Binding of heterocyclic aromatic amines by lactic acid bacteria: results of a comprehensive screening trial.

Aim of the present study was a comprehensive investigation of the detoxification capacities of lactic acid bacteria (LAB) towards heterocyclic aromatic amines (HCA) formed during cooking of meat. It has been postulated that LAB prevent genotoxic and/or carcinogenic effects of HCA in laboratory rodents and humans via direct binding mechanisms. We measured the removal of the most abundant cooked food mutagens (AαC, PhIP, IQ, MeIQx, DiMeIQx) by eight LAB species. From each species, twelve strains were tested in liquid binding experiments with HPLC coupled with coulometric electrode array detection. The highest removal rates were observed with the representatives of the L. helveticus and S. thermophilus groups, which were seven to eight times more effective than L. kefir and L. plantarum. Strong and statistically significant differences were seen in the binding behaviour of the individual amines, the ranking order of detoxification being AaC > DiMeIQx > MeIQx > IQ > PhIP. Results of Salmonella/microsome assays with strain TA98 showed that the binding of AaC and PhIP to LAB correlates with the reduction of their mutagenic activities. This study may contribute to the development of strategies concerning the adverse health effects of HCA utilizing highly protective LAB for the production of fermented foods.