Altererythrobacter xinjiangensis sp. nov., isolated from desert sand, and emended description of the genus Altererythrobacter

Qipengyuania thermophila sp. nov., isolated from a Chinese hot spring

A novel Gram-stain-negative, non-motile, short rod-shaped and aerobic bacterial strain, designated as CFH 74456 ^T, was isolated from sediment of a hot spring, Tengchong, Yunnan Province, south-western China. Growth occurred at 20-53 ºC (optimum 45 ºC), pH 7.0-9.0 (optimum pH 8.0) and up to 2.0% (w/v) NaCl (optimum 0-1.0%, w/v). The predominant respiratory quinone was ubiquinone 10 (Q-10). The major fatty acids (> 10%) were C_17:1 ω6c (17.9%) and summed feature 8 (38.6%). The polar lipid profile of strain CFH 74456 ^T was identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid, three unidentified glycolipids and three unidentified polar lipids. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain CFH 74456 ^T belongs to the genus Qipengyuania, and was most closely related to Qipengyuania sediminis CGMCC 1.12928 ^T (95.7%). The draft genome size of the isolate was 2.29 Mb with G + C content of 68.5%. The amino acid identity, average nucleotide identity and the digital DNA-DNA hybridization values between strain CFH 74456 ^T and the closest relatives ranged from 67.0 to 67.9%, 73.0 to 74.2% and 18.2-19.3%, respectively. On the basis of phenotypic, phylogenetic and genotypic analyses, it is concluded that strain CFH 74456 ^T represents a new species of the genus Qipengyuania, for which the name Qipengyuania thermophila sp. nov. is proposed. The type strain is CFH 74456 ^T (= KCTC 62921 ^T = CCTCC AB 2018237 ^T).

Selenium fertigation with nanobubbles influences soil selenium residual and plant performance by modulation of bacterial community

Although selenium (Se) is an essential microelement for humans and animals, it is a potentially toxic element due to its bioaccumulation potential. In this study, Se fertilizer was supplied in a greenhouse vegetable (cucumber) plantation using an innovative system consisting of nanobubbles (NB_Se) and compared to that under conventional conditions of fertigation (C_Se) with six doses. The results revealed that NB_Se significantly reduced soil Se accumulation (38%-144%) and increased cucumber Se content compared with the C_Se treatments at the same Se dose. NB_Se significantly lowered the soil bacterial diversity, with an initial increase and then decrease with the Se doses. Bacterial associations and potential keystone taxa also differed between the NB_Se and C_Se. The greater abundance of oxidizing bacteria (indicated by the function composition of bacterial community) and the improved soil redox environment created by NBs sustained more available Se for plants, leading to a reduction in soil Se residual and an increase in the plant Se content. Our results highlight the feasibility and efficiency of NB_Se and demonstrate the important implications of Se for the maintenance of soil health and sustainability.

Altererythrobacter lutimaris sp. nov., a marine bacterium isolated from a tidal flat and reclassification of Altererythrobacter deserti, Altererythrobacter estronivorus and Altererythrobacter muriae as Tsuneonella deserti comb. nov., Croceicoccus estronivorus comb. nov. and Alteripontixanthobacter muriae comb. nov

A yellow-coloured bacterium, designated strain JGD-16^T, was isolated from a tidal flat in Janggu-do, Garorim Bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and short ovoid to coccoid-shaped. Growth was observed at 10-37 °C (optimum, 30 °C), pH 6.0-9.0 (pH 8.0) and with 1-5% (w/v) NaCl (2%). Results of 16S rRNA gene sequence analysis indicated that strain JGD-16^T was closely related to Altererythrobacter xiamenensis LY02^T (97.1 %), Altererythrobacter aurantiacus O30^T (96.3 %), Altererythrobacter ishigakiensis JPCCMB0017^T (95.8 %), Altererythrobacter epoxidivorans JCS350^T (95.7 %) and Altererythrobacter insulae BPTF-M16^T (95.3%). Phylogenomic analysis using the maximum-likelihood algorithm showed that strain JGD-16^T formed a clade with the genus Altererythrobacter. The genomic DNA G+C content was 57.8 mol%. The predominant respiratory quinone was ubiquinone-10. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, a sphingoglycolipid, an unidentified glycolipid and an unidentified lipid. The major fatty acids were C_18:1 ω7c (31.5 %) and C_18:3 ω6c (19.6 %). On the basis of its phylogenomic, physiological and chemotaxonomical characteristics, strain JGD-16^T represents a novel species within the genus Altererythrobacter, for which the name Altererythrobacter lutimaris JGD-16^Tsp. nov. is proposed. The type strain is JGD-16^T (=KCTC 72632^T=KACC 21405^T=JCM 33750^T). We also propose the reclassification of Altererythrobacter deserti as Tsuneonella deserti comb. nov., Altererythrobacter estronivorus as Croceicoccus estronivorus comb. nov. and Altererythrobacter muriae as Alteripontixanthobacter muriae comb. nov.

Bacterial and Archaeal Structural Diversity in Several Biodeterioration Patterns on the Limestone Walls of the Old Cathedral of Coimbra

The “University of Coimbra-Alta and Sofia” area was awarded the UNESCO World Heritage Site distinction in 2013. The Old Cathedral of Coimbra, a 12th-century limestone monument located in this area, has been significantly impacted during the last 800 years by physical, chemical, and biological processes. This led to the significant deterioration of some of its structures and carvings, with loss of aesthetical, cultural, and historical values. For this work, deteriorated spots of the walls of three semi-open chapels from the cloister of the Cathedral were sampled to ascertain their bacterial and archaeal structural diversity. Based on Next-Generation Sequencing (NGS) result analysis, we report the presence of microbial populations that are well adapted to an ecosystem with harsh conditions and that can establish a diverse biofilm in most cases. While it was possible to determine dominant phylogenetic groups in Archaea and Bacteria domains, there was no clear connection between specific core microbiomes and the different deterioration patterns analyzed. The distribution of these archaeal and bacterial communities within the analyzed biodeterioration spots suggests they are more influenced by abiotic factors (i.e., water availability, salinity, etc.), although they influence (and are influenced by) the algal and fungal population composition in this ecosystem. This work provides valuable information that can assist in establishing future guidelines for the preservation and conservation of this kind of historic stone monuments.

Altererythrobacter segetis sp. nov., Isolated from Farmland Soil

A Gram-stain-negative bacterium, designated YJ20^T, was isolated from rhizosphere soil of a spinach farmland at Shinan in Korea. Strain YJ20^T was found to be aerobic, non-motile rods which can grow at 10-33 °C (optimum, 28 °C), at pH 6.5-8.5 (optimum, pH 6.5-7.5) and in the absence of NaCl. The 16S rRNA gene sequence analysis showed that strain YJ20^T belongs to the genus Altererythrobacter with moderate sequence similarities to Altererythrobacter dongtanensis KCTC 22672^T (96.8%), Altererythrobacter soli MN-1^T (96.6%) and Altererythrobacter xinjiangensis S3-63^T (96.5%). The phylogenomic analysis based on the whole-genome sequence demonstrated that strain YJ20^T formed a distinct phyletic line with Altererythrobacter soli MN-1^T and Altererythrobacter salegens XY-R17^T showing average nucleotide identity (ANI) values of 79.4 and 77.5%, respectively. The predominant ubiquinone was identified as Q-10, and the major fatty acids were C_17:1 ω6c, C_18:1 ω7c and C_15:0 2-OH. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidycholin, sphingoglycolipid, an unidentified glycolipid, an unidentified phospholipid and an unidentified lipid. The G+C content of the genome was determined to be 66.3 mol%. On the basis of phenotypic, chemotaxonomic properties and phylogenetic and phylogenomic analyses in this study, strain YJ20^T is considered to represent a novel species in the genus Altererythrobacter, for which the name Altererythrobacter segetis sp. nov. is proposed. The type strain is YJ20^T (= KACC 19554^T = NBRC 113199^T).

Pseudopontixanthobacter vadosimaris gen. nov., sp. nov., isolated from shallow sea near Kueishan Island

A Gram-stain-negative and aerobic bacterial strain, designated as JL3514^T, was isolated from surface water of the hydrothermal system around Kueishan Island. The isolate formed red colonies and cells were non-flagellated, rod-shaped and contained methanol-soluble pigments. Growth was observed at 10-50 °C (optimum, 30 °C), at pH 5.0-9.0 (optimum, pH 7.0) and in the presence of 0-9 % (w/v) NaCl (optimum, 2 %). Strain JL3514^T was positive for catalase and weakly positive for oxidase. Results of 16S rRNA gene sequence analyses showed highest similarities to species in the family Erythrobacteraceae, namely Croceibacterium atlanticum (96.1 %), Pelagerythrobacter marensis (96.0 %), Tsuneonella rigui (96.0 %) and Altericroceibacterium xinjiangense (96.0 %). Phylogenetic analysis based on core gene sequences revealed that the isolate formed a distinct branch with the related species and it had a lower average amino acid identity value than the suggested threshold for genera boundaries. The major fatty acids (>5 %) were summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c), summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c), C_16 : 0, C_17 : 1  ω6c, C_14 : 0 2-OH and C_12 : 0. The dominant polar lipids comprised diphosphatidylglycerol, sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, glycolipid, two unidentified lipids and one unidentified phospholipid. The main respiratory quinones were ubiquinone-10 (95.7 %) and ubiquinone-9 (4.3 %). The DNA G+C content from the genome was 63.0 mol%. Based on the presented data, we consider strain JL3514^T to represent a novel genus of the family Erythrobacteraceae, with the name Pseudopontixanthobacter vadosimaris gen. nov., sp. nov. The type strain is JL3514^T (=KCTC 62623^T=MCCC 1K03561^T).

Genomic-based taxonomic classification of the family Erythrobacteraceae

The family Erythrobacteraceae, belonging to the order Sphingomonadales, class Alphaproteobacteria, is globally distributed in various environments. Currently, this family consist of seven genera: Altererythrobacter, Croceibacterium, Croceicoccus, Erythrobacter, Erythromicrobium, Porphyrobacter and Qipengyuania. As more species are identified, the taxonomic status of the family Erythrobacteraceae should be revised at the genomic level because of its polyphyletic nature evident from 16S rRNA gene sequence analysis. Phylogenomic reconstruction based on 288 single-copy orthologous clusters led to the identification of three separate clades. Pairwise comparisons of average nucleotide identity, average amino acid identity (AAI), percentage of conserved protein and evolutionary distance indicated that AAI and evolutionary distance had the highest correlation. Thresholds for genera boundaries were proposed as 70 % and 0.4 for AAI and evolutionary distance, respectively. Based on the phylo-genomic and genomic similarity analysis, the three clades were classified into 16 genera, including 11 novel ones, for which the names Alteraurantiacibacter, Altericroceibacterium, Alteriqipengyuania, Alteripontixanthobacter, Aurantiacibacter, Paraurantiacibacter, Parerythrobacter, Parapontixanthobacter, Pelagerythrobacter, Tsuneonella and Pontixanthobacter are proposed. We reclassified all species of Erythromicrobium and Porphyrobacter as species of Erythrobacter. This study is the first genomic-based study of the family Erythrobacteraceae, and will contribute to further insights into the evolution of this family.

Analysis of 1,000+ Type-Strain Genomes Substantially Improves Taxonomic Classification of Alphaproteobacteria

The class Alphaproteobacteria is comprised of a diverse assemblage of Gram-negative bacteria that includes organisms of varying morphologies, physiologies and habitat preferences many of which are of clinical and ecological importance. Alphaproteobacteria classification has proved to be difficult, not least when taxonomic decisions rested heavily on a limited number of phenotypic features and interpretation of poorly resolved 16S rRNA gene trees. Despite progress in recent years regarding the classification of bacteria assigned to the class, there remains a need to further clarify taxonomic relationships. Here, draft genome sequences of a collection of genomes of more than 1000 Alphaproteobacteria and outgroup type strains were used to infer phylogenetic trees from genome-scale data using the principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families and genera, including taxa recognized as problematic long ago but also quite recent taxa, as well as a few species were shown to be in need of revision. According proposals are made for the recognition of new orders, families and genera, as well as the transfer of a variety of species to other genera and of a variety of genera to other families. In addition, emended descriptions are given for many species mainly involving information on DNA G+C content and (approximate) genome size, both of which are confirmed as valuable taxonomic markers. Similarly, analysis of the gene content was shown to provide valuable taxonomic insights in the class. Significant incongruities between 16S rRNA gene and whole genome trees were not found in the class. The incongruities that became obvious when comparing the results of the present study with existing classifications appeared to be caused mainly by insufficiently resolved 16S rRNA gene trees or incomplete taxon sampling. Another probable cause of misclassifications in the past is the partially low overall fit of phenotypic characters to the sequence-based tree. Even though a significant degree of phylogenetic conservation was detected in all characters investigated, the overall fit to the tree varied considerably.

Shear Stress as a Major Driver of Marine Biofilm Communities in the NW Mediterranean Sea

While marine biofilms depend on environmental conditions and substrate, little is known about the influence of hydrodynamic forces. We tested different immersion modes (dynamic, cyclic and static) in Toulon Bay (north-western Mediterranean Sea; NWMS). The static mode was also compared between Toulon and Banyuls Bays. In addition, different artificial surfaces designed to hamper cell attachment (self-polishing coating: SPC; and fouling-release coating: FRC) were compared to inert plastic. Prokaryotic community composition was affected by immersion mode, surface characteristics and site. Rhodobacteriaceae and Flavobacteriaceae dominated the biofilm community structure, with distinct genera according to surface type or immersion mode. Cell density increased with time, greatly limited by hydrodynamic forces, and supposed to delay biofilm maturation. After 1 year, a significant impact of shear stress on the taxonomic structure of the prokaryotic community developed on each surface type was observed. When surfaces contained no biocides, roughness and wettability shaped prokaryotic community structure, which was not enhanced by shear stress. Conversely, the biocidal effect of SPC surfaces, already major in static immersion mode, was amplified by the 15 knots speed. The biofilm community on SPC was 60% dissimilar to the biofilm on the other surfaces and was distinctly colonized by Sphingomonadaceae ((Alter)Erythrobacter). At Banyuls, prokaryotic community structures were more similar between the four surfaces tested than at Toulon, due possibly to a masking effect of environmental constraints, especially hydrodynamic, which was greater than in Toulon. Finally, predicted functions such as cell adhesion confirmed some of the hypotheses drawn regarding biofilm formation over the artificial surfaces tested here.

Croceibacterium gen. nov., with description of Croceibacterium ferulae sp. nov., an endophytic bacterium isolated from Ferula sinkiangensis K. M. Shen and reclassification of Porphyrobacter mercurialis as Croceibacterium mercuriale comb. nov

A novel endophytic bacterium, designated strain SX2RGS8^T, was isolated from the surface-sterilized roots of an endangered medicinal plant (Ferula sinkiangensis K. M. Shen) collected from Xinjiang, north-western PR China. The taxonomic position of the candidate was investigated using a polyphasic approach. Strain SX2RGS8^T was found to be aerobic, Gram-stain-negative, oxidase-negative, catalase-positive and axiolitic-shaped. Strain SX2RGS8^T grew at 4-45 °C (optimum, 28 °C), pH 4.0-10.0 (pH 7.0) and in the presence of 0-5 % (w/v) NaCl. The polar lipids detected for strain SX2RGS8^T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, unidentified phosphoglycolipids, an unidentified phospholipid and unidentified lipids. The major respiratory quinone of strain SX2RGS8^T was ubiquinone 10 and the major fatty acid was summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The DNA G+C content was determined to be 66.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the isolate belonged to the family Erythrobacteraceae and showed 99.2 % (Porphyrobacter mercurialis), 95.5 % (Porphyrobacter donghaensisi) and 95.4 % (Porphyrobacter colymbi) similarities to its closest relatives. The isolate contained carotenoids, but no bacteriochlorophyll a. On the basis of phenotypic, genotypic and phylogenetic data, strain SX2RGS8^T represents a novel species of a novel genus in the family Erythrobacteraceae, for which the name Croceibacterium ferulae gen. nov., sp. nov. is proposed. The type strain is SX2RGS8^T (=CGMCC 1.16402^T=KCTC 62090^T). In addition, Porphyrobacter mercurialis Coil et al. 2016 is proposed to be transferred to this new genus as Croceibacterium mercuriale comb. nov.

Altererythrobacter aquimixticola sp. nov., isolated from sediment sampled at the junction between the ocean and a freshwater spring

A Gram-stain-negative, aerobic, non-motile and coccoid-, ovoid- or rod-shaped bacterial strain, designated SSKS-13^T, was isolated from sediment sampled at the junction between the ocean and a freshwater spring at Jeju island, Republic of Korea. Strain SSKS-13^T grew optimally at 37 °C and in the presence of 2.0 % (w/v) NaCl. A neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that strain SSKS-13^T fell within the clade comprising the type strains of Altererythrobacter species, clustering with the type strains of Altererythrobacter lauratis, Altererythrobacter palmitatis and Altererythrobacter buctensis having 16S rRNA gene sequence similarities of 97.2-97.6 %. Strain SSKS-13^T exhibited 16S rRNA gene sequence similarities of less than 97.0 % to the type strains of the other recognized species. Strain SSKS-13^T contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c as the major fatty acid. The major polar lipids detected in strain SSKS-13^T were phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid. The DNA G+C content of strain SSKS-13^T was 64.6 mol%. The mean DNA-DNA relatedness values of strain SSKS-13^T with the type strains of A. lauratis, A. palmitatis and A. buctensis were 11.7-25.3 %. Differential phenotypic properties, together with the phylogenetic and genetic data, proved that strain SSKS-13^T is distinct from recognized Altererythrobacter species. On the basis of the data presented here, strain SSKS-13^T is considered to represent a novel species of the genus Altererythrobacter, for which the name Altererythrobacter aquimixticola sp. nov. is proposed. The type strain is SSKS-13^T (=KACC 19863^T=KCTC 62900^T=NBRC 113545^T).

Altererythrobacter lutipelagi sp. nov., isolated from a tidal mudflat, and emended description of the genus Altererythrobacter

A marine proteobacterium, designated strain GH1-16^T, was isolated from a sample of tidal mudflat collected at the seashore of Gangwha Island, Republic of Korea and the taxonomic status was examined by a polyphasic approach. The isolate was Gram-reaction-negative, strictly aerobic, catalase- and oxidase-positive, non-motile, short-rod-shaped and produced yellow-coloured colonies. An absolute requirement for Na⁺ was observed. The major respiratory quinone was ubiquinone-10. The major polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid. The dominant cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C17 : 1ω6c. The DNA G+C content was 60.6 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GH1-16^T was closely related to members of the genus Altererythrobacter. The closest relative was Altererythrobacter marensis MSW-14^T (97.3 % sequence similarity) followed by Altererythrobacter aquaemixtae JSSK-8^T (96.8 %) and Altererythrobacter epoxidivorans JCS350^T (96.7 %). The DNA relatedness of strain GH1-16^T against its closest relative was 21.8-25.0 %. On the basis of data obtained by a polyphasic taxonomic approach, strain GH1-16^T (=KCTC 52845^T=NBRC 113275^T) is considered to represent a novel species of the genus Altererythrobacter, for which the name Altererythrobacter lutipelagi sp. nov. is proposed.

Altererythrobacter aerophilus sp. nov., isolated from deep-sea water of the north-west Pacific

A Gram-stain-negative, rod-shaped bacterium, designated Ery1^T, was isolated from deep-sea seawater collected from the Mariana Trench and subjected to a polyphasic investigation for taxonomy. Strain Ery1^T was able to grow in medium containing 0-10 % NaCl (w/v; optimum, 0-1.0 %), pH 5.0-9.5 (optimum, pH 6.0-7.0) and at temperatures between 10-45 °C (optimum, 30-40 °C). The comparison of 16S rRNA gene sequences revealed that strain Ery1^T showed highest similarity to Altererythrobacterxinjiangensis S3-63^T (97.7 %) and Altererythrobacterrigui WW3^T (97.6 %), and exhibited less than 97.5 % sequence similarity to other type strains of the species with validly published names. Phylogenetic analyses indicated that strain Ery1^T fell within the cluster comprising the Altererythrobacter species and formed a coherent clade with Altererythrobacterxinjiangensis and Altererythrobactersoli. The OrthoANIu and in silico DNA-DNA hybridization values between strain Ery1^T and the reference strains were 73.8-75.9 % and 19.2-20.1 %, respectively. Strain Ery1^T contained Q-10 as the major respiratory quinone and Q-11 in a minor amount. The major fatty acids (>10 %) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, C18 : 1ω7c 11-methyl and C14 : 0 2-OH. The major polar lipids were sphingoglycolipid, diphosphatidylglycerol, phosphatidyglycerol, phatidylethanolamine, phosphatidylcholine and three unidentified glycolipids. Differential phenotypic properties, chemotaxonomic differences, phylogenetic distinctiveness, together with the genomic data demonstrated that strain Ery1^T represents a novel species of the genus Altererythrobacter, for which named as Altererythrobacter aerophilus sp. nov. with the type strain Ery1^T (=KCTC 62387^T=CGMCC 1.16499^T=MCCC 1A10037^T).

Altererythrobacter amylolyticus sp. nov., isolated from lake sediment

An aerobic, motile, Gram-stain-negative bacterium, designated strain NS1T, was isolated from interfacial sediment from Taihu Lake, China. The strain formed yellow colonies on R2A medium. Cells were ovoid to rod-shaped and non-spore-forming. Growth occurred at 15–40 °C (optimum, 28 °C), at pH 5.0–10.5 (optimum, 6.5–7.5) and in the presence of 0–1 % (w/v) NaCl (optimum, 0 %). Phylogenetic trees based on 16S rRNA gene sequences showed that strain NS1T represented a member of the genus Altererythrobacter and had the highest sequence similarity to Altererythrobacter troitsensis CCTCC AB 2015180T (97.1 %). The average nucleotide identity value between strain NS1T and the closest related strain based on their genomes was 78.6 %. The predominant ubiquinone was Q-10. The major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, an unidentified phospholipid, an unidentified glycolipid and six unidentified lipids. The genomic DNA G+C content was 66.6 mol%. On the basis of phenotypic and genotypic characteristics, strain NS1T represents a novel species of the genus Altererythrobacter , for which the name Altererythrobacter amylolyticus sp. nov. is proposed. The type strain is NS1T (=CGMCC 1.13679T=NBRC 113553T).

Altererythrobacter maritimus sp. nov., isolated from seawater

A rod-shaped, Gram-staining-negative and orange-pigmented bacterium, designated strain HME9302^T, was isolated from seawater of the Yellow Sea in the Republic of Korea. The phylogenetic tree based on 16S rRNA gene sequences showed that strain HME9302^T formed a lineage within the genus Altererythrobacter, and was most closely related to Altererythrobacter aurantiacus O30^T with 96.7 % sequence similarity. The major fatty acids were summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The major respiratory quinone was ubiquinone-10. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and four unidentified lipids. The DNA G+C content was 60.8 mol%. On the basis of the evidence presented in this study, strain HME9302^T represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter maritimus sp. nov. is proposed with the type strain HME9302^T (=KCTC 32463^T=KACC 17617^T=CECT 8417^T).

Altererythrobacter insulae sp. nov., a lipolytic bacterium isolated from a tidal flat

A lipolytic, Gram-stain-negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, designated BPTF-M16^T, was isolated from tidal flat sediment on the Yellow Sea in the Republic of Korea. Strain BPTF-M16^T grew optimally at 30 °C and in the presence of 2.0-3.0 % (w/v) NaCl. A phylogenetic tree of 16S rRNA gene sequences showed that strain BPTF-M16^T fell within the clade comprising the type strains of Altererythrobacter species. Strain BPTF-M16^T exhibited 16S rRNA gene sequence similarity values of 98.0 and 97.1 % to the type strains of Altererythrobacterishigakiensis and Altererythrobactermarinus, respectively, and of less than 97.0 % to the type strains of the other recognized species. Strain BPTF-M16^T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids detected in strain BPTF-M16^T were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid and one unidentified glycolipid. Mean DNA-DNA relatedness values of strain BPTF-M16^T with the type strains of A. ishigakiensis and A. marinus were 22 and 13 %, respectively. The average nucleotide identity value between strain BPTF-M16^T and the type strain of A. ishigakiensis was 76.80 %. Differential phenotypic properties, together with the phylogenetic and genetic data, revealed that strain BPTF-M16^T is separated from recognized Altererythrobacter species. On the basis of the data presented here, strain BPTF-M16^T is considered to represent a novel species of the genus Altererythrobacter, for which the name Altererythrobacter insulae sp. nov. is proposed. The type strain is BPTF-M16^T (=KCTC 62421^T=KACC 19609^T=NBRC 113190^T).

Altererythrobacter xixiisoli sp. nov., isolated from wetland soil

A Gram-stain-negative, coccoid, yellow, non-motile, aerobic bacterium, designated strain S36T, was isolated from soil of the Xixi wetland in Zhejiang province, PR China. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain S36T could represent a novel species of genus Altererythrobacter showing highest similarity to Altererythrobacter atlanticus 26DY36T (96.31 % 16S rRNA gene sequence similarity). The temperature, pH and NaCl concentration ranges for growth were 10-37 °C (optimum 32 °C), pH 5.0-10.0 (optimum pH 7.0) and 0.5-3 % (optimum 1 %, w/v), respectively. The predominant respiratory quinone of strain S36T was Q-10. The major fatty acids were C16 : 0, C17 : 1ω6c, C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The G+C content of the genomic DNA was 62.7 mol%. These data all support the affiliation of strain S36T to the genus Altererythrobacter. The polar lipids profile of strain S36T comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified phospholipids and two unidentified glycolipids. The results of physiological and biochemical tests allowed differentiation of strain S36T from other members of the genus Altererythrobacter. Therefore, strain S36T represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter xixiisoli sp. nov. is proposed; the type strain is S36T (=CGMCC 1.12804T=NBRC 110413T).

Altererythrobacter salegens sp. nov., a slightly halophilic bacterium isolated from surface sediment

A Gram-negative, rod-shaped and slightly halophilic bacterium, strain XY-R17T, was isolated from the surface sediment of Mai Po Inner Deep Bay Ramsar Site birdwatch in Hong Kong. The 16S rRNA gene sequence of strain XY-R17T exhibited 96.5 % similarity to that of the type strain of Altererythrobacter atlanticus. Optimal growth occurred at pH 7.0-7.5, 3-8 % (w/v) NaCl and at 30 °C. The major respiratory quinone was ubiquinone-10. The principal fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), 11-methyl C18 : 1ω7c and C17 : 1ω6c .The polar lipid profile consisted of the major compounds sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and two unknown lipids. The DNA G+C content was 64.7 mol%. Based on its phenotypic properties, chemotaxonomic characteristics and phylogenetic distinctiveness, strain XY-R17T should be designated as a novel species of the genus Altererythrobacter. Therefore, the name Altererythrobacter salegens sp. nov. (type strain XY-R17T=KCTC 52267T=MCCC 1K01500T) is proposed.

Altererythrobacter lauratis sp. nov. and Altererythrobacter palmitatis sp. nov., isolated from a Tibetan hot spring

Two Gram-negative, moderately thermophilic, yellow-pigmented, rod-shaped and motile bacterial strains, designated YIM 75003^T and YIM 75004^T, were isolated from sediment samples collected from the Tagejia hot spring in Tibet, western China. The taxonomic affiliation of the two strains was investigated by a polyphasic approach. Pairwise comparison of the 16S rRNA gene sequences showed that strains YIM 75003^T and YIM 75004^T are closely related to Altererythrobacter buctense M0322^T (97.2 and 97.1% respectively), while sharing 99.9% sequence similarity against each other. Optimum growth of the two strains was observed at 37-45 °C, pH 8.0 and in the presence of 1-6% NaCl (w/v). Their predominant respiratory quinone was found to be ubiquinone 10. The major fatty acids in both the strains were identified as summed feature 8 (C_18:1 ω6c and/or C_18:1 ω7c) and summed feature 4 (C_17:1 anteiso B and/or iso I). Their major polar lipid profiles were found to be diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid. The DNA G+C contents of strains YIM 75003^T and YIM 75004^T were determined to be 61.3 and 60.1 mol%, respectively. The DNA-DNA hybridization values between strains YIM 75003^T and YIM 75004^T, and between the two strains and their closely related phylogenetic neighbour A. buctense M0322^T (=CGMCC 1.12871^T) were less than 70%. Based on the morphological and physiological properties, phylogenetic analyses, chemotaxonomic characteristics and DNA-DNA relatedness values, the two strains can be distinguished from each other and from their phylogenetically closely related strain. Strains YIM 75003^T and YIM 75004^T are, therefore, considered to represent two novel species of the genus Altererythrobacter, for which the names Altererythrobacter lauratis sp. nov. (type strain YIM 75003^T = KCTC 52606^T = CCTCC AB2016268^T) and Altererythrobacter palmitatis sp. nov. (type strain YIM 75004^T = KCTC 52607^T = CCTCC AB2016270^T) are proposed.

Altererythrobacter soli sp. nov., isolated from desert sand

An alkaliphilic strain designed MN-1T was isolated from a desert sand sample collected from Tengger desert, north-western China. To delineate its taxonomic position, this Gram-stain-negative, rod-shaped, strictly aerobic bacterium was subjected to a polyphasic taxonomic study. Growth was observed at temperatures from 4 to 37 °C (optimum 30-32 °C), at salinities from 0 to 2 % (optimum 1 %) and at pH from 6.5 to 12.0 (optimum 7.0-9.0). Phylogenetic analysis based on 16S rRNA gene sequencing showed that strain MN-1T was a member of the genus Altererythrobacterbut could be distinguished from recognized species of this genus. Compared to the reference strains, the novel strain was flagellated and motile by means of polar flagella. The predominant respiratory quinone was ubiquinone-10 and the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, phosphatidylglycerol, phosphatidylcholine, one unidentified glycolipid, one unidentified phospholipid and four unidentified lipids. The predominant fatty acids were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. These chemotaxonomic traits were in agreement with the characteristics of the genus Altererythrobacter. Strain MN-1T was most closely related to Altererythrobacter xinjiangensis S3-63T (96.9 % 16S rRNA gene sequence similarity), followed by Altererythrobacter dongtanensis JM27T (96.4 %) and Altererythrobacter marinus H32T (96.1 %). The G+C content of the genomic DNA of strain MN-1T was 67.0 mol%. On the basis of data from this polyphasic taxonomic study, strain MN-1T is proposed as the type strain of a novel species of the genus Altererythrobacter, named as Altererythrobacter soli sp. nov. (=KCTC 52135T=MCCC 1K02066T).

Description of Altererythrobacter aerius sp. nov., isolated from air, and emended description of the genus Altererythrobacter

A Gram-stain-negative, yellow-pigmented, ovoid to rod-shaped, strictly aerobic bacterial strain, designated 100921-2T, was isolated from air at the foot of Xiangshan Mountain. Phylogenetic and phenotypic analysis of the organism revealed that the isolate belongs to the genus Altererythrobacter. Strain 100921-2T showed high 16S rRNA gene sequence similarity (96.01-94.70 %) to other type strains of the genus Altererythrobacter, with the highest similarity to Altererythrobactermarensis MSW-14T. Growth of strain 100921-2T was observed at 4-50 °C (optimum, 30 °C), at pH 4.5-10.0 (optimum, pH 7.0) and at salinities of 0-10 % (w/v) NaCl (optimum 0-0.5 %). The major fatty acids were C18 : 1ω7c (27.8 %), C17 : 1ω6c (23.1 %), 11-methyl C18 : 1ω7c(11.9 %), summed feature 3 (9.1 %) and C15 : 0 2-OH (7.9 %). The predominant respiratory quinone was ubiquinone-10 (Q-10). Polar lipid analysis indicated the presence of diphosphatidylglycerol, sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, two unknown phospholipids, five unknown polar lipids and two unknown glycolipids. The DNA G+C content of the type strain was 67.5 mol%. On the basis of the data from the polyphasic characterization, strain 100921-2T represents a novel species, for which the name Altererythrobacter aerius sp. nov. is proposed. The type strain is 100921-2T (=CFCC 14287T=KCTC 42844T).

Qipengyuania sediminis gen. nov., sp. nov., a member of the family Erythrobacteraceae isolated from subterrestrial sediment

A Gram-reaction-negative, non-motile, facultatively aerobic bacterium, designated strain M1T, was isolated from a subterrestrial sediment sample of Qiangtang Basin in Qinghai-Tibetan plateau, China. The strain formed rough yellow colonies on R2A plates. Cells were oval or short rod-shaped, catalase-positive and oxidase-negative. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the isolate belonged to the family Erythrobacteraceae and showed 96.2–96.4 % 16S rRNA gene sequence similarities to its closest relatives. Chemotaxonomic analysis revealed ubiquinone-10 (Q10) as the dominant respiratory quinone of strain M1T and C17 : 1ω6c (44.2 %) and C18 : 1ω7c (13.7 %) as the major fatty acids. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, sphingoglycolipid, three unidentified glycolipids, one unidentified phosphoglycolipid and one unidentified lipid. The DNA G+C content of strain M1T was 73.7 mol%. On the basis of phenotypic, phylogenetic and genotypic data presented in this study, strain M1T represents a novel species of a new genus in the family Erythrobacteraceae, for which the name Qipengyuania sediminis gen. nov., sp. nov. is proposed. The type strain of the type species is M1T ( = CGMCC 1.12928T = JCM 30182T).

Altererythrobacter rigui sp. nov., isolated from wetland freshwater

A non-motile and yellow-pigmented bacterium, designated strain WW3^T, was isolated from freshwater of Woopo wetland, Republic of Korea. Cells were Gram-reaction-negative, aerobic, catalase-positive and oxidase-negative. A maximum-likelihood phylogenetic tree based on 16S rRNA gene sequences showed that strain WW3^T forms an independent lineage within the genus Altererythrobacter. Strain WW3^T was related distantly to Altererythrobacter dongtanensisJM27^T and Altererythrobacter troitsensisKMM 6042^T (97.1% 16S rRNA gene sequence similarity). DNA-DNA relatedness between strain WW3^T and the reference strains was low (30-41 %). The major fatty acids of strain WW3^T were C17 : 1ω6c, C17 : 1ω8c, C15 : 0 2-OH and summed feature 8 comprising C18 : 1ω6c and/or C18 : 1ω7c. The predominant isoprenoid quinone of the isolate was ubiquinone-10. The DNA G+C content of strain WW3^T was 63 mol%. Phenotypic characteristics distinguished strain WW3^T from related species of the genus Altererythrobacter. On the basis of the evidence presented in this study,strain WW3^T represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter rigui sp. nov. is proposed. The type strain is WW3^T (=KCTC 42620^T =JCM 30975^T).

Meso and micro-scale response of post carbon removal nitrifying MBBR biofilm across carrier type and loading

This study investigates the effects of three specific moving bed biofilm reactor (MBBR) carrier types and two surface area loading rates on biofilm thickness, morphology and bacterial community structure of post carbon removal nitrifying MBBR systems along with the effects of carrier type and loading on ammonia removal rates and effluent solids settleability. The meso and micro analyses show that the AOB kinetics vary based on loading condition, but irrespective of carrier type. The meso-scale response to increases in loading was shown to be an increase in biofilm thickness with higher surface area carriers being more inclined to develop and maintain thicker biofilms. The pore spaces of these higher surface area to volume carriers also demonstrated the potential to become clogged at higher loading conditions. Although the biofilm thickness increased during higher loading conditions, the relative percentages of both the embedded viable and non-viable cells at high and conventional loading conditions remained stable; indicating that the reduced ammonia removal kinetics observed during carrier clogging events is likely due to the observed reduction in the surface area of the attached biofilm. Microbial community analyses demonstrated that the dominant ammonia oxidizing bacteria for all carriers is Nitrosomonas while the dominant nitrite oxidizing bacteria is Nitrospira. The research showed that filamentous species were abundant under high loading conditions, which likely resulted in the observed reduction in effluent solids settleability at high loading conditions as opposed to conventional loading conditions. Although the settleability of the effluent solids was correlated to increases in abundances of filamentous organisms in the biofilm, analyzed using next generation sequencing, the ammonia removal rate was not shown to be directly correlated to specific meso or micro-scale characteristics. Instead post carbon removal MBBR ammonia removal kinetics were shown to be related to the viable AOB cell coverage of the carriers; which was calculated by normalizing the surface area removal rate by the biofilm thickness, the bacterial percent abundance of ammonia oxidizing bacteria and the percentage of viable cells.

Altererythrobacter terrae sp. nov., isolated from mountain soil

A Gram-negative, non-motile, non-spore-forming, ovoid-shaped bacterium designated as SWU3(T) was isolated from mountain soil collected at Seoul Women's University, South Korea. Based on 16S rRNA sequence analysis, strain SWU3(T) was found to belong to the genus Altererythrobacter. It shares high sequence similarities with A. dongtanensis JM27(T) (96.6 %), A. epoxidivorans JCS350(T) (96.6 %), and A. troitsensis KMM 6042(T) (96.5 %). Growth was observed between 15 and 37 °C (optimum, 30 °C) with pH of 6-9 (optimum, pH 7.0). It could tolerate 0-2 % (w/v) NaCl. Its predominant quinone was found to be ubiquinone (Q-10). Its major cellular fatty acids were determined to be C17:1 ω6c, C18:1 ω7c, and summed featured 3 (C16:1 ω7c/C16:1 ω6c), all of which are similar characteristics to those of species within the genus Altererythrobacter. Its G + C molar content was found to be 58.4 mol%. Phylogenetic evidence, together with phenotypic characteristics showed that strain SWU3(T) represents a new species of the genus Altererythrobacter. The name Altererythrobacter terrae sp. nov. is proposed and the type strain is SWU3(T) (=KEMB 9004-128(T) = JCM 19177(T)).

Draft Genome Sequence of Altererythrobacter troitsensis JCM 17037, Isolated from the Sea Urchin Strongylocentrotus intermedius

The habitats of the genus Altererythrobacter are various, including marine sediment, seawater, rhizosphere of wild rice, desert sand, etc. The genome of the type strain of Altererythrobacter troitsensis JCM 17037, isolated from sea urchin, was sequenced. This study would not only facilitate the understanding of the physiology, adaptation, and evolution of the Altererythrobacter species, but also provide a good resource for the study of synthesis of astaxanthin, since several enzymes involved in the production of astaxanthin were predicted.

From lithotroph- to organotroph-dominant: directional shift of microbial community in sulphidic tailings during phytostabilization

Engineering microbial diversity to enhance soil functions may improve the success of direct revegetation in sulphidic mine tailings. Therefore, it is essential to explore how remediation and initial plant establishment can alter microbial communities, and, which edaphic factors control these changes under field conditions. A long-term revegetation trial was established at a Pb-Zn-Cu tailings impoundment in northwest Queensland. The control and amended and/or revegetated treatments were sampled from the 3-year-old trial. In total, 24 samples were examined using pyrosequencing of 16S rRNA genes and various chemical properties. The results showed that the microbial diversity was positively controlled by soil soluble Si and negatively controlled by soluble S, total Fe and total As, implying that pyrite weathering posed a substantial stress on microbial development in the tailings. All treatments were dominated by typical extremophiles and lithotrophs, typically Truepera, Thiobacillus, Rubrobacter; significant increases in microbial diversity, biomass and frequency of organotrophic genera (typically Nocardioides and Altererythrobacter) were detected in the revegetated and amended treatment. We concluded that appropriate phytostabilization options have the potential to drive the microbial diversity and community structure in the tailings toward those of natural soils, however, inherent environmental stressors may limit such changes.

Altererythrobacter aestiaquae sp. nov., isolated from seawater

A Gram-stain-negative, coccoid- or oval-shaped, gliding bacterial strain, designated HDW-31T, belonging to the class Alphaproteobacteria , was isolated from seawater of the Yellow Sea, Korea, and was subjected to a taxonomic study using a polyphasic approach. Strain HDW-31T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2–3 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain HDW-31T fell within the clade comprising the genus Altererythrobacter , clustering with the type strains of Altererythrobacter luteolus and Altererythrobacter gangjinensis , with which strain HDW-31T exhibited 97.0 and 96.0 % sequence similarity values, respectively. Sequence similarities to the type strains of the other recognized species of the genus Altererythrobacter were 93.5–96.0 %. The DNA G+C content was 57.9 mol% and mean DNA–DNA relatedness between strain HDW-31T and the type strain of A. luteolus was 5.3 %. Strain HDW-31T contained Q-10 as the predominant ubiquinone and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and C16 : 0 as the major fatty acids. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, a sphingoglycolipid, two unidentified glycolipids and an unidentified lipid. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, demonstrated that strain HDW-31T is distinguishable from recognized species of the genus Altererythrobacter . On the basis of the data presented, strain HDW-31T is considered to represent a novel species of the genus Altererythrobacter , for which the name Altererythrobacter aestiaquae sp. nov. is proposed. The type strain is HDW-31T ( = KCTC 42006T = CECT 8527T).

Altererythrobacter oceanensis sp. nov., isolated from the Western Pacific

A Gram-stain negative, ovoid-rod shaped, strictly aerobic bacterium, strain Y2(T), was isolated from a deep-sea sediment of the Western Pacific. Phylogenetic and phenotypic properties of the organism indicated that it belongs to the genus Altererythrobacter. Strain Y2(T) shares highest 16S rRNA gene sequence similarity of 96.6 % with Erythrobacter jejuensis CNU001(T), followed by the type strains of recognized members of the genus Altererythrobacter (94.8-96.5 %). Strain Y2(T) forms a clade with E. jejuensis CNU001(T) in the cluster of species of the genus Altererythrobacter. Growth of strain Y2(T) was observed at 4-40 °C (optimum, 35-37 °C), at pH 6.0-10.0 (optimum, pH 7.0-8.0) and in the presence of 0-5 % (w/v) NaCl (optimum, 2-3 %). The major cellular fatty acids were found to be C17:1 ω6c (41.5 %), summed feature 8 (C18:1 ω7c and/or C18:1 ω6c; 17.2 %), C17:1 ω8c (11.0 %) and C15:0 2OH (8.1 %). The major respiratory quinone was determine to be ubiquinone 10 (Q-10). The polar lipid analysis indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, one sphingoglycolipid, three unidentified phospholipids, two unidentified glycolipids, two unidentified aminolipids and three unknown lipids. The DNA G + C content of the type strain is 60.0 mol %. On the basis of the data from the polyphasic characterization, strain Y2(T) represents a novel species, for which the name Altererythrobacter oceanensis sp. nov. is proposed. The type strain is Y2(T) (=CGMCC 1.12752(T) =LMG 28109(T)).

Citrimicrobium luteum gen. nov., sp. nov., aerobic anoxygenic phototrophic bacterium isolated from the gut of a sea cucumber Stichopus japonicus

A Gram-stain negative, yellow-pigmented, motile, pleomorphic bacterium, designated strain CBA4602(T), was isolated from the gut of the sea cucumber Stichopus japonicus, which was collected from Jeju Island in the Republic of Korea. In a phylogenetic analysis based on the 16S rRNA gene, strain CBA4602(T) belonged to the order Sphingomonadales in the class Alphaproteobacteria. The 16S rRNA gene sequence similarity between strain CBA4602(T) and 'Citromicrobium bathyomarinum' JF-1, the most closely related strain having nonvalidly published name, was 98.4%, followed by 95.2-96.7% identities with sequence of the other closest strains in the genus Erythrobacter. Strain CBA4602(T) had bacteriochlorophyll a and carotenoids. Strain CBA4602(T) grew in 0-10% (w/v) NaCl, at 10-42°C and pH 6.0-8.0, with optimal growth in 1-2% NaCl, at 30-37°C and pH 7.0. Strain CBA4602(T) was positive for catalase and oxidase activities and was able to hydrolyse gelatine and Tween 20 and 40, but not starch, Tween 80 or L-tyrosine. The G+C content of genomic DNA from strain CBA4602(T) was 68.0 mol% and Q-10 was the major detected isoprenoid quinone. The polar lipids were three unidentified phospholipids, three unidentified glycolipids, and two unidentified lipids. The dominant fatty acids were anteiso-C15:0, C16:0, anteiso-C17:0 and C18:0. As considering the current taxonomic status of the genus 'Citromicrobium' and polyphasic taxonomic analyses, strain CBA4602(T) represents a novel genus and species. The name Citrimicrobium luteum is proposed for the type strain CBA4602(T) (=KACC 17668(T) =JCM 19530(T)).

Altererythrobacter xiamenensis sp. nov., an algicidal bacterium isolated from red tide seawater

A Gram-stain-negative, yellow-pigmented, aerobic bacterial strain, designated LY02T, was isolated from red tide seawater in Xiamen, Fujian Province, China. Growth was observed at temperatures from 4 to 44 °C, at salinities from 0 to 9 % and at pH from 6 to 10. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that the isolate was a member of the genus Altererythrobacter , which belongs to the family Erythrobacteraceae . Strain LY02T was related most closely to Altererythrobacter marensis MSW-14T (97.2 % 16S rRNA gene sequence similarity), followed by Altererythrobacter ishigakiensis JPCCMB0017T (97.1 %), Altererythrobacter epoxidivorans JCS350T (97.1 %) and Altererythrobacter luteolus SW-109T (97.0 %). The dominant fatty acids were C18 : 1ω7c, C17 : 1ω6c and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). DNA–DNA hybridization showed that strain LY02T possessed low DNA–DNA relatedness to A. marensis MSW-14T, A. ishigakiensis JPCCMB0017T, A. epoxidivorans JCS350T and A. luteolus SW-109T (mean±sd of 33.2±1.3, 32.1±1.0, 26.7±0.7 and 25.2±1.1 %, respectively). The G+C content of the chromosomal DNA was 61.2 mol%. The predominant respiratory quinone was ubiquinone-10 (Q-10). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, the novel strain most appropriately belongs to the genus Altererythrobacter , but can readily be distinguished from recognized species. The name Altererythrobacter xiamenensis sp. nov. is proposed (type strain LY02T = CGMCC 1.12494T = KCTC 32398T = NBRC 109638T).

Altererythrobacter atlanticus sp. nov., isolated from deep-sea sediment

A Gram-stain-negative, short rod-shaped bacterium, designated 26DY36T, was isolated from a deep-sea sediment sample collected from the North Atlantic Rise. The isolate required NaCl and grew best with 2 % (w/v) sea salts at a temperature of 30–35 °C and at pH 7.0. It formed yellow colonies, produced carotenoid-like pigments and did not produce bacteriochlorophyll a. Strain 26DY36T was positive for hydrolysis of aesculin, gelatin, tyrosine and Tweens 20, 40, 60 and 80, but negative for hydrolysis of casein, DNA and starch. The major respiratory quinone was ubiquinone-10. The major polar lipid profile consisted of sphingoglycolipid, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and two unidentified glycolipids. The principal fatty acids (>5 %) were C18 : 1ω7c, C17 : 1ω6c, C15 : 0 2-OH and C16 : 0. The genomic DNA G+C content was 59.4 mol%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain 26DY36T should be assigned to the genus Altererythrobacter . 16S rRNA gene sequence similarities between the isolate and the type strains of species of the genus Altererythrobacter were in the range 92.7–96.5 %. On the basis of phenotypic and genotypic data, strain 26DY36T represents a novel species of the genus Altererythrobacter , for which the name Altererythrobacter atlanticus sp. nov. (type strain, 26DY36T = CGMCC 1.12411T = JCM 18865T) is proposed.

Altererythrobacter gangjinensis sp. nov., a marine bacterium isolated from a tidal flat

A Gram-stain-negative, ochre-pigmented, strictly aerobic bacterium, designated strain KJ7T, was isolated from a tidal flat of the Gangjin bay in South Korea. Cells were halotolerant, non-motile, catalase- and oxidase-positive rods. Growth of strain KJ7T was observed at 5–35 °C (optimum, 25 °C), at pH 6.0–9.5 (optimum, pH 6.5–7.0) and in the presence of 0–9 % (w/v) NaCl (optimum, 2 %). The major cellular fatty acids were C18 : 1ω7c, C17 : 1ω6c, summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The polar lipid pattern indicated the presence of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, a sphingoglycolipid, an unidentified phospholipid and two unidentified lipids. The G+C content of the genomic DNA was 60.2±0.9 mol% and the predominant respiratory quinone was Q-10. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KJ7T formed a phyletic lineage distinct from other members of the genus Altererythrobacter and was most closely related to Altererythrobacter luteolus SW-109T and Altererythrobacter namhicola KYW48T (95.6 and 95.0 % 16S rRNA gene sequence similarity, respectively). On the basis of phenotypic, chemotaxonomic and molecular features, strain KJ7T represents a novel species of the genus Altererythrobacter , for which the name Altererythrobacter gangjinensis sp. nov. is proposed. The type strain is KJ7T ( = KACC 16190T = JCM 17802T).

Altererythrobacter troitsensis sp. nov., isolated from the sea urchin Strongylocentrotus intermedius

An aerobic, halotolerant, Gram-negative bacterium was isolated from the sea urchin Strongylocentrotus intermedius and subjected to taxonomic characterization. The strain, designated KMM 6042T, was rod-shaped, motile and yellow-pigmented. Phylogenetic analysis indicated that the strain was most closely related to the type strain of Altererythrobacter dongtanensis , and the level of 16S rRNA gene sequence similarity between the two was 99.0 %. However, the DNA–DNA relatedness between the two strains was 34.4±7.6 %. Physiological and chemotaxonomic properties clearly distinguished the novel strain from other species of the genus Altererythrobacter . It is thus evident from the phylogenetic and phenotypic analyses that strain KMM 6042T merits recognition as a novel species of the genus Altererythrobacter , for which the name Altererythrobacter troitsensis sp. nov. (type strain, KMM 6042T = KCTC 12303T = JCM 17037T) is proposed.