Detection and analysis of functional microbes in strong ammonia wastewater treatment system

Total DNA was extracted from the nitrifying biofilm in strong ammonia wastewater treatment system, and two pairs of polymerase chain reaction (PCR) primers based on the 16S rDNA sequences of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were used for PCR amplification. The special fragments of AOB and NOB were cloned into E. coli DH5α, and after digested by different restriction endonucleases, 8 strains of AOB and 8 strains of NOB were sequenced. The 8 AOB clones were found coming from different strains by comparing with the DNA sequences in GenBank (NCBI), and Nitrosomonas sp. and Nitrosococcus sp. were the dominant species for ammonia oxidation in the system. The 8 NOB clones came from 7 different strains, and Nitrobacter sp. and Afipia sp. were the dominant species for nitrite oxidation. Fig 6, Tab 1, Ref 14.