When potatoes are infected by Clostridium puniceum, the pathogen produces a nasty pink slime that destroys the valuable food crop. Researchers have long wondered how the pathogen, which normally thrives in oxygen-free environments, can be so destructive on the surface of potatoes in oxygen-rich air. The answer lies in clostrubins, a class of molecules found in the slime, according to a team of researchers led by Christian Hertweck of the Leibniz Institute for Natural Product Research & Infection Biology (Science 2015, DOI: 10.1126/science.aac9990). The team found that clostrubin A and clostrubin B, which are produced with bacterial polyketide machinery, help the pathogen survive the onslaught of reactive oxygen species found in aerobic environments. But that’s not all. Clostrubins are also antibiotics: They help C. puniceum kill off competitors that try to encroach on its tuber territory. The team argues that targeting the bacterial enzymes that build clostrubins may point the way to new antibiotics and plant protection agents.