Abstract
A bacterium belonging to Pseudomonas which was isolated from activated sludge formed floes in glycerol-containing medium. The floes were deflocculated by deoxyribonuclease treatment in the presence of magnesium ions. Floes were also deflocculated by 2 M NaCl, heating at temperatures higher than 50°C, and at pH below 1 or above 11. The observations suggest that deoxyribonucleic acid is directly involved in the association of cells and that ionic bonds are responsible for the flocculation of cells.
