Reduction of Some Enzymes Produced by Irradiated Fungal Strains Isolated from Certain Medicinal Plants

Abstract

Medicinal plants normally carry high bioburden due to their origin, offering potentials hazards to the consumer. Fungal extracellular enzymes play a role in biodeterioration of medicinal plants and undesirably effect human health cause immunotoxigenic diseases. Ten different medicinal plants were screened for their mold contamination. The isolates were identified as genera Aspergillus, Alternaria, Cladosporium and Penicillum, they tested for their enzymatic activities (protease, cellulase and lipase). All isolates were able to produce enzymes under study in a varying degree. Of the fungal isolates , Asp. niger and Asp. flavus showed high protease activity. Whereas P. roquefortii and Asp. parasiticus were the more potent strains producing cellulase. Lipase was found to be highly produced by Asp. fumigatus and P. italicum . The present study presumes to monitor the fungal growth and enzymatic activity in relation to gamma irradiation. The results showed that, the log number of survivors was found to be inversely proportional to the irradiation dose. 6.0 and 4.0 kGy resulted in complete inhibition the growth of  highly protease produces (Asp. niger and Asp.flavus). While,  P. roquefortii and Asp. parasiticus which highly produce cellulase were inhibited at 4.0 and 6.0 kGy, respectively. On the other hand, Asp.fumigatus and P. italicum which highly produce lipase were inhibited at dose 4.0 and 6.0 kGy, respectively. Subleathal doses of gamma- irradiation resulted in high significant reduction of enzymes production. The stability of acquired character for the strains under study which were exposed to gamma-irradiation was studied. Statistical analysis revealed that, the enzyme activities estimated after 6 months of storage gave difference data between the strains under study. This study indicates that gamma irradiation is an effective treatment for reduction of fungi contaminating medicinal plants as well as its ability to produce some enzymes.

Key words: medicinal plants, fungal isolates, enzymatic activity, gamma irradiation.