Nowadays, biodiesel is one of the most promising renewable energy
resources to replace fossil fuels because it’s more environmentally friendly
and can reduce greenhouse gases, which ultimately lower the level of pollution
in many countries (Naira et al., 2011).
Biodiesel can be produced from plant oils, animal
fat and microorganism such as: algae, oleaginous yeasts and fungi (Yekta et al., 2013;
Xin et al., 2008). However, according to Xin et al. (2008), the plant oil
materials require energy and space for sufficient production of oilseed crops.
On the other hand, animal fat oils need to feed the animals. So, in spite of
the favourable impacts that its commercialization could provide, the economic
aspect of biodiesel production has been reduced by the cost of oil raw
materials. If plant oil was used for biodiesel production, the cost of source
has account to 70–85% of the whole production cost. Because of these inhibition
factors, finding out new ways to reduce the high cost of biodiesel production
is one of the most popular topic in some recent researches, especially for
those methods concentrating on lowering the cost of raw material. This is why microorganisms
have often been considered for the production of oils and fats as an
alternative to agricultural and animal sources.
Not only because of economic aspect, but the
property of lipid content in microorganisms often meet the requirement for
biodiesel production (Miao and Wu, 2006) with large amounts of triglyceride and
also have a free fatty acid (FAA) component less than 2.5% leads to soap
formation, which results in the loss of feedstock as well as making glycerin
separation difficult (Tyson et al., 2004). However, bacteria and fungi have a
limited ability to produce significant biomass. In case of microalgae, although
they are characterized as high lipid-producing microorganisms, they require a
larger space and a longer fermentation period to culture than most other
microorganisms (Chinnasamy et al., 2010).
myxomycetes (plasmodial slime molds) are a group of primitive phagotrophic
eukaryotes, commonly associated with decaying plant material in all types of
terrestrial ecosystems (Stephenson and Stempen, 1994). Physarum polycephalum which is
a member of the order Physaralates of this class, has the rapid rate of growth,
the absence of cell walls and the ease of culturing. All of these advantages
already made the plasmodium of Ph. polycephalum being widely used in cell biology research.