Effect of selenium on the lipids of two unicellular marine algae
The incorporation of selenium into the lipids of two unicellar marine algae has been investigated. Axenic cultures of the green algae Dunaliella primolecta and the red algae Porphyridium cruentum were grown in the presence of sublethal quantities of selenium (10 ppm) as selenite. Both algae were found to contain selenium bound to all purified lipids, except for saturated hydrocarbons. Of the lipids which contain selenium, carotenoid pigments show the greatest selenium concentration (..beta..-carotene: 1.3..mu..gSe/mg lipid; zeaxanthin: 1.1..mu..gSe/mg lipid) in both algae. P. cruentum contains about ten times as much lipid-associated selenium as D. primolecta, even though the lipids of both algae were very similar. This selenium has been shown to be incorporated non-metabolically into the lipid molecule. The lipid-associated selenium is probably non-covalently bound to the lipid molecule and may interact with double bonds. Selenite does not affect the lipid composition of D. primolecta, as compared with algae grown in the absence of added selenium. A selenium-induced 40% decrease in the cell content of eicosapentaenoic acid (20:5omega3) and 20% decrease in arachidonic acid (20:4omega6) in polar lipids (glycolipids plus phospholipids) was observed in P. cruentum. A 25% decrease in the chlorophyll a content of this red algae also occurred. The cell content of other fatty acids, phospholipids and glycolipids was unaltered by selenium. These results are consistent with a selenite-induced oxidation of P. cruentum lipids. Selenium is able to increase the antioxidant potential of algal cells. However, no in vivo selenium-induced protection of algal lipids from oxidation was apparent.
- OSTI ID:
- 6109386
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SELENIUM
BIOLOGICAL EFFECTS
UPTAKE
ALGAE
ANTIOXIDANTS
BIOLOGICAL ACCUMULATION
CHLOROPHYLL
COMPARATIVE EVALUATIONS
DECOMPOSITION
LIPIDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
ELEMENTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYTOCHROMES
PIGMENTS
PLANTS
PORPHYRINS
SEMIMETALS
560302* - Chemicals Metabolism & Toxicology- Microorganisms- (-1987)
560303 - Chemicals Metabolism & Toxicology- Plants- (-1987)