Abstract
The desire to understand and distinguish the relative growth and activity of ammonia oxidising archaea (AOA) and ammonia oxidising bacteria (AOB) in soil nitrification has increased the search for selective inhibitors of these two groups. This study aimed to investigate the potency and specificity of simvastatin as a specific AOA inhibitor in pure cultures and in soil and to determine the effect of AOA inhibition on both ammonia oxidation activity and growth of AOB, under the hypothesis that AOB growth is higher when competition for NH4+ from AOA is removed. Simvastatin selectively inhibited pure cultures of all tested AOA at concentrations of 8 – 100 µM. In soil microcosms incubated for 21 days with low and high NH4+ concentrations, AOA but not AOB were selectively inhibited by simvastatin in both acidic (pH 4.5) and near-neutral (pH 6.5) soils. Additionally, growth of AOB significantly increased at both NH4+ concentrations following inhibition of AOA by simvastatin, suggesting that competition for substrate between AOA and AOB is a key factor restraining AOB growth in NH4+ -limitedsoils. Simvastatin can therefore be used as a selective AOA inhibitor to investigate kinetic characteristics of AOB in soils and to study competition between AOA and AOB in complex environments.
Original language | English |
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Article number | 107673 |
Number of pages | 8 |
Journal | Soil Biology and Biochemistry |
Volume | 141 |
Early online date | 18 Nov 2019 |
DOIs | |
Publication status | Published - 1 Feb 2020 |
Bibliographical note
AcknowledgementsThe authors would like to thank Dr Robin Walker for access to the experimental plots at the SRUC, Craibstone Estate, Aberdeen. JZ was funded by a Natural Environment Research Council (NERC) grant (NE/K016342/1), MOB by a University of Aberdeen Elphinstone Scholarship and by TETFund through Adekunle Ajasin University Akungba (AAUA) Nigeria, YM by a NERC grant (NE/R001529/1) and CGR by a Royal Society University Research Fellowship (URF150571).
Keywords
- activity
- nitrification
- inhibitor
- ammonia
- Thaumarchaeota
- stable isotope probing
- Ammonia
- Stable isotope probing
- Nitrification
- Activity
- Inhibitor