Antifungal Activity against the Growth of Aflatoxin Producing Fungi from Soil Actinobacteria

Abstract

—Aflatoxins are one of the highly concerning fungal toxins, which can cause the serious problems to human and animal health such as hepatotoxicity, teratogenicity, and immunotoxicity. Aspergillus flavus is the potential aflatoxin producer and it has usually been isolated from aflatoxin-contaminated crops. The biological compounds with the outstanding antifungal activity for inhibiting the growth of aflatoxin producing fungi still require. This experiment was attempt to isolate antifungal producing actinomycete from soil. Thirty isolates of soil actinobacteria were tested for an ability to inhibit the growth of A. flavus IMI 242684 using dual culture test and agar well diffusion assay. Primary screening results from dual culture test showed that 6 isolates of actinobacteria, N39Wh, N44Cr, N38Gr, LP14Wh, N13Gy, and N42Wh exhibited antifungal activity against the growth of A. flavus and with percent inhibition in the range of 21.42 to 42.85% then, their activity were confirmed by agar well diffusion assay. The freeze-dried supernatant from isolate N39Wh at concentration of 250 mg/mL showed the strongest antifungal activity with inhibitory zone of 17.25 mm followed by isolate N44Cr, LP14Wh, N38Gr, N13Gy, and N42Wh which produced the inhibition zone at 14.31 mm, 13.71mm, 13.50mm, 11.53mm, and 10.15mm, respectively.