Bacterial Community Structure in Activated Sludge Process

Microbial activity and structure of the bacterial community of activated sludge reactors, which treated industrial wastewater, were studied. Microbial communities, including ammonia oxidation bacteria, eubacteria, actinomycetic communities were studied in two different systems of the polymerase chain electrophoresis gradient denaturing gel reaction using amplified gene fragments 16S rRNA of bacteria. Both systems, which used an anoxic-aerobic process and anaerobic-anoxic-aerobic process, respectively, received the same industrial waste water, operating under the same conditions and showed the similar processing performance. Oxidizing bacterial communities of ammonia from two systems showed almost identical structures corresponding to ammonia removal like, while the bacterial community actinomycetic showed obvious differences. The anoxic-aerobic-anaerobic system showed eubacterial richer communities actinomycetic the anoxic-aerobic system. FISH results showed that the ammonia-oxidizing bacterial cells in the anaerobic-anoxic-aerobic system are increased by 3.8 ± 0.2% of the total bacterial population while those in the anoxic-aerobic system represented 1.7 ± 0.2%. Thus, the existence of an anaerobic-anoxic environment in the anaerobic-aerobic system has resulted in a marked increase in biodiversity. Keywords: Industrial waste water; 16S rRNA; Anoxic; anaerobic; aerobic; Fis