Photosynthetic polyol production

In the combustion reaction, a fuel reacts with oxygen to carbon dioxide and water. The energy liberated in this process can then be harnessed to do work, e.g. to generate electricity or drive an engine.
Excessive and increasing world-wide use of fossil fuels has led to increases in atmospheric carbon dioxide levels that are predicted to cause significant climate change.
In this thesis project, the cyanobacterium Synechocystis sp. PCC6803 is engineered for the conversion of water and carbon dioxide into glycerol and 2,3-butanediol. These compounds have attracted interest as (liquid) fuels and as precursors for both large scale (polymers) and small scale (specialised compounds) synthesis. The conversion process is driven by light energy. As such, it represents the reversion of the combustion reaction referred to above.
Furthermore it is shown that an artificial pathway from carbon dioxide to a product does not have to be confined to a single organism. Indeed, when mixtures of different organisms are used, their unique metabolic makeup can be harnessed to drive the synthesis of compounds that would be infeasible in just a single cell type. To this end, a mixture of Synechocystis and a heterotrophic organism such as Escherichia coli is shown to be able to convert carbon dioxide into optically active (i.e. enantiomerically pure) forms of 2,3-butanediol.
Lastly, a protein with an until now unknown function is demonstrated to be required for the degradation of the osmoprotectant glucosylglycerol.