Enhancement of production and activity of alkaline zinc metalloprotease from Salinivibrio proteolyticus using low intensity direct electric current and zinc nanoparticles.

Abstract

To improve the production and activity of an alkaline zinc metalloprotease from Salinivibrio proteolyticus in response to ZnSO4 (ionic and nanoparticle forms) and low intensity direct electric current (LIDC). A DC of 50 µA for 10min increased enzyme production from 35 to 53 U ml(-1) when applied to the stationary phase bacterial cells. Zn(2+) improved enzyme production better than zinc nanoparticles (52 vs. 43.5 U ml(-1)). Zinc nanoparticles (0.5mM) added to an enzyme reaction mixture containing casein (0.65%) and 20mM Tris/HCl buffer (pH 8) improved enzyme activity more than Zn(2+) (42 vs. 36 U ml(-1)). LIDC exposure (50 µA, 10min) to the stationary phase bacterial cells increases metalloprotease production in Salinivibrio. A low concentration of zinc nanoparticles (0.5mM) increases maximum enzyme activity.