Biotechnological production of the European corn borer sex pheromone in
the yeast Yarrowia lipolytica
Abstract
The European corn borer (ECB) Ostrinia nubilalis is a widespread pest of
cereals. Mating disruption with the sex pheromone is a potentially
attractive method for managing this pest. The goal of this study was to
develop a biotechnological method for the production of ECB sex
pheromone. Our approach was to engineer the oleaginous yeast Yarrowia
lipolytica to produce (Z)-11-tetradecenol (Z11-14:OH), which can be
chemically acetylated to (Z)-11-tetradecenyl acetate (Z11-14:OAc), the
main pheromone component of the Z-race of O. nubilalis. Fatty acyl-CoA
desaturases (FAD) and fatty acyl-CoA reductases (FAR) from nine
different species of Lepidoptera were screened individually and in
combinations. A titer of 29.2±1.6 mg/L Z11-14:OH was reached in
small-scale cultivation with an optimal combination of a FAD (Lbo_PPTQ)
from Lobesia botrana and FAR (HarFAR) from Helicoverpa armigera. When
the second copies of FAD and FAR genes were introduced, the titer
improved 2.1-fold. The native FAS1 gene’s overexpression led to a
further 1.5-fold titer increase. When the same engineered strain was
cultivated in controlled 1 L bioreactors in fed-batch mode, 188.1±13.4
mg/L of Z11-14:OH was obtained. Fatty alcohols were chemically
acetylated to obtain Z11-14:OAc. Electroantennogram experiments showed
that males of the Z-race of O. nubilalis were responsive to
biologically-derived pheromone blend. Behavioral bioassays in a wind
tunnel revealed attraction of male O. nubilalis at a level similar to
that of the chemically synthesized pheromone used as a control, although
full precopulatory behavior was observed less often. The study paves the
way for the production of ECB pheromone by fermentation.