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Consumption of atmospheric hydrogen during the life cycle of soil‐dwelling actinobacteria
Author(s) -
Meredith Laura K.,
Rao Deepa,
Bosak Tanja,
KlepacCeraj Vanja,
Tada Kendall R.,
Hansel Colleen M.,
Ono Shuhei,
Prinn Ronald G.
Publication year - 2014
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12116
Subject(s) - actinobacteria , hypha , microorganism , spore , biology , nutrient , botany , bacteria , ecology , genetics , 16s ribosomal rna
Summary Microbe‐mediated soil uptake is the largest and most uncertain variable in the budget of atmospheric hydrogen ( H 2 ). The diversity and ecophysiological role of soil microorganisms that can consume low atmospheric abundances of H 2 with high‐affinity [ NiFe ]‐hydrogenases is unknown. We expanded the library of atmospheric H 2 ‐consuming strains to include four soil H arvard F orest I solate ( HFI ) S treptomyces spp., S treptomyces cattleya and R hodococcus equi by assaying for high‐affinity hydrogenase ( hhyL ) genes and quantifying H 2 uptake rates. We find that aerial structures (hyphae and spores) are important for S treptomyces H 2 consumption; uptake was not observed in S . griseoflavus T u4000 (deficient in aerial structures) and was reduced by physical disruption of S treptomyces sp. HFI 8 aerial structures. H 2 consumption depended on the life cycle stage in developmentally distinct actinobacteria: S treptomyces sp. HFI 8 (sporulating) and R . equi (non‐sporulating, non‐filamentous). Strain HFI 8 took up H 2 only after forming aerial hyphae and sporulating, while R . equi only consumed H 2 in the late exponential and stationary phase. These observations suggest that conditions favouring H 2 uptake by actinobacteria are associated with energy and nutrient limitation. Thus, H 2 may be an important energy source for soil microorganisms inhabiting systems in which nutrients are frequently limited.