Consumption of atmospheric hydrogen during the life cycle of soil‐dwelling actinobacteria. Issue 3 (20th November 2013)

• Record Type: Journal Article
• Authors: Meredith, Laura K.; Rao, Deepa; Bosak, Tanja; Klepac‐Ceraj, Vanja; Tada, Kendall R.; Hansel, Colleen M.; Ono, Shuhei; Prinn, Ronald G.
• Is Part Of: Environmental microbiology reports. Volume 6:Issue 3(2014)
• Page Start: 226
• Page End: 238
• Publication Date: 2013-11-20
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; Electronic journals; 579.17
• DOI: 10.1111/1758-2229.12116
• Languages: English
• ISSNs: 1758-2229

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Microbe‐mediated soil uptake is the largest and most uncertain variable in the budget of atmospheric hydrogen (H<sub>2</sub>). The diversity and ecophysiological role of soil microorganisms that can consume low atmospheric abundances of H<sub>2</sub> with high‐affinity [NiFe]‐hydrogenases is unknown. We expanded the library of atmospheric H<sub>2</sub>‐consuming strains to include four soil Harvard Forest Isolate (HFI) <italic>S</italic><italic>treptomyces</italic> spp., <italic>S</italic><italic>treptomyces cattleya</italic> and <italic>R</italic><italic>hodococcus equi</italic> by assaying for high‐affinity hydrogenase (<italic>hhyL</italic>) genes and quantifying H<sub>2</sub> uptake rates. We find that aerial structures (hyphae and spores) are important for <italic>S</italic><italic>treptomyces</italic> H<sub>2</sub> consumption; uptake was not observed in <italic>S</italic><italic>. griseoflavus</italic> Tu4000 (deficient in aerial structures) and was reduced by physical disruption of <italic>S</italic><italic>treptomyces</italic> sp. HFI8 aerial structures. H<sub>2</sub> consumption depended on the life cycle stage in developmentally distinct actinobacteria: <italic>S</italic><italic>treptomyces</italic> sp. HFI8 (sporulating) and <italic>R</italic><italic>. equi</italic> (non‐sporulating, non‐filamentous). Strain HFI8 took up H<sub>2</sub> only after forming aerial hyphae and sporulating, while <italic>R</italic><italic>. equi</italic> only consumed H<sub>2</sub> in the late exponential and stationary phase. These observations suggest that conditions favouring H<sub>2</sub> uptake by actinobacteria are associated with energy and nutrient limitation. Thus, H<sub>2</sub> may be an important energy source for soil microorganisms inhabiting systems in which nutrients are frequently limited.</p> </abstract>