Fig. 3
Minimum inhibitory concentration determination for zinc oxide nanoparticles. a Note the formation of small pinpoint colonies (arrowheads) of A. hydrophila on the control plate (on the right), while no bacterial growth was observed after incubation with 15.75 µg/mL zinc oxide nanoparticles (on the left), b growth of A. salmonicida with production of brown pigments on the control plate (on the right), while neither bacterial growth nor pigment production was observed after incubation with 15.75 µg/mL zinc oxide nanoparticles (on the left)