EFEITO DO ÓLEO DE Moringa oleífera SOBRE O PATÓGENO PISCÍCOLA Saprolegnia parasítica

Abstract

Moringa oleifera is a plant with great potential for this purpose, due to its antimicrobial properties. In this context, the objective was to evaluate the action of M. oleifera seed oil on the fungus Saprolegnia parasitica, which causes the most important fungal disease in freshwater fish. For this purpose, the seeds were collected from the pods in a ripe state and submitted to a cold extraction process via mechanical press. A strain of the S. parasitica was used as test culture by the bioanalytical method "in vitro" on BDA (Potato, Dextrose and Agar) medium. The oil was emulsified by the low energy method, with surfactant and water, and poured onto the plates with medium at the concentrations of the treatments. The experiment was conducted in a randomized design with 5 treatments (0, 0.25, 0.50, 0.75, and 1.0 mL/L), all with 5 repetitions, maintained at a temperature of 24°C. The plates were observed every 24 hours for 96 hours for mycelial growth measurement. By 48 hours, a reduction in growth was observed at 0.25mL/L, intensifying at levels of 0.5; 0.75, and 1.0mL/L. In 72 hours, the control treatments and the 0.25mL/Ltreatment did not differ, but were different from the other treatments. However, after 96 hours all reached full extension. Therefore, M. oleifera seed oil shows fungistatic activity on the fungus S. parasitica at concentrations higher than 0.25mL/L.