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RECORD NUMBER: 8 OF 17

Main Title Direct viable counting method for meauring tolerance of aquatic microbial communities to Hg(2+1) /
Author Liebert, Cynthia. ; Barkay, T.
Other Authors
Author Title of a Work
Barkay, Tamar.
CORP Author Environmental Research Lab., Gulf Breeze, FL. ;Technology Applications, Inc., Gulf Breeze, FL.
Publisher U.S. Environmental Protection Agency, Office of Research and Development, Environmental Research Laboratory,
Year Published 1988
Report Number EPA/600/J-88/351; CONTRIB-628
Stock Number PB89-237176
Additional Subjects Aquatic microbiology ; Mercury ; Toxic tolerances ; Cells(Biology) ; Escherichia coli ; Measurement ; Cell division ; Acid treatment ; Metals ; Thymidines ; Fluorescence microscopy
Holdings
Library Call Number Additional Info Location Last
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Status
NTIS  PB89-237176 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 8 pages : illustrations ; 28 cm
Abstract
Direct counts of Hg2+ resistant cells in natural waters were obtained by fluorescence microscopy after incubation for 20 hours in the presence of a growth substrate, nalidixic acid to halt cell division, and inhibiting concentrations of Hg2+. The method discriminated Hg2+ resistant from sensitive Escherichia coli strains. Estuarine samples were used to compare this procedure with two other toxicity measurements that determine the effect of Hg2+ on colony growth and on rates of radioactive thymidine incorporation into cellular material. Toxicity measurements based on direct viable counts and thymidine incorporation rates had comparable sensitivities, and both were 3-4 orders of magnitude more sensitive than the method that utilized colony counts. Thus, the direct enumeration of Hg2+ resistant cells is useful for predicting the potential of aquatic communities to sustain heterotrophic activity, an essential microbial process, in the presence of Hg2+.
Notes
"Reprint article published in Canadian Journal of Microbiology, 34:1090-1095 1988." Caption title. "EPA/600/J-88/351." Microfiche.