Researchers will turn rose-fragranced yeast into a major industry

Environment and sustainability 6. jan 2021 3 min Associate Professor Sotirios Kampranis Written by Kristian Sjøgren

We can help nature enormously by producing rose and lavender fragrances in yeast grown in large tanks instead of harvesting plants cultivated in massive fields, says a researcher.

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As many as 500,000 rose petals are required to extract a paltry 5 mL of rose oil. This requires massive fields of roses that serve only one purpose: to make everything from soaps to perfumes smell good.

The same applies to lavender. Infinite purple fields are frantically trying to keep up with the huge demand for lavender’s attractive fragrance. The market demands 12,000 tonnes of lavender oil annually.

At a time when everyone wants to act sustainably, extracting essential oils from plants can raise many red flags. Researchers from the University of Copenhagen have therefore discovered a unique approach to producing fragrances using yeast.

“Our yeast can produce exactly the same fragrances as lavender and roses and can achieve this in higher purity and consistent composition and yield. Our method makes an organic product, without using chemicals or harming the environment. We can create the fragrance of roses in the laboratory instead of ruining the environment”, explains a researcher behind the study, Sotirios Kampranis, Associate Professor, Section for Plant Biochemistry, Department of Plant and Environmental Sciences, University of Copenhagen.

The research was recently published in the Proceedings of the National Academy of Sciences of the United States of America.

The perfume industry is an environmental disaster

The environmental cost of producing lavender oil and rose oil is huge.

Millions of square metres of land are used to create fragrances. This means that the land cannot be used to produce food for the many millions of people who need food every day.

In addition, using water, pesticides and fertilizer to keep these flowery fragrance fields productive burdens the environment even further.

And yet, despite intensive cultivation, the world’s many fields of roses and lavender can still not meet the demand for the entire industry.

Instead, about 55% of the lavender fragrance used in the world is still produced by chemical synthesis, which also gravely harms the environment.

Keeping the world smelling good requires completely different methods.

Inducing yeast to make rose and lavender fragrances

To solve this problem, Sotirios Kampranis, postdoctoral fellow Simon Dusséaux, and graduate students William Wajn and Yixuan Liu have engineered yeast to make the same fragrant oils that horticulturists extract from rose and lavender plants.

They achieved this by extracting the biosynthetic pathway from the roses and lavender and inserting it into yeast cells, which then start to produce the aromatic products of the biosynthetic pathway.

The researchers engineered the yeast to produce more than 5 grams of rose oil per litre of yeast culture, which makes the process economically viable for certain products.

“We have constructed some very efficient yeast factories. In addition to rose and lavender oils, we can also engineer the yeast to produce other attractive molecules, such as cannabinoids or other pharmaceutical compounds,” explains Sotirios Kampranis.

Isolating fragrance production in specific compartments

Inserting the biosynthetic pathway for rose oil into yeast may sound simple, but reality differs.

For many years, researchers have tried without success to do exactly what Sotirios Kampranis has finally achieved.

The problem is that yeast cells are not geared to making products that do not contribute to their own growth and well-being. Rose oil does not fulfil these requirements, and the yeast has previously withered and become totally unproductive.

Sotirios Kampranis has solved this problem by hijacking intracellular compartments called peroxisomes in the yeast and using these to separate oil production from the rest of the cell.

Yeast only use the peroxisomes when they need to grow in fat.

Since the yeast in the laboratory grow exclusively in glucose-based media, they do not need the peroxisomes, and the researchers therefore use them as enclosed compartments in which they produce the lavender and rose fragrances.

“By hijacking the peroxisomes, we have engineered the yeast to produce the compounds we want them to, without compromising the integrity of their metabolism. This has enabled the yeast to produce 10–100 times more of our products by mimicking what happens in plants, in which the plant cells also isolate the production of the oils in specific compartments inside the cells,” explains Sotirios Kampranis.

Sotirios Kampranis also explains that the novel aspect of the research is the possibility of producing many different products inside the yeast peroxisomes.

“The possibilities are endless now that we have a technology that can be used in a wide range of contexts,” says Sotirios Kampranis.

Yeast can make oil of sublime quality

Sotirios Kampranis can also make a much purer product by producing the oils in yeast than in cultivated fields.

Roses and lavender are seasonal, and some years they produce less oil or even oil of a lower quality compared with the previous year.

Not Sotirios Kampranis’s yeast. They produce the highest quality all the time – without any glitches.

The whole set-up of engineering yeast to replace endless fields of lavender and roses might sound futuristic, but it is not.

The University of Copenhagen and Sotirios Kampranis have already patented the yeast and are currently deciding which model to use in industrial production.

“This type of fragrance production will eventually replace the current industry, and we have taken the first steps in that direction. We expect that we can produce fragrances in a superior quality, organically and without harmful chemicals,” concludes Sotirios Kampranis.

Transforming yeast peroxisomes into microfactories for the efficient production of high-value isoprenoids” has been published in the Proceedings of the National Academy of Sciences of the United States of America. In 2016, the Novo Nordisk Foundation awarded a grant to Sotirios Kampranis for the project Transforming Yeast Organelles into Micro-factories for the Compartmentalization of Complex Biosynthetic Pathways and a Novo Nordisk Foundation Ascending Investigator Grant for the Biotechnological Production of Structurally Complex Plant High-value Compounds.

I work in the area of Synthetic Biology/Metabolic Engineering, aiming to devise methods to produce high-value natural products in engineered organisms...

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