Effects of arsenic speciation on its toxicity to marine phytoplankton

Conference · Thu Jun 01 00:00:00 EDT 1978 · J. Phycol.; (United States)

OSTI ID:6619674

Sanders, J G

Arsenic in seawater is predominantly in the form of arsenate (As(V)). Small amounts of arsenite (As(III)) and dimethylarsinic acid (DMA) are present due to biological reduction and methylation. As(V), a chemical analogue of PO/sub 4//sup -/, is taken up indiscriminately by the cell and inhibits the phosphate active transport system and oxidative phosphorylation. As(V) inhibits cell growth and photosynthesis at concentrations greater than 5 ..mu..g . l/sup -1/, in phosphate-limited cultures. The As(V) incorporated is reduced and methylated within the cell, forming the more mobile As(III) and the non-reactive DMA. This reduction and methylation of the arsenic effectively relieves its toxicity, since DMA is not inhibitory, even at concentrations greater than 25 ..mu..g . l/sup -1/. The toxicity of As(III) is difficult to establish, due to its rapid chemical oxidation to As(V). When phosphate is present, very little As(V) is incorporated, and no inhibition occurs.

• Research Organization: Skidaway Inst. of Oceanography, Savannah
• OSTI ID: 6619674
• Journal Information: J. Phycol.; (United States), Vol. 14; Conference: Phycological Society of America meeting, Athens, GA, USA, Aug 1978
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALGAE
ARSENIC
BIOLOGICAL EFFECTS
ARSENATES
ARSENIC COMPOUNDS
CHEMICAL PROPERTIES
COMPARATIVE EVALUATIONS
GROWTH
ORGANIC ARSENIC COMPOUNDS
PHOSPHATES
PLANT CELLS
RESPONSE MODIFYING FACTORS
SEAWATER
TOXICITY
VALENCE
BIOMASS
ELEMENTS
ENERGY SOURCES
HYDROGEN COMPOUNDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PLANTS
RENEWABLE ENERGY SOURCES
SEMIMETALS
WATER
560302* - Chemicals Metabolism & Toxicology- Microorganisms- (-1987)
560303 - Chemicals Metabolism & Toxicology- Plants- (-1987)