A review paper: “A Perspective: Photosynthetic Production of Fatty Acid-Based Biofuels in Genetically Engineered Cyanobacteria” written by Prof. Xuefeng Lu from Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, was published online in the journal of Biotechnology Advances on 1st June 2010.

In this review, bottlenecks for current biofuel preparation and technical advantages of production of biofuels in cyanobacteria were analyzed from three aspects: energy resource platforms, microbial systems and biofuel molecules (Fig. 1). And recently published papers in top academic journals such as Nature, Nature biotechnology, PNAS and Metabolic Engineering about cyanobacterial biofuels and fatty acid-based biofuels were summarized in this paper.

The paper came up with a promising strategy to develop sustainable biofuels, fatty acid-based compounds, which possess high energy density, are hydrophobic and are compatible with the existing liquid fuel infrastructure (i.e., fuel engines, refinery equipment and transportation pipelines) utilizing solar energy as the energy source, carbon dioxide as the carbon source and cyanobacteria as the biological system (Fig. 2).

Finally the review concluded that in order to successfully develop cyanobacteria as a platform for the production of fatty acid-based biofuels several hurdles must be overcome. Firstly, through gene manipulation a high-efficiency expression system must be incorporated. Secondly, through enzyme and metabolic engineering metabolic flux must be redirected to feed the fatty acyl pool. Thirdly, using a synthetic biology based approach, the fatty acid converting pathway leading to fatty acid esters, long chain fatty alcohols and fatty alkanes must be constructed. As the biotechnology moves forward, genetic engineering to increase photosynthetic efficiency of the cyanobacteria and to adapt these organisms to the unnatural environment imposed by large scale photo-bioreactors, will no doubt take central stage.

Fig.1：Routes to biofuels, where traditional biofuels was labeled by blue lines, currently hot biofuels by green lines, and novel biofuels in cyanobacteria by red line.

Fig. 2 Proposed biosynthetic pathways for production of fatty acid-based biofuels including fatty acid esters, fatty alcohols and fatty alkanes directly from solar energy and carbon dioxide in cyanobacteria.