Rubber from dandelions

Most natural rubber comes from rubber trees in Southeast Asia, but this source is now under threat from a fungus.

Fungicides still provide at least temporary protection. But if the disease was to reach epidemic proportions, chemical crop protection would be rendered useless, and experts fear that the natural latex industry could collapse if that were to happen.

To develop an alternative source, German researchers have now genetically altered the make up of the Russian dandelion, making it suitable for large-scale rubber production.

Germans, Russians and Americans produced rubber from this plant during World War II. Unfortunately, once it is cut, latex seeps out and polymerises immediately, making it difficult to use.

Bu the scientists from the Fraunhofer Institute for Molecular Biology and Applied Ecology in Aachen have now identified the enzyme responsible for the rapid polymerisation and have switched it off.

'If the plant is cut, the latex flows out instead of being polymerised. We obtain four to five times the amount we would normally,' claimed Prof Dirk Prüfer at the Institute.

If the plants were to be cultivated on a large scale, every hectare would produce 500 to 1,000kg of latex per growing season. An additional benefit is that, unlike rubber from trees, the dandelion rubber has not caused any allergies so far, making it ideal for use in hospitals.

The researchers' next step will involve cultivating the plants using conventional breeding techniques. In around five years, Prof Prüfer estimates, they may well have achieved their goal.

The dandelion is not just suitable for rubber production. The plant also produces substantial quantities of inulin, a natural sweetener.