CAPSULE FORMATION BY SULFOBACILLUS THERMOSULFIDOOXIDANS CELLS GROWINGUNDER OLIGOTROPHIC AND MIXOTROPHIC CONDITIONS

Polysaccharide capsules of the oligotrophically or mixotrophically gro wing thermoacidophilic eubacterium Sulfobacillus thermosulfidooxidans VKM-B1269 were studied cytochemically and by electron microscopy. The capsular material was found to be bound to the cell wall and could be removed only by ultracentrifugation at 40000 g. The greatest amounts o f capsular polysaccharides were synthesized by oligotrophically growin g sulfobacilli. The capsular polysaccharide content of mixotrophically growing cells was somewhat lower, suggesting that metabolic processes in such cells were more balanced.