Bacterial Community Structure of Practical-scale DHS Reactor Treating Municipal Wastewater by UASB-DHS System and Quantification of Denitrifying Bacteria

Abstract

 Bacterial community structure in municipal wastewater treatment practical-scale 3rd generation (G3) and 6th generation (G6) type Down-flow Hanging sponge (DHS) reactor was investigated by rRNA clone analysis and real-time PCR analysis. 16S rRNA gene clone-based analysis revealed different microbial composition between high-water-temperature period and low-water-temperature period was observed. Clone-based bacterial diversity was increased in high-temperature period. By contrast in low-temperature period, those composition was dramatically changed to lower diversity. Denitrifying bacteria was quantified by real-time PCR, which indicated that denitrifying bacteria were present in a ratio almost the same amount regardless of the height of the reactor. PCR-based quantifying analysis also revealed that DHS sponge can be retained denitrifying bacteria as well as activated sludge process.