Abstract:
Microbial oil has high similarity to the oil obtai
ned from plants and animals. They are
renewable sources that can be used for different pu
rposes such as production of biofuels.
Biofuels are renewable, biodegradable, and nontoxic
, which makes them highly
environmentally friendly. Producing oil from yeasts
has more advantages than that from
plants. Accordingly, isolation of oleaginous yeasts
with high ability of lipid production is
highly valuable. A total of 138 yeasts were isolate
d for the purpose of this study. From this
amount, 35 were capable of producing lipid. After e
xtracting lipid, the best strain was
selected and, by using PCR method, identified as
Rhodotorula mucilaginosa
. Optimization
was done using the design of experiments; Qualitek-
4 (W32b) software was used for
analyzing the experimental data. According to the r
esults,
Rhodotorula mucilaginosa
proved to comprise lipid, dry biomass, and lipid pr
oductivity at levels of 10.97 g L
-1
, 18.84
g L
-
1, and 58.2% in optimized conditions, respectively.
Lipid content on corn stalk and
wheat straw hydrolysate was 36.9 and 41.8%, respect
ively. The extracted lipid was
analyzed by FTIR spectroscopy and gas chromatograph
y-mass spectrometry (GC-MS).
The study showed high potential of lipid production
in
Rhodotorula mucilaginosa
and also
high efficiency of using Taguchi design in optimiza
tion of medium condition; therefore, by
using this method, the optimization process can be
done as best as possible. The economic
values of microbial lipid production become more fa
vorable when waste materials with
zero or negative economic value are utilized as car
bon source. Using bioprocesses such as
microbial lipid production from waste materials, th
e problem of shortage of energy
resources, and also air pollutions caused by fossil
fuels, could be eliminated.
Keywords:
Air pollution
,
Biofuels
,
Microbial lipid.
