Streptomyces coelicor: one microbe, many antibiotics
Juan Pablo Gomez-Escribano, John Innes Centre
Actinomycetes are Gram-positive bacteria from which we obtain two-thirds of all antibiotics we use to treat infections. Through the study of their genetics, we have found that each actinomycete strain has the capacity to produce several antibiotics, but we usually can not find all of them straight away. Streptomyces coelicor produces three coloured antibiotics, but under normal conditions we can only see the blue pigment (called actinorhodin) because its overwhelming production hides all others. But when we manipulate the genetics to abolish the production of the blue pigment, we can see then the production of the red antibiotic (called prodigiosin). With further genetic manipulation we abolish the production of prodigiosin and switch-on the production of the yellow diffusible antibiotic (called coelimycin). We can keep doing genetic manipulation to find other antibiotics, though they are not pigmented and we can not see them with our bare eyes.
These extraordinary microorganisms have an amazing potential to produce natural products, many of which have antibiotic properties. Thanks to the study and manipulation of their genetics we can now access all that potential and find very much needed new antibiotics.