385 research outputs found

    Rubritalea marina gen. nov., sp. nov., a marine representative of the phylum 'Verrucomicrobia', isolated from a sponge (Porifera)

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    A marine bacterium, strain Pol012T, was isolated from the Mediterranean sponge Axinella polypoides and subsequently characterized as belonging to subphylum 1 of the phylum ‘Verrucomicrobia’. Strain Pol012T was non-motile, Gram-negative, coccoid or rod-shaped and red in colour. The menaquinones MK-8 and MK-9 were detected. The G+C content of the genomic DNA was 50.9 mol%. Growth was possible at temperatures between 8 and 30 °C and at pH values between 6.8 and 8.2. The closest cultured relative of strain Pol012T was Akkermansia muciniphila (83 % sequence similarity), while the closest environmental 16S rRNA gene sequence was the marine clone Arctic96BD-2 (95 % sequence similarity). Strain Pol012T is the first marine pure-culture representative of ‘Verrucomicrobia’ subphylum 1 and represents a novel genus and species, for which the name Rubritalea marina gen. nov., sp. nov. is proposed. The type strain is Pol012T (=DSM 177716T=CIP 108984T). The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain Pol012T is DQ302104, and those for verrucomicrobial 16S rRNA gene sequences from sponges and seawater are DQ302105–DQ302120

    Non-grey gas radiative transfer analyses using the statistical narrow-band model

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    Peer reviewed: YesNRC publication: Ye

    Isolation, Structure Elucidation and Total Synthesis of Lajollamide A from the Marine Fungus Asteromyces cruciatus

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    The marine-derived filamentous fungus Asteromyces cruciatus 763, obtained off the coast of La Jolla, San Diego, USA, yielded the new pentapeptide lajollamide A (1), along with the known compounds regiolone (2), hyalodendrin (3), gliovictin (4), 1N-norgliovicitin (5), and bis-N-norgliovictin (6). The planar structure of lajollamide A (1) was determined by Nuclear Magnetic Resonance (NMR) spectroscopy in combination with mass spectrometry. The absolute configuration of lajollamide A (1) was unambiguously solved by total synthesis which provided three additional diastereomers of 1 and also revealed that an unexpected acid-mediated partial racemization (2:1) of the l-leucine and l-N-Me-leucine residues occurred during the chemical degradation process. The biological activities of the isolated metabolites, in particular their antimicrobial properties, were investigated in a series of assay systems

    Streptomyces sp. BV410 isolate from chamomile rhizosphere soil efficiently produces staurosporine with antifungal and antiangiogenic properties

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    Applying a bioactivity-guided isolation approach, staurosporine was separated and identified as the active principle in the culture extract of the new isolate Streptomyces sp. BV410 collected from the chamomile rhizosphere. The biotechnological production of staurosporine by strain BV410 was optimized to yield 56 mg/L after 14 days of incubation in soy flour-glucose-starch-mannitol-based fermentation medium (JS). The addition of FeSO4 significantly improved the staurosporine yield by 30%, while the addition of ZnSO4 significantly reduced staurosporine yield by 62% in comparison with the starting conditions. Although staurosporine was first isolated in 1977 from Lentzea albida (now Streptomyces staurosporeus) and its potent kinase inhibitory effect has been established, here, the biological activity of this natural product was assessed in depth in vivo using a selection of transgenic zebrafish (Danio rerio) models, including Tg(fli1:EGFP) with green fluorescent protein-labeled endothelial cells allowing visualization and monitoring of blood vessels. This confirmed a remarkable antiangiogenic activity of the compound at doses of 1 ng/ml (2.14 nmol/L) which is below doses inducing toxic effects (45 ng/ml; 75 nmol/L). A new, efficient producing strain of commercially significant staurosporine has been described along with optimized fermentation conditions, which may lead to optimization of the staurosporine scaffold and its wider applicability

    Numerical investigation of the effects of a skimmer on the structure of dense sprays

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    Peer reviewed: YesNRC publication: Ye

    Large-Scale Biotechnological Production of the Antileukemic Marine Natural Product Sorbicillactone A

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    In the search for novel bioactive compounds from sponge-derived microorganisms, we have recently identified two structurally and biosynthetically unprecedented fungal metabolites, the novel-type alkaloids sorbicillactone A and sorbicillactone B. Sorbicillactone A is active against leukemia cells without showing notable cytotoxicity. Therefore, we have developed an efficient process for its biotechnological production and isolation on a large scale supplying sufficient material for the ongoing preclinical investigations and structure-activity relationship (SAR) studies

    Numerical study of breakup processes of water jet injected into a cross air flow

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    Peer reviewed: YesNRC publication: Ye
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