Antibacterial Properties of Bacteriocin Purified from Serratia marcescens and Computerized Assessment of its Interaction with Antigen 43 in Escherichia coli

Abstract

Bacteriocins are a kind of antimicrobial peptides that kill or inhibit the growth of bacterial strains. The purpose of this study was to investigate the antibacterial effect of Serratia marcescens on several pathogenic bacterial strains. Bacteriocin produced by S. marcescens was purified by chromatography with Sephadex G-75 column, and its antibacterial effect on gram-negative bacteria, including Escherichia coli ATCC 700928, Pseudomonas aeruginosa PTCC 1707, S. marcescens PTCC 1621, Vibrio fischeri PTCC 1693, and Vibrio harveyi PTCC 1755, were evaluated by the disk diffusion method. The structure of bacteriocin was determined by nuclear magnetic resonance spectroscopy. The interaction of bacteriocin with the antigen 43 (Ag43) of E. coli was evaluated by the molecular docking method. Bacteriocin extracted from bacterial isolates had antibacterial activity on E. coli strains but not on other studied strains. Bioinformatics analysis also showed bacteriocin docking with Ag43 with an energy of -159.968 kJ/mol. Natural compounds, such as bacteriocin, can be an alternative to common chemical compounds and antibiotics. To reach a definite conclusion in this regard, there is a need for further research and understanding of their mechanism of action.

Keywords: Antibacterial property; Antigen 43; Bacteriocin; Molecular docking; Serratia marcescens.

Figure 1

H-NMR (A) and C-NMR (B) spectra and structures obtained for bacteriocin purified from Serratia marcescens

Figure 2

Three-dimensional structure of bacteriocin purified from Serratia marcescens

Figure 3

Disk diffusion test to evaluate the antibacterial properties of bacteriocin on Escherichia coli; Disk A: Negative Control (Water), Disk B: Bacteriocin

Figure 4

Molecular docking between antigen 43 protein from Escherichia coli and bacteriocin purified from Serratia marcescens, with energy of -159.968 kJ/mol

Figure 5

Schematic of some bonds between bacteriocin and amino acids involved in docking (blue dashed line: hydrogen bond, green dashed line: electrostatic bond, red dashed line: ester bond).