Publication Date


Advisor(s) - Committee Chair

Larry Elliott, James Skean, Frank Toman

Degree Program

Department of Biology

Degree Type

Master of Science


An X-ray diffraction powder photograph shows a series of lines for each of which a measurement can be made and transformed into the interplanar d value (15). Lines were obtained by the analysis of precipitates from BP plates, but no lines could be obtained from the precipitate collected from SeEy plates even when the sample was exposed to the X-rays for a 20-hr period. The lines from the tellurite sample provided d values that corresponded to neither any known tellurium compound nor to elemental tellurium. These results do not agree with those of many investigators (1, 6, 11, 19, 22) who were able to identify the reduced products produced by microorganisms grown in the presence of tellurite and selenite as being metallic tellurium and selenium.

X-ray emission analysis was performed to determine if any selenium or tellurium products had actually been taken up by the bacterial cells. Peaks were obtained for selenium as shown in Figure 2. This demonstrated that seleniun is present in the precipitate obtained from disrupted cells of S. aureus is. 523 grown on SeEy medium. X-ray emission analysis of tellurite product could not conclusively prove that tellurium was in the precipitate since the tellurium peaks were so small that they could not be separated from the background scattering. X-ray emission-semiquantitative analysis was performed on the tellurite product. At TeKα the number of counts per second was 566; at TeKα +0.5 degrees, 548; and at TeKα -0.5 degrees, 552. This indicates a trace amount of tellurium. Although these results did not identify the selenite and tellurite precipitates as t: whether they were organic or inorganic forms, they did establish that the red precipitate was composed of some form(s) of selenium, and the black precipitate was composed of some form(s) of tellurium.


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