Antibacterial action of a novel functionalized chitosan-arginine against Gram-negative bacteria.

摘要: The antimicrobial activity of chitosan and derivatives has been well established. However, although several mechanisms have proposed, the exact mode action is still unclear. Here we report on investigation antibacterial a novel water-soluble derivative, arginine-functionalized chitosan, Gram-negative bacteria Pseudomonas fluorescens Escherichia coli. Two different chitosans (6% arginine-substituted 30% arginine-substituted) each strongly inhibited P. E. coli growth. Time-dependent killing efficacy experiments showed that 5000 mg l(-1) 6%- 30%-substituted chitosan-arginine killed 2.7 logs 4.5 fluorescens, 4.8 4.6 in 4h, respectively. At low concentrations, 6%-substituted was more effective inhibiting cell growth even though appeared to be permeabilizing membranes both Studies using fluorescent probes, 1-N-phenyl-naphthylamine (NPN), nile red (NR) propidium iodide (PI), field emission scanning electron microscopy (FESEM) suggest chitosan-arginine's is, at least part, due its interaction with membrane, which it increases membrane permeability.