Statistical optimization of cultural variables for enzymatic degradation of aflatoxin B1 by Panus neostrigosus

Abstract

The aim of this study is to determine the best aflatoxin B1 degradation conditions which was optimized using a combination of the Plackett-Burman and Box-Behnken methods with Panus neostrigosus culture filtrate. Panus neostrigosus was grown in a modified Kirk Broth medium to determine optimal degradation conditions. As a result, aflatoxin B1 was degraded under varying culture conditions. The Plackett-Burman method was designed after sixteen different experiments with fifteen variables. The three most effective variables (Sucrose, yeast extract, wheat bran) were chosen for the Box-Behnken methodology. The aflatoxin B1 degradation rate was 49% in just 1 h exposure to culture filtrate which was obtained under optimal growth conditions; (g-ml/L) sucrose 10, yeast extract 3, wheat bran 3, soytone 5, KH2PO4 2, MgSO4.7H2O 0.5, CaCl2.H2O 0.1, ammonium tartrate 2, trace element solution 10; 28 °C of incubation temperature, medium pH 5, 7.5% inoculum rate, 125 rpm of agitation speed, and a twelve-day incubation period. The SDS-PAGE studies show that the enzyme responsible for AFB1 degradation has 38 kDa molecular weight and has no laccase or MnP activity. To the best of our knowledge, this is the first report for AFB1 degradation by Panus neostrigosus.