Carboxydothermus hydrogenoformans
Benjamin Huffman

Carboxydothermus. hydrogenoformans is a very interesting gram-positive bacterium that was isolated from a hot spring on one of Russia’s volcanic islands back in 1991. It is of course anaerobic because it lives under the water as well as thermophilic because it lives in hot springs, performing at an optimal temperature of 70°C. This particular bacterium is special because it has the ability to use carbon monoxide and water as its main source of energy and it forms Hydrogen gas as a byproduct. This is one of the only organisms of its kind and because of its unique characteristics it has potential to provide a promising future for alternative fuel sources.

C. hydrogenoformans’ genome has been fully sequenced since 2005 and has been found that its genes code for five different carbon monoxide dehydrogenase complexes. Most organisms that are similar to C. hydrogenoformans only have one carbon monoxide dehydrogenase complex and is thus one reason why it can grow much more rapidly and efficiently than any other organism of its type. Because of this organism’s amazing ability to convert carbon monoxide as well as carbon dioxide into Hydrogen gas it has many uses in the industrial world.

Researchers have begun suggesting use of this organism for the production of Hydrogen for a biofuel source. Another plus is that the carbon monoxide waste from some industrial processes can be used to feed C. hydrogenoformans and then they, in turn, would produce the Hydrogen needed for biofuels. This organism has actually become the frontrunner into possible Hydrogen fuel production methods and results look promising.

This organism was previously thought to not contain the ability to sporulate but that has been proven wrong in current times.C. hydrogenoformans has recently been found to have some genes that are used in spore production but it lacks many of the genes that other bacterium have. This has created an area of research into the study of the minimal amount of genes needed for sporulation. This minimal model for sporulation research is mainly directed to learn how and spores are made for anthrax as a means to try and provide protection against it.

Researchers once believed that C. hydrogenoformans are strictly dependent on carbon monoxide. One reason suggesting this is that it has no sugar phosphotransferase system and encodes no complete pathway for sugar compound degradation. But there are more genes that suggest heterotrophic capabilities. These include transporters encoded in the genome that are predicted to import diverse carbon compounds including formate, glycerol, lactate, and some amino acids. Another heterotrophic capability includes two chemotaxi systems. Studies have shown that growth of this organism is significantly slower if a heterotrophic pathway is chosen and to add to this no one knows what the electron acceptors are likely to be coupled to in this pathway.

More research is sure to come from this truly one of a kind microbe.

An electron micrograph of a C. hydrogenoformans endospore.

Sources

http://www.sciencedaily.com/releases/2005/12/051204103616.htm
http://microbewiki.kenyon.edu/index.php/Carboxydothermus_hydrogenoformans
http://en.wikipedia.org/wiki/Carboxydothermus_hydrogenoformans http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0010065

*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.

 

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