Traditional insecticides are killers: they not only kill pests, but also endanger bees and other beneficial insects, as well as affecting biodiversity in soils, lakes, rivers and seas. A team from the Technical University of Munich (TUM) has now developed an alternative: A biodegradable agent that keeps pests at bay without poisoning them.

    Brück and his team have now found an alternative: The insect repellent they have developed is biodegradable and ecologically harmless. Sprayed on plants, it works much like mosquito repellent used by bathers in the summer, spreading a smell that keeps away unwanted insects.

    The Munich researchers were inspired by the tobacco plant, which produces cembratrienol in its leaves, CBTol for short. The plant uses this molecule to protect itself from pests.

    Using synthetic biotechnology tools, Professor Brück's team isolated the sections of the tobacco plant genome responsible for the formation of the CBTol molecules. They then built these into the genome of coli bacteria. Fed with wheat bran, a by-product from grain mills, the genetically modified bacteria produced the desired active agent and separated it through centrifugal separation chromatography.

Fig: If aphids have the choice between wheat seedlings with (right) and without CBT-ol treatment (left), they avoid the treated seedlings.

Source: www.sciencedaily.com