title: Effect of short term external perturbations on bacterial ecology and activities in a partial nitritation and anammox reactor.
abstract: This research investigated the short term effects of temperature changes (lasting 2-4weeks each) from 35±2°C to 21±2°C and 13±2°C and sulfide toxicity on partial nitrification-anammox (PN/A) system. Temperatures below 20°C and sulfide content as low as 5mgSL(-1) affected both aerobic and anaerobic catabolic activities of ammonia oxidation and the expression of related functional gene markers. The activity of AOB was inversely correlated with ammonium monooxygenase (amoA) gene expression. In contrast, the activity of AMX bacteria was positively correlated with the expression of their hydrazine synthase (hzsA) gene. Although the overall activities of AMX bacteria decreased at lower temperatures, the AMX bacteria were still active at the low temperatures. The inverse correlation between amoA gene expressions and the corresponding AOB activities was surprising. 16S rDNA based high throughput amplicon sequencing revealed the dominance of Chloroflexi, Planctomycetes and Proteobacteria phyla the distribution of which changed with temperature changes.
authors: Civil and Environmental Engineering Department, University of Utah, 110 S Central Campus Drive, Salt Lake City, UT 84102, United States.
authors: Sha
authors: S
authors: Wu
authors: Civil and Environmental Engineering Department, University of Utah, 110 S Central Campus Drive, Salt Lake City, UT 84102, United States.
authors: Ananda S
authors: AS
authors: Bhattacharjee
authors: Department of Biotechnology, Delft University of Technology, Delft, The Netherlands; Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Denmark.
authors: David G
authors: DG
authors: Weissbrodt
authors: ETH Zürich, Institute of Environmental Engineering, Zürich, Switzerland; Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
authors: Eberhard
authors: E
authors: Morgenroth
authors: Civil and Environmental Engineering Department, University of Utah, 110 S Central Campus Drive, Salt Lake City, UT 84102, United States. Electronic address: ram.goel@utah.edu.
authors: Ramesh
authors: R
authors: Goel
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D064751:Ammonium Compounds / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D058465:Nitrification; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D064751:Ammonium Compounds; D009573:Nitrites; D000641:Ammonia; D009584:Nitrogen
keywords: Nitritation/anammox; Sulfide; Temperature; amoA gene and hzsA gene expressions