Susceptibility of Ammonia-Oxidizing Bacteria to Nitrification Inhibitors

Abstract

Activity of nitrification inhibitors to several typical ammonia-oxidizing bacteria isolated recently, i. e. Nitrosococcus, Nitrosolobus, Nitrosomonas, Nitrosospira and Nitrosovibrio species was assayed using 2-amino-4-methyl-6-trichloromethyl-1,3,5-triazine (MAST), 2-amino- 4-tribromomethyl-6-trichloromethyl-1,3,5-triazine (Br-MAST), 2-chloro-6-trichloromethylpyridine (nitrapyrin) and others, and compared to confirm the adequate control of ammoniaoxidizing bacteria by the inhibitors. The order of activity of the inhibitors to 13 species of ammonia-oxidizing bacteria examined was approximately summarized as Br-MAST ≥ nitrapyrin ≥ MAST > other inhibitors. Two Nitrosomonas strains, N. europaea ATCC25978 and N. sp. B2, were extremely susceptible to Br-MAST, exhibiting a pI50 ≥ 6.40. These values are the position logarithms of the molar half-inhibition concentration. The 16S rRNA gene sequence similarity for the highly susceptible 4 strains of genus Nitrosomonas was 94% to 100% of Nitrosomonas europaea, although those of the less susceptible 3 strains of ammoniaoxidizing bacteria, Nitrosococcus oceanus C-107 ATCC19707, Nitrosolobus sp. PJA1 and Nitrosolobus multiformis ATCC25196, were 77.85, 91.53 and 90.29, respectively. However, no clear correlation has been found yet between pI50-values and percent similarity of 16S rRNA gene sequence among ammonia-oxidizing bacteria.

Nitrification inhibitors effectively target N2O‐producing Nitrosospira spp. in tropical soil

“…(Nitrosovibrio RY3C), based on the decrease in abundance of these OTUs in soils with the nitrification inhibitors in comparison with the urea treatment and the correlation of these OTUs with N 2 O emissions. The Nitrosovibrio RY3C species was originally isolated from avocado rhizosphere and its nitrifying activity was susceptible to DCD (Matsuba et al, 2003). To our knowledge, just one other study has identified Nitrosospira spp.…”

Biological Nitrification Inhibition—A Novel Strategy to Regulate Nitrification in Agricultural Systems

“…There are a number of reasons why inhibitors released from roots (i.e., BNIs; estimated as BNI-activity) may be ineffective in certain soil environments. For example, the variability among soils in indigenous populations of AOB (Matsuba et al, 2003) can make BNI-activity, which is determined using a single strain of N. europaea in the bioassay, functionally ineffective in certain soils. In addition, the soil chemical and physical properties could impair the BNI-activity from functioning in some agro-ecosystems.…”

Comparison of thein vitroactivity of novel and established nitrification inhibitors applied in agriculture: challenging the effectiveness of the currently available compounds

“…Previous soil studies also demonstrated that DCD was not suppressive to Nitrospira - and Nitrobacter-like bacteria at levels up to 150 μmol Kg -1 soil (61, 62, 49). To date there are no data, either in vitro or in soil, regarding the impact of DMPP or EQ and its derivatives on NOB, while NP applied at rates up to 50 μM did not inhibit the nitrite-oxidizing activity of the widely distributed Nitrobacter agilis (20). We provide the first evidence for the toxicity of NIs on a Nitrobacter sp.…”