description |
454 pyrosequencing of 16S rDNA and rcRNA amplicons were used to investigate the responses of rare bacterial biosphere in a sewage activated sludge on the limitation of nitrogen sources as an external perturbation. The bacterial 16S rRNA and rDNA were amplified from the original activated sludge and the cultures. The activated sludge was cultured either with aerobic or microaerobic in the presence or absence of NH4Cl for 3 weeks at 20C. Total nucleic acids were extracted from original activated sludge and the cultures. cDNA was synthesized from 16S rRNA. The V3 and V4 region of 16S rcRNA and rDNA were amplified. Emalusion PCR followed by pyrosequencing was performed using a GS FLX Titanium platform. |