Responses of certain freshwater planktonic algae to fluoride

Journal Article · Fri Jun 01 04:00:00 EDT 1984 · J. Phycol.; (United States)

DOI:https://doi.org/10.1111/j.0022-3646.1984.00243.x· OSTI ID:6352936

Hekman, W E; Budd, K; Palmer, G R; MacArthur, J D

The effects of dissolved fluoride supplied as NaF at up to 150 p.p.m. F/sup -/ (7.9 mM) on growth, photosynthesis, dark respiration, enolase activity and fluoride uptake were determined for six phytoplankters: Synechococcus leopoliensis (Racib.) Komarek (Cyanophyta), Oscillatoria limnetica Lemmermann (Cyanophyta), Ankistrodesmus braunii Brun (Chlorophyta), Scenedesmus quadricauda (Turp.) Breb. (Chlorophyta), Cyclotella meneghiniana Kuetzing (Bacillariophyta) and Stephanodiscus minutus Grun. ex Cleve et Moll (Bacillariophyta). Growth (determined by absorbance at 660 nm or by cell-numbers) was unaffected by fluoride at up to 50 p.p.m. (2.6 mN) in all algae except S. leopoliensis. These effects showed a threshold at ca. 25 p.p.m. (1.3 mM) F/sup -/ and increased with increasing F/sup -/ concentration above this threshold. Photosynthetic O/sub 2/ evolution in the chlorophytes was unaffected by F/sup -/ at up to 50 p.p.m., whereas in S. leopoliensis F/sup -/ above ca. 25 p.p.m. caused a concentration-dependent inhibition of photosynthesis which was most pronounced at saturating irradiance. Dark O/sub 2/ uptake was unaffected at up to 50 p.p.m. in chlorophytes but was stimulated in S. leopoliensis. Enolase in clarified cell-extracts of all six algae was inhibited by F/sup -/, with K/sub i/ values ranging from 27 to 319 ..mu..M. Fluorine (measured by proton-induced gamma-ray emission) could not be detected in chlorophytes exposed during growth to up to 50 p.p.m. F/sup -/, but was detected in S. leopoliensis, O. limnetica and C. meneghiniana. Fluorine associated with cells of these algae increased as the external F/sup -/ concentration increased.

• Research Organization: Queen's Univ., Kingston, Ontario
• OSTI ID: 6352936
• Journal Information: J. Phycol.; (United States), Journal Name: J. Phycol.; (United States) Vol. 20:2; ISSN JPYLA
• Country of Publication: United States
• Language: English

Related Subjects

560302* -- Chemicals Metabolism & Toxicology-- Microorganisms-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AQUATIC ORGANISMS
BIOLOGICAL EFFECTS
CHEMICAL REACTIONS
ELEMENTS
ENZYME ACTIVITY
FLUORIDES
FLUORINE
FLUORINE COMPOUNDS
GROWTH
HALIDES
HALOGEN COMPOUNDS
HALOGENS
NONMETALS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYTOPLANKTON
PLANKTON
RESPIRATION
SYNTHESIS
UPTAKE