Screening of Toxigenic Aspergillus flavus Strains and Aflatoxin Content from Agricultural Commodities in Indonesia

: Infection of toxigenic A. flavus in agricultural commodities may result in production of aflatoxin, a mycotoxin which is genotoxic carcinogenic for humans and animals. The aims of this study were to screen toxigenic A. flavus strains and to determine aflatoxin content of six agricultural commodities in Indonesia. A total of 50 A. flavus strains were obtained from Phytopathology Laboratory, SEAMEO BIOTROP. The strains were isolated from nutmeg, corn, cacao, white pepper, coffee bean, ground peanut and peanut-cropped soil. The toxigenicity of A. flavus were determined bfy growth simulation on aflatoxin-inducing medium (10% coconut agar medium) followed by observation of their fluorescence using 365 nm UV light. AFB and AFG toxin produced were quantified using HPLC. The results showed that 18% (9 strains) A. flavus were toxigenic, which derived from nutmeg (5 strains), ground peanut (2 strains), cacao (1 strain), and peanut-cropped soil (1 strain). Six toxigenic strains produced AFB1 exceeding the Indonesian-regulatory maximum level (15 ug/kg). A. flavus from peanut-cropped soil (BIO 3352) produced the highest AFB1 content (90.94 ug/kg), while the other from nutmeg (BIO 3345 and BIO 33212), ground peanut (BIO 3313 and BIO 3338), and cacao (BIO 33404) had AFB1 content of 89.53, 84.24, 70.26, 40.27, and 69.06 ug/kg respectively. The producing aflatoxin capability of these strains can be potentially hazard if contaminated in agricultural commodities.