Effect of basicillus subtilis on aflatoxin

Abstract

Aflatoxin, a dangerous mycotoxin for humans and animals, can be treated by physical, chemical or biological methods; although biological method seems to be the most ecological approach. This study was carried out to demonstrate the effect of Bacillus subtilis on aflatoxin and to determine how B. subtilis could reduce its toxicity in an effort to use these bacteria in control the contamination in animal feed. Soil-isolated B. subtilis B2 was culture in TSB (Trypticase Soya broth) media containing different concentrations of aflatoxin from 0 to 800ppb. The results of this study demonstrate that strain B2 reduces the concentration, and subsequently, the toxicity of aflatoxin. After 7 days, the concentration of aflatoxin underwent reduction between 4 to 10-fold in the medium without B. subtilis. Furthermore, the medium containing B. subtilis culture underwent an approximate 25 to 80-fold reduction of aflatoxin. The results also demonstrated that the microbial toxicity of aflatoxin reduced the viability of B. subtilis in both the number of bacteria and spores. Bacillus subtilis has an apparent effect on reduction of aflatoxin, and it is possible that B. subtilis could be decomposing aflatoxin rather than using it for nutritional purpose. Moreover, aflatoxin presents a level of microbial toxicity to B. subtilis and could be hindering its growth in return. These results indicate that B. subtilis could be used as a biological additive to control aflatoxin in feed.