Abstract
Since a polyvalent strategy has recently been assumed to be adopted byDeinococcus 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.