RT Journal Article
SR Electronic
T1 Co-occurrence and cooperation between comammox and anammox bacteria in a full-scale attached growth municipal wastewater treatment process
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.12.05.519185
DO 10.1101/2022.12.05.519185
A1 Katherine Vilardi
A1 Irmarie Cotto
A1 Megan Bachmann
A1 Mike Parsons
A1 Stephanie Klaus
A1 Christopher Wilson
A1 Charles Bott
A1 Kelsey Pieper
A1 Ameet Pinto
YR 2022
UL http://biorxiv.org/content/early/2022/12/06/2022.12.05.519185.abstract
AB Cooperation between comammox and anammox bacteria for nitrogen removal has been recently reported in laboratory-scale systems including synthetic community construct; however, there are no reports of full-scale municipal wastewater treatment systems with such cooperation. Here, we report intrinsic and extant kinetics as well as genome-resolved community characterization of a full-scale integrated fixed film activated sludge (IFAS) system where comammox and anammox bacteria co-occur and appear to drive nitrogen loss. Intrinsic batch kinetic assays indicated that majority of the aerobic ammonia oxidation was driven by comammox bacteria (1.75 ± 0.08 mg-N/g TS-h) in the attached growth phase with minimal contribution by ammonia oxidizing bacteria. Interestingly, a portion of total inorganic nitrogen (∼8%) was consistently lost during these aerobic assays. Aerobic nitrite oxidation assays eliminated the possibility of denitrification as a cause of nitrogen loss, while anaerobic ammonia oxidation assays resulted in rates consistent with anammox stoichiometry. Full-scale experiments at different dissolved oxygen (DO = 2-6 mg/L) set points indicated persistent nitrogen loss that was partly sensitive to DO concentrations. Genome-resolved metagenomics confirmed high abundance (relative abundance 6.53 ± 0.34%) of two Brocadia-like anammox populations while comammox bacteria within the Ca. Nitrospira nitrosa cluster were lower in abundance (0.37% ± 0.03%) and Nitrosomonas-like ammonia oxidizers even lower (0.12% ± 0.02%). Collectively, our study reports for the first time the co-occurrence and co-operation of comammox and anammox bacteria in a full-scale municipal wastewater treatment system.Synopsis Comammox and anammox cooperation resulted in dissolved oxygen concentration dependent nitrogen loss in municipal wastewater treatment system.Competing Interest StatementThe authors have declared no competing interest.