Nitrous oxide emission potentials of Burkholderia species isolated from the leaves of a boreal peat moss Sphagnum fuscum*

Abstract

Using a culture-based nitrous oxide (N2O) emission assay, three active N2O emitters were isolated from Sphagnum fuscum leaves and all identified as members of Burkholderia. These isolates showed N2O emission in the medium supplemented with [Formula: see text] but not with [Formula: see text], and Burkholderia sp. SF-E2 showed the most efficient N2O emission (0.20 μg·vial(-1)·day(-1)) at 1.0 mM KNO3. In Burkholderia sp. SF-E2, the optimum pH for N2O production was 5.0, close to that of the phyllosphere of Sphagnum mosses, while the optimum temperature was uniquely over 30 °C. The stimulating effect of additional 1.5 mM sucrose on N2O emission was ignorable, but Burkholderia sp. SF-E2 upon exposure to 100 mg·L(-1) E-caffeic acid showed uniquely 67-fold higher N2O emission. All of the three N2O emitters were negative in both acetylene inhibition assay and PCR assay for nosZ-detection, suggesting that N2O reductase or the gene itself is missing in the N2O-emitting Burkholderia.

Estimating global nitrous oxide emissions by lichens and bryophytes with a process-based productivity model

“…Another option is that bacteria growing on lichen and moss cushions are responsible for the emissions of N 2 O. This second option is supported by a recently published study, wherein several strains of the bacterial genus Burkholderia, which were shown to emit N 2 O, were isolated from the boreal peat moss Sphagnum fuscum (Nie et al, 2015). While Lenhart et al (2015) describe that the substrate, which the organisms grew on, was thoroughly removed, further cleaning steps to remove potential bacterial colonies have not been conducted.…”

Burkholderiaceae Are Key Acetate Assimilators During Complete Denitrification in Acidic Cryoturbated Peat Circles of the Arctic Tundra

“…Isolates from Sphagnum mosses that cover a Finnish acidic mire included isolates from Burkholderia sp. that have their optimum pH at around 5 and emit N 2 O, when NO 3 − was supplemented during incubation (Nie et al, 2015). All isolates possessed the narG gene for nitrate reduction, but amplification of either typical or atypical nosZ gene was not successful, suggesting these Burkholderia sp.…”

An Unknown Non-denitrifier Bacterium Isolated from Soil Actively Reduces Nitrous Oxide under High pH Conditions

“…Winograsky's mineral solution containing 0.5% (w/v) sucrose and 5 mM KNO 3 (0.52 g L -1 ) was used as the medium in the culture-based N 2 O reduction assay (Hara et al, 2009;Nie et al, 2015). Since pH plays a key role in the emission of N 2 O (Nie et al, 2015), the pH of the solution was adjusted to various values (4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, and 9.0) using 2 M H 2 SO 4 and 1 M KOH that was gelled with 0.5% (w/v) gellan gum and then autoclaved. The same medium was used in subsequent experiments.…”

“…The same medium was used in subsequent experiments. N 2 O levels were measured as described in a previous study (Nie et al, 2015). N 2 O was emitted in the culture at pH 4.5-7.5 ( Fig.…”

“…To screen for N 2 O-consuming microorganisms, colonies were isolated as described in a previous study (Nie et al, 2015). Fifteen distinguishable bacterial colonies, marked A to O, were identified.…”