(547f) Computational Investigation of Photosynthetic Host Strains for Industrial Biotechnology

As photosynthetic organisms attract rapidly increasing attention as host strains for sustainable chemical production, it will be essential to understand fundamental aspects of their metabolism to guide strain design and optimization. We believe computational approaches using reconstructed metabolic models can be powerful tools in these efforts.

In particular, the efficiency of photosynthetic assimilation of light energy and atmospheric CO2 into useful products is currently far too low to be economically feasible. Of the two types of organisms that have been studied the most, cyanobacteria are simpler and easier to engineer, and have been the focus of most published studies, although reported productivities and efficiencies have been low. Eukaryotic algae are more complex and difficult to engineer but can, according to some reports, accumulate higher levels of hydrocarbon products, making them potentially more attractive.

We have used metabolic reconstructions of two photosynthetic organisms - iJN678, of a cyanobacterium, and iRC1080, of a eukaryotic alga - to compare these two main classes of photosynthetic organisms as host strains and shed light on fundamental limitations to high-efficiency chemical production. We hope this work will help inform future engineering projects and contribute to a richer understanding of photosynthetic metabolism.