Dandelion - the new source for rubber

Rubber is the raw material for more than 50,000 different products, primarily for car tires, but also for seals, mattresses, shoe soles or condoms. Almost 14 million metric tons of natural rubber were produced in 2018 and processed through vulcanization into rubber, a material that is both strong and elastic even when cold.

Today, the raw material is extracted almost exclusively from the latex of a tree that is known botanically as Hevea brasiliensis. This tree is originally native to the tropical forests of Brazil, but its main cultivation areas today are in Southeast Asia. Since 2000, global natural rubber production has doubled from just under 7 million tons to 13.9 million tons in 2018. The intensive cultivation of rubber trees creates problems: use of large amounts of pesticides, the trees require a lot of water, which in some cases causes the water table to sink. Above all, however, the plantations need space. To create this space, large areas of tropical forest have been cleared in producing countries such as Thailand and Indonesia. Not only in its country of origin, Brazil, but also in the new cultivation areas, are the monocultures susceptible to disease infestation. In Brazil, the fungus Microcyclus ulei was a major contributor to the collapse of the rubber empire.

So far, plantations in Southeast Asia have been spared from this fungus, but experts suspect that this may change quickly with direct flight connections between Brazil and Southeast Asia. Indigenous fungi do affect the tree plantations in Asia: in October 2019, the Rubber Authority of Thailand reported that a key growing area in the south was being hit by a fungal disease that could halve the area's production. The disease is spreading rapidly, leaving trees bare and unable to be tapped. The fungus is also hampering the rubber harvest in neighboring Indonesia and Malaysia. According to the International Rubber Consortium, around 382,000 hectares of rubber plantations are currently affected.

Although petroleum-based synthetic rubber is available, it can only partially replace the natural product.

Because of all these factors, we urgently need to develop alternative, sustainable sources of natural rubber.

At Fraunhofer IME in Münster, researchers have been focusing on the Russian dandelion (Taraxacum koksaghyz) as an alternative for many years. Although it looks like the native dandelion, it has an enormous advantage: its latex contains larger quantities of natural rubber. When Prof. Dr. Dirk Prüfer, Professor of Plant Biotechnology at WWU Münster and Head of Department Functional and Applied Genomics at Fraunhofer IME, and his team started their research, they faced major challenges. The Russian dandelion was still a wild plant with an increased concentration of natural rubber, but still too low for industrial use. Through targeted breeding, the researchers succeeded in doubling the rubber content within a short time. The scientists refrained from genetic engineering, instead analyzing the dandelion DNA and defining DNA markers could tell already in a very early stage of plant development if a given plant will possess the desired trait.

By this technology the scientists determined whether seedlings already possessed traits that would have a positive effect on rubber production. The successful cooperation with partners Julius Kühn-Institut and plant breeding expert ESKUSA also resulted in plants with a significantly increased content of natural rubber.

Subsequently, the natural rubber passed the real-life test conducted by the industrial partner of the consortium Continental Reifen Deutschland GmbH, resulting in the opening of the "Taraxagum Lab Anklam" research and testing laboratory at the end of 2018, which represents a milestone on the road to the industrialization of dandelion rubber.

In 2019, Continental Reifen Deutschland GmbH presented the Urban TARAXAGUM®, the first mass-produced bicycle tire made of dandelion rubber. The plans - assuming further positive results - envisage car and truck tires made from dandelion rolling off the production line in the next years.