Search

In the present study we reported, for the first time, the gamma irradiation induced synthesis of chitosan/Au/bioactive glass (CS/Au/BG) nanocomposite. The bioactive glass (BG), with the composition 45% SiO2, 32.5% CaO, 15% Na2O, and 7.5% P2O5 wt% was synthesized through the sol–gel technique. XRD, SEM, EDX, and elemental mapping images were utilized to evaluate the structure of pure BG and CS/Au/BG nanocomposite. The antimicrobial efficacy was evaluated by zone of inhibition (ZOI), minimum inhibitory concentration (MIC), growth curve assay, and Ultraviolet irradiation effect. Investigation was carried on the antibiofilm effectiveness. Membrane leakage as well as SEM imaging were used to evaluate the antibacterial reaction mechanism. The crystallite size of CS/Au/BG nanocomposite was determined via Scherer equation as 22.83 nm. CS/Au/BG possessed the most ZOI activity against the tested microbes. The highest inhibition % of BG, and CS/Au/BG nanocomposite was investigated for S. aureus (15.65%, and 77.24%), followed by C. albicans (13.32%, and 64.75%). The quantity of protein leakage was directly-proportional after increasing the concentration of BG, and CS/Au/BG and counted to be 70.58, and 198.25 µg/mL, respectively (after applied 10 mg/mL). The promising results suggested the use of novel CS/Au/BG nanocomposite as an encourage candidate for wastewater treatment application against pathogenic microbes. [ABSTRACT FROM AUTHOR]

Potato plants can be infected by different bacterial diseases, among them, the potato brown rot disease, caused by Ralstonia solanacearum. The novelty of the present research is to assess the potential impact of the synthesized copper oxide NPs (CuO NPs)-streptomycin nano-drug synthesized by gamma irradiation for inducing the systemic resistance against potato brown rot disease. CuO NPs-streptomycin was completely-characterized by UV–Vis., XRD, FTIR, HRTEM, SEM, and EDX elemental analysis. In the greenhouse experiment, the efficiency of CuO NPs was tested after three times of application. Disease index percent, phytochemicals, and metabolic indicators of resistance (as a response to induction of systemic resistance) were investigated. Our results indicated that treatment with CuO NPs during planting was more effective for increasing the protection percent by 55.8% and reducing the disease severity by 37.5% in the infected potato plants. CuO NPs-streptomycin increased not only the photosynthetic pigments but also the osmolytes contents. The highest reduction in malondialdehyde (44.89%) and hydrogen peroxide (32.9%) contents was achieved in the case of potato plants treated one week after planting. Therefore, it suggested applying CuO NPs-streptomycin in controlling plant disease since they are cost-effective and eco-friendly. [ABSTRACT FROM AUTHOR]