Nitrous oxide production in soil isolates of nitrate-ammonifying bacteria
Article first published online: 31 OCT 2011
© 2011 Society for Applied Microbiology and Blackwell Publishing Ltd
Environmental Microbiology Reports
Thematic issue: Taxonomy and Biodiversity
Volume 4, Issue 1, pages 66–71, February 2012
How to Cite
Stremińska, M. A., Felgate, H., Rowley, G., Richardson, D. J. and Baggs, E. M. (2012), Nitrous oxide production in soil isolates of nitrate-ammonifying bacteria. Environmental Microbiology Reports, 4: 66–71. doi: 10.1111/j.1758-2229.2011.00302.x
- Issue published online: 7 FEB 2012
- Article first published online: 31 OCT 2011
- Received 29 November, 2010; accepted 28 September, 2011.
Here we provide the first demonstration of the potential for N2O production by soil-isolated nitrate-ammonifying bacteria under different C and N availabilities, building on characterizations informed from model strains. The potential for soil-isolated Bacillus sp. and Citrobacter sp. to reduce NO3-, and produce NH4+, NO2- and N2O was examined in batch and continuous (chemostat) cultures under different C-to-NO3- ratios, NO3--limiting (5 mM) and NO3--sufficient (22 mM) conditions. C-to-NO3- ratio had a major influence on the products of nitrate ammonification, with NO2-, rather than NH4+, being the major product at low C-to-NO3- ratios in batch cultures. N2O production was maximum and accompanied by high NO2- production under C-limitation/NO3-sufficiency conditions in chemostat cultures. In media with lower C-to-NO3-N ratios (5- and 10-to-1) up to 2.7% or 5.0% of NO3- was reduced to N2O by Bacillus sp. and Citrobacter sp., respectively, but these reduction efficiencies were only 0.1% or 0.7% at higher C-to-NO3- ratios (25- and 50-to-1). As the highest N2O production did not occur under the same C-to-NO3- conditions as highest NH4+ production we suggest that a re-evaluation may be necessary of the environmental conditions under which nitrate ammonification contributes to N2O emission from soil.