Antifungal activity and mechanism of d-limonene against foodborne opportunistic pathogen Candida tropicalis

Limonene can inhibit the common spoilage fungi in food, but few studies elucidated its antifungal activity and mechanism against Candida tropicalis to date. Therefore, this study aimed to the antifungal activity and mechanism of d-limonene against C. tropicalis. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of d-limonene against C. tropicalis were 20 μL/mL and 40 μL/mL in potato dextrose broth (PDB) medium, respectively. After treatment with d-limonene in PDB medium, the decrease of the potential, the increase of the permeability and the integrity damage of cell membrane indicated the failure of ion transshipment and ATP generation in membrane, the disruption of intracellular ion homeostasis, the leakage of intracellular proteins of C. tropicalis, and thus altering the cell morphology. These results suggest that the d-limonene has the potential to prevent C. tropicalis contamination in the food industry.