Measuring the Success of a PCC. 6803d-Sufr Knockout at the Transcriptional Level

Used in crucial processes such as ammonia synthesis and petroleum refining, hydrogen has great importance as a commodity chemical.  Hydrogen also holds promise as an alternative fuel since it has one of the highest energy to mass ratios and cleanest combustion of any fuel.  Currently 95% of Hydrogen in the U.S. is generated through steam reforming of methane which both perpetuates dependence on fossil fuels and pollutes the environment through carbon dioxide emissions. ¹  The Swartz lab seeks a solution: hydrogen production powered by photosynthesis.  It is hoped that this can be accomplished by “hardwiring” photosystem I to a hydrogenase via a ferrodoxin that docks to both proteins.   The photosynthetic organism we have chosen is the model organism Synechocystis sp. PCC 6803.  The hydrogenase and ferredoxin we are currently considering originate from Clostridium pasteurianum.   We expect that the rate of hydrogen production will strongly depend on the levels of active hydrogenase and ferredoxin in 6803 which will in turn depend on the availability of assembled iron-sulfur clusters.  The Suf operon in thought to be the most important for iron-sulfur cluster assembly in cyanobacteria.  The Suf operon is usually regulated by an upstream repressor, SufR.  Therefore, to attempt to increase the iron-sulfur cluster availability we have created a DSufR knockout of 6803, and now attempt to show the success of this knockout at the transcriptional level.

 

1) "Natural Gas Reforming." U.S. Department of Energy, n.d. Web. 31 May 2013.