Synergistic interactions between anammox and dissimilatory nitrate reducing bacteria sustains reactor performance across variable nitrogen loading ratios

• DOI: 10.3389/fmicb.2023.1243410
• Publication Date: 2023-08-09T13:43:04Z
• Authors: Christian White; Edmund Antell; Sarah L. Schwartz; Jennifer E. Lawrence; Ray Keren; Lijie Zhou; Ke Yu; Weiqin Zhuang; Lisa Alvarez-Cohen
• Keywords: Anammox; Carbon-to-nitrogen ratio

Anaerobic ammonium oxidizing (anammox) bacteria are utilized for high efficiency nitrogen removal from nitrogen-laden sidestreams in wastewater treatment plants. The anammox form a variety of competitive and mutualistic interactions with heterotrophic that often employ denitrification or dissimilatory nitrate reduction to (DNRA) energy generation. These can be heavily influenced by the influent ratio nitrite, NH 4 + :NO 2 − , where deviations widely acknowledged stoichiometric (1:1.32) have been demonstrated deleterious effects on efficiency. Thus, it is important understand how variable ratios impact microbial ecology reactors. We observed response community lab scale membrane bioreactor (MBR) changes using both 16S rRNA gene shotgun metagenomic sequencing. Ammonium decreased 99.77 ± 0.04% when was 1:1.32 (prior day 89) 90.85 0.29% 1:1.1 (day 89–202) 90.14 0.09% changed 1:1.13 169–200). Over this same timespan, overall (NRE) remained relatively unchanged (85.26 0.01% 0–89, compared 85.49 89–169, 83.04 When slightly increased 1:1.17–1:1.2 202–253), 97.28 0.45% NRE 88.21 0.01%. Analysis 16 S sequences relative abundance taxa belonging Bacteroidetes, Chloroflexi, Ignavibacteriae over course experiment. Planctomycetes, phylum which belong, 77.19% at beginning experiment 12.24% end metagenome assembled genomes (MAGs) indicated nrfAH genes used DNRA after introduction lower ratios. coinciding sustained performance indicates relationship between bacteria. Understanding these could support more robust operation loading