Physical adsorption immobilization of antimicrobial peptide (bacitracin) producing bacillus strain GU215 on polystyrene film

Abstract

The physical immobilization of Bacillus sp GU215 on polystyrene polymer film by adsorption was performed and
bacitracin (antimicrobial peptide) production by both free and immobilized cells were investigated at optimum
conditions. The immobilized cells presented immediate log time within 4 h, while the free cells showed a 24 h
delayed response. Likewise, free cells of Bacillus spp GU215 showed maximum zones of inhibition (18 mm)
within 72 h at 30°C temperature and pH 8, whereas polystyrene polymer immobilized cells presented largest 14
mm zones of inhibitions within 48 h at same conditions as free cells. We concluded that there existed a weak
physical adsorption between polystyrene polymer film and immobilized bacterial cells that rendered earlier
detachment of cells and resulted in a decrease in antimicrobial activity as compared to free cells.