Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Society for Applied Microbiology for personal use, not for redistribution. The definitive version was published in Environmental Microbiology Reports 6 (2014): 226-238, doi:10.1111/1758-2229.12116.
Description:
Microbe-mediated soil uptake is the largest and most uncertain variable in the budget of
atmospheric hydrogen (H2). The diversity and ecophysiological role of soil microorganisms that
can consume low atmospheric abundances of H2 with high-affinity [NiFe]-hydrogenases is unknown. We expanded the library of atmospheric H2-consuming strains to include four soil
Harvard Forest Isolate (HFI) Streptomyces spp., Streptomyces cattleya, and Rhodococcus equi by
assaying for high-affinity hydrogenase (hhyL) genes and quantifying H2 uptake rates. We find
that aerial structures (hyphae and spores) are important for Streptomyces H2 consumption; uptake
was not observed in Streptomyces griseoflavus Tu4000 (deficient in aerial structures) and was
reduced by physical disruption of Streptomyces sp. HFI8 aerial structures. H2 consumption
depended on the life cycle stage in developmentally distinct actinobacteria: Streptomyces sp.
HFI8 (sporulating) and R. equi (non-sporulating, non-filamentous). Strain HFI8 took up H2 only
after forming aerial hyphae and sporulating, while R. equi only consumed H2 in the late
exponential and stationary phase. These observations suggest that conditions favoring H2 uptake
by actinobacteria are associated with energy and nutrient limitation. Thus, H2 may be an
important energy source for soil microorganisms inhabiting systems in which nutrients are
frequently limited.
Description:
L.K.M. was
supported by from the following funding sources: NSF Graduate Research Fellowship, multiple grants from NASA to MIT for the Advanced Global Atmospheric Gases Experiment (AGAGE),
MIT Center for Global Change Science, MIT Joint Program on the Science and Policy of Global
Change, MIT Martin Family Society of Fellows for Sustainability, MIT Ally of Nature Research
Fund, MIT William Otis Crosby Lectureship, and MIT Warren Klein Fund. D. R. was funded
through MIT Undergraduate Research Opportunities Program (UROP) with support from the
Lord Foundation and Jordan J. Baruch Fund (1947) and was supported by the Harvard Forest
REU Program.
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
Permalink
