||Mechanisms of Microbial Movement in Subsurface Materials.
Reynolds, P. J. ;
Sharma, P. ;
Jenneman, G. E. ;
McInerney., M. J. ;
||Oklahoma Univ., Norman. Dept. of Botany and Microbiology.;Robert S. Kerr Environmental Research Lab., Ada, OK.
Escherichia coli ;
Penetration tests ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
The biological factors important in the penetration of Escherichia coli through anaerobic, nutrient-saturated, Ottawa sand-packed cores were studied under static conditions. In cores saturated with galactose-peptone medium, motile strains of E. coli penetrated four times faster than mutants defective only in flagellar synthesis. Studies with motile nonchemotactic and chemotactic microbes indicated that chemotaxis may not be required for bacterial penetration through unconsolidated porous media. Studies using motile and nonmotile E. coli strains together with their respective isogenic non-gas-producing mutants indicated that gas production may be an important mechanism for the movement of non-motile bacteria through such media, but has little effect on the penetration rate of motile organisms. Results obtained with motile strains implied that the penetration rate for motile bacteria through unconsolidated porous media is regulated by the in situ bacterial growth rate. A sigmoidal relationship was found between the specific growth rates of all of the motile bacteria used in the study and the penetration rates through cores saturated with galactose-peptone medium. (Copyright (c) 1989 American Society for Microbiology.)