Specification of the conjugative pili and surface mating systems of Pseudomonas plasmids.

Conjugative pili were identified for representative Pseudomonas plasmids of incompatibility groups P-2, P-3, P-5, P-7, P-8, P-10, P-11, and P-13, pili for groups P-1 and P-9 having already been described in detail. FP5 pili (unclassified) were also found. In most cases pili could be characterized by electron microscopy as rigid or flexible. The majority of Pseudomonas plasmids transferred significantly better on a surface than in a liquid. Examples of all incompatibility groups were tested.