Transfer of plasmids from Escherichia coli and Pseudomonas aeruginosa to methylotrophic bacteria and their detection in the new hosts.

Several plasmids of incompatibility group P were transferred from Escherichia coli and Pseudomonas aeruginosa strains to Methylophilus methylotrophus and two other methylotrophs to test their recipient ability. The presence of plasmids in transconjugants was confirmed by electrophoretic analysis. Optimal conditions for detection of plasmid DNA in the strains tested based on alkaline lysis of cells at elevated temperature were established. Special behaviour of plasmids carrying the Mu phage in methylotrophic hosts is described.