Purification and Characterization of Plantaricinvgw8, A Bacteriocin Produced by Lactobacillus Plantarum VGW8

Abstract

PlantaricinVGW8, a bacteriocin produced by Lactobacillus plantarum VGW8 was purified by two steps method including extraction with n-butanol followed by gel filtration chromatography on Sepharose 6B column, the results showed that the specific activity was 10666.67AU/mg protein with 13.067purification folds and 12% recovery yield. Plantaricin VGW8 was characterized and the results showed that the molecular weight of it was 14400 Dalton by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Plantaricin VGW8 activity was stable at pH values (3-9) but 50% of its activity was lost at (2 and 10) pH values, and whole activity was lost at extreme alkali pH values(11 and 12).Also, plantaricin VGW8 showed high thermostability at different temperatures (20- 100)°C for (10,30 and 60)min, it remained active after being treated with (20- 80)°C for the periods above, but it retained only 50% of its activity after treatment at 100°C for one hour and autoclaving treatment (121°C/ 15 min).Also, the results showed that the activity of plantaricin VGW8 disappeared when it treated with proteolytic enzymes (pepsin, trypsin and papain), whereas it retained whole activity when treated with lipase, lysozyme and ?-amylase, indicating pure proteinaceous nature of purified plantaricin. As well as, treatment of plantaricin VGW8 with organic solvents (chloroform, acetonitrile, diethyl ether, ethanol, methanol, isopropanol, toluene and ethyl acetate), surfactants (tween 80, tween 20, triton X-100, SDS, EDTA and urea) and the metal ions: Na, K, Ca, Ba, Zn and Fe, showed no effect of these treatments on the activity of plantaricin VGW8, while treatment with Mn and Mg reduced its activity to the half. In conclusion, the characteristics of plantaricin VGW8 are promising for application of it in the food production processes as food preservative instead of chemicals food preservatives.

Keywords: purification of plantaricin, Lactobacillus plantarum, plantaricin activity, characterization of plantaricin.