Evonik commercialises first biosurfactants

GERMAN chemicals major Evonik has commercialised a process to make a yeast-derived biosurfactant using biotechnology on an industrial scale.

It is the first time biotechnology has been used to produce surfactants at this scale. The first consumer products made with the surfactants, household cleaners launched by Belgian firm Ecover, have already hit the supermarket shelves. Evonik says that the new biosurfactants have good cleaning properties, are much gentler to skin, much safer to organisms in the environment, and can biodegrade in the environment completely, as they are a natural product. A growing number of consumers are seeking to move away from petroleum-derived and palm oil-derived products, the source of many current commonly-used surfactants.

The biosurfactants in question are sophorolipids, produced by the yeast Starmarella bombicola, which is found in the honey produced by bumblebees. Evonik has set up a production facility at its Slovenská L’up?a biotechnology site in Slovakia. The trade name for the biosurfactant is Rewoferm.

The proprietary process uses an industrial stirred fermenter. The yeast are fed with a combination of starch-derived dextrose and rapeseed oil, and air is pumped in. As more biosurfactants are produced, there is a problem with foam formation, desirable for the consumer but not in production. However, Hans Henning Wenk, head of research for biobased materials in Evonik Nutrition and Care, explains that the company has developed an innovative way to control foam formation, as well as a special purification process to remove the cells and byproducts from the biosurfactant. Developing the process involved 20 international experts and took five years.

'Biotechnological methods allow surfactants to be produced without petroleum or tropical oils [like palm oil],' said Wenk, adding: 'Biosurfactants promise significant growth and will complement our conventionally manufactured products. Evonik sees itself as a future leader in this market, which is still in its infancy.'

Evonik is currently working to improve the sophorolipid production process still further, to produce even greater volumes of the surfactant. It is also constructing a pilot plant, again at Slovenská L’up?a, to produce another class of biosurfactants – rhamnolipids – by fermenting bacteria, rather than yeast. For the third generation of biosurfactants, Evonik hopes to be able to produce the necessary sugars from waste materials rather than foodstuffs. Wenk told The Chemical Engineer that the company will also consider the use of genetic modification of bacteria in future, which would allow biosurfactant production pathways from dangerous or pathogenic microorganisms to be transferred to more benign ones.