The transport of microorganisms in soils is of major importance for bioremediation of subsurface polluted zones and for pollution of groundwater with pathogens. A procedure for evaluating the relative mobility and recovery of bacteria in the soil matrix was developed. In the method devised, movement of bacteria along the walls of the column of soil and channeling were prevented. Changes in population size during the test period were minimal because temperatures of 2-5 C were maintained and predators and parasites were eliminated by (60)Co irradiation. The 19 strains of bacteria tested had markedly different degrees of transport. From 0.01 to 15% of the added cells passed through a 5-cm long column of Kendaia loam with four pore volumes of water and from 4.3% to essentially all of the added bacteria were recovered. The marked differences in the mobilities of the various bacteria and the high recoveries of most of the isolates suggested that the procedure developed is a useful means for selecting bacteria according to their mobilities in soils, aquifer materials, and other porous media. (Copyright (c) 1991 Pergamon Press plc.)

Caption title. "EPA/600/J-92/076." "PB92-153329." "Accepted 28 June 1991." Includes bibliographical references (p. 1159-1160).