A nitrite-oxidising bacterium constitutively consumes atmospheric hydrogen

0560709 - BC 2023 RIV GB eng J - Článek v odborném periodiku
Leung, P.M. - Daebeler, Anne - Chiri, E. - Hanchapola, I. - Gillett, D.L. - Schittenhelm, R.B. - Daims, H. - Greening, Ch.
A nitrite-oxidising bacterium constitutively consumes atmospheric hydrogen.
The ISME Journal. Roč. 16, č. 9 (2022), s. 2213-2219. ISSN 1751-7362. E-ISSN 1751-7370
Grant CEP: GA ČR(CZ) GM21-17322M
Institucionální podpora: RVO:60077344
Klíčová slova: nitrite-oxidising bacterium * Nitrospira * atmospheric H2 oxidation
Obor OECD: Microbiology
Impakt faktor: 11, rok: 2022
Způsob publikování: Open access
https://www.nature.com/articles/s41396-022-01265-0.pdf

Chemolithoautotrophic nitrite-oxidising bacteria (NOB) of the genus Nitrospira contribute to nitrification in diverse natural environments and engineered systems. Nitrospira are thought to be well-adapted to substrate limitation owing to their high affinity for nitrite and capacity to use alternative energy sources. Here, we demonstrate that the canonical nitrite oxidiser Nitrospira moscoviensis oxidises hydrogen (H2) below atmospheric levels using a high-affinity group 2a nickel-iron hydrogenase [Km(app) = 32 nM]. Atmospheric H2 oxidation occurred under both nitrite-replete and nitrite-deplete conditions, suggesting low-potential electrons derived from H2 oxidation promote nitrite-dependent growth and enable survival during nitrite limitation. Proteomic analyses confirmed the hydrogenase was abundant under both conditions and indicated extensive metabolic changes occur to reduce energy expenditure and growth under nitrite-deplete conditions. Thermodynamic modelling revealed that H2 oxidation theoretically generates higher power yield than nitrite oxidation at low substrate concentrations and significantly contributes to growth at elevated nitrite concentrations. Collectively, this study suggests atmospheric H2 oxidation enhances the growth and survival of NOB amid variability of nitrite supply, extends the phenomenon of atmospheric H2 oxidation to an eighth phylum (Nitrospirota), and reveals unexpected new links between the global hydrogen and nitrogen cycles. Long classified as obligate nitrite oxidisers, our findings suggest H2 may primarily support growth and survival of certain NOB in natural environments.
Trvalý link: https://hdl.handle.net/11104/0340124