Several lactic acid bacteria have been reported to have a capability in binding aflatoxins, either physically surface binding or internally binding. Aim of this study was to screen lactic acid bacteria strains which have capability in the binding of aflatoxin B1 in the buffer system. Seven lactic acid bacteria strains from several sources have been used in this study. To collect biomass of lactic acid bacteria, each strain was cultivated in MRS broth for 24 h and harvested by centrifugation. To perform the binding ability, a certain concentration of each strain was added into phosphate buffer saline (PBS) containing AFB1 followed by incubation for 48 h at 370C. After incubation the amount of unbound AFB1 was determined by HPLC.
The results showed that all lactic acid bacteria strains have an ability in binding AFB1 with different strength. Lactobacillus acidopilus SNP-2 (probiotic strain), Streptococcus thermophilus FNCC-0040 and Lb. bulgaricus FNCC-0041 (yoghurt strains), Lb. plantarum FNCC-0265 (from fermented cassava), Lb. plantarum-pentosus FNCC-0249 (tape cassava), Lactobacillus sp Dad-13 (fermented milk), Lactobacillus sp RS-12 (from tempe) bound AFB1 61,85%; 31,09%; 37,56%; 28,52%, 9,33%; 26,12% and 7,21% respectively. When the complexes (LAB-AFB1) were washed with PBS up to five times, variables amount of AFB1 were released into the washing solution. However, after five times washing the complexes were more stable. Since no AFB1 were detected in the solution after the complexes were applied to sonication. Results also showed that binding between LAB and AFB1 was affected by pH of the environment (pH 3-7).
Keywords: Binding, lactic acid bacteria, aflatoxin B1