Karolis Petkevicius

and 15 more

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.