Radiação gama sobre a micobiota de ração avícola e Aspergillus spp

RIBEIRO J.M.M.; CAVAGLIERI L.R.; VITAL H.C.; KRUGER C.D.; ROSA C.A.R.

CIêNCIA RURAL

UNIV FEDERAL SANTA MARIA

Año: 2009 vol. 39 p. 1 - 5

0103-8478

The research aimed to investigate the effect of gamma radiation on the mycoflora of natural ingredients and poultry feed, and its impact on species of Aspergillus spp. Corn meal, soybean meal and feed were irradiated with 0, 3.5, 8 and 15 kGy from source of 137Cs. Maize inoculated with spore suspension of Aspergillus spp. was subject to rates of 0 to 8 kGy. The results show that reducing the counting is intensified with increasing dose and mycoflora is completely eliminated with 15 kGy. There is a greater radiossensibilidade of yeast compared to filamentous fungi. Those who resist dose of 3.5 kGy mainly belong to the genera Cladosporium spp., Curvularia spp., Fusarium spp. and Aspergillus spp. There is variation in radiation sensibility between species, A. flavus and A. parasiticus are more radiation resistant that the other evaluated. Reduction in production of spores and presence of structures of resistance are observed in isolated irradiated. After culture on nutritional media these isolated again near the present growth pattern. The evidence that a metabolic stress caused by radiation, which promotes also increase the production of aflatoxin B1 and ochratoxin A.