INHIBITION OF THE MOLDS GROWTH BY SELECTE D ORGANIC-ACIDS

Fungicidal effects of five selected organic acids (lactic, acetic, for mic, oxalic, and propionic) in concentrations 3, 5, 10, 20 and 50 ml/l on nine selected species of moulds were tested. Lactic and oxalic aci ds did not prove the satisfactory fungicidal activity in any of the ch osen concentrations. The antifungal effect of die other three acids, m anifested by the growth inhibition of the tested moulds is shown in Ta b. I and it can be expressed by sequence: propionic acid, formic acid, and acetic acid. These acids also had effects only in concentrations 20 ml/l and 50 ml/l. Propionic acid in concentration 20 ml/l inhibited the growth of five moulds (Penicillium glabrum, Aspergillus niger, Fu sarium moniliforme, Aspergillus fumigatus, Cladosporium sphaerospermum ). In testing of concentration 50 ml/l, the lower fungicidal ability w as ascertained only in growth suppression of Aspergillus flavus. The f ungicidal activity of formic acid was registered in concentration 20 m l/l in two cases and in concentration 50 ml/l in six cases. Acetic aci d inhibited the growth in concentration 50 ml/l only in two cases. Tab . II shows the percentual evaluation of propionic acid and formic acid with regard to their inhibition abilities. The fungicidal efficiency of propionic acid resulting from the experiment is 88.9