Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Purification, characterization and antibacterial mechanism of bacteriocin from Lactobacillus acidophilus XH1

Ruixiang Zhao¹ , Gaili Duan¹, Tianyou Yang², Shengyang Niu¹, Ying Wang¹

¹School of Food Science; ²College of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China.

For correspondence:- Ruixiang Zhao Email: zhaoruixiang@hist.edu.cn

Received: 18 July 2014 Accepted: 24 May 2015 Published: 29 June 2015

Citation: Zhao R, Duan G, Yang T, Niu S, Wang Y. Purification, characterization and antibacterial mechanism of bacteriocin from Lactobacillus acidophilus XH1. Trop J Pharm Res 2015; 14(6):989-995 doi: 10.4314/tjpr.v14i6.8

© 2015 The authors.
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Abstract

Purpose: To carry out the extraction, purification and biological characterization, and assess the antibacterial activity of bacteriocin from Lactobacillus acidophilus XH1.

Methods: Chloroform extraction method was used for bacteriocin extraction while characterization of bacteriocin was carried out by flat-dug well agar diffusion assay. The antibacterial mechanisms of bacteriocin were examined by scanning electron microscopy and atomic emission spectroscopy. The molecular weight of lactobacillin XH1 was measured using Tricine - SDS - PAGE electrophoresis.

Results: The bacteriocin (lactobacillin XH1) inhibited Escherichia coli, Staphylococcus aureus and Bacillus anthracis. It showed a wide range of antimicrobial activity at pH 1.0 - 5.0 while at 37 – 120 °C, it was sensitive to trypsin, pepsin and papain, but insensitive to proteinase K and neutral protease. The intracellular UV-absorbing substances,, namely, lactate dehydrogenase macromolecules, K⁺ and ATP of E. coli, decreased rapidly. The molecular weight of lactobacillin XH1 was approximately 16 kDa.

Conclusion: Lactobacillin XH1 is a broad-spectrum antimicrobial substance that is thermostable. Its antibacterial mechanism on Escherichia coli is similar to that of bacteriocins on Gram-positive bacteria. The agent is a hydrophobic protein with more acidic groups.

Keywords: Lactobacillus acidophilus, Lactobacillin, Bacteriocin, Purification, Antibacterial mechanism, Atomic emission spectroscopy