Seasonal Variation of Archaeal amoA In Two-Stage Trickling Filter and Moving Bed Bioreactor Systems

Seasonal variation of archaeal and bacterial ammonia oxidizers was investigated in two stage-tricking filters (TF) at Fargo wastewater treatment plant (WWTP) in North Dakota and moving bed bioreactor (MBBR) at Moorhead WWTP in Minnesota. Biofilm samples were collected from 17 months period from nitrifying trickling filter (NTF) and BOD trickling filter (BTF), and from the MBBR media. The ammonia monooxygenase subunit A (amoA) of both archaea and bacteria were detected more in warm period than cold period in WWTPs. Both NTF and MBBR showed more archaeal amoA than bacterial amoA. The BTF was dominated by bacterial amoA throughout the sampling period and archaeal amoA was only detected in warm period. In conclusion, archaeal amoA dominated quantitatively over bacterial amoA and might have played the most significant role in the aerobic biological treatment of both WWTPs.