Altererythrobacter namhicola sp. nov. and Altererythrobacter aestuarii sp. nov., isolated from seawater

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 muriae sp. nov., isolated from hypersaline Añana Salt Valley spring water, a continental thalassohaline-type solar saltern

A novel salt-tolerant alpha-proteobacterium, designated SALINAS58^T, was isolated from Santa Engracia hypersaline spring water in the Añana Salt Valley, Álava, Spain. The isolate was Gram-negative, aerobic, non-motile, catalase-positive, oxidase-negative, rod-shaped and formed orange colonies on marine agar. Optimal growth was observed at pH 6.0-6.5, at 30 °C and in the presence of 1% (w/v) NaCl. The main cellular fatty acids (>20%) were summed feature 8 (C_{18 : 1} ω7c and/or C_{18 : 1} ω6c) and summed feature 3 (C_{16 : 1} ω7c and/or C_{16 : 1} ω6c). The major respiratory quinone was ubiquinone Q-10 and the major polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidilglycerol, four unidentified glycolipids and one unidentified phospholipid. Strain SALINAS58^T had the highest 16S rRNA gene sequence similarity to Altererythrobacter marensis MSW-14^T (96.6%), Altererythrobacter aquaemixtae JSSK-8^T (96.5%) and Pontixanthobacter luteolus SW-109^T (96.5%) followed by Altererythrobacter atlanticus 26DY36^T (96.4%). Results of the phylogenetic analysis, based on 16S rRNA gene sequences, and phylogenetic approaches based on whole genome nucleotide differences, showed that strain SALINAS58^T could be distinguished from recognized species of the genus Altererythrobacter. The genomic DNA G+C content was 61.4 mol%. Digital DNA-DNA hybridization, average nucleotide identity and average aminoacid identity values between the genome of strain SALINAS58^T and A. marensis MSW-14^T were 18.4, 73.1 and 68.1%, respectively. Based on data from this polyphasic characterization, strain SALINAS58^T (=CECT 30029^T=LMG 31726^T) is considered to be classified as representing a novel species in the genus Altererythrobacter, for which the name Altererythrobacter muriae sp. nov. is proposed.

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.

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 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).

Genomewide characterisation of the genetic diversity of carotenogenesis in bacteria of the order Sphingomonadales

The order Sphingomonadales is a taxon of bacteria with a variety of physiological features and carotenoid pigments. Some of the coloured strains within this order are known to be aerobic anoxygenic phototrophs that contain characteristic photosynthesis gene clusters (PGCs). Previous work has shown that majority of the ORFs putatively involved in the biosynthesis of C₄₀ carotenoids are located outside the PGCs in these strains. The main purpose of this study was to understand the genetic basis for the various colour/carotenoid phenotypes of the strains of Sphingomonadales. Comparative analyses of the genomes of 41 strains of this order revealed that there were different patterns of clustering of carotenoid biosynthesis (crt) ORFs, with four ORF clusters being the most common. The analyses also revealed that co-occurrence of crtY and crtI is an evolutionarily conserved feature in Sphingomonadales and other carotenogenic bacteria. The comparisons facilitated the categorisation of bacteria of this order into four groups based on the presence of different crt ORFs. Yellow coloured strains most likely accumulate nostoxanthin, and contain six ORFs (group I: crtE, crtB, crtI, crtY, crtZ, crtG). Orange coloured strains may produce adonixanthin, astaxanthin, canthaxanthin and erythroxanthin, and contain seven ORFs (group II: crtE, crtB, crtI, crtY, crtZ, crtG, crtW). Red coloured strains may accumulate astaxanthin, and contain six ORFs (group III: crtE, crtB, crtI, crtY, crtZ, crtW). Non-pigmented strains may contain a smaller subset of crt ORFs, and thus fail to produce any carotenoids (group IV). The functions of many of these ORFs remain to be characterised.

Effect of reflux ratio on nitrogen removal in a novel upflow microaerobic sludge reactor treating piggery wastewater with high ammonium and low COD/TN ratio: Efficiency and quantitative molecular mechanism

A novel upflow microaerobic sludge reactor (UMSR) was constructed to treat manure-free piggery wastewater with high NH₄⁺-N and low COD/TN ratio. In the light of the potential effect of effluent reflux ratio (RR) on nitrogen removal, performance of the UMSR was evaluated at 35°C and hydraulic retention time 8h with RR decreased from 45 to 25 by stages. A COD, NH₄⁺-N and TN removal of above 77.1%, 80.0% and 86.6%, respectively, was kept with a RR over 35. To get an effluent of TN not more than 80mg/L with a TN load removal above 0.88kg/(m³·d), the RR should be at least 34. Real-time quantitative polymerase chain reaction of functional bacteria revealed that the RR of less than 34 stimulated ammonium oxidation but badly inhibited anammox, the dominant nitrogen removal pathway, resulting in the remarkable decrease of nitrogen removal in the reactor.

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 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).

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).

Altererythrobacter buctense sp. nov., isolated from mudstone core

A yellow-pigmented, Gram-negative, non-flagellated, rod-shaped bacterial strain, designated M0322(T), was isolated from a mudstone core sample of the Mohe Basin, China. Growth of strain M0322(T) was observed at 15-40 °C (optimum, 30 °C), at pH 5.0-10.0, (optimum, pH 6.0-7.0) and in the presence 0-4 % NaCl (optimum, 0 %). Phylogenetic analyses of 16S rRNA gene sequences revealed that strain M0322(T) formed a distinct phyletic lineage with the members of the genus Altererythrobacter and is closely related to Altererythrobacter aestuarii JCM 16339(T) (96.1 %) and Altererythrobacter namhicola JCM 16345(T) (95.7 %). The only isoprenoid quinone was identified as ubiquinone 10 (Q-10), major polar lipids were determined to be phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified glycolipid and three unidentified phospholipids, while major cellular fatty acids were summed feature 8 (C18:1 ω6c and/or C18:1 ω7c), summed feature 3 (C16:1 ω6c and/or C16:1 ω7c) and 11-Methyl C18:1 ω7c. The DNA G+C content of strain M0322(T) was determined to be 64.6 mol%. Based on the results of the polyphasic taxonomic study, strain M0322(T) is considered to represent a novel species of the genus Altererythrobacter, for which the name Altererythrobacter buctense sp. nov. is proposed. The type strain is M0322(T) (=CGMCC 1.12871(T) = JCM 30112(T)).

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.

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.

Altererythrobacter ishigakiensis sp. nov., an astaxanthin-producing bacterium isolated from a marine sediment

A Gram-negative, non-motile, non-spore-forming, halophilic rod, designated JPCCMB0017T, was isolated from a marine sediment of the coastal area of Okinawa, Japan. The isolate formed orange–red colonies on marine agar. Bacteriochlorophyll α was absent and sphingoglycolipid 1 and other carotenoids, including astaxanthin, adonixanthin and zeaxanthin, were present. Ubiquinone-10 (Q-10) was the main respiratory quinone and C18 : 1ω7c was the major cellular fatty acid. The G+C content of DNA was 59.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that the isolate was a member of the genus Altererythrobacter in the family Erythrobacteraceae. Strain JPCCMB0017T exhibited 96.8 % 16S rRNA gene sequence similarity with Altererythrobacter marinus H32T. Unlike other members of the genus Altererythrobacter, strain JPCCMB0017T reduced nitrate. On the basis of genotypic and phenotypic data, a novel species is proposed to accommodate this isolate, with the name Altererythrobacter ishigakiensis sp. nov. The type strain is JPCCMB0017T ( = NITE-AP48T = ATCC BAA-2084T = NBRC 107699T).

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

A Gram-negative, rod-shaped, non-motile, strictly aerobic bacterium, strain S3-63(T), was isolated from desert sand of Xinjiang, China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain S3-63(T) had highest similarity to type strains of the genus Altererythrobacter, i.e. Altererythrobacter marinus H32(T) (97.2% similarity), Altererythrobacter marensis MSW-14(T) (95.9%), Altererythrobacter aestuarii KCTC 22735(T) (95.5%), Altererythrobacter epoxidivorans JCS350(T) (95.1%), Altererythrobacter namhicola KCTC 22736(T) (95.1%), Altererythrobacter luteolus SW-109(T) (95.0%) and Altererythrobacter indicus LMG 23789(T) (93.5%). Growth occurred at 20-37 °C (optimum 30 °C), at pH 7.0-9.0 (optimum pH 8.0) and in 0-3% (w/v) NaCl (optimum 1%). The major respiratory quinone was ubiquinone-10 and the predominant cellular fatty acids were C(18:1)ω7c (50.8%), summed feature 3 (C(16:1)ω7c and/or C(16:1)ω6c; 12.6%), C(16:0) (12.3%), C(14:0) 2-OH (7.3%) and C(17:1)ω6c (4.5%). The DNA G+C content was 64.6 mol%. Therefore, the phylogenetic, physiological and chemotaxonomic data demonstrated that strain S3-63(T) represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter xinjiangensis sp. nov. is proposed; the type strain is S3-63(T) (=CCTCC AB 207166(T)=CIP 110125(T)). An emended description of the genus Altererythrobacter is provided.

Altererythrobacter dongtanensis sp. nov., isolated from a tidal flat

A Gram-negative, rod-shaped and non-spore-forming bacterial strain, JM27(T), was isolated from a tidal flat of Dongtan Wetland, Chongming Island, China. The strain formed smooth yellow colonies on R2A plates. Growth occurred at 10-37 °C (optimum, 30-37 °C), at pH 6.0-10.0 (optimum, pH 7.0-9.0) and in the presence of 0-1 % NaCl (optimum, 0 %). Catalase test was positive and oxidase test was negative. Ubiquinone 10 (Q10) was the major respiratory quinone. C₁₈:₀ω7c and C₁₇:₁ω6c were the most abundant fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were the major polar lipids. The DNA G+C content of strain JM27(T) was 66.4 mol%. The 16S rRNA gene sequence of the isolate showed highest similarity to that of Altererythrobacter marinus H32(T) (96.4 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain belonged to the genus Altererythrobacter of the family Erythrobacteraceae of the class Alphaproteobacteria. On the basis of phylogenetic analysis, whole-cell fatty acids, polar lipid compositions, and biochemical and physiological characteristics, strain JM27(T) is proposed to represent a novel species of the genus Altererythrobacter for which the name Altererythrobacter dongtanensis sp. nov. is proposed. The type strain is JM27(T) ( = KCTC 22672(T)  = CCTCC AB 209199(T)).