Traditional insecticides not only kill pests, they may also endanger bees and other beneficial insects as well as afect 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 they claim keeps pests at bay without poisoning them.
“It’s not just about the bees, it’s about the survival of humanity,” says Professor Thomas Brück, who heads the Werner Siemens Chair of Synthetic Biotechnology at TU Munich.
“Without the bees that pollinate a wide variety of plants, not only would our supermarket shelves be quite bare, but within a short time, it would no longer be possible to supply the world’s population with food.”
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.
“With our approach, we are opening the door to a fundamental change in crop protection,” says Brück. “Instead of spraying poison, which inevitably also endangers useful species, we deliberately merely aggravate the pests.”
The Munich researchers were inspired by the tobacco plant, which produces cembratrienol, CBTol for short, in its leaves. 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 bacteria. Fed with wheat bran, a by-product from grain mills, the genetically modified bacteria now produce the desired active agent.