Effect of Isolated Lactobacillus acidophilus and Lactobacillus brevis on Growth of Aspergillus flavus and Reduction of Aflatoxin B1

Aflatoxin B1 is the most toxigenic aflatoxin and one of the most liver carcinogenic agent produced by some of the Aspergillus species. Successful control of this mold growth would be an important step in the prevention of cancer. This study was carried out for evaluating the effect of isolated Lactobacillus acidophilus and Lactobacillus brevis on growth of Aspergillus flavus and reduction of aflatoxin B1.
In this laboratory study conducted in 2014, after identification of lactic acid bacteria (LAB) isolated from a traditional sourdough using polymerase chain reaction, the effect of these isolates on growth of Aspergillus flavus and reduction of aflatoxin B1 was studied by direct competitive ELISA. The effects of incubation time and heat treatment on residue of aflatoxin B1 in present of mentioned isolated LAB were also determined. Results were analysed by using t-test and one way ANOVA followed by LSD test.
After incubation period, the diameter of Aspergills flavus colonies in present of Lactobacillus acidophilus, Lactobacillus brevis and control sample were 1.50, 3.46 and 9.00 cm, respectively. The amount of aflatoxin B1 residue, after 0, 24 and 48 h incubation in present of Lactobacillus acidophilus were 50.60%, 48.93%, 41.24% and in present of Lactobacillus brevis were also 66.26%, 64.40% and 55.61%, respectively. Furthermore, non-viable cells of mentioned isolated LAB reduced the amount of aflatoxin B1, more effective than their viable cells (P By considering the high potential of LAB studied in this project for growth control of Aspergillus flavus and reduction of aflatoxin B1, it is possible to use their biopreservative ability for reduction of cancer risk.