RAPISARDA Viviana Andrea
congresos y reuniones científicas
OXIDATIVE TREATMENT INHIBITS THE GROWTH OF Penicillium expansum
LAZARTE, M. A.; CERIONI, L.; RAPISARDA, V. A.; RODRÍGUEZ-MONTELONGO, L.; VOLENTINI, S. I.
Congreso; VII CONGRESO DE LA SOCIEDAD ARGENTINA DE MICROBIOLOGÍA GENERAL (SAMIGE) Bicentenario; 2011
Argentina is the main producer of apple in southern hemisphere. Blue mold rot caused by Penicillium expansum is the most important postharvest disease of apples, causing major economic losses. Synthetic fungicides are used to control this disease, but the effectiveness of them has been seriously compromise with the appearance of certain resistant biotypes of P. expansum. Therefore, is desirable to find alternative methods to the conventional fungicides for control of blue mold rot. In our laboratory, we have standardized a sequential oxidative treatment (SOT), which is able to inhibit the growth of Penicillium digitatum, P. italicum and Geotrichum candidum, causal agents of citrus postharvest diseases. The SOT consists on a first incubation with NaClO followed by a second incubation with H2O2 and CuSO4. The combination of these compounds in the SOT generated a synergistic effect. Here, we analyzed the effects of the oxidizing compounds on P. expansum growth and conidia germination. We determined the MIC for each compound and we established conditions for an oxidative treatment against this fungal pathogen. Results shown that P. expansum was more sensitive than P. digitatum and P. italicum, since in vitro growth was completely inhibited by a brief incubation of 2 min with 5 ppm NaClO, 6 mM CuSO4 and 100 mM H2O2. Moreover, when we analyzed the conidia germination in lethal and sublethal conditions, we found a direct correlation with conidia growth inhibition. Thus, we demonstrate that the oxidative treatment could be used as an alternative methodology to eliminate P. expansum conidia.