|Genomic organization of C. hydrogenoformans|
Scientists at The Institute for Genomic Research (TIGR) have sequenced the genome of Carboxydothermus hydrogenoformans, a fast-growing thermophilic microbe that lives on carbon monoxide and produces hydrogen gas and CO2 as waste.
The analysis of the genome is providing insights into the metabolism of this organism that should aid those trying to develop this and similar species into systems to produce hydrogen gas biologically from water.
C. hydrogenoformans is one of the fastest-growing microbes that can convert water and carbon monoxide to hydrogen. So if you’re interested in making clean fuels, this microbe makes an excellent starting point.—Jonathan Eisen, senior author of the TIGR study, published in PLoS Genetics
C. hydrogenoformans serves as a model for studies of hydrogenogens—diverse bacteria and archaea that grow anaerobically utilizing carbon monoxide (CO) as their sole carbon source and water as an electron acceptor, producing CO2 and H2 as waste products. Organisms that make use of CO do so through enzymes called carbon monoxide dehydrogenases (CODH).
Eisen and his collaborators discovered that C. hydrogenoformans encodes five different forms of carbon monoxide dehydrogenase (CODH). Most species have no CODH and even species that utilize CO usually have only one or two.
Each form of the enzyme appears to have different cellular roles—i.e., allows the organism to use carbon monoxide in a different way.
|Locations of genes predicted to encode five CODH complexes. Possible cellular roles for four of the five CODH complexes are indicated.|
Building off this work, TIGR scientists are leveraging the information from the genome of this organism to study the ecology of microbes living in diverse hot springs, such as those in Yellowstone National Park. The C. hydrogenoformans in the study was isolated from a Russian volcanic hot-spring.
Support for the TIGR project came from the US Department of Energy, Office of Biological Energy Research.
Life in Hot Carbon Monoxide: The Complete Genome Sequence of Carboxydothermus hydrogenoformans Z-2901; Martin Wu, Qinghu Ren, A. Scott Durkin, Sean C. Daugherty, Lauren M. Brinkac, Robert J. Dodson, Ramana Madupu, Steven A. Sullivan, James F. Kolonay, William C. Nelson, Luke J. Tallon, Kristine M. Jones, Luke E. Ulrich, Juan M. Gonzalez, Igor B. Zhulin, Frank T. Robb, Jonathan A. Eisen; PLoS Genetics Vol. 1, No. 5, e65; DOI:10.1371/journal.pgen.0010065