Weird and wonderful Nootkatone can now be made from sugar

It’s not a name that rolls easily off the tongue, but Nootkatone is an organic substance that punches far above its weight. It’s an important ingredient for the food, pharmaceutical and chemical industries. As an insecticide it is effective against ticks, mosquitoes and bedbugs, while in the medical field, the substance has shown activity against cancer cell lines. Its scent is sought after in cosmetics and it contributes a fine, subtle taste to soft drinks.

The only downside until now has been its scarcity, as the substance can be found only in minute quantities in grapefruits. This led in turn to its high cost - more than $5000 per kilo.

A synthetic variant had been developed, but the process for creating it was energy-consuming and environmentally unfriendly.

Now, the Austrian Centre of Industrial Biotechnology (acib) has used the positive aspects of synthetic biology for the ecofriendly production of Nootkatone.

“We have installed new genetic information in the yeast Pichia pastoris, so that our cells are able to produce Nootkatone from sugar,” said 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 of synthesising the highly prized, natural flavour cheaply and in useful quantities from sugar. Ultimately, the aroma found in one grapefruit leads to millions of litres of juice.