Immobilization of Urease onto Modified Egg Shell Membrane through Cross Linking

Background:Immobilization is an approach in industry to improve stability and reusability of urease. The efficiency of this technique depends on the type of membrane and the method of stabilization. Methods:The PEI-modified egg shell membrane was used to immobilize urease by absorption and glutaraldehyde cross-linking methods. The membranes were characterized by FTIR and AFM, and Nessler method was applied to measure the kinetic of the immobilized enzymes. Finally, the storage stability (6 °C for 21 days) and reusability (until enzyme activity reached to zero) of the immobilized enzymes were investigated. Results:Based on FTIR, three new peaks were observed in both the absorption- (at 1389.7, 1230.8, and 1074.2 cm^-1) and the cross-linking (at 1615-1690, 1392.7, 1450 cm^-1) immobilized enzymes. The surface roughness of the native membrane was altered after PEI treatment and enzyme immobilization. The optimal pH of cross-linking immobilized enzymes was shifted to a more neutral pH, while it was alkaline in adsorption-immobilized and free enzymes. The reaction time decreased in all immobilized enzymes (100 min for free enzyme vs. 60 and 30 min after immobilizing by adsorption and cross-linking methods, respectively). The optimal temperature for all enzymes was 70 °C and they had a higher K_m and a lower V_max than free enzyme. The stability and reusability of urease were improved by both methods. Conclusion:Our findings propose these approaches as promising ways to enhance the urease efficiency for its applications in industries and medicines. Key Words: Egg shell, Immobilization, Polyethylenimine, Urease     

Effects of nitrogen forms and calcium amounts on growth and elemental concentration in Rosa hybrida cv. ‘Vendentta’

An experiment was conducted to investigate the effects of calcium and nitrogen on quality and quantity of Rosa hybrida in hydroponic culture, using factorial complete randomized design with different levels of ammonium-N (0, 2.5, and 5 mM) and calcium (1.6 and 4.8 mM). The results indicated that ammonium-N concentration of 2 mM increased the number of flowers, length of pedicles, and fresh weight of flower stem per plant. 5 mM of ammonium-N caused a significant decrease in most of the measured characteristics. Increase in calcium concentration enhanced nitrogen, calcium, manganese, and boron; while, potassium, zinc, and copper decreased in the leaf. Flower diameter and fresh weight of flower stems per plant increased significantly. With application of ammonium in the nutrient solution, calcium and potassium concentration in the leaf decreased, whereas phosphorus, zinc, manganese, iron, and boron significantly increased. Therefore, application of 2.5 mM ammonium-N and 4.8 mM calcium are recommended.     

The Healing Potential of Plantago lanceolata Ointment on Collagenase-Induced Tendinitis in Burros (Equus asinus)

This study was carried out to evaluate the healing potential of water-soluble extract of Plantago lanceolata as a topical ointment on experimental tendinitis in burros. Tendinitis was induced by injection of 2,500 U of bacterial collagenase in the superficial digital flexor tendon of both forelimbs of six male burros. Tendinitis was confirmed ultrasonographically. 48 hours after collagenase injection, two grams of 10% P lanceolata ointment was applied on one limb (treatment group) and the same amount of eucerin (the vehicle of the ointment) on the other limb (control group), every other day for 6 weeks. Ultrasonographic examination of the tendon was performed weekly during the study and mean cross-sectional area of the superficial digital flexor tendon was measured, which was found to increase significantly after injection of collagenase in both groups. From the third week, it decreased significantly in the treatment group in comparison with the control group. At the end of the study, the animals were euthanized for histopathological study of the tendons. In control group, degenerative changes in tendon could be seen, whereas significant degree of healing was observed in the treatment group. It can thus be concluded that the P lanceolata ointment was effective in promoting the healing process of the tendon.     

The evaluation of lycopene and cysteamine supplementation effects on sperm and oxidative stress parameters during chilled storage of canine semen

The aim of this study was to evaluate the effects of different concentrations of lycopene and cysteamine on characteristics of sperm, liquid peroxidation and enzymatic activities in seminal plasma of canine semen preserved at 5°C for 72 hr. The semen samples were divided into eight aliquots: control, control sham (dimethyl sulfoxide 5%), lycopene groups (250, 500 and 750 µg/ml) and cysteamine groups (2.5, 5 and 10 mM). Motility, viability, membrane integrity, DNA integrity, total antioxidant capacity (TAC) and malondialdehyde (MDA) levels were evaluated. Progressive motility and total motility were higher with the 500 and 750 µg/ml lycopene concentrations, respectively, compared to the control group and the cysteamine groups following 72 hr of storage in the liquid storage. Motility characteristics, viability and hypo-osmotic swelling test (HOST) percentages were significantly improved in 500 µg/ml lycopene compared to other groups. The 500 and 750 µg/ml lycopene concentrations, respectively, showed significantly reduced percentages of spermatozoa with DNA integrity compared to the control group. The 500 and 750 µg/ml lycopene concentrations, respectively, led to the significant decrease of MDA levels. The 500 µg/ml lycopene enhanced TAC levels after 48 and 72 hr that was not observed in other groups. In conclusion, the findings of this study showed that lycopene supplementation in canine semen extenders improved canine semen parameters and TAC levels and decreased MDA levels in the chilling process.     

Production of an Antibody Fragment (scFv) Targeting PcrV Protein of Pseudomonas aeruginosa in Fed-Batch Cultivation Mode

Background: Pseudomonas aeruginosa is one of the opportunistic pathogens causing frequent hospital-acquired life-threatening infections in mechanically ventilated patients. The most significant virulence factor of P. aeruginosa is T3SS. PcrV is an important structural protein of the T3SS. Methods:In the current investigation, a recombinant scFv mAb against the PcrV protein was expressed in EnBase® (fed-batch) cultivation mode. The pETiteTM N-His SUMO Kan vector, including anti-PcrV scFv gene, was transformed into Escherichia coli (BL21) cells. The expression and solubility of anti-PcrV scFv protein were investigated at two different temperatures (25 °C and 30 °C) and at different induction times (4, 6, 8, 12, and 24 hours). Results:Increased efficiency was achieved by EnBase® compared to LB broth; owing to the slow release of glucose, the maximum level of solubility and total protein expression was observed in EnBase® cultivation system at 30 °C and 24 h post induction. Furthermore, IC₅₀ for anti-PcrV scFv protein was determined to be approximately 7 μg/mL. Conclusion:Anti-PcrV scFv produced in this study showed promising in vitro results, protecting RBC from lysis by P. aeruginosa (exoU+). Key Words: Fed Batch, recombinant protein, Pseudomonas aeruginosa, scFv     

Effect of different levels of raw and heated grass pea seed (Lathyrus sativus) on nutrient digestibility,intestinal villus morphology and growth performance of broiler chicks

This study aimed to investigate chemical composition and effect of different levels (0%, 10% and 20%) of raw grass pea (RGP) and heat‐treated (120 °C for 30 min) grass pea seed (HGP) on nutrient digestibility, dressing percentage, relative internal organ weights, intestinal villous morphology and broiler chicks' performance. A total number of 200 day‐old male chicks were raised under similar condition for 10 days. On day 11, chicks were randomly assigned to five dietary treatments and four replicates of 10 birds each. The result of chemical analysis indicated that Iranian grass pea seed has low levels of total and condensed tannin, and it may be considered as a good source of protein (36.1%) and energy (17.09 kJ GE/g). Heat treatment reduced (p < 0.05) the total and condensed tannin to 21% and 78% respectively. Grass peas seed had higher levels of nitrogen‐free extract, P, Na, Mg and Zn than soya bean meal. The apparent digestibility of gross energy and lipid was affected (p < 0.01) by the treatment diets, and it was the lowest after feeding 20% of HGP (p < 0.05). The relative weight of breast and pancreas (p < 0.05) was affected by treatments. Percentage weight of breast and pancreas increased (p < 0.05) after feeding high levels (20%) of RGP and HGP. Substitution of 20% of RGP and HGP increased the duodenal crypt depth (p < 0.05); however, it had no suppressive effect on villus height as the absorptive surface of intestine. The feed conversion ratio was not affected by the treatments in the total experimental period. This study showed that, although the high level of grass pea seed caused a remarkable increase in the relative weight of pancreas and decreased the apparent digestibility of gross energy and lipid, it had beneficial effect on breast relative weight. It seems that heat processing is not effective method for improving quality of Iranian grass pea seed.