Antibacterial activity of lyase-depolymerized products of alginate.

摘要

A series of mannuronic acid (M-block) and guluronic acid (G-block) fractions (M1-M5 and G1-G5) with different molecular weights were obtained by lyase depolymerization of alginate and evaluated for in vitro antibacterial activity against 19 bacterial strains. The antibacterial data revealed that both types of fractions generally showed activity against certain tested bacteria, whereas M-block fractions showed broader spectra and more potent inhibition than G-block fractions. Among these fractions, M3 (molecular weight 4.235 kDa) exhibited the broadest spectrum of inhibition and high inhibitory activity against Escherichia coli (minimal inhibitory concentration, MIC=0.312 micro g mL-1), Salmonella paratyphi B (MIC=0.225 micro g mL-1), Staphylococcus aureus (MIC=0.016 micro g mL-1) and Bacillus subtilis (MIC=0.325 micro g mL-1)..