Improving biofuel production in phototrophic microorganisms with systems biology

Biofuels derived from algal energy carriers, including lipids, starch and hydrogen, offer a promising, renewable alternative to fossil fuels. Unfortunately, native algal metabolisms are not optimized for the accumulation of these renewable bioenergy carriers. Systems biology, which includes genomics, transcriptomics, proteomics, metabolomics and lipidomics, can inform and provide key insights to advance algal strain development for biotechnological applications. Recent advances in analytical technologies have enabled these sophisticated, high-throughput, holistic 'omics' techniques to generate highly accurate and quantitative datasets that can be leveraged to improve biofuel phenotypes in phototrophic microorganisms. The study of algal genomes and transcriptomes allows for the identification of genes, metabolic pathways and regulatory networks. Investigations of algal proteomes reveal protein levels, locations and post-translational modifications, while study of the metabolome reveals metabolite fluxes and intermediates. All of these systems-biology tools are integral for investigating algal metabolism from the whole-cell perspective. This review focuses on how systems biology has been applied to studying metabolic networks in algae and cyanobacteria, and how these technologies can be used to improve bioenergy-carrier accumulation.