Abstract
This study explores the application of metabolic engineering in
Aspergillus terreus to re-route the precursor flow towards the
lovastatin biosynthetic pathway by simultaneously overexpressing the
gene for acetyl-CoA carboxylase (acc) to increase the precursor
and eliminating (+)-geodin biosynthesis (competing metabolite), by
knocking out emodin anthrone polyketide synthase (gedC).
Alterations to metabolic flux in the double mutant (gedCΔ*accox)
strain and the effects of using two different substrate formulations
were examined. Cultivation of gedCΔ*accox strain with a mixture
of glycerol and lactose, had greatly increased levels of precursors
malonyl-CoA (48%) and acetyl-CoA (420%), complete inhibition of
(+)-geodin biosynthesis and a maximum production of lovastatin (152
mg/L), 143% more than the wild-type (WT) strain. This study
demonstrates the manipulation of A. terreus metabolic pathways to
increase the efficiency of carbon flux towards lovastatin, elevating its
production. It provides a framework for new opportunities to synthesize
valuable compounds using cheap and renewable carbon sources.