So-called 'cryptic' bacterial genes that preside over the production of medically important compounds can be switched on using environmental triggers, German scientists have shown. The researchers used soil extracts to persuade a Clostridium species to produce a hitherto unknown antibiotic that is active against methicillin-resistant Staphylococcus aureus (MRSA).
Many antibiotics made by bacteria are produced through non-essential biosynthetic pathways - they are secondary metabolites. But getting anaerobic bacteria, like those from the Clostridium genus, to produce these compounds has, until now, proved difficult. Having delved into the recently published genome of C. cellulolyticum, however, Christian Hertweck at the Hans Knöll Institute in Jena was convinced it would be worth the trouble.
'We saw some typical genes that code for biosynthetic machineries such as those in antibiotic producers,' says Hertweck. 'We call these cryptic gene clusters, because it's absolutely not clear what they're good for.' Their plan was to wake up these sleeping genes by exposing the bacteria to different environmental conditions.