Inhibition of growth and biosynthesis of ochratoxin A in Aspergillus sulphureus NRRL 4077 by propolis extract.

Growth inhibition of Aspergillus sulphureus NRRL 4077 and biosynthesis of ochratoxin A in the presence of propolis was investigated. Although the growth of the micro-organism was inhibited at all concentrations of applied propolis extract up to d 10 of incubation, only the 2.0 mg/ml concentration of propolis exhibited definite fungistatic activity. Ochratoxin A was detected in all culture media, but its amounts were low in the first 10 d of experiment. In comparison with the control culture, the amounts of ochratoxin A were proportional to the growth of A. sulphureus and reciprocal to the amounts of propolis extract used.