Zooshikella ganghwensis gen. nov., sp. nov., isolated from tidal flat sediments

Proposal of Zooshikellaceae fam. nov. to accommodate the genera Zooshikella and Spartinivicinus and reclassification of Zooshikella marina as a later heterotypic synonym of Zooshikella ganghwensis based on whole genome sequence analysis

The genus Spartinivicinus, affiliated to the class Gammaproteobacteria, is an important marine member that produces prodiginines. Currently, its taxonomic assignment to family level is not well presented. Phylogeny of 16S rRNA gene sequences indicated that Spartinivicinus forms a monophyletic clade with Zooshikella, which is neighboured by Aestuariirhabdus of the family Aestuariirhabdaceae and another monophyletic clade of the family Endozoicomonadaceae. The 16S rRNA gene of Spartinivicinus ruber S2-4-1H^T had sequence similarities to those of Aestuariirhabdus litorea GTF13^T, Zooshikella members and Endozoicomonas members of 93.4%, 93.2-93.4  and <92.5 %, respectively. Phylogenomic analysis based on 120 bacterial conserved single-copy genes highly supported placing Spartinivicinus as a sister member of Zooshikella, neighboured by Aestuariirhabdaceae and Endozoicomonadaceae members, indicating that Spartinivicinus and Zooshikella could be considered to belong to the same family. Thus, Zooshikellaceae fam. nov. is proposed to accommodate the two genera. Colonies of Spartinivicinus and Zooshikella are red-pigmented, which is different from Aestuariirhabdus (pale-yellow pigmented). The major respiratory quinone of S. ruber was ubiquinone (Q-9), similar to Zooshikella, but distinct from Aestuariirhabdus (Q-9 and Q-8). The predominant fatty acids and polar lipids of Spartinivicinus also showed a similar patterns to Zooshikella, but they were different from Aestuariirhabdus. Lastly, Spartinivicinus possessed a genome size of 6.68 Mbp and DNA G+C content of 40.1mol%, similar to Zooshikella, but much larger than Aestuariirhabdus. In addition, the 16S rRNA genes of Z. ganghwensis JC2044^T and Z. marina JC333^T possess sequence similarity of 99.79 %. Whole genome comparisons indicated that they shared 79.8 % digital DNA-DNA hybridization, 97.78 % average nucleotide identity and 97.31 % average amino acid identity values. Activities of catalase and oxidase for the two strains were positive. Hydrolysis of skimmed milk and Tweens (40, 60 and 80) was positive. Interestingly, the two strains produced different kinds of prodiginines. We propose that Z. marina is a later heterotypic synonym of Zooshikella ganghwensis.

Priestia veravalensis sp. nov., isolated from coastal sample

The taxonomic position of two isolates, SGD-V-76^T and SGD-M-37, isolated from sediment sample of Veraval coast, India, was examined using the polyphasic taxonomic approach. The morphological and chemotaxonomic characteristics of these two organisms are typical of the genus Priestia. The phylogenetic analyses performed using almost complete 16S rRNA gene sequences demonstrated that the isolate belongs to the Bacillaceae family, and forms a clade within the cluster containing Priestia flexus MTCC 2909^T, Priestia aryabhattai B8W22^T and Priestia megaterium KCTC 3007^T and both strains showed highest similarity of > 98% with 3-29 nucleotide differences. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant isoprenoid quinone was MK-7 and the G + C content of strains was 37.5-37.7 mol%. However, the DNA-DNA hybridization and the phenotypic characteristics revealed that, the strain SGD-V-76^T and strain SGD-M-37 are similar species but different from any known Priestia species with ANI values of 79.2, 79.3 and 79.2 and the dDDH values of 17.7, 17.8 and 18.0% respectively. On the basis of phenotypic characteristics, phylogenetic analysis and the results of biochemical and physiological tests, and genomic data strain SGD-V-76^T was clearly distinguished from closely related members of the Priestia genus. Based on the above data analysis strain SGD-V-76^T (= DSM28242^T = KCTC33802^T = CIP111056^T = NCIM5510^T) represents a novel species of the genus Priestia, and we propose the name Priestia veravalensis sp. nov.

An Overview on Industrial and Medical Applications of Bio-Pigments Synthesized by Marine Bacteria

Marine bacterial species contribute to a significant part of the oceanic population, which substantially produces biologically effectual moieties having various medical and industrial applications. The use of marine-derived bacterial pigments displays a snowballing effect in recent times, being natural, environmentally safe, and health beneficial compounds. Although isolating marine bacteria is a strenuous task, these are still a compelling subject for researchers, due to their promising avenues for numerous applications. Marine-derived bacterial pigments serve as valuable products in the food, pharmaceutical, textile, and cosmetic industries due to their beneficial attributes, including anticancer, antimicrobial, antioxidant, and cytotoxic activities. Biodegradability and higher environmental compatibility further strengthen the use of marine bio-pigments over artificially acquired colored molecules. Besides that, hazardous effects associated with the consumption of synthetic colors further substantiated the use of marine dyes as color additives in industries as well. This review sheds light on marine bacterial sources of pigmented compounds along with their industrial applicability and therapeutic insights based on the data available in the literature. It also encompasses the need for introducing bacterial bio-pigments in global pigment industry, highlighting their future potential, aiming to contribute to the worldwide economy.

Reclassification of the Taxonomic Framework of Orders Cellvibrionales, Oceanospirillales, Pseudomonadales, and Alteromonadales in Class Gammaproteobacteria through Phylogenomic Tree Analysis

Orders Oceanospirillales and Pseudomonadales play important roles in various ecosystems as the keystone taxa of microbiomes. However, the two orders present a close evolutionary relationship, which might have caused taxonomic misinterpretation and resulted in an incorrect understanding of their evolutionary history. In this study, first, we used the 16S rRNA gene sequences of 2,049 species of Gammaproteobacteria to build a phylogenetic tree, which demonstrated that reports regarding the evolutionary relationship of orders Cellvibrionales, Oceanospirillales, and Pseudomonadales based on a single conserved gene with a poor resolution have been conflicting; in particular, the major families Moraxellaceae and Pseudomonadaceae of order Pseudomonadales were separated from orders Cellvibrionales and Oceanospirillales Subsequently, we constructed the bac120 trees of all representative reference genomes of class Gammaproteobacteria based on 120 ubiquitous single-copy proteins from bacteria and a phylogenomic tree based on the 119 core genes of 257 reference genomes obtained from orders Cellvibrionales, Oceanospirillales, and Pseudomonadales to cross validate and infer their intrinsic evolutionary relationships. These results indicated that two novel orders, Moraxellales ord. nov. and Kangiellales ord. nov., and three novel families, Marinobacteraceae fam. nov., Perlucidibacaceae fam. nov., and Zooshikellaceae fam. nov., should be proposed. Additionally, orders Cellvibrionales and Oceanospirillales were merged into the order Pseudomonadales except for families Moraxellaceae and Kangiellaceae in class Gammaproteobacteria, which currently includes 18 families. Our work sheds some light on the evolutionary history of class Gammaproteobacteria, which could facilitate the detection and taxonomic analysis of natural communities.IMPORTANCE The orders Cellvibrionales, Oceanospirillales, and Pseudomonadales, as three major orders of the largest bacterial class, Gammaproteobacteria, play important roles in various ecosystems as the keystone taxa of microbiomes, but their evolutionary relationship is currently polyphyletic and chaotic. Here, we constructed a bac120 tree and core-genome tree and calculated the amino acid identity (AAI) value to explore their intrinsic evolutionary history. In this study, we proposed two novel orders and three novel families. This evolution study vastly reconstructed the taxonomic framework of class Gammaproteobacteria and could provide a more distinct perspective on global distribution and evolutionary patterns of these environmental microorganisms.

Spartinivicinus ruber gen. nov., sp. nov., a Novel Marine Gammaproteobacterium Producing Heptylprodigiosin and Cycloheptylprodigiosin as Major Red Pigments

The red pigment prodiginines are identified as bacterial secondary metabolites and display a wide range of bioactive properties. Here, a novel rose-red pigmented bacterium, designated strain S2-4-1H^T, was isolated from coastal sediment of cordgrass Spartina alterniflora. Interestingly, it simultaneously produced heptylprodigiosin (C₂₂H₂₉N₃O) and cycloheptylprodigiosin (C₂₂H₂₇N₃O) as major red pigments, of which their chemical structures were established by liquid chromatography–mass spectrometry (LC–MS) and nuclear magnetic resonance (NMR). Bioactive assays revealed that both heptylprodigiosin and cycloheptylprodigiosin had antibacterial and antifungal activities, and notably, cycloheptylprodigiosin showed stronger bioactivity than heptylprodigiosin. The complete genome of strain S2-4-1H^T was determined to be 6,687,090 bp in length with a G + C content of 40.13 mol%, including a circular chromosome with a size of 6,361,125 bp and three plasmids with a size of 141,078, 102,423, and 82,464 bp, respectively. The biosynthetic gene cluster of two red pigments was predicted on a ∼41-kb gene fragment organized on the chromosome and displayed highly conserved features compared to several gammaproteobacterial species encoding the homologous genes. Finally, based on phenotypic, genotypic, and chemotaxonomic characteristics, strain S2-4-1H^T represented a novel genus-level species named Spartinivicinus ruber gen. nov., sp. nov. (type strain S2-4-1H^T = MCCC 1K03745^T = KCTC 72148^T). Our study provided a novel bacterial source and novel prodigiosin analogs as promising pharmaceuticals in biotechnological application.

Applications of Prodigiosin Extracted from Marine Red Pigmented Bacteria Zooshikella sp. and Actinomycete Streptomyces sp

This study is aimed to determine the distribution, diversity and bioprospecting aspects of marine pigmented bacteria (MPB) isolated from pristine Andaman Islands, India. A total of 180 samples including seawater, sediment, marine plants, invertebrates, and vertebrates were collected and investigated for isolating pigmented bacteria. Results revealed that sediment, invertebrates, and seawater samples were colonized with a greater number of pigmented bacteria pertains to 27.9 × 10³ CFU/mL, 24.1 × 10³ CFU/mL and 6.7 × 10³ CFU/mL respectively. Orange (21.6 × 10³ CFU/mL) and red (8.0 × 10³ CFU/mL) MPB were predominant than other pigmented bacteria. Fourteen potential MPB were selected based on their intense pigmentation and tested for bioactive nature and food colorant applications. Out of 14, two red pigmented strains BSE6.1 & S2.1 displayed potential multifaceted applications, such as antibacterial, antioxidant, food colorant, and staining properties. Brown pigmented strains CO8 and yellow pigmented strain SQ2.3 have displayed staining properties. Chemical characterization of red pigment using TLC, HP-LC, GC-MS, FT-IR and ¹H-NMR analysis revealed prodigiosin as a main chemical constituent. Pure form of prodigiosin compound fractions obtained from both the strains displayed effective antibacterial activity against different human pathogens. MIC and MBC assays revealed that S2.1 requires 300 µg and 150 µg, respectively, and BSE6.1 require 400 µg concentrations of pigment compound for complete inhibition of S. aureus subsp. aureus. On the basis of 16S rRNA sequence analysis, strains S2.1 and BSE6.1 were identified as Zooshikella sp. and Streptomyces sp. and assigned under the GenBank accession numbers: MK680108 and MK951781 respectively.

An Indonesian Marine Bacterium, Pseudoalteromonas rubra, Produces Antimicrobial Prodiginine Pigments

Red pigmented marine bacteria, Pseudoalteromonas rubra strains PS1 and SB14, were isolated from two sampling locations in different ecosystems on Alor Island, Indonesia, and cultured in the laboratory. We analyzed the 16S rRNA gene sequences and examined the pigment composition and found that both strains produced cycloprodigiosin (3), prodigiosin (4), and 2-methyl-3-hexyl-prodiginine (5) as major compounds. In addition, we detected three minor compounds: prodigiosin derivatives 2-methyl-3-propyl prodiginine (1), 2-methyl-3-butyl prodiginine (2), and 2-methyl-3-heptyl-prodiginine (6). To our knowledge, this is the first report that P. rubra synthesizes not only prodigiosin and cycloprodigiosin but also four prodigiosin derivatives that differ in the length of the alkyl chain. The antimicrobial activity of cycloprodigiosin, prodigiosin, and 2-methyl-3-hexyl-prodiginine was examined by a disk-diffusion test against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Candida albicans. We found that, at a concentration of 20 μg/mL, cycloprodigiosin showed the greatest inhibition (25.1 ± 0.55 mm) against S. aureus.

Draft genome sequence of marine sediment-derived red pigmented bacteria Zooshikella sp. strain S2.1 with potential biomedical applications

The present study is aimed to determine the draft genome of novel species of Zooshikella strain S2.1, a potential red pigmented strain isolated recently from the coastal sediment of Andaman and Nicobar Islands, India. This Gram negative, rod shaped aerobic bacterium produces pink, yellowish-red and dark red with metallic green sheen pigmentation on agar plates. It is able to grow under NaCl concentrations of 1 to 9%. This species has antimicrobial, antioxidant, dye and food colorant applications. Whole genome sequence analysis revealed that strain S2.1 represents a novel species of the genus Zooshikella. Draft genome and 16 s rRNA sequences of this species were deposited in GenBank under the Sequence Read Archive accession number PRJNA514840 and GenBank number MK680108, respectively. Here we report the draft genome of Zooshikella sp. strain S2.1 with ~5.9 Mb of chromosomal content and ~0.34 Mb of extra-chromosomal content.

Genome sequence analysis of Zooshikella ganghwensis strain VG4 and its potential for the synthesis of antimicrobial metabolites

•

Draft genome sequence of Z. ganghwensis VG4 is reported.

•

Culture supernatant of Z. ganghwensis VG4 exhibit antimicrobial properties.

•

A total of 7634 genes are identified out of which 74% were annotated.

•

Z. ganghwensis VG4 has genetic potential to synthesize bioactive secondary metabolites, such as, polyketides and nonribosomal peptides.

With antimicrobial resistance on the rise, the discovery of new compounds with novel structural scaffolds exhibiting antimicrobial properties has become an important area of research. Such compounds can serve as starting points for the development of new antimicrobials. In this report, we present the draft genome sequence of the Zooshikella ganghwensis strain VG4, isolated from Red Sea sediments, that produces metabolites with antimicrobial properties. A genomic analysis reveals that it carries at least five gene clusters that have the potential to direct biosynthesis of bioactive secondary metabolites such as polyketides and nonribosomal peptides. By using in-silico approaches, we predict the structure of these metabolites.

Description of Sansalvadorimonas verongulae gen. nov., sp. nov., a gammaproteobacterium isolated from the marine sponge Verongula gigantea

A Gram-stain-negative, strictly aerobic, motile, rod-shaped bacterium, designated strain RKSG058^T, was isolated from the marine sponge Verongula gigantea, collected off the west coast of San Salvador, The Bahamas. Phylogenetic analyses based on 16S rRNA gene sequences revealed that RKSG058^T formed a distinct lineage within the family Hahellaceae (order Oceanospirillales, class Gammaproteobacteria), and was most closely related to the genus Endozoicomonas, with sequence similarities to members of this genus ranging from 92.0 to 93.7 %. Optimal growth occurred at 30 °C, at pH 7 and in the presence of 2-3 % (w/v) NaCl. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The major and minor respiratory quinones were Q-9 and Q-8, respectively. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified aminolipids, an unidentified phospholipid and five unidentified lipids. The DNA G+C content was 42.3 mol%. Biochemical, chemotaxonomic and phylogenetic analyses indicated that strain RKSG058^T represents the first cultured isolate of a novel bacterial genus and species within the family Hahellaceae, for which the name Sansalvadorimonas verongulae gen. nov., sp. nov. is proposed. The type strain of Sansalvadorimonas verongulae is RKSG058^T (=TSD-72^T=LMG 29871^T). An emended description of the genus Kistimonas is provided.

Parendozoicomonas haliclonae gen. nov. sp. nov. isolated from a marine sponge of the genus Haliclona and description of the family Endozoicomonadaceae fam. nov. comprising the genera Endozoicomonas, Parendozoicomonas, and Kistimonas

Two Gram-stain-negative, facultative anaerobic, motile, rod-shaped strains, S-B4-1U^T and JOB-63a, forming small whitish transparent colonies on marine agar, were isolated from a sponge of the genus Haliclona. The strains shared 99.7% 16S rRNA gene sequence identity and a DNA-DNA hybridization value of 100%, but were differentiated by genomic fingerprinting using rep-PCRs. 16S rRNA gene sequence phylogeny placed the strains as a sister branch to the monophyletic genus Endozoicomonas (Oceanospirillales; Gammaproteobacteria) with 92.3-94.3% 16S rRNA gene sequence similarity to Endozoicomonas spp., 91.9 and 92.1% to Candidatus Endonucleobacter bathymodiolin, and 91.9 to 92.1% to the type strains of Kistimonas spp. Core genome based phylogeny of strain S-B4-1U^T confirmed the phylogenetic placement. Major fatty acids were summed feature 3 (C_16:1 ω7c/C_16:1 ω6c) and 8 (C_18:1 ω7c/C_18:1 ω6c) followed by C_10:0 3-OH, C_16:0, and C_18:0. The G+C content was 50.1-51.4mol%. The peptidoglycan diamino acid of strain S-B4-1U^T was meso-diaminopimelic acid, the predominant polyamine spermidine, the major respiratory quinone ubiquinone Q-9; phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine were major polar lipids. Based on the clear phylogenetic distinction, the genus Parendozoicomonas gen. nov. is proposed, with Parendozoicomonas haliclonae sp. nov. as type species and strain S-B4-1U^T (=CCM 8713^T=DSM 103671^T=LMG 29769^T) as type strain and JOB-63a as a second strain of the species. Based on the 16S rRNA gene sequence phylogeny of the Oceanospirillales within the Gammaproteobacteria, the Endozoicomonaceae fam. nov. is proposed including the genera Endozoicomonas, Parendozoicomonas, and Kistimonas as well as the Candidatus genus Endonucleobacter.

Fungal and Bacterial Pigments: Secondary Metabolites with Wide Applications

The demand for natural colors is increasing day by day due to harmful effects of some synthetic dyes. Bacterial and fungal pigments provide a readily available alternative source of naturally derived pigments. In contrast to other natural pigments, they have enormous advantages including rapid growth, easy processing, and independence of weather conditions. Apart from colorant, bacterial and fungal pigments possess many biological properties such as antioxidant, antimicrobial and anticancer activity. This review outlines different types of pigments. It lists some bacterial and fungal pigments and current bacterial and fungal pigment status and challenges. It also focuses on possible fungal and bacterial pigment applications.

Zooshikella marina sp. nov. a cycloprodigiosin- and prodigiosin-producing marine bacterium isolated from beach sand

A red-pigmented bacterium producing a metallic green sheen, designated strain JC333T, was isolated from a sand sample collected from Shivrajpur-Kachigad beach, Gujarat, India. Phylogenetic analyses based on the 16S rRNA gene sequence of strain JC333T showed highest sequence similarity to Zooshikella ganghwensis JC2044T (99.24 %) and less than 91.94 % similarity with other members of the class Gammaproteobacteria. DNA-DNA hybridizations between JC333T and Z. ganghwensis JC2044T showed low relatedness values of 19 ± 1.3 % (reciprocal 21 ± 2.2 %). The major respiratory quinone was ubiquinone-9 (Q9) and the polar lipid profile was composed of the major components diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminophospholipid and an unidentified lipid. The presence of C16 : 1ω7c/C16 : 1ω6c, C16 : 0, C18 : 1ω7c and C12 : 0 as major fatty acids supported the affiliation of strain JC333T to the genus Zooshikella. Prodigiosin, cycloprodigiosin and eight other prodigiosin analogues were the pigments of JC333T. Characterization based on 16S rRNA gene sequence analysis, physiological parameters, pigment analysis, ubiquinone, and polar lipid and fatty acid compositions revealed that JC333T represents a novel species of the genus Zooshikella, for which the name Zooshikella marina sp. nov. is proposed. The type strain is JC333T ( = KCTC 42659T = LMG 28823T).

Bacillus encimensis sp. nov. isolated from marine sediment

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium designated SGD-V-25(T) was isolated from Veraval sediment sample, India. Strain SGD-V-25(T) was capable of growing at 25-50 °C (optimum 37 °C), pH 6-12 (optimum pH 7.0) and with 0-5% (w/v) NaCl. The taxonomic position of this strain was deduced using a polyphasic approach and the 16S rRNA gene sequence analysis showed that the isolate belongs to the phylum Firmicutes , forming the cluster with Bacillus badius MTCC 1548(T), with which it shares highest similarity of 99.1% with 13 nt differences. Other type strains of the genus Bacillus showed less than 96% similarity. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The polar lipid profile of strain SGD-V-25(T) showed the presence of diphosphatidylglycerol, phosphatidylglycerol, phsophoglycolipid and two aminophospholipids. The predominant isoprenoid quinone was MK-7. The major cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0, C16 : 1ω11c and C16 : 0. The genomic DNA G+C content of strain SGD-V-25(T) was 37.6 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA hybridization, strain SGD-V-25(T) could be clearly distinguished from closely related members of the genus Bacillus , and the name Bacillus encimensis sp. nov., is proposed to accommodate this strain. The type strain is SGD-V-25(T) ( =NCIM 5513(T) =DSM 28241(T)).

Permianibacter aggregans gen. nov., sp. nov., a bacterium of the family Pseudomonadaceae capable of aggregating potential biofuel-producing microalgae

A novel bacterial strain, capable of aggregating potential biofuel-producing microalgae, was isolated from the phycosphere of an algal culture and designated HW001T. The novel bacterial strain was identified on the basis of its phylogenetic, genotypic, chemotaxonomic and phenotypic characteristics in this study. Cells were aerobic, Gram-negative rods. 16S rRNA gene-based phylogenetic analysis revealed that strain HW001T is affiliated with the family Pseudomonadaceae in the phylum Proteobacteria , but forms a distinct clade within this family. The DNA G+C content of strain HW001T was 55.4 mol%. The predominant cellular fatty acids were iso-C15 : 0, summed feature 9 (iso-C17 : 1ω9c), C16 : 0 and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c). Q-8 was the main respiratory quinone. The polar lipid profile contained phosphatidylethanolamine, an unidentified aminophospholipid and some unidentified lipids. Based on the extensive polyphasic analysis, strain HW001T represents a novel species of a new genus in the family Pseudomonadaceae , for which the name Permianibacter aggregans gen. nov., sp. nov., is proposed. The type strain of the type species is HW001T ( = CICC 10856T = KCTC 32485T).

Imperialibacter roseus gen. nov., sp. nov., a novel bacterium of the family Flammeovirgaceae isolated from Permian groundwater

A novel bacterial strain, designated P4T, was isolated from Permian groundwater and identified on the basis of its phylogenetic, genotypic, chemotaxonomic and phenotypic characteristics. Cells were aerobic, Gram-stain-negative rods. 16S rRNA gene sequence-based phylogenetic analysis revealed that P4T is affiliated with the family Flammeovirgaceae in the phylum Bacteroidetes , but forms a distinct cluster within this family. The DNA G+C content of strain P4T was 45.2 mol%. The predominant cellular fatty acids were C16 : 1ω6c/C16 : 1ω7c and iso-C15 : 0. MK-7 was the main respiratory quinone. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, unidentified phospholipids, an unidentified aminolipid, unidentified glycolipids and unidentified polar lipids. Based on our extensive polyphasic analysis, a novel species in a new genus, Imperialibacter roseus gen. nov., sp. nov., is proposed. The type strain of Imperialibacter roseus is P4T ( = CICC 10659T = KCTC 32399T).

A novel agent (Endozoicomonas elysicola) responsible for epitheliocystis in cobia Rachycentrum canadum larvae

Aquaculture of cobia has gained popularity in the last decade, and this species is now farmed in several countries in Latin America and Asia. Despite recent improvement in production techniques that allowed the expansion of the industry, little is known about the diseases that affect cobia during the larviculture stage. In this article we investigated the cause of mass mortalities occurring 13-20 d post-hatching in 3 cycles of cobia larviculture. Wet mounts from diseased larvae gills revealed the presence of cyst-like basophilic inclusions. DNA from the cysts was extracted and PCR amplified using the 16S rRNA gene universal primers for prokaryotes. The amplified products were sequenced and analyzed using BLAST, finding a similarity of 99% with Endozoicomonas elysicola, a Gram-negative bacterium. Confirmation of E. elysicola was conducted by designing a specific probe for in situ hybridization. Specific primers were also designed for diagnostic purposes. This is the first report of epitheliocystis in cobia larvae and also the first report of E. elysicola as an epitheliocystis-causing agent.

Salinisphaera orenii sp. nov., isolated from a solar saltern

A taxonomic study was performed on two isolates, designated strains MK-B5(T) and MK-B7, isolated from sediment of a solar saltern pond in Gomso Bay, Republic of Korea. Comparative 16S rRNA gene sequence analysis showed that strains MK-B5(T) and MK-B7 belong to the Gammaproteobacteria and are related most closely to Salinisphaera shabanensis JCM 11575(T) ( = E1L3A(T)) (96.3 and 96.5% similarity, respectively), Salinisphaera dokdonensis KCCM 90064(T) ( = CL-ES53(T)) (95.6 and 95.6%) and Salinisphaera hydrothermalis JCM 115514(T) ( = EPR70(T)) (95.1 and 95.3%). The level of 16S rRNA gene sequence similarity between strains MK-B5(T) and MK-B7 was 99.8%. The G+C contents of their genomic DNAs were 63.4 and 63.6 mol%, respectively, and the major respiratory quinone was ubiquinone-8. DNA-DNA relatedness between strains MK-B5(T) and MK-B7 was 98%, indicating that the two isolates represent a single species. However, the level of DNA-DNA relatedness between the two isolates and S. shabanensis E1L3A(T) (26.4-30.8%) indicates that they represent a novel species. Strains MK-B5(T) and MK-B7 possessed C(14:0), C(16:0) and C(19:0)ω8c cyclo as major fatty acids. The two isolates were Gram-stain-negative, strictly aerobic, short rod-shaped and motile. They grew at 10-40 °C (optimum, 35-37 °C), at pH 5.0-8.5 (optimum, 7.0-7.5) and with 5-25% (w/v) NaCl (optimum, 15% NaCl). On the basis of phenotypic and phylogenetic analyses, strains MK-B5(T) and MK-B7 are thus considered to represent a novel species of the genus Salinisphaera, for which the name Salinisphaera orenii sp. nov. is proposed. The type strain is MK-B5(T) ( = KCTC 23198(T) = JCM 17073(T)).

Bioactive pigments from marine bacteria: applications and physiological roles

Research into natural products from the marine environment, including microorganisms, has rapidly increased over the past two decades. Despite the enormous difficulty in isolating and harvesting marine bacteria, microbial metabolites are increasingly attractive to science because of their broad-ranging pharmacological activities, especially those with unique color pigments. This current review paper gives an overview of the pigmented natural compounds isolated from bacteria of marine origin, based on accumulated data in the literature. We review the biological activities of marine compounds, including recent advances in the study of pharmacological effects and other commercial applications, in addition to the biosynthesis and physiological roles of associated pigments. Chemical structures of the bioactive compounds discussed are also presented.

Exceptional production of both prodigiosin and cycloprodigiosin as major metabolic constituents by a novel marine bacterium, Zooshikella rubidus S1-1

A Gram-negative, red-pigment-producing marine bacterial strain, designated S1-1, was isolated from the tidal flat sediment of the Yellow Sea, Korea. On the basis of phenotypic, phylogenetic, and genetic data, strain S1-1 (KCTC 11448BP) represented a new species of the genus Zooshikella. Thus, we propose the name Zooshikella rubidus sp. nov. Liquid chromatography and mass spectrometry of the red pigments produced by strain S1-1 revealed that the major metabolic compounds were prodigiosin and cycloprodigiosin. In addition, this organism produced six minor prodigiosin analogues, including two new structures that were previously unknown. To our knowledge, this is the first description of a microorganism that simultaneously produces prodigiosin and cycloprodigiosin as two major metabolites. Both prodigiosin and cycloprodigiosin showed antimicrobial activity against several microbial species. These bacteria were approximately 1.5-fold more sensitive to cycloprodigiosin than to prodigiosin. The metabolites also showed anticancer activity against human melanoma cells, which showed significantly more sensitivity to prodigiosin than to cycloprodigiosin. The secondary metabolite profiles of strain S1-1 and two reference bacterial strains were compared by liquid chromatography-mass spectrometry. Multivariate statistical analyses based on secondary metabolite profiles by liquid chromatography-mass spectrometry indicated that the metabolite profile of strain S1-1 could clearly be distinguished from those of two phylogenetically related, prodigiosin-producing bacterial strains.

Intracellular Oceanospirillales bacteria inhabit gills of Acesta bivalves

A novel bacterium was discovered in the gills of the large bivalve Acesta excavata (Limidae) from coral reefs on the northeast Atlantic margin near the shelf break of the fishing ground Haltenbanken of Norway, and confirmed present in A. excavata from a rock-wall in the Trondheimsfjord. Purified gill DNA contained one dominant bacterial rRNA operon as indicated from analysis of broad range bacterial PCR amplicons in denaturant gradient gels, in clone libraries and by direct sequencing. The sequences originated from an unknown member of the order Oceanospirillales and its 16S rRNA gene fell within a clade of strictly marine invertebrate-associated Gammaproteobacteria. Visual inspection by fluorescent in situ hybridization and transmission electron microscopy indicated a pleomorphic bacterium with no visible cell wall, located in aggregates inside vacuoles scattered within the gill cells cytoplasm. Intracellular Oceanospirillales exist in bathymodiolin mussels (parasites), Osedax worms and whiteflies (symbionts). This bacterium apparently lives in a specific association with the Acesta.

Dietary administration of Zooshikella sp. enhance the innate immune response and disease resistance of Paralichthys olivaceus against Sreptococcus iniae

We report the growth, innate immune response, and disease resistance in olive flounder (Paralichthys olivaceus) challenged with Streptococcus iniae after feeding with diet enriched with Zooshikella sp. strain JE-34 three different concentration i.e. Low (3.4 x 10(4), n = 50), medium (3.5 x 10(6), n = 50), and high (3.4 x 10(8), n = 50) cfu ml(-1) supplemented diets, the changes were monitored on weeks 1, 2, 4, 8, 12, and 16. With all diets the innate immune parameters, such as superoxide anion production, phagocytic and lysozyme activity were not enhanced on week 1 and 4. On the other hand, all tested immune parameters in the treated groups significantly enhanced after 8th week; the weight gain significantly increased after 4th week in fish fed with enriched diets. The mortality in olive flounder after administration with high concentration diet showed 25%. With low and medium enriched diets the mortality was 40% and 35%, respectively. In the infected untreated group mortality was 85% while there was no mortality in the control group. The results suggested that Zooshikella sp. strain JE-34 enriched diets could be used to enhance the innate immune response and disease resistance of P. olivaceus against S. iniae.

Marinicella litoralis gen. nov., sp. nov., a gammaproteobacterium isolated from coastal seawater

A Gram-negative, aerobic, greyish–yellowish-pigmented, stenohaline, rod-shaped, non-motile bacterium, strain KMM 3900T, was isolated from a coastal seawater sample collected from the Sea of Japan. Based on phylogenetic analysis, strain KMM 3900T was positioned within the Gammaproteobacteria on a separate branch adjacent to members of the genera Reinekea and Kangiella, sharing less than 88 % 16S rRNA gene sequence similarity with all recognized species of the Gammaproteobacteria. The major isoprenoid quinone was Q-8. Polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and two unknown phospholipids. Fatty acid analysis revealed iso-C15 : 0, C16 : 1 ω7c and C16 : 0 as the dominant components. The DNA G+C content was 43.8 mol%. Based on its unique phenotypic characteristics and phylogenetic remoteness, marine isolate KMM 3900T is considered to represent a novel genus and species, for which the name Marinicella litoralis gen. nov., sp. nov. is proposed. The type strain of Marinicella litoralis is KMM 3900T (=NRIC 0758T =JCM 16154T).

Identification and characterization of metagenomic fragments from tidal flat sediment

Phylogenetic surveys based on cultivation-independent methods have revealed that tidal flat sediments are environments with extensive microbial diversity. Since most of prokaryotes in nature cannot be easily cultivated under general laboratory conditions, our knowledge on prokaryotic dwellers in tidal flat sediment is mainly based on the analysis of metagenomes. Microbial community analysis based on the 16S rRNA gene and other phylogenetic markers has been widely used to provide important information on the role of microorganisms, but it is basically an indirect means, compared with direct sequencing of metagenomic DNAs. In this study, we applied a sequence-based metagenomic approach to characterize uncultivated prokaryotes from tidal flat sediment. Two large-insert genomic libraries based on fosmid were constructed from tidal flat metagenomic DNA. A survey based on end-sequencing of selected fosmid clones resulted in the identification of clones containing 274 bacterial and 16 archaeal homologs in which majority were of proteobacterial origins. Two fosmid clones containing large metagenomic DNAs were completely sequenced using the shotgun method. Both DNA inserts contained more than 20 genes encoding putative proteins which implied their ecological roles in tidal flat sediment. Phylogenetic analyses of evolutionary conserved proteins indicate that these clones are not closely related to known prokaryotes whose genome sequence is known, and genes in tidal flat may be subjected to extensive lateral gene transfer, notably between domains Bacteria and Archaea. This is the first report demonstrating that direct sequencing of metagenomic gene library is useful in underpinning the genetic makeup and functional roles of prokaryotes in tidal flat sediments.

Kistimonas asteriae gen. nov., sp. nov., a gammaproteobacterium isolated from Asterias amurensis

A novel marine bacterium, strain KMD 001(T), was isolated from the starfish Asterias amurensis, which inhabits the East Sea of Korea. Strain KMD 001(T) was aerobic, light-yellow pigmented and Gram-stain-negative. Analyses of the 16S rRNA gene sequence revealed that strain KMD 001(T) represents a novel lineage within the class Gammaproteobacteria. Strain KMD 001(T) is closely related to the genera Endozoicomonas and Zooshikella, which belong to the family Hahellaceae and to the order Oceanospirillales. The 16S rRNA gene sequence of strain KMD 001(T) shows similarities of approximately 91.8-94.6 % with the above-mentioned genera. The DNA G+C content of KMD 001(T) is 47.6 mol%. It contains Q-9 as the major isoprenoid quinone. The predominant fatty acids were determined to be anteiso-C(15 : 0), iso-C(15 : 0), iso-C(14 : 0) and iso-C(16 : 0). Strain KMD 001(T) should be assigned to a novel bacterial genus within the class Gammaproteobacteria based on its phylogenetic, chemotaxonomic and phenotypic characteristics. The name Kistimonas asteriae gen. nov., sp. nov. is proposed. The type strain is KMD 001(T) (=KCCM 90076(T) =JCM 15607(T)).

Widespread occurrence of an intranuclear bacterial parasite in vent and seep bathymodiolin mussels

Many parasitic bacteria live in the cytoplasm of multicellular animals, but only a few are known to regularly invade their nuclei. In this study, we describe the novel bacterial parasite "Candidatus Endonucleobacter bathymodioli" that invades the nuclei of deep-sea bathymodiolin mussels from hydrothermal vents and cold seeps. Bathymodiolin mussels are well known for their symbiotic associations with sulfur- and methane-oxidizing bacteria. In contrast, the parasitic bacteria of vent and seep animals have received little attention despite their potential importance for deep-sea ecosystems. We first discovered the intranuclear parasite "Ca. E. bathymodioli" in Bathymodiolus puteoserpentis from the Logatchev hydrothermal vent field on the Mid-Atlantic Ridge. Using primers and probes specific to "Ca. E. bathymodioli" we found this intranuclear parasite in at least six other bathymodiolin species from vents and seeps around the world. Fluorescence in situ hybridization and transmission electron microscopy analyses of the developmental cycle of "Ca. E. bathymodioli" showed that the infection of a nucleus begins with a single rod-shaped bacterium which grows to an unseptated filament of up to 20 microm length and then divides repeatedly until the nucleus is filled with up to 80,000 bacteria. The greatly swollen nucleus destroys its host cell and the bacteria are released after the nuclear membrane bursts. Intriguingly, the only nuclei that were never infected by "Ca. E. bathymodioli" were those of the gill bacteriocytes. These cells contain the symbiotic sulfur- and methane-oxidizing bacteria, suggesting that the mussel symbionts can protect their host nuclei against the parasite. Phylogenetic analyses showed that the "Ca. E. bathymodioli" belongs to a monophyletic clade of Gammaproteobacteria associated with marine metazoans as diverse as sponges, corals, bivalves, gastropods, echinoderms, ascidians and fish. We hypothesize that many of the sequences from this clade originated from intranuclear bacteria, and that these are widespread in marine invertebrates.

Litoricolaceae fam. nov., to include Litoricola lipolytica gen. nov., sp. nov., a marine bacterium belonging to the order Oceanospirillales

A Gram-negative, non-motile, chemoheterotrophic, facultatively aerobic, short-rod-shaped bacterium, designated IMCC1097(T), was isolated from coastal seawater (10 m depth) of the East Sea, Korea. The temperature, pH and NaCl ranges for growth were 15-30 degrees C, pH 5.0-10.0 and 1.5-10 % NaCl. The colonies of the strain were very small, having a mean diameter of 0.05 mm. 16S rRNA gene sequence data indicated that the strain was most closely related to genera within the class Gammaproteobacteria. Members of the most closely related genera showed less than 90 % sequence similarity and included Saccharospirillum (89.3 %), Oleiphilus (88.7 %), Reinekea (88.2 %), Alcanivorax (86.4-87.6 %) and Zooshikella (87.6 %), which represent five different families of the order Oceanospirillales. Phylogenetic analyses showed that this marine strain represented a distinct phylogenetic lineage in the order Oceanospirillales and could not be assigned to any of the defined families in the order. The predominant fatty acids were C(16 : 1) omega 7c and/or iso-C(15 : 0) 2-OH, C(18 : 1) omega 7c and C(10 : 0) 3-OH, and the DNA G+C content was 57.9 mol%. These chemotaxonomic properties, together with phenotypic characteristics, served to differentiate the strain from phylogenetically closely related genera. The very low sequence similarities (<90 %) and distant relationships between IMCC1097(T) and members of the order Oceanospirillales suggested that the strain merited classification within a novel genus within a novel family in the order. On the basis of taxonomic evidence collected in this study, a novel genus and species are proposed, Litoricola lipolytica gen. nov., sp. nov., within a new family Litoricolaceae fam. nov. Strain IMCC1097(T) (=KCCM 42360(T) =NBRC 102074(T)) is the type strain of Litoricola lipolytica.

Identification of a red-pigmented bacterium producing a potent anti-tumor N-alkylated prodigiosin as Serratia marcescens

A bacterial strain producing a novel prodigiosin analogue 2,2'-[3-methoxy-1'amyl-5'-methyl-4-(1''-pyrryl)] dipyrrylmethene (MAMPDM) possessing potent cytotoxic activity towards cancer cells was isolated and identified. The bacterial cells were spherical and occurred singly, and some of the biochemical tests matched with Micrococcus. Therefore, the isolate was earlier tentatively reported to be Micrococcus sp. In the present studies, analytical profile index (API) suggested this organism to be Klebsiella. However, Klebsiella is not known to produce the red pigment prodigiosin, which is produced by Serratia species and some other bacteria. Based on other biochemical characteristics, particularly DNase, gelatinase, lipase, ornithine decarboxylase, presence of a cell-associated N-alkylated prodigiosin (MAMPDM) and organic solvent tolerance, the strain has now been identified as a variant of Serratia marcescens. 16S rRNA gene analysis conclusively established this organism as S. marcescens ost3. The red pigment (MAMPDM) of this organism showed selective cytotoxic activity in cancer cell lines of different origin (LS-A and U937) and reduced toxicity to non-malignant cells. The LC50 of MAMPDM was 1.59 microM and 0.176 microM for U937 and LS-A cells, respectively, while there was no effect on the viability of L929, a non-malignant cell line, at these concentrations. Thus, S. marcescens ost3 may serve as a source of a new anti-cancer compound.

Marinobacterium halophilum sp. nov., a marine bacterium isolated from the Yellow Sea

A moderately halophilic, aerobic, Gram-negative bacterium was isolated from a tidal flat area of Dae-Chun, Chung-Nam, Korea. The strain, designated mano11T, comprised rod-shaped cells that were motile by means of polar flagella. It grew with 3–12 % NaCl and at 4–37 °C and pH 5.3–9.3. The predominant menaquinone present in this strain was MK-7 and diaminopimelic acid was not found in the cell-wall peptidoglycan. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain mano11T belongs to the genus Marinobacterium. Strain mano11T exhibited 92.8–98.3 % 16S rRNA gene sequence similarity when compared with the type strains of three other species of the genus Marinobacterium. DNA–DNA hybridization between strain mano11T and Marinobacterium georgiense DSM 11526T, its closest relative in terms of 16S rRNA gene sequence similarity, was 13 %. On the basis of the phenotypic, genetic and phylogenetic data, strain mano11T represents a novel species of the genus Marinobacterium, for which the name Marinobacterium halophilum sp. nov. is proposed. The type strain is mano11T (=KCTC 12240T=DSM 17586T).

Endozoicomonas elysicola gen. nov., sp. nov., a gamma-proteobacterium isolated from the sea slug Elysia ornata

A Gram-negative, strictly aerobic, rod-formed bacterium, strain MKT110(T), was isolated from a mollusk, the sea slug Elysia ornata collected in seawater off the coast of Izu-Miyake Island, Japan at a depth of 15m. Comparative 16S rRNA gene sequences analysis indicated that the isolate MKT110(T) constituted a novel lineage in gamma-proteobacteria related to the genera Zooshikella, Oceanospirillum, Microbulbifer, Marinobacter, Saccharospirillum and Pseudomonas. The strain MKT110(T) was closely related to the clones from marine sponge Halichondria okadai (AB054136, AB054161) and the coral Pocillopora damicornis (AY700600, AY700601). The phylogenetic tree based on the 16S rRNA gene sequences showed that MKT110(T) and four clones formed a sub-lineage related to the genus Zooshikella, with a bootstrap value of 100%. MKT110(T) required salt for its growth and was mesophilic. The bacterium contained 16:1omega7c, 16:0 and 14:0 as major cellular fatty acids, and 3-OH 14:0, 3-OH 10:0 and 3-OH 12:0 as major hydroxy fatty acids. The DNA base composition of the isolate was 50.4 mol% G+C. The major quinone was Q-9. The bacterium is distinguished from currently recognized bacterial genera based on phylogenetic and phenotypic features and should be classified in a novel genus for which the name Endozoicomonas elysicola gen. nov., sp. nov. is proposed. (type strain MKT110(T)=IAM 15107(T)=KCTC 12372(T); GenBank accession no. AB196667).

Clostridium ganghwense sp. nov., isolated from tidal flat sediment

A Gram-negative, strictly anaerobic, halophilic, motile, sporulating and rod-shaped bacterium, designated strain HY-42-06T, was isolated from tidal flat sediment from Ganghwa Island in South Korea. The isolate produced glycerol, ethanol and CO2 as fermentation end-products from glucose. Strain HY-42-06T grew optimally at 35 °C, pH 7·5 and 3 % (w/v) artificial sea salts. No growth was observed in the absence of sea salts. In phylogenetic analyses based on 16S rRNA gene sequence, strain HY-42-06T showed a distinct phyletic line within the members of cluster I of the order Clostridiales. The closest phylogenetic neighbour to strain HY-42-06T was Clostridium novyi ATCC 17861T (94·91 % 16S rRNA gene sequence similarity). Several phenotypic characters readily differentiate the tidal flat isolate from phylogenetically related clostridia. On the basis of polyphasic evidence, strain HY-42-06T should be classified as a representative of a novel species, for which the name Clostridium ganghwense sp. nov. is proposed. The type strain is HY-42-06T (=IMSNU 40127T=KCTC 5146T=JCM 13193T).

Extremely halophilic denitrifying bacteria from hypersaline inland lakes, Halovibrio denitrificans sp. nov. and Halospina denitrificans gen. nov., sp. nov., and evidence that the genus name Halovibrio Fendrich 1989 with the type species Halovibrio variabilis should be associated with DSM 3050

Anaerobic enrichments with acetate as electron donor and nitrate as electron acceptor at 4 M NaCl from inland, hypersaline lake sediments from Central Asia resulted in the isolation of several extremely halophilic bacteria that comprised two subgroups, most with vibrio-shaped cells and a single strain with rod-shaped cells. Members of both subgroups were extremely halophilic, with growth occurring in 2–5 M NaCl with an optimum at 2–3 M. 16S rRNA gene sequence analysis showed a close affiliation of the new isolates with Pseudomonas halophila DSM 3050 in the Gammaproteobacteria. However, phenotypic comparison of the denitrifying halophiles with the original description of P. halophila demonstrated that they were more similar to another bacterium isolated from the same source at the same time, the extremely halophilic Halovibrio variabilis, which has since been reclassified as Halomonas variabilis (DSM 3051). Direct cross-comparison showed that the characteristics of these two halophilic bacteria do not correspond with the original descriptions associated with these names and DSM numbers. While it is desirable that this problem be solved, in connection with the present investigations, this is a matter that can only be solved by a Request for an Opinion. On the basis of the phenotypic and genetic comparison of these isolates, it is proposed that the new denitrifying vibrio-shaped isolates represent a novel species, Halovibrio denitrificans sp. nov. (type strain HGD 3T=DSM 15503T=UNIQEM U232T) and that the rod-shaped isolate represents a novel genus and species, Halospina denitrificans gen. nov., sp. nov. (type strain HGD 1-3T=DSM 15505T=UNIQEM U233T).

Bacillus litoralis sp. nov., isolated from a tidal flat of the Yellow Sea in Korea

A Gram-variable, motile, endospore-forming, slightly halophilic bacterial strain, designated SW-211T, was isolated from a tidal flat of the Yellow Sea in Korea, and was characterized taxonomically by using a polyphasic approach. The organism grew optimally at 37 °C and in the presence of 2–3 % NaCl. Comparative 16S rRNA gene sequence analysis showed that strain SW-211T forms a distinct phylogenetic lineage within the radiation of the cluster comprising Bacillus species. Strain SW-211T had cell-wall peptidoglycan based on meso-diaminopimelic acid. The predominant menaquinone was MK-7 and the major fatty acids were anteiso-C15 : 0 (34·8 %), iso-C15 : 0 (15·6 %), iso-C16 : 0 (12·5 %) and iso-C14 : 0 (10·0 %). The DNA G+C content was 35·2 mol%. Strain SW-211T exhibited levels of 16S rRNA gene sequence similarity of <96·2 % with respect to the type strains of recognized Bacillus species. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain SW-211T (=KCTC 3898T=DSM 16303T) was classified in the genus Bacillus as the type strain of a novel species, for which the name Bacillus litoralis sp. nov. is proposed.

Erythrobacter seohaensis sp. nov. and Erythrobacter gaetbuli sp. nov., isolated from a tidal flat of the Yellow Sea in Korea

Two Gram-negative, non-spore-forming, slightly halophilic strains, SW-135T and SW-161T, which were isolated from a tidal flat of the Yellow Sea in Korea, were subjected to a polyphasic taxonomic study. The two isolates lacked bacteriochlorophyll a and contained ubiquinone-10 (Q-10) as the predominant respiratory lipoquinone and C18 : 1 ω7c and C17 : 1 ω6c as the major fatty acids. The DNA G+C contents of strains SW-135T and SW-161T were 62·2 and 64·5 mol%, respectively. Phylogenetic analyses based on 16S rRNA gene sequences showed that the two strains fall within the radiation of the cluster comprising Erythrobacter species. Strains SW-135T and SW-161T exhibited a 16S rRNA gene sequence similarity value of 96·9 % and a mean DNA–DNA relatedness level of 12·3 %. Sequence similarities between strains SW-135T and SW-161T and the type strains of recognized Erythrobacter species ranged from 96·7 to 98·5 %. Levels of DNA–DNA relatedness were low enough to indicate that strains SW-135T and SW-161T represent members of two species separate from all recognized Erythrobacter species. On the basis of polyphasic taxonomic data, strains SW-135T (=KCTC 12228T=DSM 16221T) and SW-161T (=KCTC 12227T=DSM 16225T) were classified as two novel Erythrobacter species, for which the names Erythrobacter seohaensis sp. nov. and Erythrobacter gaetbuli sp. nov. are proposed, respectively.

Kangiella koreensis gen. nov., sp. nov. and Kangiella aquimarina sp. nov., isolated from a tidal flat of the Yellow Sea in Korea

Two Gram-negative, non-motile, non-spore-forming, rod-shaped organisms, strains SW-125T and SW-154T, were isolated from tidal flat sediment of the Yellow Sea in Korea, and subjected to a polyphasic taxonomic study. Strains SW-125T and SW-154T grew optimally at 30–37 °C and in the presence of 2–3 % (w/v) NaCl. They contained ubiquinone-8 (Q-8) as the predominant respiratory lipoquinone and iso-C15 : 0 as the major fatty acid. The DNA G+C contents of strains SW-125T and SW-154T were 44 mol%. Phylogenetic trees based on 16S rRNA gene sequences revealed that the two strains form deep evolutionary lineages of descent within the γ-Proteobacteria. Strains SW-125T and SW-154T exhibited 16S rRNA gene sequence similarity levels of less than 90 % to members of the γ-Proteobacteria used in this analysis. Strains SW-125T and SW-154T showed a 16S rRNA gene sequence similarity level of 98·5 % and a mean DNA–DNA relatedness level of 9·4 %. Therefore, on the basis of phenotypic, phylogenetic and genomic data, a new genus, Kangiella gen. nov., is proposed to accommodate the novel strains, comprising two novel species, Kangiella koreensis sp. nov. (type strain, SW-125T=KCTC 12182T=DSM 16069T) and Kangiella aquimarina sp. nov. (type strain, SW-154T=KCTC 12183T=DSM 16071T).

Thalassomonas ganghwensis sp. nov., isolated from tidal flat sediment

A Gram-negative, aerobic, halophilic bacterium, designated strain JC2041(T), was isolated from a sediment sample of getbol, the Korean tidal flat. Results of 16S rDNA sequence analyses indicated a moderate relationship to Thalassomonas viridans within the gamma-Proteobacteria (94.9 % similarity). Depending on the tree-making algorithm used, the isolate either formed a monophyletic clade with T. viridans or was recovered as a sister group of a class containing the genera Thalassomonas and Colwellia. Phenotypic features of the getbol isolate were similar to those of T. viridans, but several physiological and chemotaxonomic properties, including nitrate reduction, amylase, lecithinase, Tweenase and utilization of 13 carbon sources, distinguished strain JC2041(T) from T. viridans. The polyphasic data presented in this study indicate that the isolate should be classified as a novel species in the genus Thalassomonas. The name Thalassomonas ganghwensis sp. nov. is therefore proposed for the getbol isolate; the type strain is JC2041(T) (=IMSNU 14005(T)=KCTC 12041(T)=DSM 15355(T)).

Aestuariibacter salexigens gen. nov., sp. nov. and Aestuariibacter halophilus sp. nov., isolated from tidal flat sediment, and emended description of Alteromonas macleodii

Two strictly aerobic, halophilic strains of the γ-Proteobacteria, designated JC2042T and JC2043T, were obtained from a sediment sample of getbol, the Korean tidal flat. Comparative 16S rDNA sequence studies revealed that the test strains were related most closely to the type strains of the genera Alteromonas (93·5–95·5 %) and Glaciecola (91·1–93·3 %). Phylogenetic analyses demonstrated that strains JC2042T and JC2043T formed a distinct monophyletic clade within the family Alteromonadaceae and clustered distantly with the genera Alteromonas and Glaciecola. Physiological, biochemical and chemotaxonomic data also indicated that the two getbol isolates were significantly different from members of these two genera and others with validly published names. Cells were rod-shaped and motile with a polar flagellum. The major isoprenoid quinone was Q8. The predominant cellular fatty acids were C16 : 0, C18 : 1 ω7c and a mixture of C16 : 1 ω7c and iso-C15 : 0 2-OH. DNA G+C contents were 48–54 mol%. On the basis of this polyphasic study, Aestuariibacter gen. nov. is proposed with two novel species, Aestuariibacter salexigens sp. nov. (type strain, JC2042T=IMSNU 14006T=KCTC 12042T=DSM 15300T) and Aestuariibacter halophilus sp. nov. (type strain, JC2043T=IMSNU 14007T=KCTC 12043T=DSM 15266T). Aestuariibacter salexigens is the type species of the genus. In addition, an emended description of Alteromonas macleodii is proposed.

Hongiella mannitolivorans gen. nov., sp. nov., Hongiella halophila sp. nov. and Hongiella ornithinivorans sp. nov., isolated from tidal flat sediment

Three marine strains of the Cytophaga–Flavobacterium–Bacteroides group, designated JC2050T, JC2051T and JC2052T, were obtained from a single sediment sample of getbol, the Korean tidal flat. Comparative 16S rDNA sequence studies revealed that the test strains were not closely related to any validly published genera and that these strains were only distantly related to the genus Cyclobacterium (88·7–91·2 %). Phylogenetic analyses demonstrated that the three getbol isolates formed a distinct monophyletic clade within the family Cytophagaceae. Physiological, biochemical and chemotaxonomic data also indicated that these three getbol isolates differed significantly from members of other genera and were sufficiently different from each other to be recognized as separate species. On the basis of polyphasic evidence, a new genus, Hongiella gen. nov., is proposed, with three novel species, Hongiella mannitolivorans sp. nov. (type strain JC2050T=IMSNU 14012T=DSM 15301T), Hongiella halophila sp. nov. (type strain JC2051T=IMSNU 14013T=DSM 15292T) and Hongiella ornithinivorans sp. nov. (type strain JC2052T=IMSNU 14014T=DSM 15282T). Hongiella mannitolivorans is the type species of the genus.