Date of Award:
5-1-1983
Document Type:
Dissertation
Degree Name:
Doctor of Philosophy (PhD)
Department:
Biology
Department name when degree awarded
Life Sciences:Biology
Committee Chair(s)
Raymond I. Lynn
Committee
Raymond I. Lynn
Committee
Gene W. Miller
Committee
Frederick J. Post
Committee
James T. Bowman
Committee
William F. Campbell
Abstract
The effects of various concentrations of fluoride on growth of two thermophilic cyanophytes, Synechococcus lividus (unicellular) and Phormidium laminosum (filamentous) were studied. Growth of both algae was inhibited by fluoride in the concentrations tested. As the concentrations of fluoride increased, an extended adaptation lag phase was encountered. Synechcoccus lividus was more sensitive to fluoride than was Phormidium laminosum, being inhibited in total growth as well as growth rate. Fluoride effects on growth were compared to chloride and to chloride plus fluoride. The growth of S. lividus was stimulated by chloride alone and in combination with fluoride at all concentrations used; however, with P. laminosum stimulation was concentration dependent. Determination of fluoride content in laboratory-grown cultures and in field collected algal materials showed that both S. lividus and P. laminosum can accumulate high fluoride concentrations. The maximum accumulation by P. laminosum was higher than was that by S. lividus, and both appeared generally to accumulate more fluoride when chloride was supplemented to the cultures. In addition to fluoride effect on growth, changes in the morphology of S. lividus cells by fluoride were observed. The unicellular alga became filamentous when treated with high fluoride concentrations. The "filaments" were not septate and were variable in width. The changes in shape of S. lividus caused by fluoride were not due to mutation but to inhibition of cell division. Supplying chloride or fluoride plus chloride to cultures of S. lividus caused no morphological changes. Phormidium laminosum was morphologically unaffected by fluoride, chloride, or by combinations of fluoride and chloride at the concentrations tested.
Recommended Citation
Arif, Ibrahim A., "Fluoride Effects on the Growth and Morphology of Two Thermophilic Cyanophytes Synechcoccus lividus and Phormidium laminosum" (1983). Biology. 497.
https://digitalcommons.usu.edu/etd_biology/497
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