Extracellular production of azurin from Pseudomonas aeruginosa in the presence of Triton X-100 or Tween 80

Azurin which is a bacterial secondary metabolite has attracted much attention as potential anticancer agent in recent years. This copper-containing periplasmic redox protein supresses the tumor growth selectively. High-level secretion of proteins into the culture medium offers a significant advantage over periplasmic or cytoplasmic expression. The aim of this study was to investigate the effect of nonionic surfactants on the expression of the Pseudomonas aeruginosa azurin. Different concentrations of Triton X-100 and Tween 80 were used as supplements in growth media and extracellular azurin production was stimulated by both surfactants. According to western blot analysis results, in the presence of Triton X-100, maximum azurin expression level was achieved with 96 h of incubation at 1% concentration, and 48 h at 2% concentration. On the other hand, maximum azurin expression level was achieved in the presence of 1% Tween 80 at 72 h incubation. This study suggested for the first time a high level of azurin secretion from P. aeruginosa in the presence of Triton X-100 or Tween 80, which would be advantageous for the purification procedure.