Biofuel produced by microalgae

Scientists at Tokyo Institute of Technology have identified unique lysophosphatidic acid acyltransferases as being the central enzymes for triacylglycerol synthesis by oleaginous alga Nannochloropsis, thus uncovering the mechanisms of biofuel production in microalgae. 

In the modern society, energy generation heavily relies on fossil fuels, which, however, lead to environmental pollution and depletion of non-renewable resources.

Photosynthetic organisms such as plants and green algae can transform atmospheric carbon dioxide into carbon storage molecules, especially oils such as triacylglycerols (TAGs), which can be used as biofuels. In this context, microalgae provide advantages of high oil content and growth in extreme environments, including high salinity, temperature, or pH.

Nannochloropsis is a genus of microalgae which can accumulate TAGs up to 50% of dry weight; however, the mechanisms underlying their oleaginous trait are largely unknown.

Scientists from Tokyo Institute of Technology lead by Professor Hiroyuki Ohta have addressed this problem by investigating lipid metabolism in Nannochloropsis oceanica. Among the participating enzymes, the scientists focused on four lysophosphatidic acid acyltransferases (LPATs 1-4) responsible for the addition of fatty acids at position 2.

LPAT1 was found to mainly participate in the synthesis of membrane lipids, while LPAT4 was responsible for TAG biosynthesis, and LPAT2 and LPAT3 contributed to both processes.