Inhibitory effects of Akacid (R)(plus) on growth and aflatoxin production by Aspergillus parasiticus
The effects of Akacid (R)(plus), a novel guanidine-based polymer first introduced as a biocidal and disinfectant agent were studied on Aspergillus parasiticus growth and its aflatoxin (AF) productivity. The fungus was cultured on yeast extract-sucrose (YES) broth in presence of various twofold serial dilutions of 25% Akacid (R)(plus) (1.5-96 mu L/50 mL medium) and then incubated in shaking condition with 150 rev./min at 28 degrees C for 96 h. Based on obtained results, Akacid (R)(plus) was found to significantly inhibit both growth and aflatoxin B-1 (AFB(1)) synthesis in very low concentrations in a dose-dependent manner. Fungal growth inhibition was determined in the range of 9.6-99.6% in mycelia exposed to the total concentration range of 1.5-48 mu L. A final concentration of 96 mu L was necessary to completely inhibit the growth of fungus. Under similar conditions, AFB(1) synthesis was found to be strongly inhibited by 8.1-98.0% in presence of 1.5-24 mu L Akacid (R)(plus) stop with a maximum of 100% by 48 mu L concentration. With respect to the unique physico-chemical properties of Akacid (R)(plus), its marked inhibitory effects on A. parasiticus growth and its AFB(1) synthesis shown for the first time in this study make it a promising candidate for application in prevention programmes of AF contamination of susceptible crops.