Carboxydotrophic growth of Geobacter sulfurreducens.
This study shows that Geobacter sulfurreducens grows on carbon monoxide (CO) as electron donor with fumarate as electron acceptor. Geobacter sulfurreducens was tolerant to high CO levels, with up to 150 kPa in the headspace tested. During growth, hydrogen was detected in very slight amounts (∼5 Pa). In assays with cell-free extract of cells grown with CO and fumarate, production of hydrogen from CO was not observed, and hydrogenase activity with benzyl viologen as electron acceptor was very low. Taken together, this suggested that CO is not utilized via hydrogen as intermediate. In the presence of CO, reduction of NADP(+) was observed at a rate comparable to CO oxidation coupled to fumarate reduction in vivo. The G. sulfurreducens genome contains a single putative carbon monoxide dehydrogenase-encoding gene. The gene is part of a predicted operon also comprising a putative Fe-S cluster-binding subunit (CooF) and a FAD-NAD(P) oxidoreductase and is preceded by a putative CO-sensing transcription factor. This cluster may be involved in a novel pathway for CO oxidation, but further studies are necessary to ascertain this. Similar gene clusters are present in several other species belonging to the Deltaproteobacteria and Firmicutes, for which CO utilization is currently not known.
Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands. jeanine.geelhoed@nioz.nl.|NIOZ Royal Netherlands Institute for Sea Research, Korringaweg 7, 4401 NT, Yerseke, The Netherlands. jeanine.geelhoed@nioz.nl.
Jeanine S
JS
Geelhoed
Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.|Centre for Biomolecular Sciences, University of Nottingham, University Park, NG7 2EF, Nottingham, UK.
Anne M
AM
Henstra
Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.
Alfons J M
AJ
Stams
D001594:Benzyl Viologen; D002248:Carbon Monoxide / Q000378:metabolism*; D020564:Deltaproteobacteria / Q000235:genetics; D005290:Ferric Compounds; D000068536:Bacillota / Q000235:genetics; D005650:Fumarates; D016680:Genome, Bacterial; D045302:Geobacter / Q000201:enzymology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism; D005810:Multigene Family; D009876:Operon; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics
D005290:Ferric Compounds; D005650:Fumarates; D001594:Benzyl Viologen; D002248:Carbon Monoxide; D006859:Hydrogen; D010088:Oxidoreductases
Carbon monoxide; Carboxydotrophic growth; Fumarate reduction; Geobacter sulfurreducens; Microbial metabolism