Role of Zn2+ in the synthesis of antimicrobial and antiadhesive surfactants Acinetobacter calcoaceticus ІMV B-7241

Abstract

The effect of Zn²⁺ ions on NADP⁺-dependent glutamate dehydrogenase activity and the biological properties of surface-active substances produced by Acinetobacter calcoaceticus IMV B-7241 using ethanol and n-hexadecane as carbon sources was investigated. The addition of Zn²⁺ to a medium containing Cu²⁺ and Fe²⁺ increased enzyme activity to 1739±87 and 8333±416 nmol·min⁻¹·mg⁻¹ protein, respectively, and promoted the formation of surfactants with enhanced antimicrobial and antiadhesive activities. The minimum inhibitory concentrations of the surfactants against the tested bacteria were 1.6–3.3-fold lower, while adhesion of Escherichia coli IEM-1 to treated surfaces decreased by 10–19% compared with preparations obtained without Zn²⁺. These findings demonstrate the potential for regulating the biological properties of A. calcoaceticus surfactants by modifying the cultivation medium with zinc ions