Journal of Pure and Applied MicrobiologyVol. 7 No. 1

Study on Effect of Antimicrobial Lipopeptide from Bacillus subtilis against E. coli

Xuemin Zhu1,2, Lan Wei2 and Xianqing Huang1*

1Henan Agricultural University, Zhengzhou, People's Republic of China. 2College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, People's Republic of China.

Received on 21 January 2013 and accepted on 03 March 2013

 

ABSTRACT

Antimicrobial lipopeptides (AMLPs) (surfactin, fengycin and their isoforms) produced by Bacillus subtilis strain exhibit a broad antimicrobial spectrum against Gram-positive bacteria, Gram-negative bacteria, fungi and virus. In this paper, antimicrobial activity of AMLPs aginst Escherichia coli ATCC 25922 was determined, and the effects of AMLPs on morphological, growth, multiplication, membrane permeability were investigated. Results indicated growth and multiplication of E. coli were inhibited efficiently, which was sensitive to AMLPs. The minimal inhibitory concentration (MIC) was 125?M. Studies on bacterial growth curve and microstructure indicated that AMLPs could kill or lyse the E. coli cells. Membrane permeability study showed significant increase of permeability of E. coli cells. This study indicated the AMLPs could affected the biomembrane.

Keywords : Antimicrobial lipopeptides, B. subtilis; E. coli, Membrane permeability, Minimal inhibitory concentration.