Ilumatobacter nonamiense sp. nov. and Ilumatobacter coccineum sp. nov., isolated from seashore sand.

Bacterial strains YM16-303(T) and YM16-304(T) were isolated from a sample of seashore sand using a medium with an artificial seawater base. Both isolates grew slowly on marine agar, and were found to be Gram-reaction-positive, aerobic, non-motile and rod-shaped. The cell-wall peptidoglycan contained ll-diaminopimelic acid, glycine, alanine and hydroxyglutamic acid, and the acyl type of the muramic acid was glycolyl. The predominant menaquinone was MK-9(H8). The 16S rRNA gene sequences of strains YM16-303(T) and YM16-304(T) were most similar to that of Ilumatobacter fluminis YM22-133(T), and phylogenetic analyses also indicated that they belong to the genus Ilumatobacter. Ilumatobacter fluminis YM22-133(T) and strains YM16-303(T) and YM16-304(T) should be classified as distinct species in the genus Ilumatobacter, however, since the 16S rRNA gene sequence similarity between them was low and the major cellular fatty acids and some physiological properties were different. Moreover, average nucleotide identity and maximal unique exact matches index values also supported the conclusion that they represent different species. On the basis of the above analyses, two novel species, Ilumatobacter nonamiense sp. nov. (type strain YM16-303(T) = NBRC 109120(T) = KCTC 29139(T)) and Ilumatobacter coccineum sp. nov. (type strain YM16-304(T) = NBRC 103263(T) = KCTC 29153(T)), are proposed. The order Acidimicrobiales, which contains the genus Ilumatobacter, currently includes six genera and only six species, and they are phylogenetically very far from each other. Phylogenetic analyses revealed that strains YM16-303(T) and YM16-304(T) clustered with closely related uncultured actinobacteria but not Ilumatobacter fluminis YM22-133(T), suggesting that many uncultured bacteria related to these isolates exist in the environment. This is the first report on interspecies relationships in the order Acidimicrobiales.

Endozoicomonas numazuensis sp. nov., a gammaproteobacterium isolated from marine sponges, and emended description of the genus Endozoicomonas Kurahashi and Yokota 2007.

Two non-motile, rod-shaped gammaproteobacteria were isolated from marine sponges collected from the coast of Japan at Numazu. The isolates were oxidase- and catalase-positive facultative anaerobes that fermented carbohydrates. They required sodium ions for growth and were slightly halophilic, growing in the presence of 1.0-5.0 % (w/v) NaCl (optimum of 2.0 % NaCl). Under aerobic conditions, the major isoprenoid quinones were ubiquinone-9 and menaquinone-9 and the minor quinones were ubiquinone-8 and menaquinone-8. The major cellular fatty acids were C(18 : 1)ω7c, C(16 : 1)ω7c and C(16 : 0) and the hydroxy acids were C(10 : 0) 3-OH and C(12 : 0) 3-OH. The DNA G+C content was 48.3-48.7 mol%. Phylogenetic analysis of 16S rRNA gene sequences placed the isolates within the radiation of the genus Endozoicomonas in a broad clade of uncultured clones recovered from various marine invertebrates. The isolates exhibited 96.5-96.9 % 16S rRNA gene sequence similarity with Endozoicomonas elysicola MKT110(T) and Endozoicomonas montiporae CL-33(T), with which the isolates formed a monophyletic cluster with 100 % bootstrap support. The phenotypic features (carbohydrate fermentation, quinone system and some major cellular fatty acids) differed from those of members of the genus Endozoicomonas, which are aerobic, produce little or no menaquinone under aerobic conditions and possess different amounts of C(14 : 0) and C(18 : 1)ω7c. Although some phenotypic differences were identified, the isolates should be assigned to the genus Endozoicomonas on the basis of congruity of phylogeny and should be classified as representatives of a novel species, for which the name Endozoicomonas numazuensis sp. nov. is proposed. The type strain is HC50(T) ( = NBRC 108893(T)  = DSM 25634(T)). An emended description of the genus Endozoicomonas is presented.

Streptobactin, a tricatechol-type siderophore from marine-derived Streptomyces sp. YM5-799.

A new catechol-type siderophore, streptobactin (1), was isolated from a culture broth of the marine-derived actinomycete Streptomyces sp. YM5-799. The structure of streptobactin was determined by NMR and MS analyses and ESIMS/MS experiments to be a cyclic trimer of benarthin. A dibenarthin (2), a tribenarthin (3), and benarthin (4) were also obtained. The production of 1 was regulated by an iron concentration in the culture. The iron-chelating activity of the compounds was evaluated by the chrome azurol sulfonate assay.

Isolation and structure elucidation of tumescenamides A and B, two peptides produced by Streptomyces tumescens YM23-260.

Two peptides, tumescenamides A and B, were isolated from the fermentation broth of a marine bacterium, Streptomyces tumescens YM23-260. The structure of tumescenamide A was determined to be a cyclic depsipeptide consisting of α-amino-2-butenoic acid, tyrosine, valine, leucine and threonine, substituted with a 2,4-dimethylheptanoyl residue at the α-NH(2) position. Tumescenamide B possesses a 2,4,6-trimethylnonanoyl residue in place of the 2,4-dimethylheptanoyl substituent in tumescenamide A. Tumescenamide A induced reporter gene expression under the control of the insulin-degrading enzyme promoter.

Terpenoids produced by actinomycetes: isolation, structural elucidation and biosynthesis of new diterpenes, gifhornenolones A and B from Verrucosispora gifhornensis YM28-088.

New terpenoids named gifhornenolones A (1) and B (2) were isolated from the culture broth of Verrucosispora gifhornensis YM28-088, and their structures were established as hydroxylated isopimaradiene derivatives on the basis of extensive NMR and MS spectral analyses. In addition, a known sesquiterpene compound cyperusol C (3) was isolated. The absolute configuration of 1 was determined by nuclear Overhauser effect spectroscopy (NOESY) and CD spectra as 4R, 5S, 9R, 10S, 13R, and that of 2 was determined by NOESY experiments as 3R, 4R, 5R, 9R, 10S, 13R. Labeling experiments with [1-(13)C]glucose and [U-(13)C(6)]glucose confirmed that the MEP (2-C-methyl-D-erythritol-4-phosphate) pathway was used for the biosynthesis of terpenoids in this organism. 1 showed potent inhibitory activity to the androgen receptor with an IC(50) of 2.8 microg ml(-1).

Salinisporamycin, a novel metabolite from Salinispora arenicola. [corrected].

A new rifamycin antibiotic, salinisporamycin (1), has been isolated from a culture of a marine actinomycete. The producing organism was identified as Salinispora arenicola [corrected] on the basis of the 16S rRNA sequence. High-resolution FAB-MS established the molecular formula of 1 as C(33)H(43)NO(9). The planar structure of 1 was elucidated by NMR spectral analysis including COSY, heteronuclear single quantum coherence and heteronuclear multiple bond correlation. The relative stereochemistry of 1 was determined on the basis of rotating frame nuclear Overhauser effect spectroscopy. In addition, the solvatochromic behavior of 1 was investigated by measuring the UV spectra. This compound inhibited the growth of A549 cells, the human lung adenocarcinoma cell line, with an IC(50) value of 3 microg ml(-1), and also showed antimicrobial activity.

Ilumatobacter fluminis gen. nov., sp. nov., a novel actinobacterium isolated from the sediment of an estuary.

Bacterial strain YM22-133T was isolated from the sediment of an estuary and grew in media with an artificial seawater base. Strain YM22-133T was Gram-positive, aerobic, non-motile and rod shaped. The cell-wall peptidoglycan contained LL-DAP, glycine, alanine and hydroxyglutamate. The predominant menaquinone was MK-9 (H8), with MK-9 (H0), MK-9 (H2), MK-9 (H4) and MK-9 (H6) present as minor menaquinones. The G+C content of the genomic DNA from the strain was 68 mol%. Phylogenetic analysis of the 16S rRNA gene sequence showed that the strain is nearest to Acidimicrobium ferrooxidans DSM 10331T. However, the similarity is relatively low (87.1%) and the physiological characteristics are also different: Acidimicrobium ferrooxidans is thermotolerant and acidophilic. Therefore, strain YM22-133T can be classified as a novel genus and species, Ilumatobacter fluminis gen. nov., sp. nov. (type strain YM22-133T = DSM 18936T = MBIC 08263T).

A novel diol-derivative of chalcone produced by bioconversion, 3-(2,3-dihydroxyphenyl)-1-phenylpropan-1-one, activates PKA/MEK/ERK signaling and antagonizes Abeta-inhibition of the cascade in cultured rat CNS neurons.

Chalcone compounds have been widely studied for their anti-inflammatory, anti-pyretic, anti-invasive and anti-proliferative activities in various cell lines. However, their effects on the central nervous system (CNS) are still largely unexplored. We have recently developed a bioconversion system using a recombinant Escherichia coli that enables us to produce chemical compounds that are naturally rare and usually difficult to chemically synthesize. One such compound is 3-(2,3-dihydroxyphenyl)-1-phenylpropan-1-one, a novel chalcone-diol. Here we show, for the first time, that the chalcone-diol enhanced the phosphorylation of extracellular signal-regulated kinase (ERK) in a time- and concentration-dependent manner in cultured cortical neurons. Also, this chalcone-diol increased intracellular cyclic AMP (cAMP) concentration, thereby enhancing phosphorylation of ERK and cAMP-response element-binding protein (CREB), and CRE-mediated transcription via the cAMP-dependent protein kinase (PKA)/mitogen-activated protein kinase/ERK kinase (MEK) pathway in cultured rat hippocampal neurons. Recent studies have demonstrated that PKA/CREB-dependent signaling, which is required for long-term potentiation, is inhibited by sublethal concentrations of amyloid beta-peptide (Abeta) in cultured hippocampal neurons. After treatment with the chalcone-diol at 50 muM prior to treatment with a sublethal concentration of Abeta(1-42), the Abeta(1-42)-induced inhibition of phosphorylation of PKA substrates and CREB was prevented in cultured hippocampal neurons, indicating the potential for protection against the Abeta-induced impairment of PKA/CREB signaling observed in Alzheimer's disease. Therefore, these results suggest that our present study provides a new approach for discovering novel lead compounds for the treatment of neurodegenerative CNS diseases associated with impaired PKA/CREB signaling, including Alzheimer's disease.

Marihabitans asiaticum gen. nov., sp. nov., a meso-diaminopimelic acid-containing member of the family Intrasporangiaceae.

Strain HG667(T), isolated from surface seawater collected at the Kesennuma ferry port in Miyagi Prefecture, Japan, was found to be a Gram-positive, catalase-positive bacterium comprising irregular short rods and cocci. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The major menaquinone was MK-8(H4). Mycolic acids were not detected. The G+C content of the DNA was 70 mol%. Analysis of the 16S rRNA gene sequence revealed that the strain represents a novel lineage within the family Intrasporangiaceae, order Actinomycetales, being associated with the genus Kribbia. On the basis of morphological, biochemical and chemotaxonomic properties of the strain, together with phylogenetic data relating to the 16S rRNA gene sequence, HG667(T) represents a novel genus and species in the family Intrasporangiaceae, for which the name Marihabitans asiaticum gen. nov., sp. nov. is proposed. The type strain of Marihabitans asiaticum is HG667(T) (=MBIC07497(T) =DSM 18935(T)).

Efrapeptin J, a new down-regulator of the molecular chaperone GRP78 from a marine Tolypocladium sp.

A new down-regulator of the molecular chaperone GRP78, efrapeptin J, was isolated from a marine fungus, Tolypocladium sp. AMB18. The molecular formula of efrapeptin J was established as C(81)H(139)N(18)O(16)(+) by high-resolution FAB-MS. The structure was elucidated to be a linear pentadecapeptide containing a hexahydropyrrolo[1,2-a]pyrimidinium moiety by NMR and MS analyses. Efrapeptins F, G and J dose-dependently inhibited 2-deoxyglucose-induced luciferase expression in HT1080 human fibrosarcoma cells transfected with a luciferase reporter plasmid containing the GRP78 promoter. Efrapeptin J also inhibited the protein expression of GRP78 in HT1080 cells and MKN-74 human gastric cancer cells. Efrapeptin J induced cell death in HT1080 cells under endoplasmic reticulum stress.

Robiginitalea myxolifaciens sp. nov., a novel myxol-producing bacterium isolated from marine sediment, and emended description of the genus Robiginitalea.

A marine, Gram-negative, deep-orange-coloured, rod/coccoid-shaped, strictly aerobic, non-motile, oxidase- and catalase-positive bacterial strain, designated YM6-073(T), was isolated from sediment collected in Okinawa, Japan. Strain YM6-073(T) produced the carotenoid (3R,2'S)-myxol. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YM6-073(T) belonged to a distinct lineage in the family Flavobacteriaceae, the closest relative being Robiginitalea biformata HTCC2501(T) (93.7 % sequence similarity). Strain YM6-073(T) could be distinguished from other members of the family Flavobacteriaceae by means of a number of phenotypic characteristics. The DNA G+C content was 50.1 mol%. The predominant cellular fatty acids were iso-C(15 : 0), iso-C(15 : 1)omega10c, iso-C(17 : 0) 3-OH and C(15 : 0,) and menaquinone-6 was the only respiratory quinone. DNA-DNA hybridization between strain YM6-073(T) and R. biformata DSM 15991(T) showed less than 10 % DNA-DNA relatedness. On the basis of phenotypic, genotypic and phylogenetic features, strain YM6-073(T) represents a novel species of the genus Robiginitalea, for which the name Robiginitalea myxolifaciens sp. nov. is proposed. The type strain is YM6-073(T) (=MBIC 06409(T)=KCTC 22216(T)=DSM 21019(T)).

Ascochytatin, a novel bioactive spirodioxynaphthalene metabolite produced by the marine-derived fungus, Ascochyta sp. NGB4.

Ascochytatin, a new spirodioxynaphthalene metabolite produced by a marine-derived fungus, was found from a screening program focused on the bacterial two-component regulatory system. The structure of ascochytatin was determined by spectroscopic methods, including NMR and MS. The relative stereochemistry was determined by an X-ray crystallographic analysis, and the absolute stereochemistry was determined by the modified Mosher's method.

New sulfoalkylresorcinol from marine-derived fungus, Zygosporium sp. KNC52.

A new sulfoalkylresorcinol (1) was isolated from the marine-derived fungus, Zygosporium sp. KNC52. The structure of 1 was elucidated by spectroscopic methods including MS and NMR, and the absolute stereochemistry was determined by the modified Mosher's method. Compound 1 inhibited FtsZ polymerization in vitro and exhibited weak antimicrobial activity against multi-drug-resistant bacteria.

Ariakemicins A and B, novel polyketide-peptide antibiotics from a marine gliding bacterium of the genus Rapidithrix.

Ariakemicins A (1) and B (2), unusual linear hybrid polyketide-nonribosomal peptide antibiotics, were discovered from the fermentation extract of the marine gliding bacterium Rapidithrix sp. These metabolites were positional isomers with regard to a double bond and chromatographically inseparable, rendering the structure study on a mixture basis. The ariakemicins were composed of threonine, two omega-amino-(omega-3)-methyl carboxylic acids with diene or triene units, and delta-isovanilloylbutyric acid. The antibiotics selectively inhibited the growth of Gram-positive bacteria.

Structural determination and proposed biosynthesis of alcanivorone, a novel alpha-pyrone produced by Alcanivorax jadensis.

A novel alpha-pyrone designated as alcanivorone was found in a culture broth of the marine bacterium, Alcanivorax jadensis, and its structure was determined by an analysis of 1D NMR, 2D NMR and MS data. Alcanivorone was produced by A. jadensis only when sodium pyruvate was added to the culture medium as a carbon source. Incorporation experiments using stable isotope-labeled pyruvate indicated that alcanivorone was biosynthesized from four molecules of pyruvate.

Three new polyketide-terpenoid hybrids from Penicillium sp.

Three novel hybrid polyketide-terpenoid metabolites were isolated from a Penicillium minioluteum strain. Their structures were determined by NMR spectroscopic analyses and X-ray crystallography. The proposed biosynthetic pathway including a unique retro-Claisen migration of methyl carbonate correlates the three compounds with berkeleydione and berkeleytrione.

Unnarmicins A and C, new antibacterial depsipeptides produced by marine bacterium Photobacterium sp. MBIC06485.

Two new antibiotic depsipeptides, unnarmicins C (1) and A (2), were isolated from the fermentation broth of a marine bacterium, Photobacterium sp. strain MBIC06485. The structure of 1 was established by spectroscopic studies and chiral analyses of its chemical degradation/conversion products, and that of 2 by comparing its NMR, MS, and CD data with those of 1. Both compounds selectively inhibited the growth of two strains belonging to the genus Pseudovibrio, one of the most prevalent genera in the marine environments within the class Alphaproteobacteria.

Inhibition of fungal ABC transporters by unnarmicin A and unnarmicin C, novel cyclic peptides from marine bacterium.

Novel inhibitors of fungal ATP-binding cassette transporters were obtained by screening compounds and crude extracts from marine-derived fungi and bacteria using disk diffusion assays of Saccharomyces cerevisiae strains overexpressing a variety of fungal multi-drug efflux pumps. The cyclodepsipeptides unnarmicin A and unnarmicin C were able to sensitize cells overexpressing azole drug pumps ScPdr5p, CaCdr1p, CgCdr1p, and CgPdh1p to sub-MIC concentrations of fluconazole without affecting the growth of CaCdr2p and CaMdr1p overexpressing cells. Unnarmicin A and unnarmicin C were potent inhibitors of rhodamine 6G efflux of CaCdr1p expressing cells with IC50 values of 3.61 and 5.65 microM, respectively. They inhibited the in vitro CaCdr1p ATPase activity at IC50 values of 0.495 and 0.688 microM, respectively. And most importantly, they were able to sensitize azole-resistant Candida albicans clinical isolates to fluconazole. Unnarmicin A and unnarmicin C are candidate efflux pump inhibitors with the potential to be used as adjuvants for antifungal chemotherapy.