Among several industries in southern Thailand, palm oil, natural
rubber, and biodiesel processing wastes are of particular interest
because of their high organic loading and abundance. The high
chemical oxygen demand (COD) of palm oil mill effluent makes its
disposal a pollution problem. Palm oil mill effluent is rich in minerals
and contains vitamins that may provide valuable nutrients to
stimulate cell growth and product formation (Habib et al., 1997).
Serum latex obtained during the process of separating natural rubber
latex also contains highly concentrated proteins that could be
used as a nitrogenous compound to cultivate various kinds of
microorganisms (Tripetchkul et al., 1992). Crude glycerol is the
main by-product of the conversion of vegetable oil into biodiesel,
and comprises approximately 10% by mass of the oils fed to the
system (Xie et al., 2011). Incorporation of oleaginous yeast cultivation
with conventional wastes or wastewater treatment systems
would offer the combined advantages of treating wastes and
simultaneously producing a cheap lipid that can be used as a biodiesel
feedstock. Wastewater treatment by the microbial culture
has several major advantages: it rests on the principles of natural
ecosystems and is therefore not environmentally hazardous; it
causes no secondary pollution, as long as the biomass produced
is reused; and it allows for an efficient recycling of nutrients (An
et al., 2003).