Desulfurococcus fermentans
Jacob Glotfelty

Desulfurococcus fermentans is a prokaryotic microbe that was found in a pit of a collapsed volcano in a freshwater hot spring in the Kamchatka Peninsula in Russia.  The microbe is an obligately anaerobic, hyperthermophilic, chemoheterotrophic archeon in the genus Desulfurococcus.  The bacteria are shaped as coccus shapes with one long flagellum on each cell.  The temperature range for growth is 63 to 89 degrees Celsius with the optimum around 80 degrees Celsius.  The pH range for the microbe is 4.8 to 6.8 pH with an optimum pH of around 6.  This microbe also requires to be grown on medium involving starch but not involvig some simple sugars like glucose, xylose, mannitol and sorbitol.

This microbe was very interesting to me for what it does.  D. fermentans like all of the other species in the genus ferments cellulose and starch but unlike all of the others in the genus, can produce hydrogen in the presence of hydrogen without an inhibition of growth.  Also, D. fermentans is not affected by either sulfur or hydrogen thus not requiring sulfur or being poisoned by hydrogen.  All of the other microbes in the family produce hydrogen sulfide instead of hydrogen so it does not inhibit their growth.  Because of this, using this microbe in the production of hydrogen for use as an alternative energy is very enticing.  Being able to make hydrogen without producing carbon dioxide makes this a very environmentally friendly method.  Also, since the microbe optimally grows around 80 degrees Celsius, most of the other microbes cannot survive at those temperatures thus not contaminating the bacteria.

Because of this potential for alternative energy production, researchers are motivated to sequence the Desulfurococcus species.  After they are able to sequence the species, they are going to be able to investigate what differences in the genomes highlight differences in their metabolism since each microbe in the species is closely related.  Comparing the genomes of the four microbes in the genus will allow for a rapid development of hypotheses about the special molecular tools that allow for starch degradation and the ability to ferment and produce hydrogen.  This study will also reveal the differences in proton reduction and sulfur reduction and define those two fermentation pathways.  With this information, it will help define the evolutionary and metabolic relationships of this species and how they differ from other species.

As Biswarup Mukhopadhyay, an assistant professor at the Virginia Bioinformatics Institute, said, “Advance energy production could be quite an understatement.  Imagine making available large quantities of biomass based free hydrogen for fuel production.  This could make fuel production a very different matter than worrying about oil prices.”  Being able to convert an abundant waste product into fuel for no cost would really change how the world sees fuel production.  Being able to use pathways that microbes have been able to use for millions of years to basically create fuel from nothing would be a big step into switching to alternative energy production.

Sources

http://newenergyandfuel.com/http:/newenergyandfuel/com/2008/07/11/a-bacterium-that-makes-hydrogen-from-cellulose/

http://www.enn.com/energy/article/37589

http://www.jgi.doe.gov/sequencing/why/desulfurococcus.html

http://ijs.sgmjournals.org/cgi/content/abstract/55/3/995

 

*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.

 

Return to Missouri S&T Microbiology HomePage Go to DJW's HomePage