The Austrian Centre of Industrial Biotechnology (acib), using synthetic biology technology, developed a new method to produce Nootkatone, an expensive grapefruit aroma. The biotechnological process uses cheap sugar as substrate for a “turbo-yeast”.
The extremely expensive substance is used in soft drinks, pharmaceutical products or even as an insect repellent, and it is found only in very small quantities in grapefruits. The challenge of the biotechnologists Tamara Wriessnegger and Harald Pichler in Graz was to produce Nootkatone in large quantities.
“We have installed new genetic information in the yeast Pichia pastoris, so that our cells are able to produce Nootkatone from sugar”, says acib researcher Tamara Wriessnegger. The genome of the yeast cells has been extended with four foreign genes derived from the cress Arabidopsis thaliana, the Egyptian henbane Hyoscyamus muticus, the Nootka cypress Xanthocyparis nootkatensis and from baker’s yeast Saccharomyces cerevisiae. With the help of the new genes the yeast is capable to synthesize the high-prized, natural flavor in a cheap way and in useful quantities from sugar.
Because the natural sources cannot meet the demands, the acib method replaces chemical synthesis, an energy-consuming and anything but environmentally friendly process. The common biotech variant via Valencene and a chemical synthesis step is less ecofriendly, more difficult and expensive.
Dr. Pichler, stated: “With our method, the important and expensive terpenoid Nootkatone can be produced industrially in an environmentally friendly, economical and resource-saving way in useful quantities.”
Thanks to this innovative approach, Nootkatone production will drop substantially from more than €3.7k per kilo, to around €1 per kilo, the price of the sugar substrate.
This is yet another example of the vital importance of synthetic biology. Not so long time ago, the US researcher Jay Keasling was able to transfer the appropriate production route of Artemisinin from plant to bacteria. Artemisinin and its derivates are the drugs that possess the most rapid action of all current drugs against Plasmodium falciparum malaria. Thanks to this substance malaria is curable but, unfortunately, it could be found only in tiny quantities in the sweet wormwood, until Dr. Keasling’s research. With these “synthetic” organisms the active ingredient is produced at much lower costs.