Assessment of Lactobacillus Delbruekii and Bifidobacterium Animalis Abilities to Absorb Aflatoxin M1 from Milk

Background and Aims: Microbial detoxification is one of the methods for eliminating of aflatoxins, including aflatoxin M1. Reports indicate that some strains of lactic acid bacteria family through surface adsorption of aflatoxin in their cellwall can be effective in removing them and as a primer culture. In this study, the ability of Bifidobacterium animalis and Lactobacillus delbrueckii in the adsorption of aflatoxin M1 in skim milk was assessed. Materials and Methods: For this purpose, about 108 and 109 cfu/ ml of B. animalis (Lactis) and L. delbrueckii (Blegaricus) were inoculated into skim milk without aflatoxin M1. Then, the samples were spiked by aflatoxin M1 in concentrations of 0.25, 0.5 and 0.75 ng/ ml. The concentration of the aflatoxin reside in supernatant of milk samples after different storage times (0.5, 1, 2 and 24 h) and temperatures of 4 and 37°C was measured by ELISA method, and the results were confirmed by HPLC. Results: The results showed that the highest amount of aflatoxin M1 removal was respectively related to B. animalis (60 ± 2.5%) with a concentration of 108 cells/ ml and L. delbrueckii (58.5 ± 2.5%) with a concentration of 109 cells/ ml and a concentration of 0.5 ng/ml poison at 37°C for 30 minutes. By comparing the concentration of both bacteria, it also appeared that the B. animalis concentration at 37°C and L. delbrueckii concentration at 4°C were more effective. Also, the results indicate that the ability of bacteria to reduce the amount of poison in half an hour in milk samples with values of 0.75 ng/ml poison at 4°C and 0.5 ng/ml poison at 37°C is higher; but over time, contaminated milk at a concentration of 0.75 ng/ml poison compared to 0.5 ng/ml poison showed an increased amount of aflatoxin removal. Calclusion: B. animalis and L. delbrueckii can act as two useful probiotics to reduce the harmful effects of aflatoxin M1.