Determination of the concentrations of possible endogenous photosensitizers in <i>Candida auris</i> via two-dimensional fluorescence spectroscopy

Candida auris is an emerging pathogenic yeast. In order to investigate possible light-based disinfection systems or therapeutic approaches, this study examined the formation of possible photosensitizers under different growth conditions. The yeast was cultivated under aerobic conditions in YEPG medium and minimal medium with 10% NaCl. 2D fluorescence spectroscopy (15 excitation wavelengths from 320 to 450 nm) at different time points was performed to calculate the concentrations and proportions of dry mass of various fluorophores. Comparing the different growth conditions, higher concentrations of porphyrins were observed with minimal medium + 10% NaCl than with the YEPG medium. When determining the concentrations of different fluorophores over time, different dynamics could be observed for both aerobic growth conditions. For both growth conditions, NADH, followed by thiamine and lumichrome, exhibited the highest concentrations; coproporphyrin III showed the lowest.