that strain S1-66T belongs to the family Flavobacteriaceae and showed 94.2 % sequence similarity to the most closely related type strain, Ulvibacter antarcticus IMCC3101T. On the basis of phenotypic and phylogenetic features, S1-66T is classified in a novel genus and species within the family Flavobacteriaceae , for which the name Aureitalea marina gen. nov., sp. nov. is proposed. The type strain of Aureitalea marina is S1-66T ( = NBRC 107741T  = KCTC 23434T).

Soonwooa buanensis gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from seawater

A Gram-negative, non-motile, non-gliding, strictly aerobic, pale yellow colony-forming, rod-shaped bacterial strain, designated HM0024(T), was isolated from coastal seawater of the Yellow Sea and subjected to a polyphasic taxonomy study. Based on 16S rRNA gene sequence similarities, strain HM0024(T) was most closely related to Chryseobacterium balustinum LMG 8329(T) (94.4 %), Chryseobacterium scophthalmum LMG 13028(T) (94.4 %), Chryseobacterium piscium LMG 23089(T) (94.3 %) and Elizabethkingia meningoseptica ATCC 13253(T) (94.0 %) and shared less than 92 % sequence similarity with other members of the family Flavobacteriaceae. Phylogenetic analyses showed that strain HM0024(T) formed an independent phyletic line of descent within the family Flavobacteriaceae. The DNA G+C content of the strain was 29.6 mol% and its major cellular fatty acids (>10 %) were iso-C(15 : 0), iso-C(17 : 0) 3-OH, iso-C(17 : 1)ω 7c and summed feature 3 (C(16 : 1)ω 6c and/or C(16 : 1)ω 7c). The major isoprenoid quinone was MK-6 and the major polar lipids were phosphatidylethanolamine and several aminolipids. Strain HM0024(T) was differentiated from phylogenetically related members of the family by having lower DNA G+C content, larger proportions of summed feature 3, anteiso-C(15 : 0) and iso-C(16 : 0) 3-OH and particular phenotypic characteristics. On the basis of phenotypic and phylogenetic data, strain HM0024(T) is classified as a representative of a novel genus and species, for which the name Soonwooa buanensis gen. nov., sp. nov. is proposed. The type strain of Soonwooa buanensis is HM0024(T) (=KCTC 22689(T) =CECT 7503(T)).