ABSTRACT: Nitrogen removal pathways and denitrification products of the cold-tolerant heterotrophic nitrification and aerobic denitrification bacterium Pseudomonas fragi EH-H1
Project description:Roothans et al., analyzed heterotrophic denitrification processes that can be an important source of nitrous oxide. We employed planktonic nitrification-inhibited denitrifying enrichment cultures under alternating oxic-anoxic conditions. The dynamic conditions resulted in a general presence of the denitrifying enzymes. Overall, we show that aerobic denitrification should not be neglected as an ecologically relevant process. Contact author: m.laureni@tudelft.nl
Project description:This study systematically evaluated the denitrification performance and tolerance mechanisms of the highly efficient heterotrophic nitrifying–aerobic denitrifying strain Klebsiella sp. WH-E under Zn²⁺ stress. Under 100 mg/L Zn²⁺ stress, the heterotrophic nitrification and aerobic denitrification capabilities of Klebsiella sp. WH-E resulted in an ammonia nitrogen removal rate of 95.53% and a nitrate nitrogen removal rate of 74.00%. and the nitrite nitrogen removal rate was 72.75%. The activities of the key denitrification enzymes NAR and NIR remained largely stable, and the accumulation of NO₃⁻-N and NO₂⁻-N during nitrogen transformation was limited. Multi-omics analysis revealed that Zn²⁺ stress significantly upregulated nitrogen metabolism-related genes (narG, nirB) and metal homeostasis regulatory genes (zntA, arsR, czcC), while simultaneously regulating ABC transporters and two-component systems to maintain intracellular Zn²⁺ homeostasis. The abundance of sulfur metabolism and antioxidant-related metabolit
Project description:Nitrogen and arsenic contaminants often coexist in groundwater, and microbes show the potential for simultaneous removal of nitrogen and arsenic. Here, we reported that Hydrogenophaga sp. H7 was heterotrophic nitrification and aerobic denitrification (HNAD) and arsenite [As(III)] oxidation bacterium. Strain H7 presented efficient capacities for simultaneous NH4+-N, NO3--N, or NO2--N removal with As(III) oxidation during aerobic cultivation. Strikingly, the bacterial ability to remove nitrogen and oxidize As(III) has remained high across a wide range of temperatures, pH values, and shaking speeds, exceeding that of the most commonly reported HNAD bacteria. Additionally, the previous HNAD strains exhibited a high denitrification efficiency, but a suboptimal concentration of nitrogen remained in the wastewater. Here, strain H7 combined with FeCl3 efficiently removed 96.14% of NH4+-N, 99.08% of NO3--N, and 94.68% of total nitrogen (TN), and it oxidized 100% of As(III), even at a low nitrogen concentration (35 mg/L). The residues in the wastewater still met the Surface Water Environmental Quality Standard of China after five continuous wastewater treatment cycles. Furthermore, genome and proteomic analyses led us to propose that the shortcut nitrification-denitrification pathway and As(III) oxidase AioBA are the key pathways that participate in simultaneous nitrogen removal and As(III) oxidation.
Project description:Highly Efficient Nitrogen Removal via Heterotrophic Nitrification and Aerobic Denitrification in a Novel Zobellella sp.
| PRJNA1222198 | ENA
Project description:Heterotrophic nitrification aerobic denitrification bacteria for high salt wastewater treatment
| PRJNA1025948 | ENA
Project description:Metabolic pathway elucidation and transcriptomic response mechanisms of a high free ammonia-tolerant heterotrophic nitrification-aerobic denitrification bacterium
| PRJNA1269988 | ENA
Project description:Heterotrophic nitrification-aerobic denitrification (HNAD) in the treatment of marine aquaculture wastewater: nitrogen removal performance, mechanism and microbial characteristics
| PRJNA1144369 | ENA
Project description:Nitrification, denitrification and phosphorus removal , NiDeMP
Project description:Metagenomic insights into mechanisms of nitrogen removal by heterotrophic nitrification-aerobic denitrification process under high ammonia stress Raw sequence reads
| PRJNA1404909 | ENA
Project description:Multi-metabolism pathways insights into nutrients removal performance with adding heterotrophic nitrification-aerobic denitrification bacteria in tidal flow constructed wetlands