[Morphology of bacteria belonging to Propionibacterium genus in scanning and transmission electron microscopy]

Bacteria belonging to Propionibacterium genus reveal a characteristic shape of short rods. Their length is from 0.8 micrometer to 1.5 micrometer and their width reaches from 0.3 micrometer to 0.5 micrometer. Most bacteria of this genus have a constant ratio of cell length and their diameter is 2: 1. Their surface is smooth and has no cilia. Certain species of this genus, grown on liquid media, demonstrate the capacity of developing involution forms and of linking the cells into greater complexes which may appear in a form of flocculus. The characteristic feature, distinguishing this genus of bacteria from other ones, is that on their surface, the undefined scars and not-stated till now, structural formations were visible.