Production of Hydrogen Gas from Light and the Inorganic Electron Donor Thiosulfate by Rhodopseudomonas palustris

A challenge for photobiological production of hydrogen gas (H₂) as a potential biofuel is to find suitable electron-donating feedstocks. Here, we examined the inorganic compound thiosulfate as a possible electron donor for nitrogenase-catalyzed H₂ production by the purple nonsulfur phototrophic bact...

Full description

Saved in:
Bibliographic Details
Published in:Applied and Environmental Microbiology 2010-12, Vol.76 (23), p.7717-7722
Main Authors: Huang, Jean J, Heiniger, Erin K, McKinlay, James B, Harwood, Caroline S
Format: Article
Language:English
Subjects:
Acetates - metabolism
Acetic acid
Bicarbonates - metabolism
Biodiesel fuels
Biological and medical sciences
Biomass
Cell culture
Cells
Electrons
Fundamental and applied biological sciences. Psychology
Gases - metabolism
Gram-negative bacteria
Hydrogen - metabolism
Light
Microbiology
Nitrogen - metabolism
Nitrogenase - metabolism
Oxidation-Reduction
Physiology
Rhodopseudomonas - metabolism
Rhodopseudomonas palustris
Succinic Acid - metabolism
Thiosulfates - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A challenge for photobiological production of hydrogen gas (H₂) as a potential biofuel is to find suitable electron-donating feedstocks. Here, we examined the inorganic compound thiosulfate as a possible electron donor for nitrogenase-catalyzed H₂ production by the purple nonsulfur phototrophic bacterium (PNSB) Rhodopseudomonas palustris. Thiosulfate is an intermediate of microbial sulfur metabolism in nature and is also generated in industrial processes. We found that R. palustris grew photoautotrophically with thiosulfate and bicarbonate and produced H₂ when nitrogen gas was the sole nitrogen source (nitrogen-fixing conditions). In addition, illuminated nongrowing R. palustris cells converted about 80% of available electrons from thiosulfate to H₂. H₂ production with acetate and succinate as electron donors was less efficient (40 to 60%), partly because nongrowing cells excreted the intermediary metabolite α-ketoglutarate into the culture medium. The fixABCX operon (RPA4602 to RPA4605) encoding a predicted electron-transfer complex is necessary for growth using thiosulfate under nitrogen-fixing conditions and may serve as a point of engineering to control rates of H₂ production. The possibility to use thiosulfate expands the range of electron-donating compounds for H₂ production by PNSBs beyond biomass-based electron donors.
ISSN:0099-2240
1098-5336
1098-6596
DOI:10.1128/AEM.01143-10