A rose is a rose is a rose, except when it's actually a yeast. A company called Gingko BioWorks in Boston is partnering with French fragrance company Robertet to create a genetically modified yeast that makes the rose oil used in perfumes.
Why go through all the trouble of recreating rose oil with yeast? The goal is to decouple the scent of roses from its unpredictable supply chain. New Scientist's Aviva Rutkin describes how rose oil is currently made:
Traditionally, roses are grown in vast fields in Bulgaria or Turkey, then picked by hand and distilled to extract the aromatic oil. But from the fragrance companies' perspective, this approach is unreliable. Both the quality and the price of roses can fluctuate wildly from year to year, influenced by factors such as natural disasters, labour shortages, diseases or simply a poor growing season. "You have raw materials that will go from $US10 to $US100 a kilo because there's a shortage or an embargo," says Bob Weinstein, chief operating officer at [French perfume company] Robertet.
Making rose oil from yeast is the latest effort to create the smell of roses without the flowers. Previously, manufacturers have tried is to synthesise rose oil from petrochemicals, but experts say the petrochemical process results in an oil that lacks the complexity of the real thing. That's why recreating a rose scent in yeast will be daunting, too.
It isn't a simple matter of splicing one gene from roses into yeast. Scientists have to recreate the entire molecular machinery that makes rose oil inside a tiny yeast cell. The scent of a rose comes from several different compounds, each of which may require multiple enzymes for synthesis. And an enzyme that works one way in a rose cell may not work the same, if at all, in a yeast cell. Scientists have long tried to turn yeast into little chemical factories -- like for making opioids -- and encountered plenty of challenges.
So far, Rutkin writes that Gingko's "rose" scent does smell vaguely plant-like, even flower-like. But it's not perfect. Scents made by yeast still carry the microorganism's characteristic sour smell, which is another problem to solve.
But Gingko is ploughing full speed ahead, even tackling more ambitious projects -- or at least talking about them. Rutkin reports the company is looking for DNA samples of Ice Age flowers preserved in permafrost, so that it may create the scents of a bygone age. Call it olfactory de-extinction. [New Scientist]