EFFECT OF GAMMA-RADIATION ON THE SURVIVAL OF FUNGAL AND ACTINOMYCETALFLORAE CONTAMINATING MEDICINAL-PLANTS

This study evaluates the effect of gamma radiation on the viability of fungi and actinomycetes that contaminate medicinal plants. The relati onship between the total lipids of some fungi and actinomycetes and th eir sensitivity to gamma radiation is also investigated. The data reve al that the viable counts of these florae decrease approximately expon entially with the radiation dose, the effective dose for the eliminati on of these microorganisms being about 5 kGy for all the medicinal pla nts under study. Response of pure cultures of fungi and actinomycetes isolated from medicinal plants to increasing absorbed doses of gamma r adiation indicate that an increase in radioresistance is in the follow ing order: Streptomyces rimosus, Fusarium solani, Nocardia kuroishii. F. oxysporum, A. fumigatus, A. flavus, A. parasiticus and A. ochraceus . The total lipid contents of molds and actinomycetes have been report ed to be increased by increasing the radio-resistance of microorganism s, and hence there is a relationship between the radio-sensitivity of microorganisms and the total lipid mass of flora mycella. Copyright (C ) 1997 Elsevier Science Ltd