[Morphology and growth cycle of Hyphomicrobium with a screw-like prostheca]

Hyphomicrobium with a screw-like prostheca was isolated from a mixed culture of soil bacteria. Its morphology and growth cycle were studied by electron microscopy. The adult organisms are 1.6-1.8 mcm long and 0.8 mcm thick. The diameter of the prostheca is 0.2-0.3 mcm and sometimes up to 10-12 mcm. It has a peculiar screw-like structure of the cell wall surface and forms branches at whose ends daughter organisms develop. The bacterium multiplies not only by vegetative growth but also by conjugation.