Enhancement of Fatty Acids Production from Saccharomyces cerevisiae by Overexpression of Malic enzyme and Heterologous Expression of Thioesterase from Corynebacterium glutamicum (#404)
Due to an increasing demand of environmentally
friendly biofuel, It is necessary to look for the way which continue to provide
renewable energy sources. Fatty acids production from renewable feedstock has
currently attracted significant attention as an important platform for producing
of the renewable bio-fuel. Here, we engineered Saccharomyces cerevisiae to enhance fatty acids biosynthesis
pathway by insertion of three genes related to fatty acids production. First,
the acetyl-CoA carboxylase I (AccI) from Corynebacterium
glutamicum was introduced into S.
cerevisiae. AccI is most important rate limiting step to produce fatty acids
and it converts the acetyl CoA into malonyl CoA. Second, we introduced the
putative acyl-CoA thioesterase (Cgl1664) from C. glutamicum which converts fatty acyl CoA into fatty acids.
Third, we overexpressed the malic enzyme I (MaeI) to regenerate the NADPH which
consumed during the elongation step of fatty acids. The heterologous
overexpression of the AccI led to 1.7-fold increase in recombinant yeast YPH499
(pAccI), which represented 220.2 mg/g DCW. Also, YPH499 (pCgl1664) which
contains the Cgl1664 showed 232.7 mg/g DCW, which is 1.7-fold higher than wild
type. We also overexpressed the MaeI in the recombinant strain YPH499 (pMaeI)
and it can produce the fatty acids with 261.5 mg/g DCW, and it was 2.0-fold
higher than wild type. Continually, we constructed the shuttle vector paccImaeIcgl1664 which has all three
genes accI, maeI, and cgl1664. This recombinant plasmid was
introduced into S. cerevisiae and YPH499
(pAccIMaeICgl1664) can produce the fatty acids of 356.3 mg/g DCW, which is
higher than 2.7-fold than wild type. The MaeI provide the NADPH to be in
balance and the overexpression of AccI and Cgl1664 increase the yield of fatty
acids. These results represent the potential to development of an industrial
platform effective producing fatty acids and fatty acids-derived molecules.