Preliminary investigation of Incorporation and Viability of Crystal Violet in Aspergillus flavus

The abusive use of antimicrobials have caused resistance in the microorganisms. Therefore, inovations in research of modern microbiology developed the photodynamic inactivation that is non-toxic and do not promote microbian resistance since it has multiples action sites. When a photoactive molecule is activated by light, it becomes more toxic for the microorganism than for the human cells, increasing the phototoxic effect against such cells. We tested the incorporation of the photosensitizer crystal violet by Aspergillus flavus and its viability in different periods of time of incubation (6 and 18 hours), concentrations of crystal violet (4M, 10M e 15 M) and different conditions (resting and agitation). We also tested the photoinactivation of Aspergillus flavus containing crystal violet. The incorporation rate does not depend on the concentration of CV neither on the condition of incubation. It depends exclusively on the medium, since it presented higher values in lack ingredients medium. The assays of viability of fungi after exposure to crystal violet show that there is fungic growth when samples are maintained in the dark. However, when the culture were submitted to excitation via laser, there was a decrease in the biomass growth, which indicates that there was photodynamic inactivation of the fungi.