[Characteristics of the R-plasmid pM3 (IncP-9) of a broad circle of hosts].

A new broad host range plasmid pM3 (IncP-9) was found in a facultative methylotrophic bacteria Pseudomonas putida and described. The pM3 plasmid is characterized by thermo-instability in Enterobacteriaceae family of bacteria at 36 degrees C or higher temperatures. It is also unable to be inherited as an autonomous element in the obligate methylotrophic bacteria Methylobacillus M75. The peculiarities of plasmid inheritance make possible to use it as a tool for genetic research, for instance, to construct the donor strains in Methylobacillus M75 able to mobilize the chromosomal genes for conjugational transfer in isogenic systems of crosses.