Inactivation of Candida albicans in water using advanced oxidation processes

Pathogenic microorganisms such as bacteria, viruses, fungi and protozoa have played a central role in the safety of drinking water, since they spread easily in the water network, constituting an environmental problem for human and animal health. Currently in water treatments, Advanced Oxidative Processes (AOPs) have been increasing importance in the microbiological disinfection of water. Thus, the present study aimed to inactivate C. albicans, a commensal yeast species in Vertebrates that can cause disease, using Advanced Oxidative Processes (AOPs). To achieve this objective, an advanced oxidation process based on hydroxyl radicals (HR-AOP) was tested, combining an oxidant (hydrogen peroxide) with UV radiation on the inactivation of C. albicans. In view of the results obtained, it was verified that the application of 2.5 mM, 5 mM and 10 mM H₂O₂ reached a cell reduction of 3 log after 180, 360 and 300 min, respectively. Subsequently, the use of UV-A radiation proved to be even more promising, as the H₂O₂ + UV-A system reached an inactivation of 3 log after 240, 180 and 60 min, respectively. These results support that UV-A radiation increases the conversion of H₂O₂ in hydroxyl radicals, responsible for the inactivation of C. albicans cells. Thus, HR-AOPs are capable of reducing this microorganism in an aqueous matrix, avoiding potential hazard to human and animal health.