Abstract
For the release of microbial strains including recombinants, appropriate methods to detect and control the strains and their DNA in the field, especially in the soil, are a prerequisite. For the control of microorganisms in the field, it is important to study their life cycle in their natural micro habitats. This implies that microbial autecology should be developed to the level of "molecular ecology" whereby the morphology and physiology of each microbial strain are defined at the molecular level. A series of experiments on the detection and control of microorganisms in the soil is currently being carried out using P. paucimobilis BHC^+ with a view to solving the problems associated with the release of recombinants in the environment and in relation to general microbiology. The results obtained are as follows: (1) This strain was able to grow rapidly even in nonsterile soils by completely decomposing BHC without disturbing the microflora of the soils. (2) A few cells of this strain in one gram of nonsterile soil could be easily and accurately detected. (3) Populations of this strain in nonsterile soils could be readily controlled. In addition, the genes responsible for the BHC-decomposition ability will be analysed, to clarify their fate in the field, and to utilize them as markers for other microorganisms.
