In vitro aflatoxin B 1 binding capacity by two E nterococcus faecium strains isolated from healthy dog faeces

Aim This study evaluated the binding capacity of aflatoxin B 1 ( AFB 1 ) by two Enterococcus faecium strains ( MF 4 and GJ 40) isolated from faeces from healthy dogs. Materials and Methods The binding assay was performed using 50 and 100 ppb of AFB 1 analysing the effects of the viability, incubation time and pH on AFB 1 binding . Binding stability was determined by washing three times the bacteria‐ AFB 1 complexes with phosphate buffer saline. Results Both GJ 40 and MF 4 strains have the ability to remove AFB 1 from aqueous solution. Viable cells were slightly more effective in AFB 1 binding than nonviable ones for both strains. Enterococcus faecium GJ 40 removes 24–27% and 17–24%, and Ent. faecium MF 4 removes 36–42% and 27–32% of AFB 1 (50 and 100 ppb, respectively) throughout a 48 h incubation period. In general, the removal of AFB 1 was highest at pH 7·00 for both strains. The stability of the bacteria‐ AFB 1 complex formed was found to be high (up to 50% of AFB 1 remained bounded in bacterial cell after three washes with phosphate buffered saline). Conclusion The Ent. faecium strains assayed are capable of removing AFB 1 under different conditions in vitro . Significance and Impact of the Study This is the first AFB 1 binding assay performed with Ent. faecium strains isolated from dog faeces, being an interesting strategy for AFB 1 decontamination of pet food.