Antibacterial activity of chitosan solution against Xanthomonas pathogenic bacteria isolated from Euphorbia pulcherrima

The antibacterial activity of chitosan solution against Xanthomonas pathogenic bacteria isolated from Euphorbia pulcherrima was investigated in this study. Results showed that chitosan solution at 0.10 mg/mL markedly inhibited the growth of Xanthomonas pathogenic bacteria from different geographical origins. The antibacterial activity of chitosan solution against the selected strain R22580 of Xanthomonas axonopodis pv. poinsettiicola increased with the increase of chitosan concentration up to 0.10 mg/mL. The antibacterial activity of chitosan solution was also enhanced by the addition of NaCl, but was unaffected by the type of nutrient and sterilization. In addition, chitosan solution exhibited strong antibacterial activity against strain R22580 over the pH range of 5.5-7.0. Overall, the results indicated that chitosan was a potential bactericide against bacterial pathogens of E pulcherrima under different environmental conditions. (c) 2007 Elsevier Ltd. All rights reserved.