Bacteria are highly adaptable and can live in very hostile environments. Hydrogen sulphide (H2S) is a small gas molecule produced by bacteria in our intestine, and is a powerful inhibitor of cellular respiration by blocking the enzyme responsible for oxygen consumption in human cells. The aim of this study was to assess the hypothesis that some enzymes help bacteria to produce energy and survive despite the presence of acid, often damaging human health. The team led by Ibpm, in collaboration with the University of Rome 'La Sapienza', Moscow, Lisbon, Sheffield and the Toronto Hospital for sick children, has discovered that one of the two enzymes that enable E. Coli (our common bacterial hosts) to use oxygen, called cytochrome bd, is resistant to H2S. Cytochrome bd is only present in prokaryotes and enables them to grow even in sulphide-rich environments, such as our intestine. Recently, the Nobel Prize awardee Hartmut Michel published the crystallographic structure of cytochrome bd. It will thus be possible to combine computational and experimental approaches to identify effective, selective inhibitors and open the way to the development of new generation antibiotics.
Forte, V.B.Borisov, M.Falabella, H.G. Colaço, M.Tinajero-Trejo, R.K. Poole, J.B. Vicente, P.Sarti & A.Giuffrè, The Terminal Oxidase Cytochrome bd Promotes Sulfide-resistant Bacterial Respiration and Growth. Sci. Rep. 6, 23788; doi: 10.1038/srep23788 (2016).