Swain Abildgaard (phonedeer7)
Considered together, these results determine that the susceptible cucumber cultivar elicits immunity after perception of priming with chitosan to upregulate phytohormones and synthesize defense-responsive enzymes, thereby induce resistance against powdery mildew disease and strengthen the growth-promotion of cucumber plants.The thermoalkalophilic lipase from Bacillus atrophaeus (BaL) was immobilized onto amine-functionalized graphene oxide nanosheets coated with the poly (maleic anhydride-alt-1-octadecene) copolymer (GO-NH2-PMAO) and activated with glutaraldehyde as spacer arm through interfacial activation and subsequent multipoint covalent attachment. Experimental design method was applied for optimization of immobilization conditions including GO-NH2-PMAO concentration, buffer concentration, pH, sonication time, enzyme concentration, glutaraldehyde concentration, time, and temperature. The optimum specific activity of the immobilized BaL (105.95 ± 2.37 U/mg) reached at 5 mg/mL for GO-NH2-PMAO, 25 mM of buffer, pH 6.0, 60 min sonication time, 100 mM glutaraldehyde, 60 U/mL of enzyme, and 4 h of immobilization time at 25 °C, which was very close to the predicted amount (106.08 ± 1.42 U/mg). Maximum immobilization yield (81.35%) and efficiency (277.63%) were determined in optimal immobilization conditions. The obtained results clearly indicated that the immobilized BaL exhibited better stability at extreme temperature and pH than the free BaL. At temperature of 90 °C and pH 11, more than 90% of the initial activity of the immobilized BaL was retained. Furthermore, the immobilized BaL retained about 90% of its initial activity after 10 days of storage and 6 cycles of application. The esterification studies showed that maximum bioconversion of valeric acid to pentyl valerate using the free BaL (34.5%) and the immobilized BaL (96.3%) occurred in the xylene medium after 48 h of incubation at 60 °C. Therefore, the BaL immobilized on GO-NH2-PMAO was introduced as an effective biocatalyst to synthesize green apple flavour ester.In this study, a nanobiocomposite scaffold was fabricated by combining sodium alginate, polyvinyl alcohol, silk fibroin and magnesium hydroxide nanorods. The structural characteristics and properties of the scaffold were identified by field emission scanning electron microscope (FE-SEM), thermogravimetric analysis (TGA), Fourier-transformed infrared (FT-IR) and energy dispersive X-Ray (EDX) analyses. To introduce the application, biocompatibility, mechanical properties and biological activity of the scaffold were obtained. The composite was found to have high porosity, no cytotoxicity, excellent cellular adaptation, and most importantly Mg(OH)2 nanorod had antibacterial activity and inhibited the growth of bacteria. In addition, silk fibroin and alginate increased the scaffold strength due to mechanical tests. Hemolytic assay and cell metabolic activity of this novel nanobiocomposite showed that the hemolytic effect was less than 8% and about 92% of cells survived. Due to considerable biological activities and acceptable mechanical properties, the mentioned nanobiocomposite can be considered as a scaffold for possible use in wound dressing, tissue engineering and drug delivery systems.Poly (lactic acid)-based functional films incorporated with curcumin have been prepared using a solution casting method. The PLA/curcumin composite film was flexible and highly transparent with bright yellow color. Curcumin was uniformly dispersed in the PLA matrix and showed excellent compatibility with PLA, as evidenced by the FE-SEM, DSC and FTIR test results. The addition of curcumin increased the mechanical properties slightly without changing the thermal stability of the PLA film. The composite film also exhibits excellent UV-barrier properties without much-sacrificing transparency of the PLA film. The water vapor permeability (WVP) and water contact angle (WCA) of the PLA film were slightly increased by the addition of c