Aetokthonos hydrillicola is particularly challenging for researchers. It is notoriously difficult to cultivate and produces one of its toxins only under specific conditions. The fact that it produces two toxins with very different chemical makeups is also unusual. Cyanobacteria normally produce only one toxin—and A. hydrillicola was established as the source of aetokthonotoxin in 2021.
Markus Schwark from MLU was able to provide evidence of the second, previously unknown toxin and characterized the compound in detail."We were very surprised when we worked out the structure of this toxin. It resembles toxins that have been found in marine cyanobacteria. They are even already being used in cancer-cell killing drugs," says Schwark. Based on the bacterium and the similar, known toxins, the researchers have named the newly discovered toxin"aetokthonostatin.
However, further examinations revealed that the bird toxin only causes minor direct cell damage. Extracts with zero aetokthonotoxin content still destroyed cells even in extremely low concentrations. So A. hydrillicola had to be producing another very powerful toxin.