Genus Algoriphagus Research Articles

Identification of a novel monocyclic carotenoid and prediction of its biosynthetic genes in Algoriphagus sp. oki45

Bacteria belonging to the genus Algoriphagus have been isolated from various sources, such as Antarctic sea ice, seawater, and sediment, and some strains are known to produce orange to red pigments. However, the pigment composition and biosynthetic genes have not been fully elucidated. A new red-pigmented Algoriphagus sp. strain, oki45, was isolated from the surface of seaweed collected from Senaga-Jima Island, Okinawa, Japan. Genome comparison revealed oki45’s average nucleotide identity of less than 95% to its closely related species, Algoriphagus confluentis NBRC 111222 T and Algoriphagus taiwanensis JCM 19755 T. Comprehensive chemical analyses of oki45’s pigments, including 1H and 13C nuclear magnetic resonance and circular dichroism spectroscopy, revealed that the pigments were mixtures of monocyclic carotenoids, (3S)-flexixanthin ((3S)-3,1′-dihydroxy-3′,4′-didehydro-1′,2′-dihydro-β,ψ-caroten-4-one) and (2R,3S)-2-hydroxyflexixanthin ((2R,3S)-2,3,1′-trihydroxy-3′,4′-didehydro-1′,2′-dihydro-β,ψ-caroten-4-one); in particular, the latter compound was new and not previously reported. Both monocyclic carotenoids were also found in A. confluentis NBRC 111222 T and A. taiwanensis JCM 19755 T. Further genome comparisons of carotenoid biosynthetic genes revealed the presence of eight genes (crtE, crtB, crtI, cruF, crtD, crtYcd, crtW, and crtZ) for flexixanthin biosynthesis. In addition, a crtG homolog gene encoding 2,2ʹ-β-hydroxylase was found in the genome of the strains oki45, A. confluentis NBRC 111222 T, and A. taiwanensis JCM 19755 T, suggesting that the gene is involved in 2-hydroxyflexixanthin synthesis via 2-hydroxylation of flexixanthin. These findings expand our knowledge of monocyclic carotenoid biosynthesis in Algoriphagus bacteria.Key points• Algoriphagus sp. strain oki45 was isolated from seaweed collected in Okinawa, Japan.• A novel monocyclic carotenoid 2-hydroxyflexixanthin was identified from strain oki45.• Nine genes for 2-hydroxyflexixanthin biosynthesis were found in strain oki45 genome.Graphical

Genomic insight into Algoriphagus limi sp. nov. isolated from a mudflat on the Yellow Sea coast.

A Gram-negative, non-motile, and reddish-orange colored bacterium, designated CAU 1643T, was isolated from a mudflat collected in Ganghwa Island, Republic of Korea. The bacterium was found to grow optimally at 30°C, pH 9.0-9.5, and with 0%-1% (w/v) NaCl. The highest 16S rRNA gene sequence similarities to the bacterium were Algoriphagus kandeliae XY-J91T (97.9%), A. aquimaris F21T (97.1%), A. formosus XAY3209T (97.0%), and A. marincola DSM 16067T (96.2%). The DNA G+C content of the type strain was 40.35 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain CAU 1643T and the reference strains were below the threshold value for species demarcation. The predominant cellular fatty acids were iso-C15:0, iso-C17:0 3-OH, and Summed Feature 9. The major respiratory quinone was menaquinone-7. The genome showed three putative biosynthetic gene clusters that are responsible for different secondary metabolites. Moreover, CAU 1643T contains 72 genes that encode carbohydrate-active enzymes. Based on phenotypic, phylogenetic, and chemotaxonomic evidence, strain CAU 1643T represents novel species in the genus Algoriphagus, for which the name A. limi sp. nov. is proposed. The type strain is CAU 1643T ( = KCTC 92080T, = MCCC 1K07150T).

Scale-dependent enhancement of productivity and stability in xenic Nannochloropsis cultures

Although bacterial amendments can enhance algal productivity and stability, the development of algal-bacteria consortia for commercial-scale utilization is limited. Here, we used an established high-throughput approach to generate algal-bacteria consortia, and tested consortia performance at spatial scales from microplates to 320 L raceway ponds. We used both lab and field-reared strains of Nannochloropsis oceanica to build consortia. In some experiments, we imposed environmental perturbations to test the ability of bacteria to enhance algal culture stability. In repeated assays at the scale of well plates, flasks, and bioreactors, strong effects of bacterial amendments on N. oceanica were observed. These effects were most dramatic when cultures experienced stressors such as temperature perturbations or removal of CO2 augmentation. Isolates that were advanced for field testing included species in the genera Algoriphagus, Oceanicaulis, and Marinobacter. When consortia were generated in the field, positive effects of bacterial amendments were not observed. The amended bacteria were outcompeted, and bacterial community composition across treatments converged after the first grow out. These results highlight the complexity of using consortia in open systems, where interactions between the existing bacterial community, inoculated bacteria, and changing environmental conditions are layered upon other differences in scale and cultivation regimes. Moreover, functionally redundant bacteria are likely present in the field. Following this work, we hypothesize that tight interactions (e.g., obligate relationships between partners) will scale more predictably to outdoor systems. We suggest relying on true synthetic ecological approaches in which the relationships between bacteria and algae partners are well understood, or synthetic ecological approaches coupled with high throughput approaches to design and test consortia. We also recommend future work to examine the effect of algae-bacteria inoculation ratios on productivity and stability, track dynamics of partners through time, and manage ponds to retain beneficial symbioses.

Algoriphagus algorifonticola sp. nov., a marine bacterium isolated from cold spring area of South China Sea.

A Gram-stain-negative, aerobic, non-motile, short-rod-shaped bacterium, designated strain hg1T, was isolated from marine sediment within the cold spring area of South China Sea and subjected to a polyphasic taxonomic investigation. Colonies were circular and 1.0-2.0 mm in diameter, coral in colour, convex and smooth after growth on marine agar at 28 °C for 3 days. Strain hg1T was found to grow at 4-40 °C (optimum, 35-37 °C), at pH 6.5-9.0 (optimum, pH 7.5) and with 0-8 % (w/v) NaCl (optimum, 1.5-2 %). Chemotaxonomic analysis showed the sole respiratory quinone was MK-7, and the principal fatty acids are iso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), and iso-C16 : 0. The major polar lipids are phosphatidylethanolamine, an unidentified phospholipid and five unidentified glycolipids. The DNA G+C content of strain hg1T was 39.6 mol% based on the genome sequence. The comparison of 16S rRNA gene sequence similarities showed that hg1T was closely related to Algoriphagus ornithinivorans DSM 15282T (98.6 % sequence similarity), Algoriphagus zhangzhouensis MCCC 1F01099T (97.9 %) and Algoriphagus vanfongensis DSM 17529T (97.2 %); it exhibited 97.0 % or less sequence similarity to the type strains of other species of the genus Algoriphagus with validly published names. Phylogenetic trees reconstructed with the neighbour-joining, maximum-parsimony and maximum-likelihood methods based on 16S rRNA gene sequences showed that strain hg1T constituted a separate branch with A. ornithinivorans, A. zhangzhouensis, A. vanfongensis in a clade of the genus Algoriphagus. OrthoANI values between strain hg1T and A. ornithinivorans, A. zhangzhouensis and A. vanfongensis were 94.3, 74.1, 73.2 %, respectively, and in silico DNA-DNA hybridization values were 56.2, 18.5 and 18.3 %, respectively. Differential phenotypic properties, together with phylogenetic distinctiveness, demonstrated that strain hg1T is clearly distinct from recognized species of genus Algoriphagus. On the basis of these features, we propose that strain hg1T (=MCCC 1K03570T=KCTC 72111T) represents a novel species of the genus Algoriphagus with the name Algoriphagus algorifonticola sp. nov.

Algoriphagus pacificus sp. nov. and Algoriphagus oliviformis sp. nov., isolated from a mariculture fishpond.

Two Gram-stain-negative, catalase-positive, oxidase-negative, rod-shaped, non-flagellated, non-spore-forming and non-motile strains (YJ13CT and H41T) were isolated from a mariculture fishpond in PR China. Comparisons based on 16S rRNA gene sequences indicated that YJ13CT and H41T shared 16S rRNA gene sequences similarities between 92.6 and 99.2 % with species of the genus Algoriphagus. YJ13CT only shared 93.8 % 16S rRNA gene sequence similarity with H41T. The reconstructed phylogenetic and phylogenomic trees indicated that YJ13CT and H41T clustered closely with species of the genus Algoriphagus. The calculated pairwise orthologous average nucleotide identity with usearch (OrthoANIu) values between strains YJ13CT and H41T and other related strains were all less than 79.5 %. The OrthoANIu value between YJ13CT and H41T was only 69.9 %. MK-7 was the predominant respiratory quinone of YJ13CT and H41T and their major cellular fatty acids contained iso-C15 : 0, C16 : 1 ω7c and C17 : 1 ω9c. The polar lipids profiles of YJ13CT and H41T consisted of phosphatidylethanolamine and several kinds of unidentified lipids. Combining the above descriptions, strains YJ13CT and H41T represent two distinct novel species of the genus Algoriphagus, for which the names Algoriphagus pacificus sp. nov. (type strain YJ13CT=GDMCC 1.2178T=KCTC 82450T) and Algoriphagus oliviformis sp. nov. (type strain H41T=GDMCC 1.2179T=KCTC 82451T) are proposed.

Algoriphagus lacus sp. nov., isolated from a freshwater lake.

A Gram-stain-negative, non-motile, rod-shaped, oxidase-positive, red-pigmented bacterium, strain N3T, was isolated from Fuxian lake, a freshwater lake in Yunnan Province, PR China. Strain N3T was facultatively anaerobic, heterotrophic and negative for catalase. Optimal growth occurred at 30 °C (range 4-45 °C), pH 7.0-8.0 (range 6.5-9.5) and in the presence of 0-3 % (w/v) NaCl (range 0-3 %). The results of phylogenetic analysis based on 16S rRNA gene sequencing revealed that strain N3T was close to the type strains of Algoriphagus aquaeductus, Algoriphagus shivajiensis and Algoriphagus alkaliphilus with sequence similarities of 97.4, 97.3 and 97.2 % respectively. The G+C content of the genomic DNA was 43.9 mol%. The quinone system contained menaquinone MK-7 as the sole component. The major fatty acids were iso-C15 : 0, summed feature 9 (10-methyl C16 : 0 and/or iso-C17 : 1 ω9c), summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω 7c) and iso-C16 : 0. Major polar lipids were phosphatidylcholine, phosphatidylethanolamine, an unidentified glycolipid, one unidentified phospholipid, two unidentified aminolipids and four unidentified lipids. On the basis of physiological, chemotaxonomic and molecular properties as well as phylogenetic distinctiveness, strain N3T should be placed into the genus Algoriphagus as a novel species, for which the name Algoriphagus lacus sp. nov. is proposed. The type strain is N3T (=KCTC 62622T=MCCC 1H00308T).

Algoriphagus sanaruensis sp. nov., a member of the family Cyclobacteriaceae, isolated from a brackish lake in Hamamatsu, Japan.

Strain M8-2T, which was isolated from brackish lake water (Lake Sanaru) in Japan, was characterized for representation of a novel species in the genus Algoriphagus. Cells of strain M8-2T were aerobic, Gram-stain-negative and curved-rod-shaped (0.2-0.5 µm wide and 0.7-1.9 µm long). Strain M8-2T grew optimally at 30 °C, pH 6.5-7.5 and in the presence of 0.5-1.0 % (w/v) NaCl. MK-7 was the sole isoprenoid quinone. The major polar lipids were phosphatidylethanolamine, an unidentified phospholipid and an unidentified polar lipid. The predominant cellular fatty acids were iso-C15 : 0 and anteiso-C15 : 0. Phylogenetic analysis based on its 16S rRNA gene sequence showed that strain M8-2T belonged to the genus Algoriphagus and was closely related to Algoriphagus aquatilis A8-7T, Algoriphagus boseongensis BS-R1T, Algoriphagus aquaeductus T4T, Algoriphagus olei CC-Hsuan-617T, Algoriphagusshivajiensis NIO-S3T and Algoriphagus mannitolivorans DSM 15301T with sequence similarities of 96.6-97.4 %. Results of average nucleotide identity (<75 %) and digital DNA-DNA hybridization (<19 %) studies showed that M8-2T was distinct from its phylogenetic relatives. Based on the results of tests for acid production, the predominant cellular fatty acid composition, the DNA G+C content and phylogenetic position, a novel species in the genus Algoriphagus, with the name Algoriphagussanaruensis sp. nov., is proposed for strain M8-2T (=JCM 31446T=LMG 29969T).

Algoriphagus litoralis sp. nov., isolated from the junction between the ocean and a freshwater lake.

A Gram-stain negative, non-motile and short rod shaped bacterium, designated strain DSL-12T, was isolated from seawater of the East China Sea and characterised phylogenetically and phenotypically. Optimal growth was found to occur at 28°C (range 4-40°C), pH 7 (range 6-12) and with 3%(w/v) NaCl (range 0-8%). Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain DSL-12T is related to members of the genus Algoriphagus and shares high sequence similarities with Algoriphagus boritolerans DSM 17298T (97.6%) and Algoriphagus alkaliphilus DSM 22703T (97.6%). The 16S rRNA gene sequence identities between strain DSL-12T and other current members of the genus Algoriphagus were below 96.4%. The digital DNA-DNA hybridization values between strain DSL-12T and the type strains A. boritolerans DSM 17298T and A. alkaliphilus DSM 22703T were found to be 21.2 ± 2.4% and 20.2 ± 2.4%, respectively. The average nucleotide identity (ANI) values between strain DSL-12T and A. boritolerans DSM 17298T and A. alkaliphilus DSM 22703T were found to be 83.2% and 82.8%, respectively. The sole respiratory quinone was identified as MK-7. The major polar lipids were identified as phosphatidylethanolamine, diphosphatidylglycerol, one unidentified phospholipid and two unidentified lipids. The major fatty acids identified as were iso-C15:0, summed feature 8 (C18:1ω7c and/or C18:1ω6c), C16:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and iso-C17:0. The G+C content of the genomic DNA was determined to be 43.3mol%. The combined genotypic and phenotypic data indicate that strain DSL-12T represents a novel species of the genus Algoriphagus, for which the name Algoriphagus litoralis sp. nov. is proposed, with the type strain DSL-12T (=KCTC 62647T=MCCC 1K03536T).

Algoriphagus formosus sp. nov., isolated from coastal sediment.

A Gram-stain negative, facultative anaerobic, non-motile, strongly orange-pigmented and rod-shaped bacterium, designated XAY3209T, was isolated from a marine sediment sample collected from the coast of Weihai, China. Strain XAY3209T was found to grow optimally at 30°C, at pH 7.0 and in the presence of 2.0% (w/v) NaCl. Its genomic DNA G+C content was 41.9mol%. On the basis of 16S rRNA gene sequence similarity, the novel isolate belongs to the family Cyclobacteriaceae and is related to the genus Algoriphagus. It shares 98.1% 16S rRNA sequence identity with Algoriphagus marincola, its close phylogenetic relative, but did not show similarities more than 97% with other members of the genus Algoriphagus with validly published names. It contained menaquinone-7 (MK-7) as the sole respiratory quinone, iso-C15:0, iso-C17:1 ω9c and Summed feature 3 (C16:1 ω7c and/or iso-C15:0 2-OH) as the major fatty acids. The major polar lipids were phosphatidylethanolamine, one unidentified aminolipid, one unidentified phospholipid and five unidentified lipids. Results of physiological experiments, biochemical tests and genome average nucleotide identity value (with A. marincola MCCC 1F01203T) indicate that strain XAY3209T is genetically and phenotypically distinct from the species of the genus Algoriphagus with validly published names. Strain XAY3209T therefore represents a novel species, for which the name Algoriphagus formosus sp. nov. is proposed. The type strain is XAY3209T (=KCTC 52842T=MCCC 1H00189T).

Algoriphagus marisflavi sp. nov., isolated from water of an estuary environment.

A Gram-stain-negative, non-motile, aerobic and rod-shaped or ovoid bacterial strain, designated KEM-106T, was isolated from water of an estuary environment on the Yellow Sea, South Korea, and subjected to a polyphasic taxonomic study. Strain KEM-106T grew optimally at 30 °C and pH 7.0-8.0 and in the presence of 1.0-2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain KEM-106T belonged to the genus Algoriphagus, clustering with the type strains of Algoriphagus litorisediminis and Algoriphagus aquaemixtae. Strain KEM-106T exhibited 16S rRNA gene sequence similarities of 96.5, 96.2 and 96.0 % to the type strains of Algoriphagus boritolerans, A. litorisediminis and A. aquaemixtae, respectively, and of 92.5-95.8 % to the type strains of the other Algoriphagus species. Strain KEM-106T contained MK-7 as the predominant menaquinone and iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the major fatty acids. The major polar lipids were phosphatidylethanolamine and phosphatidylcholine. The DNA G+C content of strain KEM-106T was 42.7 mol%. Differential phenotypic properties, together with its phylogenetic distinctiveness, revealed that strain KEM-106T is separated from recognized species of the genus Algoriphagus. On the basis of the data presented, strain KEM-106T is considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus marisflavi sp. nov. is proposed. The type strain is KEM-106T (=KCTC 52979T=NBRC 112904T).

Algoriphagus aquaemixtae sp. nov., isolated from water in an estuary environment.

A Gram-stain-negative, non-flagellated, non-gliding, aerobic and rod-shaped or ovoid bacterium, designated strain KEM-10T, was isolated from water in an estuary environment in the Yellow Sea, South Korea, and subjected to a polyphasic taxonomic study. Strain KEM-10T grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain KEM-10T belonged to the genus Algoriphagus, joining the type strain of Algoriphagus litorisediminis showing 97.4 % sequence similarity. Strain KEM-10T exhibited 16S rRNA gene sequence similarity of 92.2-96.1 % to the type strains of the other Algoriphagus species. Strain KEM-10T contained MK-7 as the predominant menaquinone and iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the major fatty acids. The major polar lipids detected in strain KEM-10T were phosphatidylethanolamine and phosphatidylcholine. The DNA G+C content of strain KEM-10T was 40.6 mol%. The mean DNA-DNA relatedness value between strain KEM-10T and the type strain of A. litorisediminis was 12 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain KEM-10T is separated from recognized species of the genus Algoriphagus. On the basis of the data presented, strain KEM-10T is considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus aquaemixtae sp. nov. is proposed. The type strain is KEM-10T (=KCTC 52839T=NBRC 112780T).

Algoriphagus marinus sp. nov., isolated from marine sediment and emended description of the genus Algoriphagus.

A Gram-stain-negative, facultatively anaerobic coccobacilli approximately 0.4-0.5×0.5-1.1 µm, non-motile, orange-pigmented bacterial strain, designated am2T, was isolated from the coastal area of Weihai, PR China (121° 57' E, 37° 29' N). The temperature, pH and NaCl ranges for growth were 4-40 °C, pH 6.5-8.5 and 0.0-6.0 % (w/v) NaCl. The results of phylogenetic analyses based on 16S rRNA gene sequences revealed that am2T was phylogenetically related to members of the genus Algoriphagus and was closely related to Algoriphagus boritolerans, Algoriphagus namhaensis and Algoriphagus antarcticus with 96.4, 96.2 and 95.8 % sequence similarities, respectively. The quinone system contained menaquinone MK-7 as the predominant component. The dominant fatty acids were iso-C17 : 1ω9c,iso-C16 : 1H and iso-C15 : 0. The major polar lipids consisted of one phospholipid, phosphatidylethanolamine and six unknown lipids. The DNA G+C content was 40.6 mol%. On the basis of morphological, physiological and molecular properties as well as on phylogenetic distinctiveness, am2T should be placed into the genus Algoriphagus as a novel species, for which the name Algoriphagus marinus sp. nov. is proposed. The type strain is am2T (=KCTC 52549T=MCCC 1H00178T).

Algoriphagus resistens sp. nov., isolated from marine sediment.

Strain NH1T, a pink-pigmented, facultatively anaerobic, heterotrophic, catalase-positive and oxidase-negative, Gram-stain-negative marine bacterium, was isolated from marine sediment on the coast of Weihai, China. Cells of strain NH1T were rod-shaped, 0.8-2.0 µm in length and 0.5-1.0 µm in width. The strain was able to grow at 13-37 °C, pH 5.5-8.5, in the presence of 0.0-8.0 % (w/v) NaCl. Optimal growth was observed at 28 °C, with 3.0 % (w/v) NaCl and pH 6.5-7.0. Nitrate was reduced. The G+C content of the DNA was 41.9 mol%. The major isoprenoid quinone was MK-7 and the main cellular fatty acids (>10 %) were summed feature 3 (33.6 %) comprising iso-C15 : 0 2-OH and/or C16 : 1ω7c, and iso-C15:0 (19.2%). The major polar lipids in strain NH1T were phosphatidylethanolamine, unidentified lipids, phospholipid and aminolipids. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NH1T was highly related to the type strains of Algoriphagus antarcticus (97.87 % 16SrRNA gene sequence similarity) and Algoriphagus ratkowskyi (97.56 %). On basis of the phenotypic and phylogenetic data, strain NH1T should be classified as representing a novel species of the genus Algoriphagus, for which the name Algoriphagus resistens sp. nov. is proposed. The type strain is NH1T (=MCCC 1H00140T=KCTC 52228T).

Algoriphagus aestuariicola sp. nov., isolated from estuary sediment.

A Gram-staining-negative and strictly aerobic bacterium, designated strain S2-A1T, was isolated from estuary sediment in South Korea. Cells of strain S2-A1T were oxidase- and catalase-positive rods without a gliding motility. Growth was observed at 15-40 °C (optimum, 37 °C), at pH 6.0-10.0 (optimum, pH 7.0-7.5) and in the presence of 0-4.0 % (w/v) NaCl (optimum, 0.5-1.0 %). The sole respiratory quinone was MK-7. iso-C15 : 0, summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c) and summed feature 9 (comprising iso-C17 : 1ω9c/C16 : 0 10-methyl) were found as the major fatty acids (>5 % of the total fatty acids). The polar lipids of strain S2-A1T consisted of phosphatidylethanolamine, an unidentified aminophospholipid, three unidentified aminolipids and five unidentified lipids. The G+C content of the genomic DNA was 45.6 mol%. Strain S2-A1T was most closely related to Algoriphagus taeanensisHMC4223T with a 97.7 % 16S rRNA gene sequence similarity. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain S2-A1T formed a tight phyletic lineage with members of the genus Algoriphagus. On the basis of phenotypic, chemotaxonomic and molecular features, strain S2-A1T clearly represents a novel species of the genus Algoriphagus, for which the name Algoriphagus aestuariicola sp. nov. is proposed. The type strain is S2-A1T (=KACC 18987T=JCM 31546T).

Description of Algoriphagus iocasae sp. nov., isolated from deep-sea sediment.

In this paper, we report on the identification and species characterization of a novel Gram-staining-negative bacterium, strain S61T, isolated from the deep-sea sediment of the Okinawa Trough. Growth of strain S61T occurred at 4-37 °C (optimum, 25 °C), pH 6.0-10.0 (optimum, pH 7.0) and with 0-8 % (w/v) NaCl (optimum, 2 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S61T belonged to the genus Algoriphagus. The closest phylogenetic neighbours of strain S61T were Algoriphaguslutimaris S1-3T (98.1 %), Algoriphagushalophilus JC2051T (98.1 %), Algoriphaguschungangensis CAU 1002T (98.0 %) andAlgoriphagusaestuarii MDM-1T (97.4 %). The sequence similarities between strain S61T and other close members of the genus were below 97 %. The values of DNA-DNA relatedness between strain S61T and its closest relatives in the genus Algoriphagus were well below 70 %. The genomic DNA G+C content of strain S61T was 40.2 mol%. The major menaquinone was MK-7. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unidentified phospholipids and one unidentified lipid. The major fatty acids were iso-C15 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). Phylogenetic, physiological, biochemical, and morphological analyses suggested that this strain represents a novel species of the genus Algoriphagus, for which the name Algoriphagus iocasae sp. nov. is proposed with the type strain S61T (=KCTC 52359T=CCTCC AB 2015446T).

Algoriphagus litorisediminis sp. nov., isolated from a tidal flat.

A Gram-stain-negative, non-flagellated, non-gliding, aerobic and rod-shaped bacterium, designated strain OITF-19T, was isolated from a tidal flat in Oido, an island of South Korea, and subjected to a polyphasic taxonomic study. Strain OITF-19T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0 % (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain OITF-19T belonged to the genus Algoriphagus, clustering with the type strain of Algoriphagus namhaensis, with which it shared 96.5 % sequence similarity. Strain OITF-19T exhibited the highest 16S rRNA gene sequence similarity to Algoriphagus chungangensis CAU 1002T (97.0 %) and of 92.0-96.8 % to the type strains of other Algoriphagus species. Strain OITF-19T contained MK-7 as the predominant menaquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain OITF-19T were phosphatidylcholine, phosphatidylethanolamine and three unidentified lipids. The DNA G+C content of strain OITF-19T was 38.3 mol%. Mean DNA-DNA relatedness between strain OITF-19T and the type strain of A. chungangensis was 26 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain OITF-19T is separated from recognized species of the genus Algoriphagus. On the basis of the data presented, strain OITF-19T is considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus litorisediminis sp. nov. is proposed. The type strain is OITF-19T (=KCTC 52456T=NBRC 112418T).

Algoriphagus roseus sp. nov., isolated from a hexachlorocyclohexane-contaminated dumpsite.

A Gram-staining negative, reddish-pink, non-motile, rod-shaped bacterial strain designated W29T, was isolated from a hexachlorocyclohexane-contaminated dumpsite located in the northern part of India at Ummari Village, Lucknow. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain W29T formed a lineage within the genus Algoriphagusand exhibited highest sequence similarity to Algoriphagus trabzonensis MS7T (98.8 %), followed by Algoriphagusalkaliphilus AC-74T (97.1 %). The 16S rRNA gene sequence similarity between strain W29T and other species of the genus Algoriphagusranged from 93.3-98.8 %. The DNA-DNA relatedness between strain W29T and A. trabzonensisMS7T was 47 % and with other related strains was found to be less than 45 %, confirming strain W29T represents a novel species. The DNA G+C content of strain W29T was 46.2 mol%. Strain W29T was oxidase- and catalase-positive. The major fatty acids (>10 %) of strain W29T were iso-C15 : 0, summed feature 9 (comprising 10-methyl C16 : 0 and/or iso-C17 : 1ω9c) and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c). The respiratory quinone was MK-7. The polar lipid profile consisted of phosphatidylethanolamine, diphosphatidylglycerol, two unidentified aminolipids, an unidentified aminophospholipid, an unidentified phospholipid and unidentified lipids. On the basis of the results obtained from DNA-DNA hybridization, and biochemical and physiological tests in this study, strain W29T represents a novel species of the genus Algoriphagus for which the name Algoriphagus roseus sp. nov. is proposed. The type strain is W29T (=KCTC 42940T=MCC 2876T=DSM 100160T).

Algoriphagus confluentis sp. nov., isolated from the junction between the ocean and a freshwater lake.

A Gram-stain-negative, non-flagellated, non-gliding, aerobic and rod-shaped bacterium, designated HJM-2T, was isolated from the place where the ocean and a freshwater lake meet at Hwajinpo, South Korea, and subjected to a taxonomic study using a polyphasic approach. Strain HJM-2T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 1.0-2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain HJM-2T belonged to the genus Algoriphagus, clustering coherently with the type strain of A. taiwanensis. Strain HJM-2T exhibited 16S rRNA gene sequence similarities of 98.6 and 97.2 % to A. taiwanensis CC-RR-82T and A. boseongensis BS-R1T, respectively, and 92.7-96.7 % to the type strains of the other species of the genus Algoriphagus. Strain HJM-2T contained MK-7 as the predominant menaquinone and iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain HJM-2T were phosphatidylcholine, phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain HJM-2T was 45 mol% and mean DNA-DNA relatedness values with the type strains of A. taiwanensis and A. boseongensis were 10-19 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain HJM-2T is separated from recognized species of the genus Algoriphagus. On the basis of the data presented, strain HJM-2T represents a novel species of the genus Algoriphagus, for which the name Algoriphagus confluentis sp. nov. is proposed. The type strain is HJM-2T ( = KCTC 42704T = NBRC 111222T).

Algoriphagus aestuarii sp. nov., a member of the Cyclobacteriaceae isolated from a tidal-flat sediment of the Yellow Sea in Korea.

A Gram-strain-negative, coccoid or oval-shaped, non-motile bacterial strain, designated MDM-1T, was isolated from a tidal-flat sediment on the Korean peninsula. Strain MDM-1T was found to grow optimally at pH 7.0-8.0, at 30 °C and in the presence of 2-3 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain MDM-1T falls within the clade comprising species of the genus Algoriphagus, clustering with the type strains of Algoriphagus halophilus, A. lutimaris, A. chungangensis and A. machipongonensis, with which it exhibited 97.2-98.5 % 16S rRNA gene sequence similarity. Sequence similarities to the type strains of the other recognized species of the genus Algoriphagus were 92.8-97.6 %. Strain MDM-1T was found to contain MK-7 as the predominant menaquinone and iso-C15 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) as the major fatty acids. The major polar lipids were identified as phosphatidylcholine, phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain MDM-1T was determined to be 42.7 mol% and the mean DNA-DNA relatedness with A. halophilus KCTC 12051T, A. lutimaris S1-3T, A. chungangensis KCTC 23759T, A. machipongonensis DSM 24695T and A. ratkowskyi CIP 107452T was 19.7-5.2 %. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain MDM-1T is distinguishable from recognized species of the genus Algoriphagus. On the basis of the data presented, strain MDM-1T is proposed to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus aestuarii sp. nov. is proposed. The type strain is MDM-1T ( = KCTC 42199T = NBRC 110552T).

Algoriphagus trabzonensis sp. nov., isolated from freshwater, and emended description of Algoriphagus alkaliphilus.

A Gram-staining-negative, non-motile, catalase- and oxidase-positive strain, designated MS7(T), was isolated from freshwater of a river near Trabzon, Turkey. Its taxonomy was investigated using a polyphasic approach. The strain grew optimally at 28 °C and pH 7.5 and in the presence of 2.0% NaCl. 16S rRNA gene sequence analysis revealed that the strain belonged to the genus Algoriphagus; strain MS7(T) showed highest sequence similarity to the type strains of Algoriphagus alkaliphilus (97.3%), Algoriphagus terrigena (96.8%), Algoriphagus jejuensis (96.2%), Algoriphagus boritolerans (96.1%) and Algoriphagus aquatilis (95.8%). The major fatty acids of strain MS7(T) were iso-C15 : 0 (30.14%) and summed future 9 (10-methyl C16 : 0 and/or iso-C17 : 1ω9c 18.75%). Polar lipid analysis revealed phosphatidylethanolamine, a variety of unidentified lipids, an unidentified aminophospholipid, an unidentified phospholipid and an unidentified aminolipid. The major isoprenoid quinone was MK-7.The DNA G+C content of MS7(T) was 41.6 mol%, a value consistent with that of members of the genus Algoriphagus. The level of DNA-DNA relatedness between strain MS7(T) and A. alkaliphilus LMG 22694(T) was 41%, which is clearly below the 70% threshold accepted for species delineation. Thus, our results support the placement of strain MS7(T) within a separate and previously unrecognized species. On the basis of these data, the strain is considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus trabzonensis sp. nov. is proposed. The type strain is MS7(T) ( = NCCB 100372(T) = LMG 26290(T)). An emended description of A. alkaliphilus is also provided.