Synthesis, characterization, and antibacterial activity of chitosan/TiO2 nanocomposite against Xanthomonas oryzae pv. oryzae

•Chitosan/TiO2 nanocomposites with different CS-TiO2 ratios were synthesized.•Chitosan/TiO2 nanocomposites exhibited better performance than the single one.•Chitosan/TiO2 nanocomposites showed antibacterial activity in both light and dark.•The improved effect may be due to the new properties of this nanocomposite.•EPS was involved in the antibacterial activity of chitosan/TiO2 nanocomposites.

This present study deals with synthesis, characterization and antibacterial activity of chitosan/TiO2 nanocomposites. Results indicated that chitosan/TiO2 nanocomposite at the ratio of 1:5 showed the strongest inhibition in growth of rice bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo). Furthermore, the antibacterial activity of chitosan/TiO2 nanocomposite against Xoo is significantly higher than that of the two individual components under both light and dark conditions. Regardless of the presence or absence of extracellular polymeric substances, chitosan/TiO2 nanocomposite showed strong antibacterial activity, however, the absence increased the sensitivity of Xoo to chitosan/TiO2 nanocomposite. In addition, the surface morphology and physicochemical properties of chitosan/TiO2 nanocomposite is different from the two individual components based on scanning electron microscopic observation, fourier transform infrared spectra, and X-ray diffraction pattern, as well as elemental and thermo gravimetric analysis. Overall, this study indicated that this synthesized chitosan/TiO2 nanocomposite is promising to be developed as a new antibacterial material.