antibacterial activity of chitosan against escherichia coli

introduction: chitosan possesses more than 5000 glucossamine residue. since chitosan possesses potentially reactive amino functional groups, this polymer has been shown to be of potential use in many different fields, including as an antifungal compound in agriculture, flocculating in waste water treatment, a food additive and alimentary industries, hydrating agent in cosmetics and more recently, in biomedicine and several pharmaceutical preparations. more research is needed to study the effects of chitosan on the escherichia coli. it is necessary to do more research on the effect of chitosan on the escherichia cell. the purpose of the investigation was to determine the antibacterial effects of chitosan against escherichia cell. materials and methods: escherichia coli:atcc 25992 and eosine-methylen blue agar was used .a standard of e.coli (1000000 per ml) is incubated for 24 hourse in a series of tubes concentration. the effects of reaction temperature, ph value and salts on the inhibitory activity of chitosan against escherichia coli were investigated. results: chitosan had inhibitory effects on escherichia coli activity (100% activity vs 1978%, p<0/05). our results show that higher temperature and acidic ph increased the antibacterial effects of chitosan. sodium ions might complex with chitosan and accordingly reduce chitosan activity against escherichia coli. divalent cations reduced the antibacterial activity of chitosan. conclusion: our results show that higher temperature and acidic ph increased the antibacterial effects of chitosan. sodium ions might complex with chitosan with chitosan and accordingly reduce activity againts escherichia coli. monovalent and divalent cations might complex with chitosan and accordingly reduce chitosan activity against escherichia coli.