Record Display for the EPA National Library Catalog

RECORD NUMBER: 204 OF 725

OLS Field Name OLS Field Data
Main Title Effect of Growth Rate and Hydrophobicity on Bacteria Surviving Protozoan Grazing.
Author Gurijala, K. R. ; Alexander, M. ;
CORP Author Cornell Univ. Agricultural Experiment Station, Ithaca, NY. Dept. of Agronomy.;Environmental Research Lab., Gulf Breeze, FL.;Andrew W. Mellon Foundation, New York.
Publisher c1990
Year Published 1990
Report Number EPA/600/J-90/368;
Stock Number PB91-163824
Additional Subjects Escherichia coli ; Species diversity ; Soil microbiology ; Population dynamics ; Graphs(Charts) ; Chloramphenicol ; Reprints ; Protozoan predation ; Tetrahymena thermophila
Holdings
Library Call Number Additional Info Location Last
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Status
NTIS  PB91-163824 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/13/1991
Collation 8p
Abstract
Measurements were made of the predation by Tetrahymena thermophila on several bacterial species in media containing heat-killed Escherichia coli cells to serve as an alternative prey. If grazing pressure was initially not intense on a mixture of bacterial species, the species that survived protozoan feeding at greater densities were those that grew quickly before the onset of active predation. If members of several species were incubated individually at similar initial densities with actively grazing T. thermophila, some species survived at ca. 10,000/ml, some survived at ca. 100/ml, and others were eliminated. Members of the first two groups but not the third group were able to multiply in the medium in the absence of the protozoan, but the growth rates in the protozoan-free medium did not correlate with the number of survivors. However, the species that persisted at the higher densities possessed highly hydrophobic cell surfaces. The size of the surviving population of four bacterial species whose growth was prevented by chloramphenicol correlated with the initial cell density that was incubated with T. thermophila. It is concluded that the individual species surviving predation on a mixture of species is related to the capacity of the bacterium to grow, the hydrophobicity of its cell surface, and the population density of the species before the onset of intense grazing. (Copyright (c) 1990, American Society for Microbiology.)