Aflatoxin B1-degrading activity fromBacillus subtilisBCC 42005 isolated from fermented cereal products

Aflatoxin B(1)is a naturally occurring mycotoxin that is produced as secondary metabolite byAspergillusspp., especiallyA. flavusandA. parasiticus. This is the most severe toxin due to its carcinogenic, mutagenic, and teratogenic properties. Hence, methods for toxin degradation have been received increasing interest from both scientific communities and industries. In this study, 32 isolates ofBacillusspp. from various fermented cereal products were screened for their aflatoxin B(1)degradation ability. The results indicated the extracellular fraction ofBacillus subtilisBCC 42005 isolated from Iru (African locust bean) potentially possessed aflatoxin B-1-degrading ability. The maximum activity of the active fraction was at 50 degrees C and pH 8.0. The activity was stable in a wide range of pH (5.0-8.0) and temperature (25-60 degrees C). The aflatoxin B-1-degrading mechanisms of this strain may be possibly involved by enzyme(s). This extracellular fraction was not toxic at IC(50)4 mg/ml and it can be combined with water as a soaking agent for maize, which results in 54% of aflatoxin B(1)reduction after contact time 120 min. Hence, the extracellular fraction ofBacillus subtilisBCC 42005 can be further applied as an effective soaking agent in a pretreatment process with a practical and easy-to-implement condition and also probably used to reduce the aflatoxin B(1)contamination in other foods and feeds commodities.