Heterologous expression of azurin from in food-grade .

In this study, azurin, a bacteriocin with anticancer property, was produced by food-grade using the Nisin Controlled Gene Expression (NICE) System. In addition, the antibacterial and cytotoxic properties of recombinant azurin in the culture supernatant were also investigated. Azurin gene from was cloned into the pNZ8149 vector and the resulting recombinant DNA was transformed into food grade NZ3900. The expression of azurin protein was induced by the optimum concentration of nisin for 3 h. Inhibition zones for and were observed at 5.0 and 10 mg/mL concentrations of lyophilized supernatants containing azurin, but no inhibition zone at azurin-free lyophilized supernatants. When HUVEC, HT29, HCT116, and MCF7 cell lines were treated with lyophilized culture supernatants with azurin or without azurin, cell viability decreased with increasing concentrations of the supernatant. Furthermore, the supernatants containing azurin showed more anti-proliferative effect than the azurin-free supernatants. This work provides a practicable method to produce recombinant azurin in the food grade strain. As a result, the recombinant strain, producing azurin, can be used in the investigation of food biopreservatives and in the development of a therapeutic probiotic.