Paper Report for: Mania_2014_Environ.Microbiol_16_3196
Reference
Title: The nitrate-ammonifying and nosZ-carrying bacterium Bacillus vireti is a potent source and sink for nitric and nitrous oxide under high nitrate conditions Mania D, Heylen K, van Spanning RJ, Frostegard A Ref: Environ Microbiol, 16:3196, 2014 : PubMed
Several Gram-positive bacteria carry genes for anaerobic reduction of NO3(-) via NO2(-) to NH4(+) or gaseous nitrogen compounds, but the processes are understudied for these organisms. Here, we present results from a whole-genome analysis of the soil bacterium Bacillus vireti and a phenotypic characterization of intermediate and end-products, formed under anoxic conditions in the presence of NO3(-). Bacillus vireti has a versatile metabolism. It produces acetate, formate, succinate and lactate from fermentation and performs dissimilatory nitrate reduction via NO2(-) to ammonium (DNRA) using NrfA, while NirB may detoxify NO2(-) in the cytoplasm. Moreover, it produces NO from an unknown source and reduces it via N2O to N2 using two enzymes connected to denitrification: an unusual NO reductase, qCuA Nor encoded by cbaA, and a z-type N2O reductase, encoded by nosZ. In batch cultures, B. vireti reduced all NO3(-) to NO2(-) before the NO2(-) was reduced further. The quantities of all products varied with the initial NO3(-) concentration. With 5 mM NO3(-) , 90% was reduced to NH4 (+) while with >/= 20 mM NO3(-), 50% was reduced to NO, N2O and N2. This organism is thus an aggressive NO2(-) accumulator and may act as a net source and sink of NO and N2O.
Mania D, Heylen K, van Spanning RJ, Frostegard A (2014) The nitrate-ammonifying and nosZ-carrying bacterium Bacillus vireti is a potent source and sink for nitric and nitrous oxide under high nitrate conditions Environ Microbiol16: 3196-210
Mania D, Heylen K, van Spanning RJ, Frostegard A (2014) Environ Microbiol16: 3196-210