Sharif Digital Repository

Penicillin G Acylase is the key enzyme in producing semi-synthetic antibiotics such as Ampicillin and Amoxicillin. In this study, we used E.coli ATCC 11105 in order to produce it. This enzyme was an intracellular one which was produced under suitable conditions. Crude enzyme was released after cell disruption by ultrasonic waves (sonication method) and was partially purified by ammonium sulphate precipitation. Immobilization is investigated at different pHs around the iso-electric pH of Penicillin G Asylase enzyme. Therefore, optimum pH and optimum concentration of ammonium sulphate cuts were determined. Also immobilization process of this enzyme was studied on chitosan polymer, activated by... 

The enzyme L-Asparaginase (L-asparagine amidohydrolase, EC 3.5.1.1) has been thoroughly researched by many researchers worldwide because of its immensely useful medical applications. It can catalyze the hydrolysis of L-asparagine to L-aspartic acid and ammonia that is effective for the cure of leukemia, especially for puerile Acute Lymphocytic Leukemia [ALL] and Lymphosarcomas. The present study discusses the studies carried out for the optimal production of the enzyme from Escherichia coli ATCC 11303. For extraction of the intracellular enzyme, Sonication is more useful method for cell disruption than alkali lysis and enzymatic method. We improved Luria Bertani (LB) media (tryptone 1% w/v,... 

In this study, Pseudomonas aeruginosa BBRC-10036 was used for lipase production. The organism secreted the enzyme extracellulary. First of all, effect of initial pH of the culture broth on lipase activity was studied in order to determine the optimum condition for lipase production. After production, this enzyme must be separated from culture and after that the enzyme must be purified for using in analysis and industry. Different methods are used for purification of the enzyme. In this research, first precipitation was used and then this lipase has been purified by Ion exchange Chromatography leading to 2.33- fold purification and 11.47% recovery. In precipitation by acetone, maximum... 

In this work, we have tried to synthesize, recognize and evaluate the performance of a composite ceramic membrane to purify hydrogen and obtain high H2 separation values from other gases such as methane, carbon dioxide and nitrogen at high operating temperatures (837- 1073 K). The membrane was prepared by modification of a tubular alpha- alumina support with a series of gamma- alumina layers using sol- gel method. The membrane was then covered with a Nano-composite silica- alumina layer using CVD method. The thickness of this layer is estimated to be around 80- 100 nm and with a completely dense structure. EDX, XRD, DLS, BET and mercury porosietery analysis plus SEM and FESEM images were... 

Fresh water has always been one of the basic needs of human. Thus using different methods for water purification becomes more important in recent years. In classic methods such as distillation chamber and thermal method, water flux was always low and salt rejection wasn’t satisfactory. So investigating new methods such as nanofiltration becomes more important. This method has high efficiency and good water flux in compare with old methods. One of the useful materials in nanofiltration is grapheme oxide (GO). GO sheets make an array of nanochannels and this membrane improves filtration and water flux. Different parameters affect water flux and salt rejection in this membrane. Restructuring... 

Conjugated linoleic acid (CLA), a mixture of positional and geometrical isomers of linoleic acid with conjugated double bonds, has gained considerable attention because of its anticarcinogenic and obesity treatment properties. The most biologically active CLA isomers are 9c, 11t-18:2 and 10t, 12c-18:2. Natural sources of CLA are fat of meat and dairy products derived from ruminant animals. About 3 grams of CLA per day is necessary to provide human health needs, but each person receives about 10% of this value from natural resources, thus production of CLA as a dietary supplement is necessary. CLA is produced from biological and chemical methods but because of high yield of chemical... 

Boric acid (H3BO3) is a weak monobasic acid that exist as a white powder in the standard conditions. In industry, it is used in manufacturing of fiberglas filaments, precious metals soldering and production of flat panel LCD displays. In all of these applications, normal grade boric acid is used, but nuclear industry demands an ultrapure boric acid (UPA) for controlling of the reactivity and power levels in pressurized water reactors. Annual consumption of UPA in Bushehr Power Plant (BPP) is around 60 metric tons. Currently, this amount is imported from Russia, but atomic energy organization of Iran plans to displace it by the acid made inside the country. Domestic production of UPA in... 

Titanium dioxide is one of the most important first material in many industrial applications and for producing Titanium.Although it was discovered more than 200 years ago and has been commercially processed for 85 years, it is still being actively investigated. So far Iran imports TiO2. But some projects have been planned to produce pure TiO2 from Ilmenite and Titanomagnetite ore. In the present work production of highly purity TiO2 from Ilmenite ore by chloride leaching has been investigated. Chloride leaching has been accomplished by several stages of leaching in hydrochloric acid, reduction, crystallization, hydrolysis and finally calcination of the powder. According to the result... 

Conjugated linoleic acid (CLA), a mixture of positional and geometrical isomers of linoleic acid with conjugated double bonds, has gained considerable attention because of its anticarcinogenic and obesity treatment properties. The most biologically active CLA isomers are 9c, 11t-18:2 and 10t, 12c-18:2. The aim of this study is to separate and purify the two essential isomers via enzymatic method by Candida rugosa lipase and chemical method by urea crystallization and also optimization of reaction conditions in order to better separation. For enzymatic purification, L-menthol and Lauryl alcohol were used separately. Optimization of reaction conditions by enzyme content, time and the ratio of... 

Enzymes, which are biochemical catalysts, have important applications in different industries such as food, pharmaceutical, medical, chemical identification and etc. Several methods have been used for separation of enzymes among which precipitation, chromatography and two-phase system. In this work, purification of α-amylase has been done by Ammonium Sulfate and Acetone precipitation, gel filtration based on Sephadex, and PEG-salt aqueous two-phase system. Furthermore, mass and momentum conservations’ equations were solved simultaneously to simulate the process based on the finite element method (FEM). Crude enzyme was precipitated with different saturations of ammonium sulfate and the... 

In this study a droplet-based microfluidic system is desighned and fabricated to effectiverly lyse MCF7 cells and extract and purify their DNAs. The main purpose of this study is to transfer all the steps from macro scale to a microfluidic system containing a fluidic chip. This system is a semi automatic system and every part of the lysis and purification process is performed in one step. The first step is to encapsulate single cells and multi cells inside the droplets. By controlling the concentration of the cell solution, the number of encapsulated cells inside the droplet is efficiently and easily controlled and the cells were encapsulated as single cells and as multi cells inside the... 

In all types of chromatography for the extraction and purification of proteins, a fixed substrate is needed with which the mobile phase containing the proteins interact with them. This fixed bed should contain grains that have characteristics such as sphericity, high surface area, hydrophilicity, binding power to functional groups, chemical stability, low specific absorption, reusability and low cost. Commercially, the most commonly substrates in the ranges of the molecular weight of proteins are agarose and dextran. Agar was extracted from Gracilaria salicornia seaweed and removal of ionic groups was investigated by three methods. In washing with isopropanol, the ionic groups were reduced... 

Triclosan is widely used as an antibacterial agent in personal health care products, especially in recent years with the spread of the Coronavirus. This substance is one of the emerging contaminants, and due to its stable and toxic nature, this material cannot be destroyed in the process of biological wastewater treatment. In this research, a new bacterial strain was isolated and purified from industrial wastewater for the biological removal of triclosan. Based on 16S rRNA sequencing, it was found that the isolated strain belongs to the Enterobacter cloacae family and can grow in high concentrations of triclosan. It was observed that naphthalene dioxygenase and laccase enzymes are active...