Living in a lethal atmosphere

Science publication airs new capabilities of a potato pathogen

PhD student Gulimila Shabuer at work with the colorful clostridia. (photo: HKI/Tina Kunath)

The group of Prof. Dr. Christian Hertweck from the Hans Knöll Institute in Jena has discovered the dually-functional clostrubins, antibiotic compounds, from anaerobic bacteria that infect and decompose potatoes. Their research uncovers the functions of the clostrubins, protecting the bacteria from an otherwise-lethal oxygenated environment, as well as being potent antibacterials against competitors. Their findings have now been published in the journal Science.

A quarter of all vegetable sustenance worldwide is lost because of infectious plant diseases.  Potatoes are a staple and harvest losses can be devastating to dependant communities. The perpetrators are often bacteria such as Clostridia which decompose the potatoes. These bacteria are strictly anaerobic and should only able to survive in an oxygen-free environment; yet, oxygen is present inside potatoes. So how do these bacteria overcome the seemingly impossible?

Gulimila Shabuer, a PhD student in the Biomolecular Chemistry Department at the Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, and her colleagues have studied the potato rot pathogen, Clostridium puniceum; they discovered “the bacteria produce a group of compounds, the clostrubins, which enable the bacteria to survive in an oxygenated environment.”  An antioxidant role is clear, though scientists cannot yet explain this function. Additionally, the clostrubins have high antibacterial activities against other common potato pathogens, effectively removing competitors from a resource-limited niche. 

This work from the group of Prof. Dr. Christian Hertweck follows their unprecedented discovery of closthioamide in 2010, the first antibiotic from strictly anaerobic bacteria. Nevertheless, the dually functional clostrubins represent a new survival strategy for strictly anaerobic bacteria; essential for their survival in an oxygenated environment, and potently antibacterial against competitors.

The results were obtained with the Peter Doherty Institute for Infection and Immunity in Melbourne, Australia.