IDENTIFICATION AND CHARACTERIZATION OF BACTERIAL ACTIVITIES INVOLVED IN WASTE-WATER TREATMENT BY AEROBIC FIXED-BED REACTOR

Bacterial colonization of an aerobic fixed bed reactor was studied as a function of reactor height and time during three days. After the col onization, the evolution of the quantity of fixed biomass, their hydro lytical activities and the influence of periodic backwashing were meas ured, weekly. Approximatively 100 bacteria were identified and classif ied in different metabolic groups. A decreasing gradient of biomass fr om top to bottom of the reactor was observed. Backwashing operation pe rmitted the removal of 48% of the fixed biomass. In terms of bacterial strains and their potential hydrolytical abilities (glucidolytical, p roteolytical, and lipolytical), no zonation was observed. Most of the species isolated from the granular support belong to the following gen era and family: Acinetobacter, Enterobacteriaceae, Aeromonas, Flavobac terium, and Pseudomonas.