Multiple Paths for Hydrogen Production by the Cyanobacterium Cyanothece
Many microbes can use solar energy to produce hydrogen. Researchers at Purdue University have now shown that a common photosynthetic ocean cyanobacterium, Cyanothece, can produce hydrogen by either direct reduction of protons using a hydrogenase enzyme or as a byproduct of conversion of nitrogen gas to ammonia (i.e. nitrogen fixation) by nitrogenase. Using a systems biology approach, the researchers demonstrated that genes and proteins involved in these distinct hydrogen production routes are coupled to separate branches of the cellular photosynthesis apparatus and are controlled by different regulatory systems that sense both light and nitrogen availability. The results of this study have been used to establish optimal bioreactor conditions and provide a number of promising metabolic engineering targets to enhance rates and yields of microbial hydrogen production.
H. Min & L. A. Sherman “Hydrogen Production by the Unicellular, Diazotrophic Cyanobacterium Cyanothece sp. Strain ATCC 51142 under Conditions of Continuous Light” Appl. Environ. Microbiol. 2010 76: 4293-4301.