Mearl C. Mahl

Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



Although much of the work concerning anion uptake by yeast has been done with cake yeast, the majority of the studies reported in this thesis were performed using a pure culture of Saccharomyces cerevisiae. Two media are described which produce a sufficient number of yeast cells possessing good phosphate and selenite uptake properties. A study of the relative rates of the uptake of phosphate, selenite, selenate, and sulfate shows phosphate anions to be absorbed at a much faster rate than others. Thirty minutes after its addition, selenite appeared to be inhibitory to the cells. Selenate was also inhibitory to the cells, but was not as toxic as selenite. Sulfate was absorbed at a low, constant rate by the yeast cells with no adverse effects observed. By using data obtained with selenium 75 selenite and phosphorus 32 phosphate in both Dubnoff incubation and Warburg experiments, it was found that a competitive inhibition exists between phosphate and selenite. In a brief study with radioactive elements, it was noted that phosphate might affect selenite inhibition of yeast cell respiration at concentrations of selenite that are 3.93 x 10-5 M and lower.

Library of Congress Subject Headings



Includes bibliographical references




South Dakota State University


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