Metabolic engineering of algae for fourth generation biofuels production

TLDR

Current biofuel technologies, from first‑generation crop‑based to second‑generation cellulosic, have limited ecological and economic viability, prompting a shift toward third‑ and fourth‑generation algae‑to‑biofuels approaches that rely on metabolic engineering but still face technical bottlenecks requiring post‑genome tools. This review examines the achievements of metabolic engineering of algae for fourth‑generation biofuel production to address the limitations of earlier biofuel generations. The review synthesizes recent advances in metabolic engineering strategies applied to algae to enhance biofuel yields. The authors conclude that fourth‑generation biofuel production establishes a cell‑factory paradigm that shifts the research focus.

Abstract

The ecological footprint and economic performance of the current suite of biofuel production methods make them insufficient to displace fossil fuels and reduce their impact on the inventory of Green House Gas (GHG) in the global atmosphere. Algae metabolic engineering forms the basis for 4th generation biofuel production which can meet this need. The first generation biofuels are known to be made from agricultural products such as corn or sugarcane. The second generation biofuels use all forms of (lingo)cellulosic biomass. The third and fourth generation of biofuel production involves “algae-to-biofuels” technology: the former is basically processing of algae biomass for biofuel production, while the latter is about metabolic engineering of algae for producing biofuels from oxygenic photosynthetic microorganisms. Our review focuses on the research achievement of metabolic engineering of algae for biofuel production. It is concluded that 4th generation biofuel production has introduced the “cell factory” concept in this field, and shifted the research paradigm. There still exists several technical bottlenecks in algae biofuel research and development, which can only be solved by the use of post-genome tools on these photosynthetic organisms.