Copper Binding by Lactic Acid Bacteria (LAB)

Western diet is frequently low in essential metal ions. A common method for preventing metal ion deficiency is pharmacological supplementation, especially in a highly available form such as metalo-protein complexes. Accordingly, in this work, specific lactic acid bacteria were assessed for their ability to bind copper ions. Significant amounts of copper ions were bound, and the binding potential was found to be strain specific. Differences among the strains were evaluated with the Langmuir model for biosorption. Binding of copper was a fast process, strongly influenced by ionic strength, pH and biomass concentration. During the process, copper ions significantly reduced cell viability. Discharge of copper ions in a simulated gastrointestinal tract was examined ; 85-90% of copper ions bound to LAB were discharged in the gastrointestinal model system.