Aerobic Heterotrophic Bacterial Populations of Sewage and Activated Sludge: III. Adaptation in a Synthetic Waste.

The nature and behavior of the microbial population developed on a synthetic waste containing salts and sorbitol are compared to that of a treatment-plant activated sludge. The population of the adapted sludge developed on the synthetic waste consisted approximately of only six kinds of bacteria. Experiments with radioactive sorbitol indicate that the microbial population developed on the synthetic waste showed the effects of repression by glucose on the metabolism of sorbitol; in contrast, the activated sludge from a plant treating primarily domestic waste was able to attack both substrates immediately and simultaneously.