- Number 376 |
- November 19, 2012
Sustained hydrogen production from cyanobacteria achieved in the presence of oxygen
Cultures of the microbe Cyanothece sp.
ATCC 51142 are being generated from a
novel photobioreactor designed at
Pacific Northwest National Laboratory.
As society's demand for renewable energy grows, the role of hydrogen continues to expand—both as a way to store renewable energy and create hydrocarbon fuel. However, producing it inexpensively and in sufficient amounts without using fossil fuels remains a challenge.
Scientists at DOE’s Pacific Northwest National Laboratory made headway toward that challenge by achieving uninterrupted hydrogen production from a photosynthetic microorganism for more than 100 hours in the presence of oxygen (O2). This achievement debunked the long-held belief that O2 inhibition of hydrogen (H2) production in traditional cultivation systems would make sustained H2 production during photosynthesis impossible.
It became possible because the PNNL team grew cultures of Cyanothece sp. ATCC 51142, a nitrogen gas-fixing cyanobacterium, in a novel photobioreactor they designed and built. With this bioreactor, scientists can rigorously control and monitor the light environment and composition of dissolved nutrients and the gas phase. This approach gave the microbes the favorable conditions needed to produce H2 continuously.
According to Dr. Alex Beliaev, a PNNL microbiologist, “Our study provides an important insight into the photophysiology of light-driven hydrogen production by photoautotrophic microorganisms.”
Using the bioreactor, the scientists grew the bacterial cultures under conditions where an enzyme that can produce H2, nitrogenase, was induced. The ability to monitor and control gas and light input into the system afforded high-resolution physiological details, opening a window on the relationship between O2 evolution and H2 production in the light for unicellular cyanobacteria.The research, which appeared in mBio, was supported by DOE’s Office of Biological and Environmental Research and is part of the PNNL Biofuels and Foundational Scientific Focus Areas.
[Kristin Manke, 509.372.6011,