Anaerobic microbial metabolism in soil columns affected by highly alkaline pH: Implication for biogeochemistry near construction and demolition waste disposal sites

Construction and demolition wastes (CDWs) have become a significant environmental concern due to urbanization. CDWs in landfill sites can generate high-pH leachate and various constituents (e.g., acetate and sulfate) following the dissolution of cement material, which may affect subsurface biogeochemical properties. However, the impact of CDW leachate on microbial reactions and community compositions in subsurface environments remains unclear. Therefore, we created columns composed of layers of concrete debris containing-soil (CDS) and underlying CDW-free soil, and fed them artificial groundwater with or without acetate and/or sulfate. In all columns, the initial pH 5.6 of the underlying soil layer rapidly increased to 10.8 (without acetate and sulfate), 10.1 (with sulfate), 10.1 (with acetate), and 8.3 (with acetate and sulfate) within 35 days. Alkaliphilic or alkaline-resistant microbes including Hydrogenophaga, Silanimonas, Algoriphagus, and/or Dethiobacter were dominant throughout the incubation in all columns, and their relative abundance was highest in the column without acetate and sulfate (50.7-86.6%). Fe(III) and sulfate reduction did not occur in the underlying soil layer without acetate. However, in the column with acetate alone, pH was decreased to 9.9 after day 85 and Fe(II) was produced with an increase in the relative abundance of Fe(III)-reducing bacteria up to 9.1%, followed by an increase in the methanogenic archaea Methanosarcina, suggestive of methanogenesis. In the column with both acetate and sulfate, Fe(III) and sulfate reduction occurred along with an increase in both Fe(III)- and sulfate-reducing bacteria (19.1 and 17.7%, respectively), while Methanosarcina appeared later. The results demonstrate that microbial Fe(III)- and sulfate-reduction and acetoclastic methanogenesis can occur even in soils with highly alkaline pH resulting from the dissolution of concrete debris.

Small-scale spatial beta diversity of bacteria in the mixed upper layer of a lake

Bacterial community composition among individual, experimentally generated 'lake snow' particles may be highly variable. Since such aggregates are seasonally abundant in the mixed upper layer of lakes, we hypothesized that particle-attached (PA) bacteria disproportionally contribute to the small-scale spatial beta diversity of pelagic communities. Community composition was analysed in sets of small (10 mL) samples collected from a pre-alpine lake in May, July and October 2018. Bacteria were classified as free-living (FL) or PA depending on their presence in large, 5-μm pre-filtered reference samples. FL exhibited clear seasonal differences in community composition and assembly. They were spatially uniform in May and July, and only a few FL taxa exhibited significant spatial variability. Spatial heterogeneity of FL in October was caused by high alpha and beta diversity of rare taxa, many with a presumably 'tychoplanktic' (alternating attached and free-living) lifestyle. The spatial beta diversity of PA was always high, and only about 10% of their seasonal richness was present in any single sample. Thus, most compositional variability of pelagic bacteria at spatial scales of cm to m either directly or indirectly originated from PA. On a functional level, this genotypic heterogeneity might affect the spatial distribution of rare metabolic traits.

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.

Penaeicolahalotolerans gen. nov., sp. nov., a novel bacterium of the family Cyclobacteriaceae isolated from a shrimp pond

A Gram-stain-negative, non-motile, rod-shaped, aerobic bacterium (designated as LMIT005^T) was isolated from shrimp ponds in Shantou, China. The new isolate was characterized taxonomically using a polyphasic approach. Based on 16S rRNA gene sequence analysis, strain LMIT005^T was found to be affiliated with the family Cyclobacteriaceae of the order Cytophagales while appearing as a distinct lineage. The 16S rRNA gene sequence similarity between strain LMIT005^T and Algoriphagus yeomjeoni KCTC 12309^T, the closest type strain in the family, was 91.3 %. Strain LMIT005^T grew optimally at 25 °C, pH 7 and in the presence of 2.0 % (w/v) NaCl. The DNA G+C content (data from genome sequence) was 40.5 mol%. Compared with reference strain A. yeomjeoni KCTC 12309^T, the average nucleotide identity (ANI) of LMIT005^T was 70 %. The sole respiratory quinone of LMIT005^T was menaquinone (MK-7), and the major fatty acids were summed feature 3 (C_16 : 1 ω6c / C_16 : 1 ω7c). The polar lipids of strain LMIT005^T were mainly composed of phosphatidylethanolamine, phosphatidylcholine, two unidentified amino lipids, two unidentified lipids, one unidentified glycolipid and one unidentified phospholipid. The draft genome of strain LMIT005^T comprised 3 089 781 bp (3.09 Mb) nucleotides and 2773 genes. Antimicrobial resistant-related genes (blal, mexA, and mexb) were annotated in the genome of strain LMIT005^T, which indicated that it might be able to resist β-lactam antibiotics. This was further verified by antimicrobial resistant test. Given its distinct genomic, morphological, and physiological differences from previously described type strains, strain LMIT005^T is proposed as a representative of a novel genus of the family Cyclobacteriaceae, with the name Penaeicola halotolerans gen. nov., sp. nov. The type strain is LMIT005^T (=KCTC 82616^T=CICC 25047^T).

Lunatibacter salilacus gen. nov., sp. nov., a member of the family Cyclobacteriaceae, isolated from a saline and alkaline lake sediment

A non-motile, Gram-staining negative, catalase- and oxidase-positive, crescent-rod shaped bacterium, designated strain CUG 91308^T, was isolated from a sediment sample of Qinghai Lake, Qinghai Province, China. Colonies on OSM agar were round, smooth, flat and pinkish-orange in colour. Strain CUG 91308^T could grow at 15-37 °C, pH 6-12 and in the presence of up to 7.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CUG 91308^T belonged to the family Cyclobacteriaceae and formed a clade with the genus Lunatimonas in the phylogenetic tree, but separated from any species of the known genera within the family. The genomic DNA G+C content is about 42.1 %. The predominant fatty acids (>10 %) were iso-C_15 : 0 (21.1 %), summed feature 3 (C_16 : 1  ω7c / C_16 : 1  ω6c / iso-C_15 : 0 2OH) (14.3 %), iso-C_17 : 0 3OH (12.3 %) and summed feature 9 (iso-C_17 : 1  ω9c / C_16 : 0 10-methyl) (10.6 %). The polar lipids of strain CUG 91308^T were phosphatidylethanolamine (PE) and four unidentified polar lipids. Strain CUG 91308^T contained MK-7 as the major respiratory quinone. On the basis of phenotypic, genotypic and phylogenetic data, strain CUG 91308^T represents a novel species of a novel genus in the family Cyclobacteriaceae, for which the name Lunatibacter salilacus gen. nov., sp. nov. is proposed. The type strain of the proposed new isolate is CUG 91308^T (=KCTC 62636^T=CGMCC 1.13593^T).

Algoriphagus aquimaris sp. nov., isolated from seashore sand

Strain F21^T, a marine, aerobic, Gram-negative, rod-shaped bacterium, was isolated from seashore sand sampled in Pohang, Republic of Korea. Cells of strain F21^T were non-motile, catalase-positive, oxidase-positive, non-spore-forming and formed pinkish-red colonies on marine agar. The strain grew optimally at 37°C, pH 7 and in the presence of 2-3 % NaCl (w/v). Analysis of the 16S rRNA gene sequence of strain F21^T revealed that it belonged to the genus Algoriphagus, family Cyclobacteriaceae, with similarity values of 98.1 and 96.8 % to Algoriphagus marincola DSM 16067^T and Algoriphagus ornithinivorans IMSNU 14014^T, respectively. When comparing the genome sequence of F21 ^T with those of the type strains of six species of the genus Algoriphagus, the values obtained were below the thresholds for analyses of average nucleotide identity (71.8-92.7 %) and in silico DNA-DNA hybridization using the Genome-to-Genome Distance Calculator (14.7-75.2 %). The DNA G+C content of strain F21^T was 42.0 mol%. The chemotaxonomic characteristics of F21^T included MK-7 as the predominant isoprenoid quinone, iso-C_15 : 0, iso-C_17 : 0 3-OH and summed feature 3 (C_16 : 1ω6c and/or C_16 : 1ω7c) as major cellular fatty acids, and phosphatidylcholine and phosphatidylethanolamine as major polar lipids. On the basis of phenotypic and chemotaxonomic properties, phylogenetic distinctiveness, and genomic data, we named strain F21^T as Algoriphagus aquimaris sp. nov. and proposed that strain F21^T (=KEMB 2250-007^T= KCTC 72106^T=JCM 33187^T) in the genus Algoriphagus represents a novel species.

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

Strain M8-2^T, 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 M8-2^T were aerobic, Gram-stain-negative and curved-rod-shaped (0.2-0.5 µm wide and 0.7-1.9 µm long). Strain M8-2^T 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 M8-2^T belonged to the genus Algoriphagus and was closely related to Algoriphagus aquatilis A8-7^T, Algoriphagus boseongensis BS-R1^T, Algoriphagus aquaeductus T4^T, Algoriphagus olei CC-Hsuan-617^T, Algoriphagusshivajiensis NIO-S3^T and Algoriphagus mannitolivorans DSM 15301^T with sequence similarities of 96.6-97.4 %. Results of average nucleotide identity (<75 %) and digital DNA-DNA hybridization (<19 %) studies showed that M8-2^T 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 M8-2^T (=JCM 31446^T=LMG 29969^T).

Response of Microbial Communities to Changing Climate Conditions During Summer Cyanobacterial Blooms in the Baltic Sea

Frequencies and biomass of Baltic Sea cyanobacterial blooms are expected to be higher in future climate conditions, but also of longer duration as a result of increased sea surface temperature. Concurrently, climate predictions indicate a reduced salinity in the Baltic Sea. These climate-driven changes are expected to alter not solely the phytoplankton community but also the role of microbial communities for nutrient remineralization. Here, we present the response of summer plankton communities (filamentous cyanobacteria, picocyanobacteria, and heterotrophic bacteria) to the interplay of increasing temperature (from 16 to 18°C and 20°C) and reduced salinity (from salinity 6.9 to 5.9) in the Baltic Proper (NW Gotland Sea) using a microcosm approach. Warmer temperatures led to an earlier peak of cyanobacterial biomass, while yields were reduced. These conditions caused a decrease of nitrogen-fixers (Dolichospermum sp.) biomass, while non nitrogen-fixers (Pseudanabaena sp.) increased. Salinity reduction did not affect cyanobacterial growth nor community composition. Among heterotrophic bacteria, Actinobacteria showed preference for high temperature, while Gammaproteobacteria thrived at in situ temperature. Heterotrophic bacteria community changed drastically at lower salinity and resembled communities at high temperature. Picocyanobacteria and heterotrophic bacterial biomass had a pronounced increase associated with the decay of filamentous cyanobacteria. This suggests that shifts in community composition of heterotrophic bacteria are influenced both directly by abiotic factors (temperature and salinity) and potentially indirectly by cyanobacteria. Our findings suggest that at warmer temperature, lower yield of photosynthetic cyanobacteria combined with lower proportion of nitrogen-fixers in the community could result in lower carbon export to the marine food web with consequences for the decomposer community of heterotrophic bacteria.

Algoriphagus formosus sp. nov., isolated from coastal sediment

A Gram-stain negative, facultative anaerobic, non-motile, strongly orange-pigmented and rod-shaped bacterium, designated XAY3209^T, was isolated from a marine sediment sample collected from the coast of Weihai, China. Strain XAY3209^T 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 41.9 mol%. 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-C_15:0, iso-C_17:1 ω9c and Summed feature 3 (C_16:1 ω7c and/or iso-C_15:0 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 1F01203^T) indicate that strain XAY3209^T is genetically and phenotypically distinct from the species of the genus Algoriphagus with validly published names. Strain XAY3209^T therefore represents a novel species, for which the name Algoriphagus formosus sp. nov. is proposed. The type strain is XAY3209^T (= KCTC 52842^T = MCCC 1H00189^T).

Microbial community diversity patterns are related to physical and chemical differences among temperate lakes near Beaver Island, MI

Lakes are dynamic and complex ecosystems that can be influenced by physical, chemical, and biological processes. Additionally, individual lakes are often chemically and physically distinct, even within the same geographic region. Here we show that differences in physicochemical conditions among freshwater lakes located on (and around) the same island, as well as within the water column of each lake, are significantly related to aquatic microbial community diversity. Water samples were collected over time from the surface and bottom-water within four freshwater lakes located around Beaver Island, MI within the Laurentian Great Lakes region. Three of the sampled lakes experienced seasonal lake mixing events, impacting either O₂, pH, temperature, or a combination of the three. Microbial community alpha and beta diversity were assessed and individual microbial taxa were identified via high-throughput sequencing of the 16S rRNA gene. Results demonstrated that physical and chemical variability (temperature, dissolved oxygen, and pH) were significantly related to divergence in the beta diversity of surface and bottom-water microbial communities. Despite its correlation to microbial community structure in unconstrained analyses, constrained analyses demonstrated that dissolved organic carbon (DOC) concentration was not strongly related to microbial community structure among or within lakes. Additionally, several taxa were correlated (either positively or negatively) to environmental variables, which could be related to aerobic and anaerobic metabolisms. This study highlights the measurable relationships between environmental conditions and microbial communities within freshwater temperate lakes around the same island.

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 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).

Mariniradius saccharolyticus gen. nov., sp. nov., a member of the family Cyclobacteriaceae isolated from marine aquaculture pond water, and emended descriptions of the genus Aquiflexum and Aquiflexum balticum

A novel marine, Gram-stain-negative, oxidase- and catalase- positive, rod-shaped bacterium, designated strain AK6T, was isolated from marine aquaculture pond water collected in Andhra Pradesh, India. The fatty acids were dominated by iso-C15 : 0, iso-C17 : 1ω9c, iso-C15 : 1 G, iso-C17 : 0 3-OH and anteiso-C15 : 0. Strain AK6T contained MK-7 as the sole respiratory quinone and phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipid and seven unidentified lipids as polar lipids. The DNA G+C content of strain AK6T was 45.6 mol%. Phylogenetic analysis showed that strain AK6T formed a distinct branch within the family Cyclobacteriaceae and clustered with Aquiflexum balticum DSM 16537T and other members of the family Cyclobacteriaceae . 16S rRNA gene sequence analysis confirmed that Aquiflexum balticum DSM 16537T was the nearest neighbour, with pairwise sequence similarity of 90.1 %, while sequence similarity with the other members of the family was <88.5 %. Based on differentiating phenotypic characteristics and phylogenetic inference, strain AK6T is proposed as a representative of a new genus and species of the family Cyclobacteriaceae , as Mariniradius saccharolyticus gen. nov., sp. nov. The type strain of Mariniradius saccharolyticus is AK6T ( = MTCC 11279T = JCM 17389T). Emended descriptions of the genus Aquiflexum and Aquiflexum balticum are also proposed.

Algoriphagus zhangzhouensis sp. nov., isolated from mangrove sediment

A Gram-negative, short-rod-shaped and non-motile bacterium, strain 12C11T, was isolated from an oil-degrading consortium, enriched from the Fugong mangrove sediment, Fujian Province of China. Optimum growth was observed at 25 °C, at pH 7.5 and with 4 % (w/v) NaCl. Comparative 16S rRNA gene sequence analysis demonstrated that it shared highest similarity with members of the genus Algoriphagus (97.5–93.4 %), exhibiting 97.5 % sequence similarity to Algoriphagus ornithinivorans IMSNU 14014T, followed by Algoriphagus vanfongensis KMM 6241T (97.2 %); it shared <96.0 % sequence similarity with other members of the genus. Levels of nucleotide sequence similarity between gyrB (DNA gyrase subunit B) genes of strain 12C11T and A. vanfongensis KMM 6241T, A. ornithinivorans IMSNU 14014T, Algoriphagus marincola SW-2T and Algoriphagus hitonicola 7-UAHT were 78.8, 78.6, 75.6 and 77.4 %, respectively. Phylogenetic trees based on these housekeeping genes showed that strain 12C11T and other Algoriphagus strains formed a distinct lineage. The dominant fatty acids were iso-C15 : 0 (32.1 %), C16 : 1ω7c/C16 : 1ω6c (11.6 %), iso-C17 : 1 I/anteiso-C17 : 1 B (10.1 %), iso-C17 : 0 3-OH (9.2 %) and iso-C17 : 1ω9c/C16 : 0 10-methyl (7.1 %), which accounted for 70.0 % of the total fatty acids. DNA–DNA hybridization showed that strain 12C11T shared low DNA–DNA relatedness with A. vanfongensis KMM 6241T and A. ornithinivorans IMSNU 14014T (30.7±0.9 and 30.5±1.8 %, respectively). The G+C content of the chromosomal DNA of strain 12C11T was 38.4 mol%. The major respiratory quinones were MK-7 (96.0 %) and MK-6 (4.0 %). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, the novel strain most appropriately belongs to the genus Algoriphagus , but can readily be distinguished from known Algoriphagus species. The name Algoriphagus zhangzhouensis sp. nov. is proposed (type strain 12C11T = CGMCC 1.11027T = MCCC 1F01099T = DSM 25035T).

Algoriphagus chungangensis sp. nov., isolated from a tidal flat sediment

A Gram-stain-negative, non-spore-forming, non-motile, strictly aerobic, rod-shaped bacterial strain, designated CAU 1002T, was isolated from a tidal flat sediment and its taxonomic position was investigated using a polyphasic approach. Strain CAU 1002T grew optimally at 30 °C and pH 7.5. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CAU 1002T formed a distinct lineage within the genus Algoriphagus and was most closely related to Algoriphagus lutimaris KCTC 22630T and Algoriphagus halophilus KCTC 12051T (97.75 and 97.74 % 16S rRNA gene sequence similarity, respectively). The strain contained MK-7 as the major isoprenoid quinone and iso-C15 : 0 and C16 : 1ω7c and/or iso-C15 : 0 2-OH (summed feature 3) as the major fatty acids. The cell-wall peptidoglycan of strain CAU 1002T contained meso-diaminopimelic acids. The major whole-cell sugars were glucose, arabinose, sucrose, and ribose. The polar lipid profile was composed of phosphatidylethanolamine, five unidentified aminolipids, one unidentified aminophospholipid, one unidentified phospholipid, one unidentified aminoglycolipid, one unidentified glycolipid and twelve unidentified lipids. The DNA G+C content of strain CAU 1002T was 38.0 mol%. On the basis of phylogenetic inference, phenotypic, chemotaxonomic and genotypic data, strain CAU 1002T should be classified into the genus Algoriphagus as a member of a novel species, for which the name Algoriphagus chungangensis sp. nov. is proposed. The type strain is CAU 1002T ( = KCTC 23759T = CCUG 61890T). The description of the genus Algoriphagus is emended.

Algoriphagus shivajiensis sp. nov., isolated from Cochin back water, India

Novel orange-pigmented, Gram-negative, rod-shaped, non-motile bacteria, designated strains NIO-S3(T) and NIO-S4, were isolated from a water sample collected from Cochin back waters, Thanneermukkom and Arookutty, Kerala, India. Both strains were positive for oxidase and catalase activities, and hydrolyzed gelatin and Tween 40. The predominant fatty acids were iso-C15:0, anteiso-C15:0, iso-C17:0 3OH, C16:1ω7c/C16:1ω6c (summed feature 3) and iso-C17:1ω9c/C16:0 10-methyl (summed feature 9), whereas MK-7 was the major respiratory quinone, and phosphatidylethanolamine, two unidentified phospholipids and one unidentified lipid were the only polar lipids. The DNA G+C content of the two strains was 43.7 and 43.6mol%, respectively. The 16S rRNA gene sequence analysis indicated that they were members of the genus Algoriphagus and closely related to Algoriphagus olei CC-Hsuan-617(T), Algoriphagus aquatilis A8-7(T), Algoriphagus aquaeductus LMG 24398(T) and Algoriphagus mannitolivorans DSM 15301(T), with pairwise sequence similarities of 96.8, 96.6, 96.2 and 96.2%, respectively. DNA-DNA hybridization between strains NIO-S3(T) and NIO-S4 showed a relatedness of 89%. Based on data from the current polyphasic study, the strains are proposed as a novel species of the genus Algoriphagus, for which the name Algoriphagus shivajiensis sp. nov. is proposed. The type strain of A. shivajiensis is NIO-S3(T) (=JCM 17885(T)=MTCC 11066(T)).

In situ substrate preferences of abundant bacterioplankton populations in a prealpine freshwater lake

The substrate partitioning of sympatric populations of freshwater bacterioplankton was studied via microautoradiography and fluorescence in situ hybridization. Fourteen radiolabeled tracers were used to assess microbial acquisition spectra of low-molecular-weight (LMW) organic compounds. The most abundant group, ac1 Actinobacteria, were highly active in leucine, thymidine and glucose assimilation, whereas Alphaproteobacteria from the LD12 lineage (the freshwater sister clade of SAR11) only weakly incorporated these tracers, but exhibited a distinct preference for glutamine and glutamate. Different Bacteroidetes showed contrasting uptake patterns: Flavobacteriales did not incorporate significant amounts of any LMW compound, and Cyclobacteriaceae were clearly specialized on leucine, glucose and arginine. Betaproteobacteria represented the most active and versatile bacterioplankton fraction and >90% of them could be assigned to eight species- to genus-like populations with contrasting substrate specialization. Limnohabitans sp. were the most abundant and active Betaproteobacteria, incorporating almost all tracers. While three closely related betaproteobacterial populations substantially differed in their uptake spectra, two more distantly related lineages had very similar preferences, and one population did not incorporate any tracer. The dominant phototrophic microorganism, the filamentous cyanobacterium Planktothrix rubescens, assimilated several substrates, whereas other (pico)cyanobacteria had no heterotrophic activity. The variable extent of specialization by the studied bacterial taxa on subsets of LMW compounds contrasts theoretical considerations about non-selective microbial substrate assimilation at oligotrophic conditions. This physiological niche separation might be one explanation for the coexistence of freshwater bacterioplankton species in a seemingly uniform environment.

Cecembia lonarensis gen. nov., sp. nov., a haloalkalitolerant bacterium of the family Cyclobacteriaceae , isolated from a haloalkaline lake and emended descriptions of the genera Indibacter , Nitritalea and Belliella

A novel Gram-staining-negative, rod-shaped, non-motile bacterium, designated strain LW9T, was isolated from a water sample collected from Lonar Lake of Buldhana district, Maharashtra, India. Colonies and broth cultures were reddish orange due to the presence of carotenoid pigments. Strain LW9T was positive for catalase, ornithine decarboxylase and lysine decarboxylase activities and negative for gelatinase, oxidase, urease and lipase activities. The predominant fatty acids were iso-C15 : 0 (31.3 %), iso-C16 : 0 (9.3 %), anteiso-C15 : 0 (7.3 %), iso-C16 : 1 H (6.1 %), summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c; 5.9 %), iso-C17 : 1ω9c (5.4 %) and iso-C17 : 0 3-OH (5.0 %). Strain LW9T contained MK-7 as the major respiratory quinone. The polar lipids consisted of phosphatidylethanolamine, two unidentified aminolipids and seven unidentified lipids. The DNA G+C content of strain LW9T was 40.5 mol%. 16S rRNA gene sequence analysis indicated that the type strains of Indibacter alkaliphilus and Aquiflexum balticum , two members of the family Cyclobacteriaceae (phylum ‘ Bacteroidetes ’) were the most closely related strains with sequence similarities of 93.0 and 94.0 %, respectively. Other members of the family Cyclobacteriaceae showed sequence similarities <93.0 %. Based on these phenotypic characteristics and on phylogenetic inference, strain LW9T is proposed as the representative of novel species in a new genus, Cecembia lonarensis gen. nov., sp. nov. The type strain of the type species, Cecembia lonarensis, is LW9T ( = CCUG 58316T = KCTC 22772T). Emended descriptions of the genera Indibacter , Nitritalea and Belliella are also proposed.

Mongoliicoccus roseus gen. nov., sp. nov., an alkaliphilic bacterium isolated from a haloalkaline lake

Two pink, non-motile, aerobic, alkaliphilic, halotolerant, Gram-negative cocci, designated MIM28T and MIM29, were isolated from the surface water of a haloalkaline lake on the Mongolia Plateau. The isolates grew optimally at 30–33 °C, at pH 8–9 and with 3–4 % (w/v) NaCl. The isolates were chemoheterotrophic and could assimilate carbohydrates, organic acids and amino acids. The major respiratory quinone was menaquinone MK-7. The major polar lipids were phosphatidylcholine and phosphatidylethanolamine. The predominant cellular fatty acids were iso-C15 : 0 (13.8–17.5 %), anteiso-C15 : 0 (10.5–11.2 %), iso-C16 : 0 (9.9–13.0 %), C16 : 0 (4.3–4.6 %), iso-C17 : 0 (3.8–5.3 %), anteiso-C17 : 0 (3.7–7.1 %), C17 : 1ω6c (4.6–6.4 %), iso-C17 : 0 3-OH (4.6–5.8 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 4.0–6.4 %) and summed feature 9 (iso-C17 : 1ω9c and/or C16 : 0 10-methyl; 10.4–12.5 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates were most closely related to Litoribacter ruber YIM CH208T (93.6 % 16S rRNA gene sequence similarity), the genus Echinicola (90.4–92 %) and other members of the family Cyclobacteriaceae (87.8–90 %). The DNA G+C contents of strains MIM28T and MIM29 were 62.8 and 62.2 mol%. On the basis of morphology, physiology, fatty acid composition, phylogeny and 16S rRNA gene sequence analysis, the isolates are assigned to a novel species of a new genus, for which we propose the name Mongoliicoccus roseus gen. nov., sp. nov.; the type strain of the type species is MIM28T ( = ACCC 05511T  = KCTC 19808T).

Algoriphagus namhaensis sp. nov., isolated from seawater

A Gram-staining-negative, non-motile, non-spore-forming bacterial strain, DPG-3T, was isolated from seawater from the South Sea in Korea, and its taxonomic position was investigated using a polyphasic approach. Strain DPG-3T grew optimally at 30 °C and in the presence of 2 % (w/v) NaCl. In a neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain DPG-3T fell within a clade comprising Algoriphagus species and appeared most closely related to Algoriphagus halophilus JC 2051T (96.1 %16S rRNA gene sequence similarity) and Algoriphagus lutimaris S1-3T (96.4 %). The type strains of other Algoriphagus species showed 16S rRNA gene sequence similarities of 92.9–96.0 % with strain DPG-3T. The predominant menaquinone of strain DPG-3T was MK-7. The major fatty acids were iso-C15 : 0 and iso-C15 : 0 2-OH and/or C16 : 1ω7c (summed feature 3). The major polar lipids detected in strain DPG-3T were phosphatidylcholine, phosphatidylethanolamine and an unidentified lipid. The genomic DNA G+C content was 44.8 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain DPG-3T is considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus namhaensis sp. nov. is proposed. The type strain is DPG-3T ( = KCTC 23419T = CCUG 60523T).

Mongoliitalea lutea gen. nov., sp. nov., an alkaliphilic, halotolerant bacterium isolated from a haloalkaline lake

Two bacterial isolates from the surface water of a haloalkaline lake on the Mongolia Plateau, strains MIM18T and MIM19, were characterized; their morphological, physiological and chemotaxonomic characters, and phylogenetic position based on 16S rRNA gene sequences, were determined. The two strains were alkaliphilic, halotolerant, non-motile, aerobic, Gram-negative, orange-red, rod-shaped and oxidase-positive. Growth was observed in 0–5.5 % (w/v) NaCl, with optimum growth at 1 %. The temperature range for growth was 0–41 °C, with good growth at 28–37 °C and optimum growth at 30–33 °C. The DNA G+C content was 39.8–41.2 mol%. The strains contained menaquinone MK-7 as the major respiratory quinone and phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine as the major polar lipids. Predominant cellular fatty acids were iso-C15 : 0 (28.1–29.3 %), iso-C17 : 0 3-OH (14.6–18.8 %), C15 : 1ω6c (5.3–8.6 %), C14 : 0 2-OH and/or iso-C15 : 0 2-OH (5.4–6.1 %), and iso-C17 : 1ω9c and/or C16 : 0 10-methyl (5.0–6.8 %). 16S rRNA gene sequence analysis showed that Belliella and Nitritalea of the family Cyclobacteriaceae were the closest related species with sequence similarities of 91.7–92.3 % and 88.2 %, respectively, with strains of these genera; other members of the Cyclobacteriaceae had sequence similarities lower than 88 %. Phylogenetic analysis indicated that the strains formed a deep-rooted lineage distinct from the clades represented by the genera Belliella, Nitritalea, Indibacter, Aquiflexum, Echinicola, Litoribacter, Cyclobacterium and Algoriphagus. Based on the phenotypic and phylogenetic characteristics mentioned above, the two strains are representatives of a single novel species in a new genus; the name Mongoliitalea lutea gen. nov., sp. nov. is proposed, with MIM18T ( = ACCC 05421T = KCTC 23224T) as the type strain.

Algoriphagus aquaeductus sp. nov., isolated from a freshwater pipe

A Gram-staining-negative, aerobic to microaerophilic, rod-shaped, red-coloured bacterium, strain T4T, was isolated from a freshwater pipe on Tenerife island. A polyphasic taxonomic study was performed in order to characterize the strain in detail. The isolate is surrounded by a slime capsule, occurs singly, in the form of short chains, or in aggregates, and exhibits catalase and oxidase activities. Growth was observed at 15–42 °C. Optimum growth occurred at pH 8 with mono- and disaccharides, followed by polysaccharides and deoxysaccharides, but the bacterium utilized only a restricted spectrum of alcohols, alditols, amides, amines, carboxylic acids and amino acids. Strain T4T tolerated concentrations of 0–4 % (w/v) NaCl and contained MK-7 as predominant isoprenoid quinone as well as carotenoids, but lacked pigments of the flexirubin type. The predominant fatty acids were iso-C15 : 0 (32.2 %), summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c; 22.5 %), and iso-C17 : 0 3-OH (7.9 %). Major polar lipids were phosphatidylethanolamine, phospholipids, aminophospholipids and other lipids of unknown character. The DNA G+C content was approximately 41.8 mol%. The sequence of the 16S-rRNA gene assigned strain T4T to the CFB group, forming a coherent cluster with species of the genus Algoriphagus with the highest similarity of 98.8 % to Algoriphagus aquatilis A8-7T. DNA–DNA hybridization revealed 37.5 % relatedness to strain A8-7T. Based on morphological, physiological and molecular properties as well as on phylogenetic distinctiveness, strain T4T should be placed into the genus Algoriphagus as a novel species, for which the name Algoriphagus aquaeductus sp. nov. (type strain T4T  = DSM 19759T  = LMG 24398T  = NCIMB 14399T) is proposed.

Algoriphagus machipongonensis sp. nov., co-isolated with a colonial choanoflagellate

A Gram-negative, non-motile, non-spore-forming bacterial strain, PR1(T), was isolated from a mud core sample containing colonial choanoflagellates near Hog Island, Virginia, USA. Strain PR1(T) grew optimally at 30 °C and with 3 % (w/v) NaCl. Strain PR1(T) contained MK-7 as the major menaquinone as well as carotenoids but lacked pigments of the flexirubin-type. The predominant fatty acids were iso-C(15 : 0) (29.4 %), iso-C(17 : 1)ω9c (18.5 %) and summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c; 11.3 %). The major polar lipids detected in strain PR1(T) were phosphatidylethanolamine, an unknown phospholipid, an aminophospholipid, an aminolipid and two lipids of unknown character. The DNA G+C content was 38.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PR1(T) fell within the cluster comprising the genus Algoriphagus and was most closely related to Algoriphagus halophilus JC 2051(T) (95.4 % sequence similarity) and Algoriphagus lutimaris S1-3(T) (95.3 % sequence similarity). The 16S rRNA gene sequence similarity between strain PR1(T) and the type strains of other species of the genus Algoriphagus were in the range 91-95 %. Differential phenotypic properties and phylogenetic and genetic distinctiveness of strain PR1(T) demonstrated that this strain was distinct from other members of the genus Algoriphagus, including its closest relative, A. halophilus. Based on phenotypic, chemotaxonomic, phylogenetic and genomic data, strain PR1(T) should be placed in the genus Algoriphagus as a representative of a novel species, for which the name Algoriphagus machipongonensis sp. nov. is proposed. The type strain is PR1(T) (= ATCC BAA-2233(T) = DSM 24695(T)).

Algoriphagus jejuensis sp. nov., isolated from seawater

A Gram-negative, pink-pigmented, non-motile, strictly aerobic rod, designated CNU040T, was isolated from seawater from the coast of Jeju Island in Korea. The temperature, pH and NaCl ranges for growth were 4–30 °C, pH 5.5–10.0 and 0–5.0 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CNU040T belonged to a distinct lineage in the genus Algoriphagus and exhibited high sequence similarity with Algoriphagus terrigena DS-44T (98.3 %) and Algoriphagus alkaliphilus AC-74T (96.6 %) and lower sequence similarity (<96.0 %) with all other members of the genus Algoriphagus. DNA–DNA relatedness between strain CNU040T and A. terrigena KCTC 12545T was 44.5 %. The DNA G+C content of the isolate was 48.5 mol% and the major respiratory quinone was menaquinone-7. The major cellular fatty acids were iso-C15 : 0 (28.6 %) and summed feature 3 (consisting of iso-C15 : 0 2-OH and/or C16 : 1ω7c; 24.0 %). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, one unknown amino lipid, one unknown aminophospholipid and three unknown polar lipids. On the basis of phenotypic, phylogenetic and genotypic data, strain CNU040T represents a novel species within the genus Algoriphagus, for which the name Algoriphagus jejuensis sp. nov. is proposed. The type strain is CNU040T ( = KCTC 22647T  = JCM 16112T).

Algoriphagus faecimaris sp. nov., isolated from coastal sediment

A Gram-negative, non-motile, non-sporulating bacterial strain, designated LYX05(T), was isolated from coastal sediment of Qingdao, China, on the coast of the Yellow Sea. Strain LYX05(T) was aerobic and heterotrophic. The strain grew optimally at 37 °C and pH 7.5 and in the presence of 2% (w/v) NaCl. Colonies were 1-2 mm in diameter, circular, reddish orange and shiny with entire edges on marine agar medium. Cells were rods (0.3-0.5 µm wide and 0.8-1.6 µm long). The dominant fatty acids were iso-C(15:0) (40.82%) and C(16:0) (10.45%). The DNA G+C content was 42.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LYX05(T) was phylogenetically related to the members of the genus Algoriphagus and the closest relative was Algoriphagus hitonicola 7-UAH(T) (95.8% 16S rRNA gene sequence similarity). On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain LYX05(T) was considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus faecimaris sp. nov. is proposed. The type strain is LYX05(T) (=JCM 16561(T) =DSM 23095(T) =LMG 25474(T)).

Litoribacter ruber gen. nov., sp. nov., an alkaliphilic, halotolerant bacterium isolated from a soda lake sediment

A novel alkaliphilic, halotolerant, rod-shaped bacterium, designated strain YIM CH208T, was isolated from a soda lake in Yunnan, south-west China. The taxonomy of strain YIM CH208T was investigated by a polyphasic approach. Strain YIM CH208T was Gram-negative, strictly aerobic and non-motile and formed red colonies. Optimal growth conditions were 28 °C, pH 8.5 and 0.5–2.5 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that the isolate formed a distinct line within a clade containing the genus Echinicola in the phylum Bacteroidetes and was related to the species Echinicola pacifica and Rhodonellum psychrophilum, with sequence similarity of 91.7 and 91.6 % to the respective type strains. The DNA G+C content was 45.1 mol%. The major respiratory quinone was menaquinone-7 (MK-7). The predominant cellular fatty acids were iso-C17 : 1 ω9c (19.9 %), C15 : 0 3-OH (12.1 %), iso-C17 : 0 3-OH (11.3 %), summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c; 10.7 %) and C17 : 1 ω6c (8.7 %). On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain YIM CH208T represents a novel species of a new genus, for which the name Litoribacter ruber gen. nov., sp. nov. is proposed. The type strain of Litoribacter ruber is YIM CH208T (=ACCC 05414T =KCTC 22899T).

Nitritalea halalkaliphila gen. nov., sp. nov., an alkaliphilic bacterium of the family ‘Cyclobacteriaceae’, phylum Bacteroidetes

A novel Gram-negative, rod-shaped, non-motile bacterium, designated strain LW7T, was isolated from a water sample collected at a depth of 4.5 m from Lonar Lake in Buldhana district, Maharastra, India. The cell suspension was dark-reddish orange due to the presence of carotenoids. The fatty acids were dominated by large amounts of iso-C15 : 0 (59.6 %) and iso-C17 : 0 3-OH (8.9 %). Strain LW7T contained MK-4 and MK-5 as the major respiratory quinones and phosphatidylglycerol and phosphatidylethanolamine as the major phospholipids. 16S rRNA gene sequence analysis indicated that Belliella baltica, a member of family ‘Cyclobacteriaceae’ (phylum Bacteroidetes), is the closest related species, with a sequence similarity of 94.0 % to the type strain. Other members of the family ‘Cyclobacteriaceae’ had sequence similarities of <93.3 %. Based on the above-mentioned phenotypic and phylogenetic characteristics, strain LW7T is proposed as a representative of a new genus and species, Nitritalea halalkaliphila gen. nov., sp. nov. The type strain of Nitritalea halalkaliphila is LW7T (=CCUG 57665T =JCM 15946T =NCCB 100279T). The genomic DNA G+C of strain LW7T is 49 mol%.

Ohtaekwangia koreensis gen. nov., sp. nov. and Ohtaekwangia kribbensis sp. nov., isolated from marine sand, deep-branching members of the phylum Bacteroidetes

Two Gram-stain-negative, non-motile, non-spore-forming, rod-shaped bacterial strains, designated 3B-2(T) and 10AO(T), were isolated from a sand sample collected from the west coast of the Korean peninsula by using low-nutrient media, and their taxonomic positions were investigated in a polyphasic study. The strains did not grow on marine agar. They grew optimally at 30 °C and pH 6.5-7.5. Strains 3B-2(T) and 10AO(T) shared 97.5 % 16S rRNA gene sequence similarity and mean level of DNA-DNA relatedness of 12 %. In phylogenetic trees based on 16S rRNA gene sequences, strains 3B-2(T) and 10AO(T), together with several uncultured bacterial clones, formed independent lineages within the evolutionary radiation encompassed by the phylum Bacteroidetes. Strains 3B-2(T) and 10AO(T) contained MK-7 as the predominant menaquinone and iso-C(15 : 0) and C(16 : 1)ω5c as the major fatty acids. The DNA G+C contents of strains 3B-2(T) and 10AO(T) were 42.8 and 44.6 mol%, respectively. Strains 3B-2(T) and 10AO(T) exhibited very low levels of 16S rRNA gene sequence similarity (<85.0 %) to the type strains of recognized bacterial species. These data were sufficient to support the proposal that the novel strains should be differentiated from previously known genera of the phylum Bacteroidetes. On the basis of the data presented, we suggest that strains 3B-2(T) and 10AO(T) represent two distinct novel species of a new genus, for which the names Ohtaekwangia koreensis gen. nov., sp. nov. (the type species; type strain 3B-2(T)  = KCTC 23018(T)  = CCUG 58939(T)) and Ohtaekwangia kribbensis sp. nov. (type strain 10AO(T)  = KCTC 23019(T)  = CCUG 58938(T)) are proposed.

Algoriphagus lutimaris sp. nov., isolated from a tidal flat sediment

A Gram-negative, non-motile, non-spore-forming bacterial strain, S1-3T, was isolated from a tidal flat sediment on the west coast of Korea and its taxonomic position was investigated. Strain S1-3T grew optimally at 30 °C and in the presence of 2 % (w/v) NaCl. Strain S1-3T contained MK-7 as the predominant menaquinone and C16 : 1 ω7c and/or iso-C15 : 0 2-OH and iso-C15 : 0 as the major fatty acids. The DNA G+C content was 41.4 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain S1-3T fell within the clade comprising Algoriphagus species, clustering with Algoriphagus halophilus IMSNU 14013T, with which it exhibited 99.6 % 16S rRNA gene sequence similarity. The 16S rRNA gene sequence similarity between strain S1-3T and the type strains of other Algoriphagus species was 94.0–97.1 %. Differential phenotypic properties and phylogenetic and genetic distinctiveness of strain S1-3T demonstrated that this strain is distinguishable from the other Algoriphagus species as well as A. halophilus. On the basis of phenotypic, chemotaxonomic, phylogenetic and genetic data, strain S1-3T is considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus lutimaris sp. nov. is proposed. The type strain is S1-3T (=KCTC 22630T =CCUG 57608T).