Food poisoning most often results from toxic compounds produced by microorganisms that contaminate food that is not prepared or stored properly. One such example is the contamination of tempeh cakes by the bacterial species Burkholderia gladioli, which produces the highly toxic compound bongkrekic acid. Tempeh cakes are made by fermenting soybeans, coconut flakes, or corn in the presence of the fungus Rhizopus oligosporus, which provides the binding material in the form of mycelia that hold the cakes together. If the tempeh fermentation process is not done properly, then the Rhizopus culture can become contaminated with Burkholderia, leading to the production of the toxin bongkrekic acid. Bongkrekic acid blocks the mitochondrial production of ATP by inhibiting the ATP/ADP translocase protein. Without the rapid exchange of ATP for ADP across the inner mitochondrial membrane, the ATP synthase enzyme is unable to maintain sufficient levels of ATP for cellular processes.
Everyday BioChem 