Identification of the microbial diversity of wastewater nutrient removal processes using molecular biotechnology

The microbial communities of three sludge samples were identified by using a combined cloning-Denaturing Gradient Gel Electrophoresis (DGGE) method. Two communities were taken from the aerobic and the rotating biological contactor (RBC) of a novel hybrid system, named TNCU-I, which is a combined activated sludge-RBC bioprocess. The other sample was taken from the aerobic tank of a typical anaerobic-anoxic-aerobic (A2O) process. Acidovorax defluvii, Hydrogenophaga palleronii and Streptococcus suis were the most predominant bacteria, respectively, in TNCU-I activated sludge, TNCU-I RBC biofilm and A2O activated sludge, with abundances of 13.2%, 18.7% and 16.5%. Other predominant bacteria and their characteristics in wastewater treatment process are also described.