title: Mechanisms and Control of NO2-Inhibition of Anaerobic Ammonium Oxidation (Anammox).
abstract: Nitrite (NO2-), one of the main substrates in the anaerobic ammonium oxidation (anammox) process, has the potential to inhibit anammox bacteria. The sensitivity of anammox cells with different energy status to NO2- was evaluated, and addition of nitrate (NO3-) inhibition on the basis of narK gene with the putative function of facilitating NO3-/NO2- antiporter. The results showed that the resistance of anammox bacteria to NO2- inhibition follows the order: active-cells > starved-cells > resting-cells > starved-/resting-cells. Anammmox resting cells have increasing tolerance to NO2- in the pH range from 7.0 to 7.5. Dissipating the proton gradient by using carbonyl cyanide m-chlorophenyl hydrazine (CCCP) caused severe inhibition at all pH values including pH = 7.5. Addition of NO3- enabled activity recovery of NO2--inhibited anammox bacteria regardless of whether the proton gradient was disrupted or not, supporting the hypothesis of NO3--dependent detoxification via a secondary transport system.
authors.forename: Guangbin
authors.initials: G
authors.lastname: Li
authors.forename: Jose Maria
authors.initials: JM
authors.lastname: Carvajal-Arroyo
authors.forename: Reyes
authors.initials: R
authors.lastname: Sierra-Alvarez
authors.forename: Jim A
authors.initials: JA
authors.lastname: Field
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D000693:Anaerobiosis; D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D009573:Nitrites / Q000494:pharmacology*; D010084:Oxidation-Reduction
chemical_list: D064751:Ammonium Compounds; D009573:Nitrites