Marinobacterium litorale sp. nov. in the order Oceanospirillales

Microbacterium abyssi sp. nov. and Microbacterium limosum sp. nov., two new species of the genus Microbacterium, isolated from deep-sea sediment samples

Two Gram-positive, non-motile, short rod-shaped actinomycete strains, designated as A18JL241T and Y20T, were isolated from deep-sea sediment samples collected from the Southwest Indian Ocean and Western Pacific Ocean, respectively. Both of the isolates were able to grow within the temperature range of 5-40 °C, NaCl concentration range of 0-7  % (w/v) and at pH 6.0-12.0. The two most abundant cellular fatty acids of both strains were anteiso-C15  :  0 and anteiso-C17  :  0. The major polar lipid contents of the two strains were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and one unidentified glycolipid. These two strains shared common chemotaxonomic features comprising MK-10 and MK-12 as the respiratory quinones. The genomic DNA G+C contents of the two strains were 68.1 and 70.4  mol%, respectively. The 16S rRNA gene phylogeny showed that the novel strains formed two distinct sublines within the genus Microbacterium. Strain A18JL241T was most closely related to the type strain of Microbacterium tenebrionis KCTC 49593T (98.8 % sequence similarity), whereas strain Y20T formed a tight cluster with the type strain of Microbacterium schleiferi NBRC 15075T (99.0 %). The orthologous average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values with the type strains of related Microbacterium species were in the range of 74.1-89.1  % and 19.4-36.9  %, respectively, which were below the recognized thresholds of 95-96 % ANI and 70 % dDDH for species definition. Based on the results obtained here, it can be concluded that strains A18JL241T and Y20T represent two novel species of the genus Microbacterium, for which the names Microbacterium abyssi sp. nov. (type strain A18JL241T=JCM 33956T=MCCC 1A16622T) and Microbacterium limosum sp. nov. (type strain Y20T=JCM 33960T=MCCC 1A16747T) are proposed.

Bloom of tetracycline resistance genes in mudflats following fertilization is attributed to the increases in the shared potential hosts between soil and organic fertilizers

A field experiment was carried out in mudflats adjacent to the Yellow Sea, China, amended with sewage sludge and vermicompost by one-time input at different rates to reveal the fates of tetracycline resistance genes (TRGs) and their potential hosts in the soils. Quantitative PCR results showed that soils added with either sludge or vermicompost had more abundant TRGs compared with the non-fertilized soil. This situation was more obvious in sludge fertilized soils especially at high application rates. Vermicompost exhibited a promising outlook for improvement of the mudflats. The abundances of intI1 in the non-fertilized soils were significantly higher than those in fertilizers and fertilized soils. The potential hosts for intI1 were not shared with other TRGs-contained hosts, indicating that intI1 had little effects on the dissemination of TRGs in the mudflats. Moreover, the exclusive hosts for TRGs in fertilizers were not higher than those in the non-fertilized soils, illustrating little effects of fertilization on the introduction of exogenous TRGs into soil. The shared hosts between soil and fertilizers were highest among four possible sources, contributing vastly to the bloom of TRGs following fertilization. It was also shown that different organic fertilizers caused distinct categories of shared potential hosts for TRGs. RDA analysis further indicated that the abundances of the shared potential hosts were affected by soil nutrients. These results suggested that the development of TRGs in soil following fertilization depended on the shared potential hosts with similar ecological niches between soil and fertilizers.

A watershed impacted by anthropogenic activities: Microbial community alterations and reservoir of antimicrobial resistance genes

Water is the main resource for maintaining life. Anthropic activities influence the microbial epidemiological chain in watersheds, which can act as ways of disseminating microorganisms resistant to antimicrobial drugs, with impacts on human, animal, and environmental health. Here, we characterized aquatic microbial communities and their resistomes in samples collected along Rio das Ostras watershed during two seasons. Surface water samples were collected at eleven sites from the Jundiá, Iriry, and Rio das Ostras rivers in two seasons (dry and wet season). Microbial DNA was extracted, high-throughput sequenced and screened for antimicrobial resistance genetic (ARG) markers. The physicochemical characteristics and the microbiota data confirmed that Rio das Ostras watershed can be divided into three well defined portions: rural, urban, and marine. Rural areas were enriched by bacteria typically found in limnic environments and Patescibacteria phyla. The urban portion was characterized by sites with low pH and groups associated with iron oxidation. Some genera of clinical relevance were also identified, though in relatively low abundance. The marine site was enriched mainly by Cyanobacteria and bacteria that showed strong correlation with conductivity, salinity, and chloride. Twenty-six ARG markers were identified on the resistome, being found most frequently in the urban area, despite being present in rural sites. Among them were some related to classes of great clinical concern, such as genes coding for extended-spectrum beta-lactamase (bla_CTX-M and bla_TEM), resistance to carbapenems (bla_KPC) and to methicillin by Staphylococcus aureus (mecA). These results broaden our understanding of the microbial community of a watershed impacted by anthropogenic actions. The large number of ARGs detected along the Rio das Ostras watershed contrasts with the small number of microorganisms of clinical relevance observed, suggesting that antimicrobial resistance has arisen from non-clinical environments and microbes. Our results corroborate that freshwater acts as a reservoir of antimicrobial resistance genes.

Description of Microbacterium luteum sp. nov., Microbacterium cremeum sp. nov., and Microbacterium atlanticum sp. nov., three novel C50 carotenoid producing bacteria

We have identified three Microbacterium strains, A18JL200^T, NY27^T, and WY121^T, that produce C50 carotenoids. Taxonomy shows they represent three novel species. These strains shared < 98.5% 16S rRNA gene sequence identity with each other and were closely related to Microbacterium aquimaris JCM 15625^T, Microbacterium yannicii JCM 18959^T, Microbacterium ureisolvens CFH S00084^T, and Microbacterium hibisci CCTCC AB 2016180^T. Digital DNA-DNA hybridization (dDDH) values and average nucleotide identity (ANI) showed differences among the three strains and from their closest relatives, with values ranging from 20.4% to 34.6% and 75.5% to 87.6%, respectively. These values are below the threshold for species discrimination. Both morphology and physiology also differed from those of phylogenetically related Microbacterium species, supporting that they are indeed novel species. These strains produce C50 carotenoids (mainly decaprenoxanthin). Among the three novel species, A18JL200^T had the highest total yield in carotenoids (6.1 mg/L or 1.2 mg/g dry cell weight). Unusual dual isoprenoid biosynthetic pathways (methylerythritol phosphate and mevalonate pathways) were annotated for strain A18JL200^T. In summary, we found strains of the genus Microbacterium that are potential producers of C50 carotenoids, but their genome has to be investigated further.

Taxogenomic and Metabolic Insights into Marinobacterium ramblicola sp. nov., a New Slightly Halophilic Bacterium Isolated from Rambla Salada, Murcia

A Gram-negative, motile, rod-shaped bacteria, designated D7^T, was isolated by using the dilution-to-extinction method, from a soil sample taken from Rambla Salada (Murcia, Spain). Growth of strain D7^T was observed at 15–40 °C (optimum, 37 °C), pH 5–9 (optimum, 7) and 0–7.5% (w/v) NaCl (optimum, 3%). It is facultatively anaerobic. Phylogenetic analysis based on 16S rRNA gene sequence showed it belongs to the genus Marinobacterium. The in silico DDH and ANI against closest Marinobacterium relatives support its placement as a new species within this genus. The major fatty acids of strain D7^T were C_16:0, summed feature 3 (C_16:1 ω7c/C_16:1 ω6c) and summed feature 8 (C_18:1 ω7c/C_18:1 ω6c). The polar lipid profile consists of phosphatidylethanolamine, phosphatidylglycerol and two uncharacterized lipids. Ubiquinone 8 was the unique isoprenoid quinone detected. The DNA G + C content was 59.2 mol%. On the basis of the phylogenetic, phenotypic, chemotaxonomic and genomic characterization, strain D7^T (= CECT 9818^T = LMG 31312^T) represents a novel species of the genus Marinobacterium for which the name Marinobacterium ramblicola sp. nov. is proposed. Genome-based metabolic reconstructions of strain D7^T suggested a heterotrophic and chemolitotrophic lifestyle, as well as the capacity to biosynthetize and catabolize compatible solutes, and to degrade hydrocarbon aromatic compounds.

"The Good, the Bad and the Double-Sword" Effects of Microplastics and Their Organic Additives in Marine Bacteria

Little is known about the direct effects of microplastics (MPs) and their organic additives on marine bacteria, considering their role in the nutrient cycles, e.g., N-cycles through the N₂-fixation, or in the microbial food web. To fill this gap of knowledge, we exposed marine bacteria, specifically diazotrophs, to pure MPs which differ in physical properties (e.g., density, hydrophobicity, and/or size), namely, polyethylene, polypropylene, polyvinyl chloride and polystyrene, and to their most abundant associated organic additives (e.g., fluoranthene, 1,2,5,6,9,10-hexabromocyclododecane and dioctyl-phthalate). Growth, protein overproduction, direct physical interactions between MPs and bacteria, phosphorus acquisition mechanisms and/or N₂-fixation rates were evaluated. Cyanobacteria were positively affected by environmental and high concentrations of MPs, as opposed to heterotrophic strains, that were only positively affected with high concentrations of ~120 μm-size MPs (detecting the overproduction of proteins related to plastic degradation and C-transport), and negatively affected by 1 μm-size PS beads. Generally, the organic additives had a deleterious effect in both autotrophic and heterotrophic bacteria and the magnitude of the effect is suggested to be dependent on bacterial size. Our results show species-specific responses of the autotrophic and heterotrophic bacteria tested and the responses (beneficial: the “good,” deleterious: the “bad” and/or both: the “double-sword”) were dependent on the type and concentration of MPs and additives. This suggests the need to determine the threshold levels of MPs and additives concentrations starting from which significant effects can be observed for key microbial populations in marine systems, and these data are necessary for effective environmental quality control management.

The Saltpan Microbiome is Structured by Sediment Depth and Minimally Influenced by Variable Hydration

Saltpans are a class of ephemeral wetland characterized by alternating periods of inundation, rising salinity, and desiccation. We obtained soil cores from a saltpan on the Mississippi Gulf coast in both the inundated and desiccated state. The microbiomes of surface and 30 cm deep sediment were determined using Illumina sequencing of the V4 region of the 16S rRNA gene. Bacterial and archaeal community composition differed significantly between sediment depths but did not differ between inundated and desiccated states. Well-represented taxa included marine microorganisms as well as multiple halophiles, both observed in greater proportions in surface sediment. Functional inference of metagenomic data showed that saltpan sediments in the inundated state had greater potential for microbial activity and that several energetic and degradation pathways were more prevalent in saltpan sediment than in nearby tidal marsh sediment. Microbial communities within saltpan sediments differed in composition from those in adjacent freshwater and brackish marshes. These findings indicate that the bacterial and archaeal microbiomes of saltpans are highly stratified by sediment depth and are only minimally influenced by changes in hydration. The surface sediment community is likely isolated from the shallow subsurface community by compaction, with the microbial community dominated by marine and terrestrial halophiles.

The plethora of membrane respiratory chains in the phyla of life

The diversity of microbial cells is reflected in differences in cell size and shape, motility, mechanisms of cell division, pathogenicity or adaptation to different environmental niches. All these variations are achieved by the distinct metabolic strategies adopted by the organisms. The respiratory chains are integral parts of those strategies especially because they perform the most or, at least, most efficient energy conservation in the cell. Respiratory chains are composed of several membrane proteins, which perform a stepwise oxidation of metabolites toward the reduction of terminal electron acceptors. Many of these membrane proteins use the energy released from the oxidoreduction reaction they catalyze to translocate charges across the membrane and thus contribute to the establishment of the membrane potential, i.e. they conserve energy. In this work we illustrate and discuss the composition of the respiratory chains of different taxonomic clades, based on bioinformatic analyses and on biochemical data available in the literature. We explore the diversity of the respiratory chains of Animals, Plants, Fungi and Protists kingdoms as well as of Prokaryotes, including Bacteria and Archaea. The prokaryotic phyla studied in this work are Gammaproteobacteria, Betaproteobacteria, Epsilonproteobacteria, Deltaproteobacteria, Alphaproteobacteria, Firmicutes, Actinobacteria, Chlamydiae, Verrucomicrobia, Acidobacteria, Planctomycetes, Cyanobacteria, Bacteroidetes, Chloroflexi, Deinococcus-Thermus, Aquificae, Thermotogae, Deferribacteres, Nitrospirae, Euryarchaeota, Crenarchaeota and Thaumarchaeota.

Marinobacterium boryeongense sp. nov., isolated from seawater

A Gram-stain-negative and strictly aerobic bacterium, designated DMHB-2^T, was isolated from a sample of seawater collected off the Yellow Sea coast of the Republic of Korea. Cells were short rods and motile by means of a single polar flagellum. Catalase and oxidase activities were positive. Growth occurred at pH 5.5-10.0 (optimum, pH 6.0), 15-45 °C (optimum, 25 °C) and with 1-9 % NaCl (optimum, 3 %). The respiratory quinone was ubiquinone-8 and the major fatty acids were C16 : 0 (17.9 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 26.1 %) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 37.4 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain DMHB-2^T belong to the genus Marinobacterium, with the highest 16S rRNA gene sequence similarity of 95.2 % to Marinobacterium zhoushanense KCTC 42782^T. The genomic DNA G+C content of strain DMHB-2^T was 60.8 mol%. On the basis of the phenotypic, chemotaxonomic and genotypic characteristics presented in this study, strain DMHB-2^T is suggested to represent a novel species of the genus Marinobacterium, for which the name Marinobacteriumboryeongense sp. nov. is proposed. The type strain is DMHB-2^T (=KACC 19225^T=JCM 31902^T).

Draft genome sequence of Marinobacterium rhizophilum CL-YJ9T (DSM 18822T), isolated from the rhizosphere of the coastal tidal-flat plant Suaeda japonica

The genus Marinobacterium belongs to the family Alteromonadaceae within the class Gammaproteobacteria and was reported in 1997. Currently the genus Marinobacterium contains 16 species. Marinobacterium rhizophilum CL-YJ9^T was isolated from sediment associated with the roots of a plant growing in a tidal flat of Youngjong Island, Korea. The genome of the strain CL-YJ9^T was sequenced through the Genomic Encyclopedia of Type Strains, Phase I: KMG project. Here we report the main features of the draft genome of the strain. The 5,364,574 bp long draft genome consists of 58 scaffolds with 4762 protein-coding and 91 RNA genes. Based on the genomic analyses, the strain seems to adapt to osmotic changes by intracellular production as well as extracellular uptake of compatible solutes, such as ectoine and betaine. In addition, the strain has a number of genes to defense against oxygen stresses such as reactive oxygen species and hypoxia.

Genomic sequence of 'Candidatus Liberibacter solanacearum' haplotype C and its comparison with haplotype A and B genomes

Haplotypes A and B of 'Candidatus Liberibacter solanacearum' (CLso) are associated with diseases of solanaceous plants, especially Zebra chip disease of potato, and haplotypes C, D and E are associated with symptoms on apiaceous plants. To date, one complete genome of haplotype B and two high quality draft genomes of haplotype A have been obtained for these unculturable bacteria using metagenomics from the psyllid vector Bactericera cockerelli. Here, we present the first genomic sequences obtained for the carrot-associated CLso. These two genomic sequences of haplotype C, FIN114 (1.24 Mbp) and FIN111 (1.20 Mbp), were obtained from carrot psyllids (Trioza apicalis) harboring CLso. Genomic comparisons between the haplotypes A, B and C revealed that the genome organization differs between these haplotypes, due to large inversions and other recombinations. Comparison of protein-coding genes indicated that the core genome of CLso consists of 885 ortholog groups, with the pan-genome consisting of 1327 ortholog groups. Twenty-seven ortholog groups are unique to CLso haplotype C, whilst 11 ortholog groups shared by the haplotypes A and B, are not found in the haplotype C. Some of these ortholog groups that are not part of the core genome may encode functions related to interactions with the different host plant and psyllid species.

Marinobacterium zhoushanense sp. nov., isolated from surface seawater

A Gram-stain-negative, facultatively anaerobic bacterium, designated WM3T, was isolated from surface seawater collected from the East China Sea. Cells were catalase- and oxidase-positive, short rods and motile by means of a single polar flagellum. Growth occurred at 15-43 °C (optimum 37-40 C), pH 5.5-9.5 (optimum pH 6.5-7.5) and with 0.25-9.0 % (w/v) NaCl (optimum 1.0-1.5 %). Chemotaxonomic analysis showed that the respiratory quinone was ubiquinone-8, the major fatty acids included C16 : 0 (23.6 %), C18 : 1ω7c (26.2 %) and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH, 22.1 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain WM3T was most closely related to the genus Marinobacterium, sharing the highest 16S rRNA gene sequence similarity of 95.5 % with both Marinobacterium litorale KCTC 12756T and Marinobacterium mangrovicola DSM 27697T. The genomic DNA G+C content of the strain WM3T was 55.8 mol%. On the basis of phenotypic, chemotaxonomic and genotypic characteristics presented in this study, strain WM3T is suggested to represent a novel species of the genus Marinobacterium, for which the name Marinobacterium zhoushanense sp. nov. is proposed. The type strain is WM3T (=KCTC 42782T=CGMCC 1.15341T).

Marinobacterium profundum sp. nov., a marine bacterium from deep-sea sediment

A Gram-stain-negative, rod-shaped and motile strain, designated PAMC 27536^T, was isolated from deep-sea sediment in the East Sea, Korea. Analysis of the 16S rRNA gene sequence of the strain showed an affiliation with the genus Marinobacterium. Phylogenetic analyses revealed that strain PAMC 27536^T was related most closely to Marinobacterium rhizophilum CL-YJ9^T with a 16S rRNA gene sequence similarity of 98.5 % and to other members of the genus Marinobacterium (94.0-91.7 %). Genomic relatedness analyses between strain PAMC 27536^T and M. rhizophilum KCCM 42386^T gave an average nucleotide identity of 85.6 % and an estimated DNA-DNA hybridization of 24.6 % using the genome-to-genome distance calculator, indicating that they represent genomically distinct species. Cells of strain PAMC 27536^T grew optimally at 25-30 °C and pH 7.0-7.5 in the presence of 3 % (w/v) sea salts. The major cellular fatty acids were C_16 : 1ω6c and/or C_16 : 1ω7c, C_18 : 1ω6c and/or C_18 : 1ω7c, and C_16 : 0. The major isoprenoid quinone was Q-8. The genomic DNA G+C content was 56.1-57.2 mol%. Based on the phylogenetic, chemotaxonomic, genomic and phenotypic data presented, a novel species with the name Marinobacterium profundum sp. nov. is proposed, with PAMC 27536^T ( = KCCM 43095^T = JCM 30410^T) as the type strain.

Marinobacterium aestuariivivens sp. nov., isolated from a tidal flat

A Gram-stain-negative, motile, aerobic, rod- or ovoid-shaped bacterium, designated DB-1T, was isolated from a tidal flat on the Yellow Sea in South Korea and subjected to a taxonomic study using a polyphasic approach. Strain DB-1T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 0.5-2.0% (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain DB-1T falls within the clade comprising species of the genus Marinobacterium, clustering coherently with the type strain of Marinobacterium nitratireducens and showing a sequence similarity value of 98.4 %. The novel strain exhibited 16S rRNA gene sequence similarities of 91.5-94.4 % to the type strains of other species of the genus Marinobacterium. Strain DB-1T contained Q-8 as the predominant ubiquinone and C18:1ω7c, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and C16:0 as the major fatty acids. The major polar lipids detected in strain DB-1T were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid, one unidentified glycolipid, one unidentified phospholipid and two unidentified lipids. The DNA G+C content of strain DB-1T was 62.3 mol% and the mean DNA-DNA relatedness value with the type strain of M. nitratireducens was 21±4.6%. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain DB-1T is separated from recognized species of the genus Marinobacterium. On the basis of the data presented, strain DB-1T is considered to represent a novel species of the genus Marinobacterium, for which the name Marinobacterium aestuariivivens sp. nov. is proposed. The type strain is DB-1T (=KCTC 42778T=NBRC 111756T).

Biogeochemical insights into microbe-mineral-fluid interactions in hydrothermal chimneys using enrichment culture

Active hydrothermal chimneys host diverse microbial communities exhibiting various metabolisms including those involved in various biogeochemical cycles. To investigate microbe-mineral-fluid interactions in hydrothermal chimney and the driver of microbial diversity, a cultural approach using a gas-lift bioreactor was chosen. An enrichment culture was performed using crushed active chimney sample as inoculum and diluted hydrothermal fluid from the same vent as culture medium. Daily sampling provided time-series access to active microbial diversity and medium composition. Active archaeal and bacterial communities consisted mainly of sulfur, sulfate and iron reducers and hydrogen oxidizers with the detection of Thermococcus, Archaeoglobus, Geoglobus, Sulfurimonas and Thermotoga sequences. The simultaneous presence of active Geoglobus sp. and Archaeoglobus sp. argues against competition for available carbon sources and electron donors between sulfate and iron reducers at high temperature. This approach allowed the cultivation of microbial populations that were under-represented in the initial environmental sample. The microbial communities are heterogeneously distributed within the gas-lift bioreactor; it is unlikely that bulk mineralogy or fluid chemistry is the drivers of microbial community structure. Instead, we propose that micro-environmental niche characteristics, created by the interaction between the mineral grains and the fluid chemistry, are the main drivers of microbial diversity in natural systems.

Life in the slow lane; biogeochemistry of biodegraded petroleum containing reservoirs and implications for energy recovery and carbon management

Our understanding of the processes underlying the formation of heavy oil has been transformed in the last decade. The process was once thought to be driven by oxygen delivered to deep petroleum reservoirs by meteoric water. This paradigm has been replaced by a view that the process is anaerobic and frequently associated with methanogenic hydrocarbon degradation. The thermal history of a reservoir exerts a fundamental control on the occurrence of biodegraded petroleum, and microbial activity is focused at the base of the oil column in the oil water transition zone, that represents a hotspot in the petroleum reservoir biome. Here we present a synthesis of new and existing microbiological, geochemical, and biogeochemical data that expands our view of the processes that regulate deep life in petroleum reservoir ecosystems and highlights interactions of a range of biotic and abiotic factors that determine whether petroleum is likely to be biodegraded in situ, with important consequences for oil exploration and production. Specifically we propose that the salinity of reservoir formation waters exerts a key control on the occurrence of biodegraded heavy oil reservoirs and introduce the concept of palaeopickling. We also evaluate the interaction between temperature and salinity to explain the occurrence of non-degraded oil in reservoirs where the temperature has not reached the 80-90°C required for palaeopasteurization. In addition we evaluate several hypotheses that might explain the occurrence of organisms conventionally considered to be aerobic, in nominally anoxic petroleum reservoir habitats. Finally we discuss the role of microbial processes for energy recovery as we make the transition from fossil fuel reliance, and how these fit within the broader socioeconomic landscape of energy futures.

Marinobacterium mangrovicola sp. nov., a marine nitrogen-fixing bacterium isolated from mangrove roots of Rhizophora mangle

A nitrogen-fixing marine bacterium, designated strain Gal22(T), was isolated from mangrove roots of Rhizophora mangle. Cells were Gram-stain-negative rods, motile with a single polar flagellum. Growth was observed at 4-42 °C, pH 5.5 to 10 and with 0-18 % (w/v) NaCl. Strain Gal22(T) was positive for catalase and oxidase. Q-8 was the predominant lipoquinone. The DNA G+C content was 57.0 mol%. Based on phylogenetic analysis of 16S rRNA gene, strain Gal22(T) belongs to the genus Marinobacterium. The closely related strains were shown to be Marinobacterium lutimaris DSM 22012(T) and Marinobacterium litorale IMCC1877(T) with 99 % and 96 % 16S rRNA gene sequence similarity, respectively. DNA-DNA relatedness analysis indicated that strain Gal22(T) was different from M. lutimaris DSM 22012(T). On the basis of genotypic, morphological and biochemical characteristics, a novel species, Marinobacterium mangrovicola sp. nov. (type strain, Gal22(T) = DSM 27697(T) = CIP 110653(T)), is proposed.

Motiliproteus sediminis gen. nov., sp. nov., isolated from coastal sediment

A novel Gram-stain-negative, rod-to-spiral-shaped, oxidase- and catalase- positive and facultatively aerobic bacterium, designated HS6(T), was isolated from marine sediment of Yellow Sea, China. It can reduce nitrate to nitrite and grow well in marine broth 2216 (MB, Hope Biol-Technology Co., Ltd) with an optimal temperature for growth of 30-33 °C (range 12-45 °C) and in the presence of 2-3% (w/v) NaCl (range 0.5-7%, w/v). The pH range for growth was pH 6.2-9.0, with an optimum at 6.5-7.0. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that the novel isolate was 93.3% similar to the type strain of Neptunomonas antarctica, 93.2% to Neptunomonas japonicum and 93.1% to Marinobacterium rhizophilum, the closest cultivated relatives. The polar lipid profile of the novel strain consisted of phosphatidylethanolamine, phosphatidylglycerol and some other unknown lipids. Major cellular fatty acids were summed feature 3 (C(16:1) ω7c/iso-C15:0 2-OH), C(18:1) ω7c and C(16:0) and the main respiratory quinone was Q-8. The DNA G+C content of strain HS6(T) was 61.2 mol%. Based on the phylogenetic, physiological and biochemical characteristics, strain HS6(T) represents a novel genus and species and the name Motiliproteus sediminis gen. nov., sp. nov., is proposed. The type strain is HS6(T) (=ATCC BAA-2613(T)=CICC 10858(T)).

Draft genome sequence of Marinobacterium stanieri S30, a strain isolated from a coastal lagoon in Chuuk state in Micronesia

In this study, we isolated xylan-degrading bacteria from a coastal lagoon of Micronesia and identified the bacteria as Marinobacterium stanieri S30. GSFLX 454 pyrosequencing and sequence analysis of the M. stanieri S30 genome generated 4,007 predicted open reading frames (ORFs) that could be candidate genes for producing enzymes with different catalytic functions.

Marinobacterium coralli sp. nov., isolated from mucus of coral (Mussismilia hispida)

A Gram-negative, aerobic bacterium, designated R-40509T, was isolated from mucus of the reef builder coral (Mussismilia hispida) located in the São Sebastião Channel, São Paulo, Brazil. The strain was oxidase-positive and catalase-negative, and required Na+ for growth. Its phylogenetic position was in the genus Marinobacterium and the closest related species were Marinobacterium sediminicola, Marinobacterium maritimum and Marinobacterium stanieri; the isolate exhibited 16S rRNA gene sequence similarities of 97.5–98.0 % with the type strains of these species. 16S rRNA gene sequence similarities with other type strains of the genus Marinobacterium were below 96 %. DNA–DNA hybridizations between strain R-40509T and the type strains of the phylogenetically closest species of the genus Marinobacterium revealed less than 70 % DNA–DNA relatedness, supporting the novel species status of the strain. Phenotypic characterization revealed that the strain was able to grow at 15–42 °C and in medium containing up to 9 % NaCl. The isolate could be differentiated from phenotypically related species by several features, including its ability to utilize d-alanine, l-alanine, bromosuccinic acid, β-hydroxybutyric acid and α-ketovaleric acid, but not acetate or l-arabinose. It produced acetoin (Voges–Proskauer), but did not have esterase lipase (C8) or catalase activities. It possessed C18 : 1 ω7c (35 %), summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c; 25 %) and C16 : 0 (22 %) as major cellular fatty acids. The DNA G+C content was 58.5 mol%. The name Marinobacterium coralli sp. nov. is proposed to accommodate this novel isolate; the type strain is R-40509T (=LMG 25435T =CAIM 1449T).

Marinobacterium lutimaris sp. nov., isolated from a tidal flat

A Gram-staining-negative, moderately halophilic bacterium, designated strain AN9T, was isolated from a tidal flat of the Taean coast in South Korea. Cells were catalase- and oxidase-positive short rods that were motile by means of a single polar flagellum. Growth of strain AN9T was observed at 15–40 °C (optimum, 25–30 °C) and at pH 6.0–8.0 (optimum, pH 6.5–7.5). Strain AN9T contained ubiquinone Q-8 as the predominant isoprenoid quinone and C10 : 0 3-OH (31.7 %), C18 : 1 ω7c (24.8 %), C16 : 0 (14.7 %) and summed feature 3 (comprising C16 : 1 ω7c and/or iso-C15 : 0 2-OH, 10.72 %) as the major fatty acids. The G+C content of the genomic DNA of strain AN9T was 58 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AN9T was related to members of the genus Marinobacterium and was related most closely to Marinobacterium litorale IMCC1877T (96.8 % similarity). On the basis of chemotaxonomic and molecular data, strain AN9T is considered to represent a novel species of the genus Marinobacterium, for which the name Marinobacterium lutimaris sp. nov. is proposed. The type strain is AN9T (=KACC 13703T =DSM 22012T).