Production of NO and N2O by the heterotrophic nitrifier Alcaligenes faecalis parafaecalis under varying conditions of oxygen saturation

Geomicrobiology (Impact Factor: 1.8). 07/2006; 23:165-176. DOI: 10.1080/01490450600599221

ABSTRACT Production of NO and N2O by the heterotrophic nitrifier Alcaligenes faecalis subsp. parafaecalis was studied during growth in batch and continuous culture on peptone-meat extract medium. Depending on oxygen saturation level, medium redox status and amount of substrate supplied, the microorganisms produced 0.002–0.25 mg NO-N h (g protein) and 0.16–2.4 mg N2O-N h (g protein). Maximum rates of nitrogen oxides production were observed during peak events initiated by sudden changes of oxygen supply in the medium and were due to combined nitrification/denitrification taking place simultaneously within the cells. Based on model simulations of enzymatic kinetics of denitrification, possible mechanisms of increased nitrogen oxides production during periods of changes in oxygen supply are suggested.

  • Source
    Desalination and water treatment 06/2014; DOI:10.1080/19443994.2014.927796 · 0.99 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Ammonia oxidation is a central step in the global nitrogen cycle that involves several different-conditions and metabolic bioprocesses, including aerobic versus anaerobic ammonia oxidation, and autotrophic versus heterotrophic ammonia oxidation. With the development and application of metagenomics and other modern molecular approaches, some new organisms (particularly ammonia-oxidizing archaea) and novel pathways related to ammonia oxidation have been identified. Consequently, the understanding of nitrogen cycling processes and the microorganisms that mediate them have been greatly improved. Here the authors summarize the biochemistry, microbiology, and ecophysiology of these organisms (including autotrophic ammonia-oxidizing bacteria, heterotrophic nitrifying bacteria, anaerobic ammonia-oxidizing bacteria, and ammonia-oxidizing archaea) and discuss the current knowledge and important concepts associated with their corresponding pathways. Factors influencing their distribution, abundance, community structure and potential ammonia oxidation rates in natural and engineered ecosystems are also addressed. Furthermore, the mechanism of nitrous oxide emission during these processes and the specific control strategies are explained or proposed. The significant roles of these organisms in novel biological wastewater treatment processes are also evaluated. Finally, several urgent issues and significant perspectives related to these novel pathways and players have been addressed to evoke the involvement of researchers in broadening future studies.
    Critical Reviews in Environmental Science and Technology 01/2013; 43(21). DOI:10.1080/10643389.2012.672072 · 3.24 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Using a statistical technique, i.e. response surface methodology (RSM), optimization studies were carried out for different parameters like nitrogen ammonia (N-NH 3), chemical oxygen demand (COD) and time, to optimize overall method for maximum elimination of N-NH 3 and COD from synthetic waste water using heterotrophic biomass conversion (HBC) process, and simultaneously minimizing the N-N 2 O emission. Ammonium hydroxide and glucose were used as nitrogen and carbon source. Central composite design technique was used to optimize the parameters with RSM. In this experiment, N-NH 3 and organic nutrient concentrations were varied keeping the biomass (total volatile suspended solids) concentration invariable. The pH during HBC process showed a decreasing trend may be due to consumption of alkalinity. Analyses of variance were carried out for quadratic model and were observed to be highly significant. The model was verified through experiments and tested statistically. Under optimized conditions (N-NH 3 : 210 mg/L, COD: 2.90 g/L, time: 38 h) N-NH 3 and COD removal efficiency were observed to be 82.72 and 84.78%, respectively. N-N 2 O emissions were minimized to 2.96 mg. The total desirability factor obtained was 0.9.
    CLEAN - Soil Air Water 03/2013; DOI:10.1002/clen.201200542 · 2.05 Impact Factor

Full-text (2 Sources)

Available from
May 27, 2014