Morphogenesis of cysts in Azotobacter vinelandii.

Cultures of Azotobacter vinelandii were induced to encystment with beta-hydroxybutyrate. The morphological events in the transition from cell to cyst were observed by electron microscopy of thin sections. Upon induction of encystment, cells became rounded and nonmotile. The exine coat developed by the continuous excretion of membranous components into the capsule surrounding the cell.