Earthworms have an important role in the environment. They consume rotten roots, dirt and dead leaves which makes them a key factor in the terrestrial carbon cycles. The lead author of the study metabolomics expert Jake Bundy from the Imperial College explained that among macroinvertebrates in soils earthworms play the most important role in carbon turnover.
Plants are sedentary organisms so they must find innovative means to keep predators away. For this purpose many plants produce defensive chemicals known as polyphenols. Since they eat dead leaves earthworms digest polyphenols as well. Polyphenols inhibit plant matter digestion by binding gut enzymes. The chemicals are kept even when the plants are dead.
Vertebrate such as humans have developed their own way of fighting these chemicals. We have special chemicals in our saliva which bind the polyphenols so the chemical causes no problems when passing through out gut. Researchers have analyzed 14 earthworm species in order to see how they manage to survive the toxins produced by plants.
It was discovered that earthworms produce drilodefensins, compounds that disrupt the chemical properties of polyphenols. They come from the surfactants class which resembles detergents very much. This means that you could even use a lot of purified drilodefensins to wash your dishes.
The research team used three types of IMS (imaging mass spectrometry) in order to analyze cross-selection of the worms at a very fine scale. This technique is like a biochemical microscope being able to offer pictures with objects that are smaller than a cell. Bundy explained:
We had really clear images of drilodefensins found in the earthworm gut, and only in the gut. In this particular case, the IMS was essential – traditional methods of testing involve dissecting out the gut and then scooping or squeezing out the contents, but this didn’t work in earthworms. The drilodefensins turn out to be very easily degraded, so they just disappear if you carry out a dissection.”
He also said that now that they have made this discovery they could find way to put these compounds in practice for commercial or environmental use. Bundy said that for now it is too early to decide what the applications could be but according to him biosurfactants could be used for example in stimulating bioremediation for cleaning up oil spills.
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