Multi-modal imaging reveals a small subpopulation of Deinococcus
radiodurans exhibiting correlated metabolic activities
Abstract
Since a polyvalent strategy has recently been assumed to be adopted by
Deinococcus radiodurans that can generate various resistance against
many different detrimental sources of oxidative damage (e.g. reactive
oxygen species, heavy metal ions and ionising radiation), investigating
more than one restorative metabolic activities and their interrelation
of the very same entities of Deinococcus radiodurans is of great
significance for exploring its polyextremophile nature, which will be
insightful for obtaining fundamental generic insights into life
sustainability. Herein, we apply mainly fluorescence microscopy and back
reflection microscopy to visibly assess the respective activities of
superoxide radical generation and silver ion metabolism for individual
Deinococcus radiodurans. Strikingly, only a minority (<20%)
of the bacteria which show low superoxide radical levels is revealed to
exhibit considerable formation of silver nanoparticles whilst those
containing more superoxide radicals all show minimum silver ion
metabolism. The discovery of the strong negative correlation for the
small subpopulation between the two visualised different metabolic
activities not only provides direct experimental evidence in terms of
bacterial functionality for the inferred survival regime of the extreme
microbe, but also suggests a new way of chemically examining biology
from the perspective of inter-functional relationship.