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

摘要

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 125iM. 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.