Cyanobacteria as a renewable resource for biofuel production

Cyanobacteria, a group of prokaryotic photoautotrophs, are emerging as potential candidates for the production of sustainable biofuels. Production of many fuel substitutes like ethanol and 1-butanol has been demonstrated in cyanobacteria by engineering heterologous pathways. Despite significant advances in genetic engineering and synthetic biology, final fuel titers from cyanobacteria are lower compared to their heterotrophic counterparts. Unavailability of well-characterized host cells, instability of genetic constructs, limited repertoire of synthetic biology tools, and toxicity of end products are the key challenges in developing cyanobacteria as a fuel-producing factory. Success in commercial production will depend on the development of synthetic biology techniques, systematic efforts in isolating versatile host strains, and comprehensive insights into the metabolic flux map. In the present chapter, we discuss the advances in metabolic engineering, synthetic biology, and metabolomics of cyanobacteria for renewable production of fuel substitutes discussing few representative examples of fuel molecules. Overall, there is a scope of research in interdisciplinary areas for large-scale production of biofuels and converting cyanobacteria into a cell factory.