Growth modeling to control (in vitro) Fusarium verticillioides and Rhizopus stolonifer with thymol and carvacrol

The aim of this study was to evaluate the antifungal activity (in vitro) of thymol and carvacrol alone or in mixtures against Fusarium verticillioides and Rhizopus stolonifer, and to obtain primary growth models. Minimal inhibitory concentration (MIC) was evaluated with fungal radial growth with thymol or carvacrol concentrations (0-1600 mg/l). Mixtures were evaluated using concentrations below MIC values. Radial growth curves were described by the modified Gompertz equation. MIC values of carvacrol were 200 mg/l for both fungi. Meanwhile, MIC values of thymol were between 500 and 400 mg/l for F. verticillioides and R. stolonifer, respectively. A synergistic effect below MIC concentrations for carvacrol (100 mg/l) and thymol (100-375 mg/l) was observed. Significant differences (p < 0.05) between the Gompertz parameters for the antimicrobial concentrations and their tested mixtures established an inverse relationship between antimicrobial concentration and mycelial development of both fungi. Modified Gompertz parameters can be useful to determine fungistatic concentrations. (c) 2017 Asociacion Argentina de Microbiologia. Published by Elsevier Espana, S.L.U.