The seeds of green energy - expanding the contribution of plant
oils as biofuels Plant oils represent one of the most energy
rich sources of renewable fuels available in Nature. Most of
these oils occur in the form of triacylglycerols (TAGs) that can
be transformed into biodiesel by conversion of their acyl chains
into fatty acid methyl esters. In 2009, 14 billion litres of
biodiesel were produced worldwide from plant oils (largely in
the EU). This compares with 70 billion litres of ethanol
(largely from Brazil and the USA). Both of these fuels now
depend on land and crops (e.g. oil seeds, palm trees, maize and
sugar cane) that are also used for foods. To meet growing demand
and avoid competition with food, major expansion of biofuel
production and development of new sources of biofuel are
required. In this article, we outline how plants synthesize oils
and describe some ways in which supplies of oils from plants
could be increased to provide a larger contribution to renewable
energy supplies. Ohlrogge JB & C