Nocardioides coralli sp. nov., an actinobacterium isolated from stony coral in the South China Sea.

A Gram-stain-positive, aerobic, non-pigmented and non-motile actinobacterium, designated strain SCSIO 67246T, was isolated from a stony coral sample collected from the Sanya sea area, Hainan province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SCSIO 67246T shared the highest similarities with Nocardioides rotundus MCCC 1A10561T (96.5 %) and Nocardioides sonneratiae KCTC 39565T (96.1%). The novel strain grew at 15-37 °C, at pH 5.0-10.0 and in the presence of 0-10 % (w/v) NaCl. The genome length of strain SCSIO 67246T was 3.52 Mbp with a DNA G+C content of 72.0 mol% and 3397 protein-coding genes. The novel strain showed an average nucleotide identity value of 76.5 % and a digital DNA-DNA hybridization value of 20.1 % with N. rotundus MCCC 1A10561T. Strain SCSIO 67246T contained MK-8(H4) as the major menaquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and five phospholipids. The major cellular fatty acids were iso-C16 : 0, C17 : 1 ω8c and summed feature 9 (iso-C17 : 1 ω9c/10-methyl C16 : 0). ll-2,6-Diaminopimelic acid was the diagnostic diamino acid. The whole-cell sugars were galactose, glucose and ribose. Based on this polyphasic taxonomic study, strain SCSIO 67246T represents a novel species of the genus Nocardioides, for which the name Nocardioides coralli sp. nov. is proposed. The type strain is SCSIO 67246T (=MCCC 1K06251T=KCTC 49719T).

Brevibacillus marinus sp. nov., a thermophilic bacterium isolated from deep sea sediment in the South China Sea.

A novel thermophilic bacterium, designated SCSIO 07484T, was isolated from marine sediment sampled in the South China Sea. Growth occurred at 30-60 °C, pH 6.0-8.0 and in the presence of 0-3 % (w/v) NaCl. Cells of strain SCSIO 07484T were rod-shaped and flagellum-forming. No soluble pigment was observed. The phylogenetic analysis of the 16S rRNA gene sequences indicated that SCSIO 07484T belonged to the family Paenibacillaceae and clustered with members of the genus Brevibacillus in the phylogenetic trees with less than 96.2 % similarities. The cell wall contained meso-diaminopimelic acid. Whole-cell hydrolysates contained arabinose, glucose and ribose. The predominant menaquinone was MK-7. Major fatty acids were iso-C16 : 0, iso-C15 : 0, C16 : 0 and iso-C14 : 0. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylethanolamine were its diagnostic polar lipids. The whole genome size of strain SCSIO 07484T was 4 079 826 bp with a DNA G+C content of 56.2 mol%, including one circular chromosome of 3 978392 bp and one plasmid of 101434 bp. Based on the polyphasic analysis of strain SCSIO 07484T, it is considered to represent a novel species of the genus Brevibacillus, for which the name Brevibacillus marinus sp. nov. is proposed with the type strain SCSIO 07484T (=DSM 106769T=CGMCC 1.15814T).

Repurposing a bacterial prolidase for organophosphorus hydrolysis: Reshaped catalytic cavity switches substrate selectivity.

Enzyme promiscuity is critical to the acquisition of evolutionary plasticity in cells and can be recruited for high-value chemical synthesis or xenobiotic degradation. The molecular determinants of substrate ambiguity are essential to this activity; however, these details remain unknown. Here, we performed the directed evolution of a prolidase to enhance its initially weak paraoxonase activity. The in vitro evolution led to an unexpected 1,000,000-fold switch in substrate selectivity, with a 30-fold increase in paraoxon hydrolysis and 40,000-fold decrease in peptide hydrolysis. Structural and in silico analyses revealed enlarged catalytic cavities and substrate repositioning as responsible for rapid catalytic transitions between distinct chemical reactions.

Rubrobacter tropicus sp. nov. and Rubrobacter marinus sp. nov., isolated from deep-sea sediment of the South China Sea.

Two novel Gram-stain-positive bacteria, designated as SCSIO 52909T and SCSIO 52915T, were isolated from a deep-sea sediment sample collected at about 3448 m water depth of the South China Sea. Phenotypic, chemotaxonomic and genomic characteristics were investigated. These strains were aerobic and tested positive for catalase activity, oxidase activity and nitrate reduction. Optimal growth occurred at 28 °C, pH 7 and 3% salinity over 14 days cultivation. Its peptidoglycan structure was type A3α (l-Lys-l-Ala) and the only menaquinone was MK-8. Both strains possessed diphosphatidylglycerol, phosphatidylglycerol, an unidentified phosphoglycolipid, an unidentified glycolipid and an unidentified phospholipid. Their major fatty acids differed, but both contained iso-branched components of C16 : 0 12-methyl. Genome sequencing revealed two large genomes of 4.58 Mbp with G+C content of 67.0 mol% in SCSIO 52909T and of 4.42 Mbp with G+C content of 69.1 % in SCSIO 52915T. The two novel strains encoded genes for metabolism that are absent in most other Rubrobacter species, and possessed many more gene copy numbers of alkaline phosphatase and thioredoxin reductase. Results of gANI and 16S rRNA gene analyses suggested that the two strains represent two new species, with 74.9, 95.0 % pairwise similarity between each other, and less than 74.3 and 93.5 % to other recognized Rubrobacter species, respectively. In the phylogenetic analysis, strains SCSIO 52909T and SCSIO 52915T were separately clustered together and formed a well-separated phylogenetic branch distinct from the other known species in the genus Rubrobacter. Based on the data presented here, these two strains should be recognized as two new species in the genus Rubrobacter, for which the names Rubrobacter tropicus sp. nov., with the type strain SCSIO 52909T (=KCTC 49412T=CGMCC 1.13853T), and Rubrobacter marinus sp. nov., with the type strain SCSIO 52915T (=KCTC 49411T=CGMCC 1.13852T), are proposed.

Actinomarinicola tropica gen. nov. sp. nov., a new marine actinobacterium of the family Iamiaceae, isolated from South China Sea sediment environments.

A novel marine actinobacterium, strain SCSIO 58843T, was isolated from the sediment sample collected from the South China Sea. Strain SCSIO 58843T was Gram-stain-positive, aerobic and rod shaped. The whole-cell hydrolysis of amino acids contained dd-DAP, alanine, glutamic acid, glycine and aspartic acid. The main menaquinone was MK-9(H8). The major fatty acids were C17 : 1 ω8c and C17 : 0. The major phospholipids were diphosphatidylglycerol (DPG), phosphatidylinositol (PI), phospatidylcholine (PC) and phosphatidylinositolmannoside (PIM). The G+C content of the genomic DNA was 72.5 %. Phylogenetic analysis of the 16S rRNA gene sequences showed that strain SCSIO 58843T formed a new lineage in the family Iamiaceae and had the highest similarity of 93.8 % with Iamia majanohamensis DSM 19957T. Strain SCSIO 58843T can be distinguished from these known genera in the family Iamiaceae by polyphasic data analyses, and represents a novel genus and novel species, for which Actinomarinicola tropica gen. nov., sp. nov is proposed with the type strain SCSIO 58843T(=KCTC 49408T=CGMCC 1.17503T).

Longirhabdus pacifica gen. nov., sp. nov., isolated from a deep-sea hydrothermal sediment in the West Pacific Ocean.

A novel Gram-stain-negative bacterium, designated as SCSIO 06110T, was isolated from a deep-sea sediment of the West Pacific Ocean. Cells were 0.5-0.8 µm in width and 3.0-4.0 µm in length, spore-forming, rod-shaped with peritrichous flagella. Positive for catalase and urease, negative for oxidase and nitrate reduction. Growth occurred at 15-37 °C, pH 6-9 and 1-5 % (w/v) NaCl, with optimum growth at 28 °C, pH 7 and 3 % (w/v) NaCl. MK-7 was the only menaquinone. The strain possessed diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and two unidentified phospholipids. Iso-C16 : 0, iso-C15 : 0 and iso-C14 : 0 were the major fatty acids. The novel isolate clustered with genera in the family Paenibacillaceae, but formed a separated branch with the closest relative Chengkuizengella sediminis J15A17T (91.1 % sequence similarity) when compared in a phylogenetic analysis of 16S rRNA gene sequences. The DNA G+C content of strain SCSIO 06110T was 38.5 mol%. Based on the polyphasic data presented, a new genus, Longirhabdus gen. nov., is proposed in the family Paenibacillaceae with the type species Longirhabdus pacifica sp. nov. and the type strain SCSIO 06110T (=DSM 105158T=CGMCC 1.16550T).

Staphylospora marina gen. nov., sp. nov., a novel member of the family Thermoactinomycetaceae, isolated from a deep-sea hydrothermal vent in the Pacific Ocean.

A novel bacterium, designated SCSIO 07575T, was isolated from a deep-sea hydrothermal sediment sample collected from the western Pacific Ocean. Growth at 65 °C was observed, but not at 70 °C or below 37 °C. The optimum conditions for growth were at 55-65 °C, pH 7.0 and in the presence of 2 % (w/v) NaCl. Strain SCSIO 07575T showed filamentous growth. Unstable formation of white aerial mycelia was observed, which disappeared after several times' subculture. Abundant substrate mycelia were observed with grape-like spores. No soluble pigment was observed. Phylogenetic analysis of 16S rRNA gene sequences showed that SCSIO 07575T belonged to the family Thermoactinomycetaceae and formed a distinct clade in the phylogenetic tree. The cell-wall peptidoglycan contained meso-diaminopimelic acid. Whole-cell hydrolysates contained ribose, xylose, glucose and galactose. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminophospholipid and two unidentified phospholipids. The predominant menaquinone was MK-7. Major fatty acids were iso-C15 : 0, iso-C17 : 0 and iso-C16 : 0. Based on the whole genome sequence analysis, the genome size was 2 751 094 bp with a DNA G+C value of 57.2 mol%, including one circular chromosome and one plasmid. On the basis of polyphasic data, strain SCSIO 07575T represented a novel species of a new genus within the family Thermoactinomycetaceae, for which the name Staphylospora gen. nov. is proposed with the type species Staphylospora marina sp. nov. and the type strain SCSIO 07575T (=DSM 106793T=CGMCC 1.15879T).

Indioceanicola profundi gen. nov., sp. nov., isolated from Indian Ocean sediment.

A novel basophilic bacterial strain, designated as SCSIO 08040T, was recovered from a deep-sea sediment sample collected from the Indian Ocean. The strain was Gram-stain-negative, vibrioid or spiral, light pink, 0.6-1.0 µm wide and 1.0-2.5 µm long. Growth occurred at 20-45 °C, pH 7-11 and <5 % (w/v) NaCl, with optimum growth at 28-37 °C, pH 7 and 0-3 % (w/v) NaCl. Catalase-, oxidase and urease-positive, nitrate reduction-negative. Analysis of 16S rRNA gene sequencing revealed that strain SCSIO 08040T had the highest similarity of 95.3 % to Rhodocista pekingensis 3-pT. Phylogenetic analysis based on nearly complete 16S rRNA gene sequences showed that the novel isolate formed a distinct phylogenetic lineage in the family Rhodospirillaceae. The whole-cell hydrolysate contained meso-diaminopimelic acid, galactose, mannose and xylose. The total cellular fatty acid profile was dominated by C18:1ω7c and C19:0cycloω8c. Q-10 was the predominant ubiquinone. The major phospholipids were diphosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine. The DNA G+C content of strain SCSIO 08040T was 66.82 mol%. Based on these polyphasic data, a new genus, Indioceanicola gen. nov., is proposed in the family Rhodospirillaceae with the type species Indioceanicola profundi sp. nov. and the type strain SCSIO 08040T (=DSM 105146T=CGMCC 1.15812T).

Rubrobacter indicoceani sp. nov., a new marine actinobacterium isolated from Indian Ocean sediment.

A novel mesophilic marine actinobacterial strain, designated as SCSIO 08198T, was isolated from a deep-sea sediment sample collected from the Indian Ocean. The strain was Gram-stain-positive, rod-shaped and salmon pink in colour. Good growth occurred on marine agar with 1-5 % (w/v) NaCl and incubation at 28 °C for more than a fortnight. Sensitive to short ultraviolet radiation. Analysis of 16S rRNA gene sequences revealed that strain SCSIO 08198T had the highest similarity of 97.2 % to Rubrobacter radiotolerans DSM 5868T, and loosely related (<94.2 %) to all other species in the genus Rubrobacter. Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that the novel isolate shared a lineage with members of the genus Rubrobacter. The total cellular fatty acid profile was dominated by C16 : 0 12-methyl. MK-8 was the main menaquinone. The peptidoglycan type was A3α (l-Lys-l-Ala). The major phospholipids were diphosphatidylglycerol, phosphatidylglycerol and unidentified phospholipids. Based on the whole genome sequence analysis, the genome size is 3 078 689 bp with DNA G+C value of 63.8 mol%, including one circular chromosome and two plasmids. Based on these polyphasic data, a new species, Rubrobacterindicoceani sp. nov., is proposed, with the type strain SCSIO 08198T (=DSM 105148T=CGMCC 1.16398T).

Actinophytocola sediminis sp. nov., an actinomycete isolated from a marine sediment.

A novel actinomycete strain, designated YIM M13705(T), was isolated from a marine sediment sample of the South China Sea and its characteristics were determined by a polyphasic approach. The slowly growing, Gram-stain-positive, aerobic strain produced branched substrate mycelium and aerial hyphae, and no diffusible pigment was produced on the media tested. At maturity, spore chains were formed on aerial hyphae and substrate mycelium was not fragmented. Whole-cell hydrolysates of the strain contained meso-diaminopimelic acid and galactose, glucose, ribose and rhamnose. The predominant menaquinones were MK-9(H4) and MK-10(H2). The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol and ninhydrin-positive phosphoglycolipids. The major fatty acid was iso-C(16 : 0). The G+C content of the genomic DNA was 68.2 mol%. On the basis of 16S rRNA gene sequence, the strain was shown to be most closely related to species of the genus Actinophytocola. DNA-DNA hybridization relatedness values (<70%) of the isolate with its closest neighbour Actinophytocola xinjiangensis QAIII60(T) supported classification of the isolate as a representative of a novel species. On the basis of phylogenetic analysis, and phenotypic and genotypic data, it is concluded that the new isolate belongs to a novel species of the genus Actinophytocola, for which the name Actinophytocola sediminis sp. nov. (type strain YIM M13705(T) = DSM 45939(T) = BCRC 16956(T)) is proposed.

Melghirimyces profundicolus sp. nov., isolated from a deep-sea sediment.

A novel filamentous bacterium, strain SCSIO 11153(T), was isolated from a sediment sample collected from the Indian Ocean (80° 03.099' E 01° 03.300' N) at a depth of 4593 m. Good growth was observed at 50-55 °C and pH 7.0 with 3 % NaCl. It formed ivory-white colonies with radial wrinkles. Aerial mycelium was absent on the media tested. Phenotypic characteristics and 16S rRNA gene sequence analysis indicated that strain SCSIO 11153(T) belonged to the family Thermoactinomycetaceae. It exhibited 96.4% and 96.2% 16S rRNA gene sequence similarities to Melghirimyces algeriensis NariEX(T) and Melghirimyces thermohalophilus Nari11A(T), respectively, while lower sequence similarity values (<95.4%) were observed between strain SCSIO 11153(T) and other species of genera in the family Thermoactinomycetaceae. The menaquinone type was MK-7. Major cellular fatty acids were iso-C15:0, anteiso-C15:0 and iso-C17:0. The polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain SCSIO 11153(T) was 52.6 mol%. On the basis of the genotypic and phenotypic characteristics, it is proposed that strain SCSIO 11153(T) represents a novel species of the genus Melghirimyces with the name Melghirimyces profundicolus sp. nov. The type strain is SCSIO 11153(T) ( = DSM 45787(T) = CCTCC AA 2012007(T) = NBRC 109068(T)).

Pseudonocardia antitumoralis sp. nov., a deoxynyboquinone-producing actinomycete isolated from a deep-sea sediment.

An aerobic actinomycete, designated SCSIO 01299(T), was isolated from a deep-sea sediment collected from the northern South China Sea at a depth of 3258 m. The isolate was found to be a natural producer of the synthesized antitumour agent deoxynyboquinone and its three new derivatives, pseudonocardians A, B and C. A blast search based on almost-complete 16S rRNA gene sequences showed that strain SCSIO 01299(T) had high sequence similarities with members of the genus Pseudonocardia. The 16S rRNA gene sequence phylogenetic tree revealed that strain SCSIO 01299(T) was a member of the genus Pseudonocardia. Phenotypic analysis, chemotaxonomy and DNA-DNA relatedness could readily distinguish the isolate from established members in this genus. It was concluded that strain SCSIO 01299(T) represents a novel species, for which the name Pseudonocardia antitumoralis sp. nov. is proposed. The type strain is SCSIO 01299(T) ( = DSM 45322(T)  = CCTCC M 2011255(T)).

Bacillus oceani sp. nov., a new slightly halophilic bacterium, isolated from a deep sea sediment environment.

A strictly aerobic, Gram-stain positive, slightly halophilic strain, designated SCSIO 04524(T), was isolated from a deep sea sediment sample collected from the northern South China Sea at a depth of 3415 m. The isolate slightly embedded into the medium after 72 h incubation at 30 °C. Growth was found to occur on media with 0-10 % NaCl but extremely weak growth occurred without supplying NaCl. The predominant menaquinone was determined to be MK-7. The major cellular fatty acid identified was iso-C15:0. The diagnostic polar lipids were determined to be diphosphatidylglycerol, phosphatidyl methylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA G+C content was determined to be 38 mol%. 16S rRNA gene sequences analysis showed that this strain had the highest similarities with Bacillus carboniphilus JCM 9731(T) (94.7 %) and Bacillus endophyticus 2DT(T) (94.3 %). Phylogenetic analysis revealed that strain SCSIO 04524(T) formed a distinct lineage with Bacillus chungangensis CAU 348(T) and B. carboniphilus JCM 9731(T). Physiological characteristics including utilization of sole nitrogen and carbon sources, and chemotaxonomic properties of cellular fatty acids and polar lipids could readily distinguish strain SCSIO 04524(T) from its most closely related species. Based on this polyphasic taxonomic data, a new species, Bacillus oceani sp. nov., is proposed, with the type strain SCSIO 04524(T) (=DSM 26213(T) = KCTC 33077(T)).

Streptomyces nanhaiensis sp. nov., a marine streptomycete isolated from a deep-sea sediment.

A novel aerobic streptomycete, strain SCSIO 01248T, was isolated from a sample of deep-sea sediment collected from the northern South China Sea, at a depth of 1632 m. This isolate formed yellow-white substrate mycelium and grey-white aerial hyphae. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SCSIO 01248T was most closely related to Streptomyces radiopugnans R97T (98.8 % sequence similarity), S. macrosporus NBRC 14748T (97.5 %) and S. megasporus NBRC 14749T (97.3 %). The novel strain could, however, be readily differentiated from S. radiopugnans DSM 41901T on the basis of some physiological and cellular chemical characteristics; the level of DNA-DNA relatedness between these two strains was only 40 %. Based on phylogenetic and phenotypic evidence, strain SCSIO 01248T represents a novel species, for which the name Streptomyces nanhaiensis sp. nov. is proposed. The type strain is SCSIO 01248T (=DSM 41926T=KCTC 19401T=CCTCC AA 208007T).

Rhodococcus nanhaiensis sp. nov., an actinobacterium isolated from marine sediment.

In this study, two strains (SCSIO 10187(T) and SCSIO 10197) were isolated from a sediment sample collected from the South China Sea and characterized by using a polyphasic approach. Growth was observed at 15-35 °C (optimum 28 °C) and pH 5.0-8.0 (optimum pH 6.0). Based on 16S rRNA gene sequence analysis, the strains were identified as members of the genus Rhodococcus. Phylogenetic analysis showed that the two strains clustered together and the 16S rRNA gene sequence similarities between them and other members of the genus Rhodococcus were 93.2-97.7 %. The menaquinone type was MK-8(H(2)). Major cellular fatty acids were C(16 : 0), C(18 : 1)ω9c, C(17 : 0), 10-methyl C(18 : 0), C(18 : 0), C(19 : 0) and C(17 : 1)ω8c. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The DNA G+C contents of strains SCSIO 10187(T) and SCSIO 10197 were 63.7 and 63.2 mol%, respectively. The combined genotypic and phenotypic data showed that the two strains represent a novel species of the genus Rhodococcus, for which the name Rhodococcus nanhaiensis is proposed; the type strain is SCSIO 10187(T) ( = DSM 45608(T) = CCTCC AB 2011024(T)), with SCSIO 10197 ( = DSM 45609 = CCTCC AB 2011025) as a reference strain.

Janibacter alkaliphilus sp. nov., isolated from coral Anthogorgia sp.

A novel actinobacterium, designated strain SCSIO 10480(T), was isolated from a gorgonian coral sample of Anthogorgia sp. Phylogenetic and phenotypic properties of the organism supported that it belonged to the genus Janibacter. Phylogenetic analysis indicated that the levels of 16S rRNA gene sequence similarity between strain SCSIO 10480(T) and other type strains of recognized members of the genus Janibacter were 96.0-97.8 %. Growth in the presence of up to 17 % (w/v) NaCl and optimally at pH 9.0-10.0 was a distinctive characteristic of strain SCSIO 10480(T). Other biochemical and physiological properties and the fatty acid profile also differentiated the isolate from other members of Janibacter species. Based on the results obtained in this study, we propose that strain SCSIO 10480(T) should be classified within a novel species of the genus Janibacter, for which the name Janibacter alkaliphilus sp. nov. is proposed, with SCSIO 10480(T) (=CCTCC AB 2011027(T) = DSM 24723(T)) as the type strain.

Diversity and Distribution of Uncultured and Cultured Gaiellales and Rubrobacterales in South China Sea Sediments.

Actinobacteria are ubiquitous in marine ecosystems, and they are regarded as an important, underexplored, potential pharmaceutical resource. The orders Gaiellales and Rubrobacterales are deep taxonomic lineages of the phylum Actinobacteria, both are represented by a single genus and contain only a few species. Although they have been detected frequently by high-throughput sequencing, their functions and characteristics in marine habitats remain unknown due to the lack of indigenous phenotypes. Here, we investigated the status of the orders in South China Sea (SCS) sediments using culture-independent and culture-dependent methods. Gaiellales is the second-most abundant order of Actinobacteria and was widely distributed in SCS sediments at water depths of 42-4,280 m, and four novel marine representatives in this group were successfully cultured. Rubrobacterales was present at low abundance in energy-limited marine habitats. An isolation strategy for Rubrobacterales from marine samples was proposed, and a total of 138 mesophilic Rubrobacterales strains were isolated under conditions of light and culture time combined with high-salinity or low-nutrient media. Marine representatives recovered in this study formed branches with a complex evolutionary history in the phylogenetic tree. Overall, the data indicate that both Gaiellales and Rubrobacterales can adapt to and survive in extreme deep-sea environments. This study lays the groundwork for further analysis of the distribution and diversity of the orders Gaiellales and Rubrobacterales in the ocean and provides a specific culture strategy for each group. The results open a window for further research on the ecological roles of the two orders in marine ecosystems.

Miltoncostaea marina gen. nov. sp. nov., and Miltoncostaea oceani sp. nov., a novel deep branching phylogenetic lineage within the class Thermoleophilia isolated from marine environments, and proposal of Miltoncostaeaceae fam. nov. and Miltoncostaeales ord. nov.

Two novel marine actinobacteria, designated as SCSIO 60955T and SCSIO 61214T, were isolated from deep-sea sediment samples collected from the South China Sea. The cells of these organisms stained Gram-negative and were rod shaped. These strains were aerobic, and catalase- and oxidase-positive. Optimal growth occurred at 28 °C and pH 7 over 14 days of cultivation. Both strains possessed phospholipids and phosphoglycolipids. The main menaquinone was MK-7. The major fatty acid was C16:0. The peptidoglycan structure was type A1γ' (meso-Dpm). Analysis of genome sequences revealed that the genome size of SCSIO 60955T was 3.37 Mbp with G + C content of 76.1%, while the genome size of SCSIO 61214T was 3.67 Mbp with a G + C content of 74.8%. The ANI and 16S rRNA gene analysis results showed that the pairwise similarities between the two strains were 73.4% and 97.7% and that with other recognized Thermoleophilia species were less than 69.1% and 87.8%, respectively. Phylogenetic analysis of the 16S rRNA gene sequences showed that strains SCSIO 60955T and SCSIO 61214T were separately clustered together and formed a well-separated phylogenetic branch distinct from their most related neighbor Gaiella occulta. Based on the data presented here, these two strains are proposed to represent two novel species of a novel genus, for which the name Miltoncostaea marina gen. nov., sp. nov., with the type strain SCSIO 60955T (=DSM 110281T =CGMCC 1.18757T), and Miltoncostaea oceani sp. nov., with the type strain SCSIO 61214T (=KCTC 49527T =CGMCC 1.18758T) are proposed. We also propose that these organisms represent a novel family named Miltoncostaeaceae fam. nov. of a novel order Miltoncostaeales ord. nov.

Structure and Properties Study of PA6 Nanocomposites Flame Retarded by Aluminium Salt of Diisobutylphosphinic Acid and Different Organic Montmorillonites.

Two different types of organic montmorillonite, namely quaternary ammonium salt intercalated MMT (CMMT) and quaternary phosphonium salt intercalated MMT (PMMT) were used as fillers in the flame-retardant polyamide (PA6) based on aluminium salts of diisobutylphosphinic acid (ABPA). The influence of different types of organic montmorillonite (OMMT) on the structure and properties of flame-retardant PA6 nanocomposites were systematically investigated. The X-ray diffraction and transmission electron microscopy results suggested that the introduction of OMMT improved the dispersion of the flame retardant particles independently of the type of OMMT. The derivative thermogravimetry (DTG) curve transformed to one peak from two peaks (representing the degradation of ABPA and PA6, respectively) after incorporation of the OMMT, which further confirmed better ABPA dispersion. Viscoelastic measurements demonstrated that a mechanically stable network structure was formed with the introduction of OMMT or ABPA and OMMT, while PA6/ABPA/PMMT presented the highest storage modulus and viscosity, suggesting a more efficient network structure. From UL-94 and limited oxygen index (LOI) tests, PA6/ABPA/PMMT presented the best flame performance, with a UL-94 of V-0 and a LOI of 33%. In addition, the PA6/ABPA/PMMT presented the lowest peak heat release rate (pHRR) among the investigated samples. Combined with the char layer analysis, it can be deduced that the introduction of PMMT improved the dispersion of ABPA, and promoted the formation of more efficient network structure, before promoting more compact char structures, which finally resulted in improved flame retardancy.

[Chemical constituents of mangrove plant Barringtonia racemosa].

OBJECTIVE: To study the chemical constituents of mangrove plant Barringtonia racemosa. METHODS: Chemical constituents from the ethyl acetate extract of the stem bark of this plant were isolated by silica, Sephadex LH-20 column chromatography and identified by NMR analysis. RESULTS: Five compounds were isolated and identified. They are 3,3'-dimethoxy ellagic acid (1), dihydromyticetin (2), gallic acid (3), bartogenic acid (4) and stigmasterol (5). CONCLUSION: Compounds 1-3 were isolated from this plant for the first time.