The effect of Rhodotorula mucilaginosa on degradation of citrinin production by Penicillium digitatum and its toxin in vitro

Penicillium digitatum is a mesophilic fungus belonging to the genus, Penicillium and a producer of citrinin. This mycotoxin is a secondary metabolite and its existence has been reported in several agricultural products. In this study, the effect of Rhodotorula mucilaginosa on the production of citrinin by P. digitatum and the degradation of citrinin in vitro was investigated. The effect of R. mucilaginosa was dependent on the type of media, yeast concentration, pH, and temperature. R. mucilaginosa degraded citrinin produced by P. digitatum and the toxin with a degradation rate of 91.67% and 91.61%, respectively compared to the control. The degradation of citrinin by R. mucilaginosa was significant in nutrient yeast dextrose broth compared to potato dextrose broth where it was fairly stable throughout the test period. The yeast concentration that showed better efficacy was 1 x 10(8) cells/mL with a degradation rate of 93.10% at 48 h. Numerically, degradation was highest at 28 degrees C with a pH 4.0 being the most favorable for citrinin degradation by R. mucilaginosa.