The genus Gluconobacter is frequently used for biotechnological and/or nanotechnological applications. We studied
endogenous fluorescence of nicotinamide adenine dinucleotide (phosphate) (NAD(P)H), indicator of the oxidative
metabolic state in mammalian cells, in Gluconobacter oxydans (G. oxydans). Time-resolved measurements (excitation by 375nm pulsed diode laser) were employed to record the bacterial fluorescence intensity, as well as its modifications by metabolic modulation. Results were gathered on fresh bacteria, on de-frozen ones, as well as on bacteria encapsulated
in alginate beads. NAD(P)H fluorescence increased linearly with the concentration of bacteria. Freezing, which has little effect on the viability of bacteria or the concentration-dependent fluorescence rise, affected the temperature-dependence
of NAD(P)H fluorescence. Sodium cyanide (10 mM) provoked significant rise in the NAD(P)H fluorescence, while dinitrophenol (200 μM) induced its decrease, confirming the bacterial NAD(P)H fluorescence sensitivity to modulators of electron transport chain. Gathered results demonstrate that endogenous NAD(P)H fluorescence can be successfully
recorded in the bacterial strain G. oxydans using time-resolved measurements.