Interactions between arsenic species and marine algae [electronic resource]
The arsenic concentration and speciation of marine algae varies widely, from 0.4 to 23 ng.mg⁻¹, with significant differences in both total arsenic content and arsenic speciation occurring between algal classes. The Phaeophyceae contain more arsenic than other algal classes, and a greater proportion...
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| Online Access: |
Online Access |
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| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Oak Ridge, Tenn. :
distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy,
1978.
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| Subjects: |
| Summary: | The arsenic concentration and speciation of marine algae varies widely, from 0.4 to 23 ng.mg⁻¹, with significant differences in both total arsenic content and arsenic speciation occurring between algal classes. The Phaeophyceae contain more arsenic than other algal classes, and a greater proportion of the arsenic is organic. The concentration of inorganic arsenic is fairly constant in macro-algae, and may indicate a maximum level, with the excess being reduced and methylated. Phytoplankton take up As(V) readily, and incorporate a small percentage of it into the cell. The majority of the As(V) is reduced, methylated, and released to the surrounding media. The arsenic speciation in phytoplankton and Valonia also changes when As(V) is added to cultures. Arsenate and phosphate compete for uptake by algal cells. Arsenate inhibits primary production at concentrations as low as 5 ..mu..g.1⁻¹ when the phosphate concentration is low. The inhibition is competitive. A phosphate enrichment of > 0.3 ..mu..M alleviates this inhibition; however, the As(V) stress causes an increase in the cell's phosphorus requirement. Arsenite is also toxic to phytoplankton at similar concentrations. Methylated arsenic species did not affect cell productivity, even at concentrations of 25 ..mu..g.1⁻¹. Thus, the methylation of As(V) by the cell produces a stable, non-reactive compound which is nontoxic. The uptake and subsequent reduction and methylation of As(V) is a significant factor in determining the arsenic biogeochemistry of productive systems, and also the effect that the arsenic may have on algal productivity. Therefore, the role of marine algae in determining the arsenic speciation of marine systems cannot be ignored. (ERB) |
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| Item Description: | Published through SciTech Connect. 01/01/1978. "sro-0890-t1" Sanders, J.G. North Carolina Univ., Chapel Hill (USA) |
| Physical Description: | Pages: 87 : digital, PDF file. |