α-Amylase Production by Toxigenic Strains ofAspergillusandPenicillium

Abstract

Aflatoxins are produced by a variety of fungal species and these have contrib-uted to devastating health problems globally. However, apart from the capability of the production of aflatoxins, the productions of enzymes by like fungi have been explored. Aflatoxin B1-producing-toxigenic strains of Aspergillus flavus (A 1 ), Aspergillus parasiticus (A 2 ), Penicillium citrinum (P 1 ) and Penicillium rubrum (P 2 ) isolated from rice were grown on a defined medium with varying carbon and nitrogen sources. They were also grown on rice as sole carbon and nitrogen source for fungal growth. In an attempt to purify, the extracellular α -amylases produced were subjected to ammonium sulfate precipitation (40–90% saturation) followed by dialysis. The aflatoxin B1-producing toxigenic strains of Aspergillus flavus (A 1 ), Aspergillus parasiticus (A 2 ), Penicillium citrinum (P 1 ) and Penicillium rubrum (P 2 ) were able to produce α -amylases in both the growth medium with varying C and N sources of fungal and also in the rice medium. The most active α -amylase activity was produced by toxigenic A. flavus (A 1 ) with a value of 3.25 ± 0.15 Units and this was when ammonium sulfate was nitrogen source with starch as carbon source of fungal growth in the defined growth medium. These toxigenic fungal strains can be explored for the industrial production of α -amylases. the production and activity of α -amylases by some toxigenic aflatoxin B1-producing strains of Aspergillus and Penicillium isolated from deterioration rice. Attempts were made to purify the α -amylases.