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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Hydrobiologia 235-236 (1992), S. 623-628 
    ISSN: 1573-5117
    Keywords: arsenobetaine ; arsenic ; cycle ; degradation ; microorganisms ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two growth media containing arsenobetaine [(CH3)3 As+ CH2COO−] were mixed with coastal marine sediments, the latter providing a source of microorganisms. The mixtures were kept at 25 °C in the dark and shaken for several weeks under an atmosphere of air. The disappearance of arsenobetaine and the appearance of two metabolites were followed by HPLC. The HPLC-retention time of the first metabolite agreed with that of trimethylarsine oxide [(CH3)3AsO]. The second metabolite was identified as arsenate (As(V)) using hydride generation/cold trap/GC MS analysis and thin layer chromatography. This is the first scientific evidence showing that arsenobetaine is degraded by microorganisms to inorganic arsenic via trimethylarsine oxide. The degradation of arsenobetaine to inorganic arsenic completes the marine arsenic cycle that begins with the methylation of inorganic arsenic on the way to arsenobetaine.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-5117
    Keywords: arsenobetaine ; inorganic arsenic ; trimethylarsine oxide ; bacteria ; suspended substances ; degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The substances suspended in seawater were fractionated by membrane filtration into three fractions. Fraction 1 was collected on a membrane filter of 0.22 µm pore-size, fraction 2 on a 5 µm pore-size and fraction 3 on 0.22 µm pore-size from the filtrate passed through the 5 µm membrane filter. Arsenobetaine was incubated with each of these fractions in two media (ZoBell 2216E and a solution of inorganic salts) at 25 °C in the dark under aerobic conditions. The mixture added with fraction 3 was considered to contain only bacteria. In every case, in the inorganic salt medium, inorganic arsenic(V) was derived from arsenobetaine via trimethylarsine oxide. In the ZoBell medium, arsenobetaine was not degraded to inorganic arsenic, although trimethylarsine oxide was derived in every case. We conclude that the degradation of arsenobetaine to trimethylarsine oxide or inorganic arsenic can be accomplished in seawater by bacteria alone.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 5 (1991), S. 427-430 
    ISSN: 0268-2605
    Keywords: Arsenobetaine ; trimethylarsine oxide ; dimethylarsinic acid ; degradation ; bacteria ; micro-organisms ; chitons ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The intestinal micro-organisms of Liolophura japonica chitons converted arsenobetaine [(CH3)3As+CH2COO-] to trimethylarsine oxide [(CH3)3AsO] and dimethylarsinic acid [(CH3)2AsOOH] in the arsenobetaine-containing 1/5 ZoBell 2216E medium under aerobic conditions, no conversion being observed in an inorganic salt medium. This conversion pattern of arsenobetaine → trimethylarsine oxide ← dimethylarsinic acid was comparable with that shown by the microorganisms associated with marine macroalgae. On the other hand, no conversion was observed in either medium under anaerobic conditions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 10 (1996), S. 683-688 
    ISSN: 0268-2605
    Keywords: inorganic arsenic ; methanearsonic acid ; dimethylarsinic acid ; tetramethylarsonium salt ; arsenocholine ; microorganisms ; conversion ; degradation ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sediments, as sources of microorganisms, were added to two kinds of media, 1/5 ZoBell 2216E and a solution of inorganic salts, which contained inorganic arsenic(III), inorganic arsenic(V), methanearsonic acid, dimethyl- arsinic acid, trimethylarsine oxide, tetramethylarsonium salt or arsenocholine. After 17 days of incubation at 20 °C, the arsenicals that had accumulated in the microorganisms were analysed by high-performance liquid chromatography (HPLC). While the more toxic arsenicals [inorganic arsenic(III), inorganic arsenic(V), methanearsonic acid, dimethylarsinic acid] were not converted in the microorganisms, trimethylarsine oxide and tetramethylarsonium salt were considerably degraded to inorganic arsenic(V), and arsenocholine to arsenobetaine. Arsenobetaine that had accumulated in the microorganisms was extracted and confirmed by thin-layer chromatography (TLC) and fast atom bombardment (FAB) mass spectrometry.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 5 (1991), S. 435-438 
    ISSN: 0268-2605
    Keywords: Arsonobetaine ; dimethylarsinic acid ; degradation ; bacteria ; micro-organisms ; sediment ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Arsenobetain [(CH3)3As+CH2COO-]-containing growth media (1/5 ZoBell 2216E and solution of inorganic salts) were inoculated with two bacterial strains, which were isolated from a coastal sediment and identified as members of the Vibro-Aeromonas group, and incubated under aerobic and anaerobic conditions. Arsenobetaine was converted to a metabolite only under aerobic conditions. This arsenic metabolite was identified as dimethylarsinic acid [(CH3)2AsOOH] by hydride generation/cold trap/GC MS/SIM analysis and high-performance liquid-chromatographic behaviour. The conversion pattern shown by these arsenobetaine-decomposing bacteria (that is, arsenobetaine → dimethylarsinic acid) was fairly different from that shown by the addition of sediment itself as the source of arsenobetaine-decomposing micro-organisms (that is, arsenobetaine → trimethylarsine oxide → inorganic arsenic). This result suggests to us that various micro-organisms, including the arsenobetaine-decomposing bacteria isolated in this study, participate in the degradation of arsenobetaine in marine environments.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 2 (1988), S. 539-546 
    ISSN: 0268-2605
    Keywords: Arsenic ; arsine ; methylarsine ; dimethylarsine ; trimethylarsine ; arsenobetaine ; trimethylarsine oxide ; marine organisms ; gas chromatography mass spectrometry (GC MS) ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Inorganic arsenic and methylated arsenic compounds in 60 specimens of marine organisms were investigated by hydride generation derivatization and cold-trap gas chromatography-mass spectrometry (GC MS). Chloroform-methanol extracts from seaweeds, shellfish, fish, crustaceans and other marine organisms were separated into water-soluble and lipid-soluble fractions. The arsenic compounds in each fraction were identified and analysed as arsine, methylarsine, dimethylarsine and trimethylarsine.Trimethylarsenic compounds were distributed mainly in the water-soluble fraction of muscle of carnivorous gastropods, crustaceans and fish. The amounts of dimethylated arsenic compounds were found to be larger than that of trimethylated arsenic in the lipid-soluble fraction of fish viscera. Dimethylated arsenic compounds were distributed in the water-soluble fraction of Phaeophyceae.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 6 (1992), S. 375-381 
    ISSN: 0268-2605
    Keywords: Arsenocholine ; arsenobetaine ; trimethylarsine oxide ; dimethylarsinic acid ; methanearsonic acid ; micro-organisms ; sediments ; arsenic metabolism ; marine ecosystems ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: As one of the experiments to pursue marine circulation of arsenic, we studied microbiological conversion of arsenocholine to arsenobetaine, because arsenocholine may be a precursor of arsenobetaine in these ecosystems. Two culture media, 1/5 ZoBell 2216E and an aqueous solution of inorganic salts, were used in this in vitro study. To each medium (25 cm3) were added synthetic arsenocholine (0.2%) and about 1 g of the sediment, and they were aerobically incubated at 25°C in the dark. These conversion experiments were performed in May and July 1990. In both seasons, two or three metabolites were derived in each mixture. These metabolites were purified using cation-exchange chromatography. Their structures were confirmed as arsenobetaine, trimethylarsine oxide and dimethylarsinic acid by high-performance liquid chromatography, thin-layer chromatography, FAB mass spectrometry and a combination of gas-chromatographic separation with hydride generation followed by a cold-trap technique and selected-ion monitoring mass spectrometric analysis. From this and other evidence it is concluded that, in the arsenic cycle in these marine ecosystems, as recently postulated by us, the pathway arsenocholine → arsenobetaine → trimethylarsine oxide → dimethylarsinic acid → methanearsonic acid → inorganic arsenic can be carried out by micro-organisms alone.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 11 (1997), S. 297-304 
    ISSN: 0268-2605
    Keywords: freshwater biota ; freshwater fish ; freshwater algae ; organic arsenic ; arsenic ; arsenobetaine ; arsenosugar ; dimethylarsenic ; trimethylarsenic ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Arsenic circulation in an arsenic-rich freshwater ecosystem was elucidated to detect arsenic species in the river water and in biological samples living in the freshwater environment. Water-soluble arsenic compounds in biological samples were extracted with 70% methanol. Samples containing arsenic compounds in the extracts were treated with 2 mol dm3 of sodium hydroxide and reduced with sodium borohydride. The detection of arsenic species was accomplished using a hydride generation/cold trap/cryofocus/gas chromatography-mass spectrometry (HG/CT/CF/GC-MS) system. The major arsenic species in the river water, freshwater algae and fish are inorganic arsenic, dimethylarsenic and trimethylarsenic compounds, respectively. Trimethylarsenic compounds are also detected in aquatic macro-invertebrates. The freshwater unicellular alga Chlorella vulgaris, in a growth medium containing arsenate, accumulated arsenic and converted it to a dimethylarsenic compound. The water flea Daphnia magna, which was fed on arsenic-containing algae, converted it to a trimethylarsenic species. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 4 (1990), S. 239-243 
    ISSN: 0268-2605
    Keywords: Organic arsenical ; inorganic arsenical ; microbial degradation ; marine micro-organisms ; arsenic cycle ; methylarsenicals ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two media (1/5 ZoBell 2216E and inorganic salt media) were used for degradation experiments. Each arsenical [arsenobetaine, trimethylarsine oxide (TMAO), dimethylarsinic acid (DMA), sodium methanearsonate, sodium arsenate and sodium arsenite] was added to 20cm3 of each medium (0.084% as As) in a 30-cm3 Erlenmever flask. The mixtures were kept at 25°C in the dark for 91 days for aerobic cultivation. For anaerobic cultivation, about 5 cm3 of liquid paraffin was placed on the surface of each mixture. Under aerobic conditions, arsenobetaine was the only methylarsenical which was rapidly degraded, being converted to several metabolites. In contrast, under aerobic conditions, little or no arsenobetaine (ZoBell or inorganic salt-media respectively) was converted to its metabolites, while all the methylarsenicals other than arsenobetaine were converted to less methylated compounds. The conversion of inorganic arsenic was observed only in the aerobically incubated ZoBell/arsenite mixture; arsenate was derived from it. A peculiar conversion pattern was observed in the aerobically incubated ZoBell/TMAO mixture; DMA derived from TMAO began to convert to TMAO after 14 days of incubation, and TMAO was the only arsenical in the mixture after 35 days.
    Additional Material: 2 Ill.
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  • 10
    ISSN: 0268-2605
    Keywords: arsenobetaine ; microorganisms ; sinking particles ; deep sea ; trimethylarsine oxide ; dimethylarsinic acid ; inorganic arsenic ; degradation ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The arsenobetaine-decomposing ability of microorganisms occurring in sinking particles, which play a main role in the vertical transport of organic substances produced in the photic zone, was investigated. The microorganisms in particles collected in the deep sea, 1100 and 3500 m in depth, clearly showed decomposing ability. With the particles from 1100 m, the degradation products were the same as those produced by microorganisms occurring in sources in the photic zone, i.e. trimethylarsine oxide (TMAO), dimethylarsinic acid (DMA) and inorganic arsenic(V). At 3500 m, the degradation activity was diminished, smalls amount of DMA and TMAO being produced. These results suggest that arsenobetaine contained in the animals starts to degrade immediately after the death of the animals and their transformation to particles. The degradation of arsenobetaine to inorganic arsenic in our tentative arsenic cycle in marine ecosystems (inorganic arsenic to inorganic arsenic via the biosynthesis of arsenobetaine) may apply to the deep sea as well as to the photic zone. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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