No abstract

Pectinases are an important class of enzymes distributed in many higher plants and microorganisms. One of these enzymes is pectin lyase which has an important role in industrial applications such as clarification of fruit juices. Pectin lyase was purified with 73% yield from Pseudomonas putida bacteria and was 220.7-fold using three phase precipitation technique. Molecular weight of purified pectin lyase was determined as 32.88 kDa with SDS-polyacrylamide gel electrophoresis. The pectin lyase was immobilized covalently via the L-glutaraldehyde spacer to the cellulosic structures of lily flowers (Lilium candidum L.). The immobilized enzyme was then magnetized by modifying with γ-Fe3O4 nanoparticles and determined the most appropriate immobilization conditions as pH 6 and 30 °C. Purified pectin lyase was connected to magnetized support material after 60 min at the rate of 86.4%. The optimum pH and temperatures for the free and immobilized pectin lyase was found to be 6.0 and 40 °C. pH and thermal stabilities of the free and immobilized pectin lyase enzyme have been preserved at high-low temperatures and pH. The structural characterization of the immobilized pectin lyase was performed by SEM, FT-IR, and XRD chromatographic analyses and it was observed that the support materials structure was appropriated to immobilization with pectin lyase and to modify with Fe3O4 nanoparticles.

An important component of the pectinase enzyme complex is pectin lyase (polymethylgalacturonate lyase; EC 4.2.2.10). In this study, extracellular pectin lyase enzyme was produced from Acinetobacter calcoaceticus bacteria. Pectin lyase was then purified using three-phase precipitation (TPP) technique with 25.5% yield. The pectin lyase was immobilized covalently via the L-glutaraldehyde spacer to the carboxymethyl cellulose. The immobilized pectin lyase was magnetized using Fe3O4 nanoparticles. Purified pectin lyase was connected to magnetized support material after 90 min at the rate of 80%. The most appropriate immobilization conditions were determined as pH 8 and 30°C. By characterizing the free and immobilized enzyme, KM, Vmax, and optimum pH and optimum temperature values were determined. It was optimum pH 8 and temperature 50°C for both free and immobilized pectin lyase. The structural characterization of the immobilized pectin lyase modified with Fe3O4 nanoparticles was carried out by SEM, FT-IR, and XRD chromatographic analyses. At the end of the study, free and immobilized enzymes were used for purification of some fruit juices and results were compared.

Abstract:The aim of this study was to obtain copper oxide nanoparticles (CuO NPs) through a method of green synthesis that involves using peroxidase enzymes that are partly purified from fig leaves (Ficus carica). CuO NPs were successfully synthesized using the green synthesis method in the experiments performed. Ultraviolet-visible (UV-Vis) spectrophotometry of the characteristics of the acquired CuO NPs was performed with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The optimum activation temperature for green synthesis was observed to be in 30 min, pH: 8, at 25 o C and in the concentration of 1 mM CuCl2. By using peroxidase enzymes with green synthesis, it was found that the results of the SEM and XRD measurements that acquired the CuO NPs were in the size of 50-120 nm. Afterwards, the antioxidant and antibacterial activities of these nanoparticles were measured, and it was understood from the obtained results that CuO NPs have both antioxidant and antimicrobial activities.

Fertilizers in different nitrogen forms (calcium ammonium nitrate (CAN), urea, ammonium sulfate (AS), and ammonium nitrate (AN)) and their doses (50, 100, and 150) for beetroot (BT) (Beta vulgaris L. var. conditiva Alef.) and the antioxidant and antiradical activities in the lyophilized water and alcohol extracts of BT were evaluated. In order to evaluate antioxidant and radical removing activities of BT roots, total phenolic compound amount assignment, total flavonoids amount assignment, method of Fe 3+ -Fe 2+ reduction activity using ferric cyanate reduction, cupric ions (Cu 2+ ) reducing capacity with CUPRAC method, Fe 3+ reducing capacity according to FRAP method, ferrous ions (Fe 2+ ) chelating activity, superoxide anion radical (O 2 •− ) removing activity, and 2,2 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS •+ ) radical removing activity were determined. In the study, BHA and -tocopherol were used as standard antioxidants. It was determined that water and alcohol extracts obtained from BT roots indicated reduction activities, effectively. In addition, it was also determined that these reduction activities were indicated in most BT roots grown in fertilizer media at lower percentage and that they had higher antioxidative level than that of standard antioxidants.