Test-tube perfumes for modern Cleopatras?

Press, 1 April 1985, Page 12

Test-tube perfumes for modern Cleopatras?

From ‘The Economist,’ London

The sails of Cleopatra’s barge were so perfumed that the winds were love-sick with them. Can equally exquisite perfumes be bioengineered? The $5 billion-a-year flavour and fragrance industry hopes so. Its costs would fall dramatically if stainless-steel cauldrons replaced fields of jasmine, vanilla and lavender as the source of botanically derived flavours, fragrances and colourings. Extracting smells and tastes from plants and putting them into such products as soft drinks, perfume and laundry detergent is an expensive business. Vast quantities of plants are sometimes needed to produce a few ounces of flavour, colour or scent. Most of the interesting plants grow only in hot climates and their quality and price depend on the vagaries of politics, weather and trade.

The industry has looked hard for alternatives, but found few good ones. Synthetic substitutes rarely taste or smell as good as the real think. Even when they do, customers tend to prefer natural products because they sound safer.

Some firms have tried to breed strains of exotic plants robust endough to thrive in cold but stable northern countries. But farming can be expensive: even France’s Grasse, whose jasmine has been loved for centuries, has seen its annual production slump to 80 tonnes from a high of 1,000 tonnes as markets shrink and

growers turn to less labour-inten-sive vegetables.

Hence the interest in biotechnology, despite daunting initial difficulties. The most obvious approach is fermentation — growing cell colonies to high concentrations and then extracting the product. But because plant cells grow slowly a fermentation cycle could take years. Nor do plant cells secrete their products, which makes extraction hard and yields low.

None the less, several methods show promise. One is to immobilise the cells. Since plant cells grow slowly, they can thrive without getting overcrowded when fixed to sheets of special membranes or encapsulated in microspheres. The cells are bathed with a mixture of nutrients and additives that enhance the secretion of product.

The recipes for these mixtures are kept secret. Most, it seems, work through osmosis, the tendency of substances in solution to flow from areas of high concentration to those of low concentration. The membrance in this instance acts like a one-way valve — essential oils can get out but not back in. The solution which is bathing the cells has to be continuously pased through separation processes to extract the oils. The Japanese appear to have an early lead in call culturing. Mitsui Petrochemicals has introduced the first,-. secondary plant product

brewed in a vat. The product, a red-to-purple dye called Shikonin and used in cosmetics, was a shrewd choice. It can be uused medically as an antibacterial agent, no synthetic clones have been fabricated, and the natural source (the root of the shikon plant) is on the verge of extinction. Unlike its natural counterpart, biofabricated shikonin should fall in price as demand rises, becuase of economies of scale.

In Europe, Firmenich of Switzerland is one of the first large flavour and fragrance houses to explore the new technology. It has entered a joint venture with America’s DNA Plant Technology, a New Jersey firm with experience in cell culturing. This firm is also considering some dramatically different ways to mass-pro-duce secondary plant products. One possibility is plant hybridomas (hybridomas are man-made cells that combine the desirable traits of two others). Plants get tumours, so why not combine one of these fast-growing cells with a cell that manufactures a desired compound?

Another approach is to use cells that are naturally fast growers like those found in the tip of a shoot (called the meristem). The resulting hydridomas would be “immortal” factories for anything from lilac to licorice.

The Economist.