August 1, 2011.
Rubrivivax gelatinosus CBS is a purple non-sulfur photosynthetic bacterium that has been found to produce substantial amounts of Hydrogen (H2) which could be used as a clean burning biofuel. CBS has been known to grow on a variety of carbon sources, but it is unknown as to which carbon sources it has the greatest potential to use, and this understanding could be helpful in engineering future strains of the bacteria. Hydrogen production in CBS occurs when carbon monoxide (CO) is present and is presumed to be under the control of the RcoM transcription factor. When CBS wild-type strains were grown in different carbon sources it was found that the bacteria were able to use the organic acid substrates much more successfully than the sugar substrates. This is useful in that organic acids are often waste products and we can use those products as a nutrient to support the growth of CBS. When the rcoM gene was deleted from the CBS bacteria, growth with CO in the mutant strain ceased, and H2 production and protein production were greatly reduced when compared to the wild-type. Understanding how RcoM impacts the CO to H2 pathway will allow us to better engineer the pathway to further increase the production of H2 in CBS.
Environmental Microbiology and Microbial Ecology
National Renewable Energy Laboratory (NREL)
This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation.