Novel method for selective enrichment of Nitrososphaera viennensis-like ammonia-oxidizing archaea over ammonia-oxidizing bacteria from freshwater environments

WOO, YISSUE; CRUZ, MERCEDES CECILIA; WUERTZ, STEFAN

Conferencia; SINGAPORE INTERNATIONAL WATER WEEK 2021; 2021

The use of chloramination for residual disinfection is known to increase the risk of nitrification in drinking water distribution systems (DWDS), which is caused by ammonia-oxidizing nitrifiers and nitrite-oxidizing nitrifiers. Ammonia-oxidizing bacteria (AOB) are more commonly detected than ammonia-oxidizing archaea (AOA) in both bulk waters and biofilms of DWDS. AOA are generally less studied than AOB because they are difficult to cultivate. We enriched a Nitrososphaera viennensis-like AOA strain over the co-cultured AOB Nitrosomonas by using dimethylthiourea and pyruvate to stimulate AOA growth while inhibiting the growth of AOB. This strategy promoted the wash out of AOB from the enrichment culture. The method does not require filtration and/or the use of antibiotic treatment, and shortens the time required to enrich AOA from DWDS and other natural and technical environmental settings.