Effects of repeated application of sulfadiazine-contaminated pig manure on the abundance and diversity of ammonia and nitrite oxidizers in the root-rhizosphere complex of pasture plants under field conditions

Abstract

In a field experiment, the impact of repeated application of the antibiotic sulfadiazine (SDZ)-contaminated pig manure was assessed on functional microbial communities involved in ammonia and nitrite oxidation in the root-rhizosphere complexes (RRCs) of diverse plants composing a pasture. We surveyed the abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) as well as Nitrobacter- and Nitrospira-like nitrite-oxidizing bacteria (NOB) by quantitative PCR (qPCR), and the diversity of amoA AOA and Nitrobacter-like nxrA amplicons using a cloning-sequencing approach. Whereas the first SDZ-contaminated manure application caused only slight effects on the investigated microbial communities and did not change the diversity and abundance pattern significantly, the second application of SDZ-contaminated manure induced an up to 15-fold increased ratio of AOA:AOB and a reduction of nrxA genes. The diversity of AOA amoA increased after the second application of SDZ-contaminated manure compared to the control treatment whereas a clear reduction of nrxA OTUs was visible in the same samples. The results indicate that the application of SDZ may principally affect nitrite oxidation by NOB and alternative pathways like nitrite reduction might be favored under these conditions.

Consequences of minimum soil tillage on abiotic soil properties and composition of microbial communities in a shallow Cambisol originated from fluvioglacial deposits

“…Only archaea were not affected by the different forms of tillage management. The latter observation, which is in accordance to our initial hypothesis, can be most likely explained by the dominance of ammonia oxidizers in most upland soils, which are very stable in response to shifts in environmental conditions which has been shown in a large number of studies including the effects of antibiotics (Schauss et al 2009), land use intensity (Bru et al 2011;Meyer et al 2013) or heavy metal content (Ollivier et al 2013). Only at the sites, where a strong SOC accumulation might be expected in response to shifts in tillage management, archaea might also be affected, as a result of the autotrophic lifestyle of ammonia oxidizers, which has been recently shown by Souza et al (2013) using a metagenomic approach.…”

Ammonium sorption and ammonia inhibition of nitrite-oxidizing bacteria explain contrasting soil N2O production

“…For example, the partitioning of NH 4 + between soil surfaces and solution could regulate solution-phase levels and therefore influence nitrifier activity and NH 3 toxicity 15 . Simultaneous quantification of genes associated with activities of NOB, AOB and NH 4 + oxidizing archaea in soil following amendment with N has been reported in a few studies 16 17 18 , but more data are needed to understand the role of nitrifier responses in regulating NO 2 − and N 2 O dynamics. Limited understanding of these and other factors limits our ability to predict NO 2 − dynamics for a particular soil, management practice, or climate condition, and our ability to predict N 2 O emissions resulting from NO 2 − transformations 19 20 .…”

Long‐term straw returning affectsNitrospira‐like nitrite oxidizing bacterial community in a rapeseed‐rice rotation soil

“…For example, anyone can get more nutrients and living space in a given medium will certainly function as a dominant member in the microcosm. Several previous studies showed those spatial niche differentiation patterns of a functionally redundant organisms often co‐exist at the same spatial scale , or differ in their spatial distribution .…”