4. Conclusions
This work applies optical microscopy under varying imaging modes depending on the analyte species to visualise both metabolic activities of silver ion reduction and superoxide radical generation of theD.r. colony. It is discovered that a distinct negative correlation between the two biochemical processes surfaces yet only for a minor subpopulation of the bacteria. Interestingly, this finding directly supports the current view of the single polyvalent strategy against various conditions lethal to most species for explaining the polyextremophile nature of D.r. bacteria.