FUNGICIDAL EFFECT OF 15 DISINFECTANTS AGAINST 25 FUNGAL CONTAMINANTS COMMONLY FOUND IN BREAD AND CHEESE MANUFACTURING

Resistance of 19 mold and 6 yeast species to 15 commercial disinfectan ts was investigated by using a suspension method in which the fungicid al effect and germination time were determined at 20 degrees C. Disinf ectants containing 0.5% dodecyldiethylentriaminacetic acid, 10 g of ch loramine-T per 1, 2.0% formaldehyde, 0.1% potassium hydroxide, 3.0% hy drogen peroxide, or 0.3% peracetic acid were ineffective as fungicides . The fungicidal effect of quaternary ammonium compounds and chlorine compounds showed great variability between species and among the six i solates of Penicillium roqueforti var. roqueforti tested. The isolates of P. roqueforti var. carneum, P. discolor, Aspergillus versicolor, a nd Eurotium repens examined were resistant to different quaternary amm onium compounds. Conidia and vegetative cells were killed by alcohols, whereas ascospores were resistant. Resistance of ascospores to 70% et hanol increased with age. Both P. roqueforti var. roqueforti and E. re pens showed great variability of resistance within isolates of each sp ecies.