8 - Engineered yeast for the hydrolysis of algae—a potential alternative feedstock for biofuel production

Abstract

Renewable energy sources like biofuels are gaining attention as a method to reduce fossil fuel consumption and the consequent environmental pollution. The production of third-generation biofuels from algae has several benefits since they do not require arable land and grow faster and consume less water and other resources compared to higher plants. Microalgae produce large amounts of oil, which can be converted to biodiesel, though its commercial production is unlikely to be economically feasible in the near future. Macroalgae, on the other hand, are rich in carbohydrates and can be directly used for bioethanol production. Bioethanol production usually involves a mechanical or chemical pretreatment of the biomass for the hydrolysis of polysaccharides, followed by the fermentation of the sugars by yeasts. This process can be reduced to a single step by engineering yeasts that can produce enzymes to hydrolyze the algal cell wall and simultaneously ferment the sugars released.