Bacteria were isolated from water at Alder Slough, Oregon. Of
15 isolates grown successfully in the medium employed, 100% showed
measurable uptake of Zn-65. A growth curve was established for one
isolate, a gram-negative rod designated AS-1. Increasing Zn-65 uptake
was found generally to correspond with increasing growth of
AS-1. The optimum growth temperature for this isolate was 31°C,
with very little growth at 37.5°C and 6.7°C. Growth and Zn-65 uptake
occurred in a 35 ppt medium from a temperature of 31.0°C to
13.9°C but little growth and no Zn-65 uptake was observed at 8.6°C
and 4.4°C. Growth and Zn-65 uptake in a 0 ppt medium occurred
from 31.0°C to 5.0°C, with little growth but measurable Zn-65 uptake
at 8.9°C and 5.0°C.
It was found that 200 ppm Mg added to a culture which had
already taken up Zn-65 failed to displace the zinc from the cells. A
interaction of the energy source, Casamino Acids, with the Zn-65
spike influenced the results. When cells were lysed, spiked with
Zn-65, and the debris removed by centrifugation, 84.8% of the Zn-65
remained in the supernatant. But when cells grown first in Zn-65
spiked medium were lysed and centrifuged, 74.4% of the Zn-65 was
found in the debris.
It was concluded that bacterial uptake of Zn-65 and other metal
cations must be considered in determining the fates of these materials
released into the environment. Chemical adsorption phenomena were
determined to be a major factor controlling this uptake, with other
chemical and biological factors, such as competitive binding by the
medium and active uptake or exclusion by the cells, exerting a
significant influence that requires further investigation to characterize. / Graduation date: 1971
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28953 |
| Date | 29 January 1971 |
| Creators | Tonjes, Stephen Dodd |
| Contributors | Renfro, William C. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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