Morphology microstructure, and development of colonies of Acetobacter xylinum.

Development of the morphology and microstructure of colonies of Acetobacter xylinum growing on agar was studied by optical microscopy, and transmission and scanning electron microscopy. The mass of rapidly dividing cells surrounded by a sheath of cellulose microfibrils passes from a smooth spheroid to a flattened aggregate with a characteristic "pillowed" surface. This morphology is the result of a repeated extrusion of cells from the confirming sheath, followed by regeneration of a new portion of the sheath on the extrusion of cells from the confirming sheath, followed by regeneration of a new portion of the sheath on the extruded cell mass. Relations of this mechanism to others which produce similar shapes are indicated.