Inhibition of Ammonium Oxidation by Nitrapyrin in Soil and Liquid Culture

Abstract

Inhibition of growth of axenic cultures of Nitrosomonas europaea by nitrapyrin was investigated in liquid culture and in soil. In liquid culture, exponentially growing cells were more sensitive than stationary-phase cells, possibly due to a requirement for uptake of nitrapyrin, metabolism of nitrapyrin, or both before inhibition. Differences in sensitivity were observed between the parent strain and two strains, spi and sp2, that were selected through repeated subculturing. These differences were reflected in the length of the lag period induced by nitrapyrin and in the specific growth rate and were due to different bactericidal and bacteriostatic effects. Soil provided significant protection from inhibition, with concentrations of nitrapyrin approximately one order of magnitude greater than those required for equivalent inhibition in liquid culture. The data show that strain differences alone do not explain differences in sensitivity between nitrification in soil and in liquid culture and suggest that the inhibitor may be more effective against actively nitrifying soils.

Responses of the terrestrial ammonia-oxidizing archaeonCa. Nitrososphaera viennensis and the ammonia-oxidizing bacteriumNitrosospira multiformisto nitrification inhibitors

“…There are various nitrification inhibitors available, and some of them have been used in soil management over years in several countries (Trenkel, 1997;Di & Cameron, 2005;Moir et al, 2007;Singh & Verma, 2007). The inhibitory effect of the selected six reagents has been mainly explored on AOB or in some cases also on AOA enrichment cultures (Hooper & Terry, 1973;Powell & Prosser, 1986;Amberger, 1989;Zacherl & Amberger, 1990;Hatzenpichler et al, 2008;Jung et al, 2011;Kim et al, 2012;Mosier et al, 2012a).…”

Phylogeny of nitrite reductase (nirK) and nitric oxide reductase (norB) genes fromNitrosospiraspecies isolated from soil

“…The betaproteobacterial AOB strains studied (Table 1) were grown in static liquid batch culture at 28 o C, as described by Keen & Prosser (1987) in modified Skinner and Walker medium (Powell & Prosser, 1986). All cultures were checked for heterotrophic bacterial contamination by plating on nutrient agar and by PCR amplification and denaturing gradient gel electrophoresis analysis.…”

Inhibition of phenol on the rates of ammonia oxidation by Nitrosomonas europaea grown under batch, continuous fed, and biofilm conditions

“…A study of N. europaea biofilms reported that established biofilms were less inhibited by the nitrification inhibitor nitrapyrin and exhibited reduced growth rates compared to suspended cells (Powell and Prosser, 1992). Additionally, exponential cells of N. europaea exhibited greater inhibition of NH 3 oxidation when exposed to nitrapyrin compared to stationary-phase cultures (Powell and Prosser, 1986). A study of cadmium inhibition of N. europaea, based on O 2 uptake rates, demonstrated that cells in stationary phase were less inhibited over time than during exponential growth (Chandran and Love, 2008).…”