Biodiesel is usually produced from oleaginous crops, such as rapeseed,
soybean, sunflower and palm, through a chemical transesterification
process of their oils with short chain alcohols, mainly
methanol [2]. Besides addressing environmental concerns related
to greenhouse gases, biodiesel offers new income to farmers. However,
traditional oil-rich crops are limited by land availability, as
well as environmental and social issues regarding the use of feed
and food crops for fuel. An alternative way to produce biodiesel
in a green and sustainable manner without competing with food
crops is to use microbes. Microbial oils, also called single cell oils,
are produced by some oleaginous microorganisms, such as yeast,
fungi, bacteria, and microalgae [3]. Some of these microbes have
the inherent ability to accumulate or store oil/lipid up to 60% of
their dry weight, when grown under nitrogen-limited conditions.
These lipids usually consist of 80–90% triacylglycerols with a fatty
acid composition similar to many plant seed oils [4,5]. It has been
demonstrated that the microbial oils produced by these microorganisms
can be used as feedstock for biodiesel production