3,5 billion years of R&D
To survive the early ages of our planet Deinococcus bacteria have developed unique genetic and metabolic capabilities. These properties allow them to survive in today's most hostile environments but also produce a variety of compounds from biomass components that other organisms do not know how to use.
Already present on earth 3.5 billion years ago, the Deinococcus bacteria are spherical in appearance and are less than 5 microns in diameter. In the mature state, they are in the form of four contiguous pink-red cells because of their richness in carotenoids.
The Deinococcus bacteria are survivors as they have learned to resist radiation, oxidation, heat, drought and cold.
Courtesy of Dr. Michael Daly, USIHS, New York.
Most of these attacks have one thing in common: they damage DNA. Result, the bacterial chromosome breaks into hundreds of fragments. But while in all other organisms such breaks are irreversible, the Deinococci are able to reassemble these fragments into their genome with near perfect fidelity.
In 2006, the team of Professor Miroslav RADMAN discovered the genetic mechanisms that allow Deinococcus to be "resurrected". For this, the bacterium utilizes multiple copies of its genome (some bacteria contain up to 9 copies of their chromosome!) and uses a repair mechanism of unprecedented simplicity and ingenuity. Following the attack, chromosomes are cut into fragments signal triggering the activation of the repair system of the bacteria: the chromosomes are replenished in a few hours and the bacteria is viable again.
The Deinococci feature another property that can also be found in other bacteria, but they have developed it at a hitherto unknown scale: they are able to borrow genes from other organisms such as bacteria, yeasts or plants and to sustainably integrate them in their genome, thus multiplying their capabilities.
With this tremendous genetic plasticity, the Deinococci are not only able to withstand the harshest conditions but also can be modified to develop the ability to produce rare compounds (chemical intermediates, enzymes, ethanol, new antibiotics...) from biomass components other organisms do not know how to exploit.
Deinococci: a natural source of industrial products
In deciphering the genetics of Deinococcus and in generating the first molecular tools that allow their optimization, Miroslav RADMAN has paved the way for the industrial exploitation of these bacterial micro-factories.