In vitro antifungal effect of EDTA disodium salt in tested black aspergilli

Abstract

The antifungal effect of Na2EDTA on an Aspergillus carbonarius, an A. ibericus, an ochratoxigenic A. niger and a non-ochratoxigenic A. niger strain was studied. Also, the effect of Na2EDTA on the production of ochratoxin A by A. carbonarius and the ochratoxigenic A. niger was evaluated. The poisoned food technique was used with CYA medium supplemented with 0, 1 and 10 mmol L-1 of Na2EDTA. The colony diameters were recorded daily and the amount of ochratoxin A produced was quantified every two days. Significant reductions of growth rates were observed in the presence of Na2EDTA being the calculated EC50 of 2.1 mmol L-1 for A. carbonarius, 0.9 mmol L-1 for A. ibericus, 2.0 mmol L-1 for the ochratoxigenic A. niger and 4.1 mmol L-1 for the non-ochratoxigenic A. niger. Furthermore, 10 mmol L-1 Na2EDTA delayed the production of ochratoxin A and reduced the levels in approximately 99% during 8 days. Na2EDTA is frequently used in the food industry and in agriculture agrochemicals and its effects on ochratoxigenic black aspergilli is not well known. This study showed that Na2EDTA can significantly reduce the growth rates of tested fungi and its ochratoxin A production.