5. Klebsiella Planticola: Genetically Altered Bacteria

10 Times the World Almost Ended Image source: Say No to GMOs

Klebsiella Planticola was supposedly a microbe that would convert the dead plant to ethanol, which could be used to make alcohol or even used as a fuel. Fortunately, independent testing discovered that the bacteria also could kill the live plants. Meaning, if field-tested, it could potentially cause mass plant extinction that could wipe out farms and forests around the world. Ultimately, all the productions were halted and the world was saved from a global plant super plague.