Sharif Digital Repository

Lactobacillus acidophilus is one of the major microorganisms which are famous for their effects on cholesterol. In this study, we have investigated the effect of L. acidophilus ATCC 1643 on removing the milk cholesterol and additionally, we have immobilized L. acidophilus ATCC1643 cells in sodium-alginate and observed its effect on milk cholesterol removing. Also, we have researched about the effect of some factors including: bacteria cells number (both free and immobilized cells) and immobilized cells bead size on cholesterol removing rate and ultimately the extracted results were compared together. The results indicated that free cells could reduce cholesterol to lower than 0.5mg/100ml... 

A novel organic-inorganic hybrid heterogeneous catalyst system was obtained from the reaction of the molybdenum(VI) complex of salicylidene 2-picoloyl hydrazone with mesoporous silica containing 3-chloropropyl groups prepared by a direct synthetic approach involving hydrolysis and co-condensation of tetraethylorthosilicate (TEOS) and 3-chloropropyltrimethoxysilane in the presence of the triblock copolymer P123 as template under acidic conditions. Characterization of the functionalized materials by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), N2 adsorption/desorption, FT-IR and UV-Vis spectroscopy, and thermogravimetric... 

In this study, anti-leukemic enzyme L-asparaginase (E.C.3.5.1.1) from Escherichia coli ATCC 11303 was modified by the microencapsulation technique onto calcium alginate beads. Using response surface methodology (RSM), a three-level full factorial design, the values of concentration of sodium alginate, concentration of calcium chloride, and enzyme loading were investigated to obtain the highest residual L-asparaginase (L-ASNase) activity % (immobilized enzyme activity/free enzyme activity). The effects of the studied factors on immobilization were evaluated The predicted values by the model were close to the experimental values, indicating suitability of the model. The results presented that... 

Bioactive glass has been used clinically in bone repair applications for bone grafting because of its prominent physiochemical and osteogenic properties. Various attempts have been made to enhance bioactive glass efficiency in combination with other biomaterials such as antibiotics and growth factors. In present study, we developed a modification of bioactive glass nanoparticles that insured long term antibacterial effect. Bioactive glass nanoparticles (BGNs) were functionalized with (3-Aminopropyl) triethoxysilane (APTS), then vancomycin (VAN) was immobilized onto BGNs-APTS via EDC/NHS cross-linking process. Another study group namely BGNs-VAN was synthesized as a control group without any... 

In this study, a new polymeric functionalized magnetic nanocatalyst containing a molybdenum Schiff base complex was prepared using a few consecutive steps. Poly (methylacrylate)-coated magnetic nanoparticles were synthesized via radical polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the amidation of the methyl ester groups with hydrazine. Polymeric functionalization efficiently provides the advantage that more catalytic units can be grafted on the surface of magnetic nanoparticles. The functionalization process was continued with salicylaldehyde which introduced Schiff base groups on to the surface of the polymeric support. In the final step, the desired... 

In this paper we introduce novel strategy for antibody immobilization using high surface area electrospun nanofibrous membrane based on ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling chemistry. To present the high performance of proposed biosensors, anti-staphylococcus enterotoxin B (anti-SEB) was used as a model to demonstrate the utility of our proposed system. Polymer solution of polyethersolfone was used to fabricate fine nanofibrous membrane. Moreover, industrial polyvinylidene fluoride membrane and conventional microtiter plate were also used to compare the efficiency of antibody immobilization. Scanning electron microscopy images were taken to... 

Rhamnolipids are the most common biosurfactants and P. aeruginosa strains are the most frequently studied microorganisms for the production of rhamnolipids. Eco-friendly advantages and promising applications of rhamnolipids in various industries are the major reasons for pursuing the economic production of these biosurfactants. This study shows that cultivation of P. aeruginosa MR01 in medium contained inexpensive soybean oil refinery wastes which exhibited similar levels and homologues of rhamnolipids. Mass spectrometry indicated that the Rha-C10-C10 and Rha-Rha-C10-C10 constitute the main rhamnolipids in different cultures of MR01 including one of oil carbon source analogues. Moreover,... 

Chondroitinase ABCI (cABCI) is a drug enzyme that can be used to treat spinal cord injuries. Due to low thermal stability of cABCI, this enzyme was immobilized on Fe3O4 nanoparticle to increase its thermal stability. The size and morphology, structure and magnetic property of the Fe3O4 nanoparticles were characterized by the analyses of SEM, XRD and VSM, respectively, and FTIR spectroscopy was employed to confirm the immobilization of cABCI on the surface of Fe3O4 nanoparticles. The results indicated that the optimum conditions for pH, temperature, cABCI-to-Fe3O4 mass ratio and incubation time in immobilization process were 6.5, 15 °C, 0.75 and 4.5 h, respectively, and about 0.037 mg cABCI...