ACCURATE AND SENSITIVE METHOD OF ENUMERATION OF A SPECIFIC MICROORGANISM, PSEUDOMONAS-PAUCIMOBILIS SS86, IN NONSTERILE SOIL

Selective, sensitive, and accurate counting of a specific microorganism in nonsterile soil is a prerequisite for the study of auteeology of microorganisms, including genetically engineered microorganisms (GEMs) introduced into soil. Pseudomonas paucimobilis SS86, which has the rare ability to decompose γ-HCH (γ-BHC, Lindane) rapidly and completely, is considered to be a useful microorganism for such investigations. The P. paucimobilis SS86 bacteria in nonsterile soil could be counted selectively and with a high sensitivity (100-107 cells/g soil) by using a simple and low cost MPN method. In addition, the population level of P. paucimobilis SS86 in nonsterile soil could be selectively controlled by the addition of an appropriate amount of y-HCH. These results indicated that a detailed autecological study of P. paucimobilis SS86 was possible and that the information obtained from the autecological study could be useful for the environmental release of GEMs. © 1990 Taylor & Francis Group, LLC.