Methylation of Arsenic by Freshwater Green Algae

1983 ◽  
Vol 40 (8) ◽  
pp. 1254-1257 ◽  
Author(s):  
M. D. Baker ◽  
P. T. S. Wong ◽  
Y. K. Chau ◽  
C. I. Mayfield ◽  
W. E. Inniss
Keyword(s):  
Green Algae ◽  
Lake Water ◽  
Sodium Arsenite ◽  
Basal Medium ◽  
Arsenic Species ◽  
Freshwater Ecosystems ◽  
Dimethylarsinic Acid ◽  
Additional Source ◽  
Arsenic Compounds ◽  
Methylarsonic Acid

Isolates from four genera of freshwater green algae were capable of methylating sodium arsenite in lake water and Bold's basal medium. Analysis of the liquid phase of the methylation flasks revealed the presence of methylarsonic acid, dimethylarsinic acid, and trimethylarsine oxide. Volatile arsine and methylarsines were not detected in the headspace gases presumably because of the inability of the algae to reduce completely the methylated–arsenic species. Although the algae varied with respect to their methylating abilities, the levels of methylated–arsenic compounds were always significantly higher when the algae were grown in lake water. This may have been due to the lower phosphate concentration in the lake water. We suggest that arsenic methylation by green algae constitutes an additional source for the formation and cycling of organo-arsenic compounds in freshwater ecosystems.

Arsenic metabolism in cyanobacteria

2016 ◽  
Vol 13 (4) ◽  
pp. 577 ◽  
Author(s):  
Shin-ichi Miyashita ◽  
Chisato Murota ◽  
Keisuke Kondo ◽  
Shoko Fujiwara ◽  
Mikio Tsuzuki
Keyword(s):  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Dimethylarsinic Acid ◽  
Arsenic Compound ◽  
Arsenic Compounds ◽  
Arsenic Metabolism ◽  
Methylarsonic Acid ◽  
Membrane Bound ◽  
Arsenic Transport ◽  
High Concentrations

Environmental context Cyanobacteria are ecologically important, photosynthetic organisms that are widely distributed throughout the environment. They play a central role in arsenic transformations in terms of both mineralisation and formation of organoarsenic species as the primary producers in aquatic ecosystems. In this review, arsenic resistance, transport and biotransformation in cyanobacteria are reviewed and compared with those in other organisms. Abstract Arsenic is a toxic element that is widely distributed in the lithosphere, hydrosphere and biosphere. Some species of cyanobacteria can grow in high concentrations of arsenate (pentavalent inorganic arsenic compound) (100mM) and in low-millimolar concentrations of arsenite (trivalent inorganic arsenic compound). Arsenate, which is a molecular analogue of phosphate, is taken up by cells through phosphate transporters, and inhibits oxidative phosphorylation and photophosphorylation. Arsenite, which enters the cell through a concentration gradient, shows higher toxicity than arsenate by binding to sulfhydryl groups and impairing the functions of many proteins. Detoxification mechanisms for arsenic in cyanobacterial cells include efflux of intracellular inorganic arsenic compounds, and biosynthesis of methylarsonic acid and dimethylarsinic acid through methylation of intracellular inorganic arsenic compounds. In some cyanobacteria, ars genes coding for an arsenate reductase (arsC), a membrane-bound protein involved in arsenic efflux (arsB) and an arsenite S-adenosylmethionine methyltransferase (arsM) have been found. Furthermore, cyanobacteria can produce more complex arsenic species such as arsenosugars. In this review, arsenic metabolism in cyanobacteria is reviewed, compared with that in other organisms. Knowledge gaps remain regarding both arsenic transport (e.g. uptake of methylated arsenicals and excretion of arsenate) and biotransformation (especially production of lipid-soluble arsenicals). Further studies in these areas are required, not only for a better understanding of the role of cyanobacteria in the circulation of arsenic in aquatic environments, but also for their application to arsenic bioremediation.

Occurrence and Speciation of Arsenic in Common Australian Coastal Polychaete Species

2005 ◽  
Vol 2 (2) ◽  
pp. 108 ◽  
Author(s):  
Joel Waring ◽  
William Maher ◽  
Simon Foster ◽  
Frank Krikowa
Keyword(s):  
Arsenic Concentration ◽  
Habitat Type ◽  
Arsenic Species ◽  
Water Soluble ◽  
Dimethylarsinic Acid ◽  
Total Arsenic ◽  
Arsenic Compounds ◽  
Feeding Guild ◽  
Polychaete Species ◽  
Deposit Feeders

Environmental Context. In well-oxygenated water and sediments, nearly all arsenic is present as arsenate (AsO43−). As arsenate is a phosphate (PO43−) analogue, organisms living in arsenate-rich environments must acquire the nutrient phosphorus yet avoid arsenic toxicity. Organisms take in and transform arsenic compounds by many means. Three major modes of arsenic biotransformation have been found to occur in the environment—redox transformation between arsenate and arsenite (AsO2−), the reduction and methylation of arsenic, and the biosynthesis of organoarsenic compounds such as arsenobetaine. These biotransformations lead to biogeochemical cycling of arsenic compounds and bioconcentration of arsenic in aquatic organisms and thence into the food web. Abstract. The paper reports the whole-tissue total arsenic concentrations and water-soluble arsenic species in eight common coastal Australian polychaete species. Laboratory experiments showed the period of depuration did not significantly alter the whole-tissue total arsenic concentrations in the two estuarine polychaete species tested. Significant differences were found between the whole-tissue total arsenic concentrations of the eight polychaete species (mean arsenic concentrations ranged from 18 to 101 µg g−1 dry mass). Total arsenic concentrations in polychaete species, grouped on the basis of a combination of their feeding guild and habitat type, were also significantly different with a significant interaction between these factors indicating that both factors simultaneously influence arsenic concentration in polychaetes. A large number of polychaete species contained similar arsenic species with high proportions of arsenobetaine (AB; 57–88%) and relatively low proportions of As3+, As5+, methyarsonic acid, dimethylarsinic acid, arsenocholine, trimethylarsoniopropionate, and tetramethylarsonium ion (not detected to 12%). All polychaete species contained arsenoribosides (5–30%). This study identified two Australian polychaete species with particularly unusual whole-tissue water-soluble arsenic species proportions: Australonuphis parateres contained a very high proportion of trimethylarsoniopropionate (~33%), while Notomastus estuarius had a very low proportion of arsenobetaine (9%) and high proportions of As3+ (~30%), As5+ (~8%), arsenoribosides (30%), and an unknown anionic arsenic species (~4%). Most polychaetes accumulate arsenobetaine, except deposit feeders inhabiting estuarine mud habitats. Thus most polychaetes, which are prey for higher organisms, are a source of arsenobetaine in benthic food webs. Deposit feeders inhabiting estuarine muddy substrates contain appreciable quantities of inorganic arsenic and arsenoribosides that may be metabolized to different end products in higher organisms.

scholarly journals Microbial Methylation of Metalloids: Arsenic, Antimony, and Bismuth

2002 ◽  
Vol 66 (2) ◽  
pp. 250-271 ◽  
Author(s):  
Ronald Bentley ◽  
Thomas G. Chasteen
Keyword(s):  
Public Health ◽  
Anaerobic Bacteria ◽  
Public Health Problem ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Dimethylarsinic Acid ◽  
Microbial Conversion ◽  
Microbiological Test ◽  
Methylarsonic Acid ◽  
Microbial Methylation

SUMMARY A significant 19th century public health problem was that the inhabitants of many houses containing wallpaper decorated with green arsenical pigments experienced illness and death. The problem was caused by certain fungi that grew in the presence of inorganic arsenic to form a toxic, garlic-odored gas. The garlic odor was actually put to use in a very delicate microbiological test for arsenic. In 1933, the gas was shown to be trimethylarsine. It was not until 1971 that arsenic methylation by bacteria was demonstrated. Further research in biomethylation has been facilitated by the development of delicate techniques for the determination of arsenic species. As described in this review, many microorganisms (bacteria, fungi, and yeasts) and animals are now known to biomethylate arsenic, forming both volatile (e.g., methylarsines) and nonvolatile (e.g., methylarsonic acid and dimethylarsinic acid) compounds. The enzymatic mechanisms for this biomethylation are discussed. The microbial conversion of sodium arsenate to trimethylarsine proceeds by alternate reduction and methylation steps, with S-adenosylmethionine as the usual methyl donor. Thiols have important roles in the reductions. In anaerobic bacteria, methylcobalamin may be the donor. The other metalloid elements of the periodic table group 15, antimony and bismuth, also undergo biomethylation to some extent. Trimethylstibine formation by microorganisms is now well established, but this process apparently does not occur in animals. Formation of trimethylbismuth by microorganisms has been reported in a few cases. Microbial methylation plays important roles in the biogeochemical cycling of these metalloid elements and possibly in their detoxification. The wheel has come full circle, and public health considerations are again important.

The response of tomato (Lycopersicon esculentum) to different concentrations of inorganic and organic compounds of arsenic

Biologia ◽  
2006 ◽  
Vol 61 (1) ◽  
Author(s):  
Pavel Tlustoš ◽  
Jiřina Száková ◽  
Daniela Pavlíková ◽  
Jiří Balík
Keyword(s):  
Arsenic Concentration ◽  
Vegetation Period ◽  
Dimethylarsinic Acid ◽  
Arsenic Toxicity ◽  
Arsenic Compounds ◽  
Tomato Plants ◽  
Methylarsonic Acid ◽  
Cultivation Substrate ◽  
Transformation Processes

AbstractTomato plants were cultivated in greenhouse and water solutions of arsenite (As(III)), arsenate (As(V)), methylarsonic acid (MA) and dimethylarsinic acid (DMA) were applied individually into cultivation substrate at two As levels, 5 and 15 mg kg−1 of the substrate. Comparing the availability of arsenic compounds increased in order arsenite = arsenate < MA < DMA where the arsenic contents in plants decreased during vegetation period. Within a single plant, the highest arsenic concentration was found in roots followed in decreasing order by leaves, stems, and fruits regardless of arsenic compound applied. Arsenic toxicity symptoms reflected in suppressed growth of plants and a lower number and size of fruits were most significant with DMA treatment. However, the highest accumulation of arsenic by plants growing in the soil containing DMA was caused by higher mobility of this compound in the soil due to its lower sorption affinity. Our results confirmed substantial role of transformation processes of arsenic compounds in soil in uptake and accumulation of arsenic by plants.

scholarly journals Cyanobacteria produce arsenosugars

2012 ◽  
Vol 9 (5) ◽  
pp. 474 ◽  
Author(s):  
Shin-ichi Miyashita ◽  
Shoko Fujiwara ◽  
Mikio Tsuzuki ◽  
Toshikazu Kaise
Keyword(s):  
Inductively Coupled Plasma ◽  
High Performance ◽  
Inorganic Arsenic ◽  
Freshwater Ecosystems ◽  
Dimethylarsinic Acid ◽  
Arsenic Compounds ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Synechocystis Sp ◽  
Pcc 6803

Environmental contextAlthough arsenic is known to accumulate in both marine and freshwater ecosystems, the pathways by which arsenic is accumulated and transferred in freshwater systems are reasonably unknown. This study revealed that freshwater cyanobacteria have the ability to produce arsenosugars from inorganic arsenic compounds. The findings suggest that not only algae, but cyanobacteria, play an important role in the arsenic cycle of aquatic ecosystems. AbstractMetabolic processes of incorporated arsenate in axenic cultures of the freshwater cyanobacteria Synechocystis sp. PCC 6803 and Nostoc (Anabaena) sp. PCC 7120 were examined. Analyses of arsenic compounds in cyanobacterial extracts using a high-performance liquid chromatography–inductively coupled plasma mass spectrometry system showed that both strains have an ability to biotransform arsenate into oxo-arsenosugar-glycerol within 20 min through (1) reduction of incorporated arsenate to arsenite and (2) methylation of produced arsenite to dimethylarsinic acid by methylarsonic acid as a possible intermediate product. In addition, Synechocystis sp. PCC 6803 cells are able to biosynthesise oxo-arsenosugar-phosphate from incorporated arsenate. These findings suggest that arsenosugar formation as well as arsenic methylation in cyanobacteria possibly play a significant role in the global arsenic cycle.

Arsenic Toxicity and HSP70 Expression in Xenopus laevis Embryos

2002 ◽  
Vol 30 (6) ◽  
pp. 597-603 ◽  
Author(s):  
Rosalba Gornati ◽  
Claudio Monetti ◽  
Davide Vigetti ◽  
Stefano Bosisio ◽  
Salvador Fortaner ◽  
...  
Keyword(s):  
Animal Species ◽  
Arsenic Species ◽  
Hsp70 Expression ◽  
Dimethylarsinic Acid ◽  
Arsenic Compounds ◽  
Hsp70 Mrna ◽  
Morphometrical Analysis ◽  
Several Variables ◽  
Polymerase Chain ◽  
Xenopus Laevis Embryos

The evaluation of the effect of trace metals on health can be difficult, because of their presence in the environment in various chemical forms. Exposure to arsenic compounds is an example of this complexity, as it can be present in the environment in inorganic and organic forms. The effects of arsenic in vertebrates are complicated by several variables, such as speciation of the element, the exposure route, and the susceptibility of the particular animal species. The embryotoxicity and teratogenicity of three arsenic species — sodium arsenite (NaAsO2), disodium hydrogen arsenate (Na2HAsO4) and dimethylarsinic acid [(CH3)2AsOOH] — were evaluated by the modified frog embryo teratogenic assay on Xenopus (FETAX). We also show how the classical FETAX endpoints, based on morphological and morphometrical analysis, can conveniently be integrated with the study of molecular markers. Possible changes in the expression of the mRNA for the heat-shock protein HSP70, following exposure to NaAsO2, were examined by using the reverse transcriptase polymerase chain reaction. HSP70 mRNA is strongly induced by arsenic.

scholarly journals Speciation Analysis of Arsenic Compounds by HPLC-ICP-MS: Application for Human Serum and Urine

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Manh Ha Nguyen ◽  
Tien Duc Pham ◽  
Thi Lien Nguyen ◽  
Hai Anh Vu ◽  
Thi Thao Ta ◽  
...  
Keyword(s):  
Human Serum ◽  
Ethylenediaminetetraacetic Acid ◽  
Limit Of Detection ◽  
Speciation Analysis ◽  
Arsenic Species ◽  
Dimethylarsinic Acid ◽  
Arsenic Compounds ◽  
Serum Samples ◽  
Icp Ms ◽  
Urine And Serum

A high-performance liquid chromatography (HPLC) in combination with inductively coupled plasma mass spectrometry (ICP-MS) as an elemental specific detector was used for the speciation analysis of arsenic compounds in urine and serum samples from Vietnam. Five arsenic species including arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and arsenobetaine (AsB) were studied. A gradient elution of ammonium carbonate ((NH4)2CO3), ethylenediaminetetraacetic acid disodium salt (Na2EDTA), and methanol at pH 9.0 utilizing Hamilton PRP-X100 strong anion-exchange column allowed the chromatographic separation of five arsenic species. In this study, urine and serum samples were prepared by dilution in solvent and protein precipitation by trichloroacetic acid, respectively. The extraction efficiency was greater than 91% for urine matrix, and recoveries from spiked samples were in the range of 94–139% for the arsenic species in human serum. The method limit of detection (MDL) and limit of quantification (MQL), which were calculated by signal to noise ratio, were found to be 0.3–1.5 and 1.0–5.0 ng·mL−1, respectively. The concentration of arsenic species in 17 pairs of urine and serum samples from Vietnam was also quantified and evaluated. The major species of arsenic in the urine and serum samples were AsB and DMA.

scholarly journals Elemental and Speciation Analyses of Different Brands of Yerba Mate (Ilex paraguariensis)

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2925
Author(s):  
Jędrzej Proch ◽  
Aleksandra Orłowska ◽  
Przemysław Niedzielski
Keyword(s):  
Inductively Coupled Plasma ◽  
High Performance ◽  
Optical Emission ◽  
Arsenic Species ◽  
Emission Spectrometry ◽  
Ilex Paraguariensis ◽  
Dimethylarsinic Acid ◽  
Yerba Mate ◽  
Inductively Coupled ◽  
Plasma Optical Emission Spectrometry

In this work, a methodology for determination of As(III), As(V), dimethylarsinic acid (DMA), Fe(II) and Fe(III) in fifty-eight samples (forty-nine products of thirteen brands from three countries) commercial yerba mate (Ilex paraguariensis) was performed. The hyphenated high performance liquid chromatography inductively coupled plasma optical emission spectrometry (HPLC-ICP OES) technique was used. Arsenic was determined below the quantification limit in 38 samples of yerba mate. As(III) was found at the level 0.09 and 0.08 mg kg−1. The As(V) content was in the range: 0.21 to 0.28 mg kg−1. The content of DMA was found the highest of the three arsenic species in the range: 0.21 to 0.47 mg kg−1. The content of Fe(II) and Fe(III) was found in the range: 0.61 to 15.4 mg kg−1 and 0.66 to 43.1 mg kg−1, respectively and the dominance of Fe(III) was observed. Moreover, total and extractable content of 16 elements were determined. The results have been subjected to statistical analysis in order to establish relationships between samples of the same origin (country), kind (type) and composition (purity).

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