Understanding How Bacteria Use Sunlight

New insights into the effect of light quality on bacterial metabolism and respiration.

Image courtesy of PNNL
Pacific Northwest National Laboratory photobioreactor.

The Science

New research has combined a new genome-scale, constraint-based model of the cyanobacterium Cyanothece with experiments in a novel photobioreactor.

The Impact

The results will guide development of genome-scale metabolic models for other cyanobacteria and may help with the genetic manipulation of photosynthetic microorganisms to improve biofuel production.


Cyanobacteria are prime candidates for the biological production of biofuels, especially hydrogen. They photosynthesize in sunlight, have relatively fast growth rates, are tolerant to extreme environments, and can accumulate high amounts of intracellular compounds and produce large quantities of H2. The model and experiments provide new insights into the effect of light quality on metabolism and the bacteria’s mechanisms for balancing reductant and electron flows. The model differs from similar models of other cyanobacteria in its detailed treatment of the photosynthesis and respiratory systems. The photobioreactor features dual sources of monochromatic light that can vary photon flux with wavelengths that are tuned to the two bacterial photosynthesis systems.


Dr. Alexander Beliaev
Pacific Northwest National Laboratory


Basic Research: DOE Office of Science, Office of Biological and Environmental Research


Vu TT, et al., 2012, “Genome-Scale Modeling of Light-Driven Reductant Partitioning and Carbon Fluxes in Diazotrophic Unicellular Cyanobacterium Cyanothece sp. ATCC 51142”. PLoS Comput Biol 8(4): e1002460. [DOI: 10.1371/journal.pcbi.1002460].

Highlight Categories

Program: BER , BSSD

Performer: University , DOE Laboratory , BER User Facilities , EMSL