TY - JOUR

T1 - Consumption of N2O by Flavobacterium azooxidireducens sp. nov. Isolated from Decomposing Leaf Litter of Phragmites australis (Cav.)

AU - Behrendt, Undine

AU - Spanner, Tobias

AU - Augustin, Jürgen

AU - Zak, Dominik H.

AU - Horn, Marcus A.

AU - Kolb, Steffen

AU - Ulrich, Andreas

N1 - Funding Information: The research was funded by the DFG, grant no. ZA 742/2-1, and the DFG Priority Program 1374 “Infrastructure-Biodiversity-Exploratories”, project no. 324639010. The publication of this article was supported by funds from the Leibniz Association’s Open Access Fund.

PY - 2022/11/21

Y1 - 2022/11/21

N2 - Microorganisms acting as sinks for the greenhouse gas nitrous oxide (N 2O) are gaining increasing attention in the development of strategies to control N 2O emissions. Non-denitrifying N 2O reducers are of particular interest because they can provide a real sink without contributing to N 2O release. The bacterial strain under investigation (IGB 4-14 T), isolated in a mesocosm experiment to study the litter decomposition of Phragmites australis (Cav.), is such an organism. It carries only a nos gene cluster with the sec-dependent Clade II nosZ and is able to consume significant amounts of N 2O under anoxic conditions. However, consumption activity is considerably affected by the O 2 level. The reduction of N 2O was not associated with cell growth, suggesting that no energy is conserved by anaerobic respiration. Therefore, the N 2O consumption of strain IGB 4-14 T rather serves as an electron sink for metabolism to sustain viability during transient anoxia and/or to detoxify high N 2O concentrations. Phylogenetic analysis of 16S rRNA gene similarity revealed that the strain belongs to the genus Flavobacterium. It shares a high similarity in the nos gene cluster composition and the amino acid similarity of the nosZ gene with various type strains of the genus. However, phylogenomic analysis and comparison of overall genome relatedness indices clearly demonstrated a novel species status of strain IGB 4-14 T, with Flavobacterium lacus being the most closely related species. Various phenotypic differences supported a demarcation from this species. Based on these results, we proposed a novel species Flavobacterium azooxidireducens sp. nov. (type strain IGB 4-14 T = LMG 29709 T = DSM 103580 T).

AB - Microorganisms acting as sinks for the greenhouse gas nitrous oxide (N 2O) are gaining increasing attention in the development of strategies to control N 2O emissions. Non-denitrifying N 2O reducers are of particular interest because they can provide a real sink without contributing to N 2O release. The bacterial strain under investigation (IGB 4-14 T), isolated in a mesocosm experiment to study the litter decomposition of Phragmites australis (Cav.), is such an organism. It carries only a nos gene cluster with the sec-dependent Clade II nosZ and is able to consume significant amounts of N 2O under anoxic conditions. However, consumption activity is considerably affected by the O 2 level. The reduction of N 2O was not associated with cell growth, suggesting that no energy is conserved by anaerobic respiration. Therefore, the N 2O consumption of strain IGB 4-14 T rather serves as an electron sink for metabolism to sustain viability during transient anoxia and/or to detoxify high N 2O concentrations. Phylogenetic analysis of 16S rRNA gene similarity revealed that the strain belongs to the genus Flavobacterium. It shares a high similarity in the nos gene cluster composition and the amino acid similarity of the nosZ gene with various type strains of the genus. However, phylogenomic analysis and comparison of overall genome relatedness indices clearly demonstrated a novel species status of strain IGB 4-14 T, with Flavobacterium lacus being the most closely related species. Various phenotypic differences supported a demarcation from this species. Based on these results, we proposed a novel species Flavobacterium azooxidireducens sp. nov. (type strain IGB 4-14 T = LMG 29709 T = DSM 103580 T).

KW - Clade II nosZ

KW - Flavobacterium azooxidireducenssp. nov

KW - nitrous oxide reduction

KW - non-denitrifier

KW - phylogenomic analysis

UR - http://www.scopus.com/inward/record.url?scp=85149627611&partnerID=8YFLogxK

U2 - 10.3390/microorganisms10112304

DO - 10.3390/microorganisms10112304

M3 - Article

VL - 10

JO - Microorganisms

JF - Microorganisms

SN - 2076-2607

IS - 11

M1 - 2304

ER -