Analysis of Bacterial Communities in Treated Water and Activated Sludge and Evaluation of an Easy Methodology for Preparing PCR-Compatible DNA Extracts

摘要

In the present study, the authors attempted to grasp the entire bacterial communities in treated water and activated sludge derived from a laboratory-scale activated sludge reactor using polymerase chain reaction/terminal-restriction fragment length polymorphism (PCR/T-RFLP) that targeted a partial 16S rRNA gene. The authors introduced the sonication-dilution method, an easy and rapid method to prepare PCR-compatible DNA extracts from target samples, and assessed its reproducibility. Results showed that bacterial communities in treated water and activated sludge were successfully profiled using the template DNA prepared by this method. The bacterial community structures in treated water had significant differences from those in activated sludge. Certain peaks in T-RFLP profiles were more intense with the treated water sample, whereas other peaks were found to be more intense with the activated sludge sample. The species corresponding to the peaks that were more intense in treated water samples had a higher tendency to be discharged with treated water, whereas other species detected in activated sludge were more associated with stable flocs. However, principal component analysis (PCA) of the T-RFLP data demonstrated a similar trend of the bacterial communities present in the treated water and activated sludge samples.