Preferred Language
Articles
/
ijcpe-822
Production of 7-methylxanthine from Theobromine by Metabolically Engineered E. coli
...Show More Authors

In this work, a novel biocatalytic process for the production of 7-methylxanthines from theobromine, an economic feedstock has been developed. Bench scale production of 7-methlxanthine has been demonstrated. The biocatalytic process used in this work operates at 30 OC and atmospheric pressure, and is environmentally friendly. The biocatalyst was E. coli BL21(DE3) engineered with ndmB/D genes combinations. These modifications enabled specific N7- demethylation of theobromine to 7-methylxanthine. This production process consists of uniform fermentation conditions with a specific metabolically engineered strain, uniform induction of specific enzymes for 7-methylxanthine production, uniform recovery and preparation of biocatalyst for reaction and uniform recovery of pure 7-methylxanthine.

   Many E. coli BL21(DE3) strains metabolically engineered with single and/or multiple ndmB/D genes were tested for catalytic activity, and the best strains which had the higher activity were chosen to carry out the N-demethylation reaction of theobromine. Strain pBD2dDB had the highest activity for the production of 7-methylxanthine from theobromine. That strain was used to find the optimum amount of cells required to achieve complete conversion of theobromine to 7-methylxanthine within two hours. It was found that the optimum concentration of pBD2dDB strain to achieve 100% conversion of 0.5 mM theobromine to 7-methylxanthine was 5 mg/mL. The cell growth of pBD2dDB strain was studied using two different growth media, (Luria-Bertani Broth and Super Broth). Super broth was found to be the best medium to produce the highest amount of cell paste (1.5 g). Subsequently, the process was scaled up in which 2 L reaction volume was used to produce 7-methylxanthine (100% conversion) from 0.5 mM theobromine catalyzed by pBD2dDB strain. The reactions was carried out at 30 oC and 250 rpm shaker speed, and the reaction medium was 50 mM potassium phosphate buffer (pH=7). 7-methylxanthines was separated by preparative chromatography with high recovery, and the product solution was collected, purified by drying at 120-140 oC for 4 hours and, recovered (127 mg). Purity of the isolated 7-methylxanthine was comparable to authentic standards with no contaminant peaks, as observed by HPLC, LC-MS, and NMR. 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Aug 01 2017
Journal Name
International Journal Of Scientific & Engineering Research
Integrated System of Information hiding by Applying Three levels
...Show More Authors

MB Mahmood, BN Dhannoon

View Publication
Publication Date
Tue May 23 2023
Journal Name
Journal Of Engineering
Competitive Adsorption of Three Reactive Dyes by Activated Carbon
...Show More Authors

In this study three reactive dyes (blue B, red R and yellow Y) in single , binary and ternary solution were adsorbed by activated carbon AC in equilibrium and kinetic experiments. Surface area, Bulk and real density, and porosity were carried out for the activated carbon.
Batch Experiments of pH (2.5-8.5) and initial concentration (5-100) mg/l were carried out for single solution for each dye. Experiments of adsorbent dosage effect (0.1-1)g per 100 ml were studied as a variable to evaluate uptake% and adsorption capacity for single dyes(5, 10) ppm, binary and ternary (10) ppm of mixture solutions solution of dyes. Langmuir, and Freundlich, models were used as Equilibrium isotherm models for single solution. Extended Langmuir and Freun

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Mon Feb 18 2019
Journal Name
Iraqi Journal Of Physics
Derivative of an image that corrupted by additive noise
...Show More Authors

In this paper the behavior of the quality of the gradient that implemented on an image as a function of noise error is presented. The cross correlation coefficient (ccc) between the derivative of the original image before and after introducing noise error shows dramatic decline compared with the corresponding images before taking derivatives. Mathematical equations have been constructed to control the relation between (ccc) and the noise parameter.

View Publication Preview PDF
Crossref
Publication Date
Thu Jun 06 2019
Journal Name
Indian Journal Of Public Health, Research And Development
Clinical Manifestation of Singleton Pregnancy Complicated by Diabetes Mellitus
...Show More Authors

Scopus
Publication Date
Mon Apr 01 2019
Journal Name
Journal Of Engineering
Rehabilitation of Reinforced Concrete Deep Beam by Epoxy Resin
...Show More Authors

This investigation presents an experimental and analytical study on the behavior of reinforced concrete deep beams before and after repair. The original beams were first loaded under two points load up to failure, then, repaired by epoxy resin and tested again. Three of the test beams contains shear reinforcement and the other two beams have no shear reinforcement. The main variable in these beams was the percentage of longitudinal steel reinforcement (0, 0.707, 1.061, and 1.414%). The main objective of this research is to investigate the possibility of restoring the full load carrying capacity of the reinforced concrete deep beam with and without shear reinforcement by using epoxy resin as the material of repair. All be

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Aug 31 2019
Journal Name
Iraqi Journal Of Physics
Spectroscopic Diagnostic of Cadmium Sulfide Plasma Produced By LIBS
...Show More Authors

Abstract

       The current study was carried out to reveal the plasma parameters such as ,the electron temperature ( ), electron density (ne) , plasma frequency (fp), Debye length ( ) , Debye number (   for  CdS to employ the LIBS for the purpose of analyzing and determining spectral emission lines using . The results of electron temperature for CdS range (0.746-0.856) eV , the electron density(3.909-4.691)×1018 cm-3. Finally ,we discuss plasma parameters of CdS  through  nano second  laser generated plasma .

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon Mar 01 2021
Journal Name
Journal Of Physics: Conference Series
Some Theorems of Fixed Point Approximations By Iteration Processes
...Show More Authors
Abstract<p>The purpose of this paper, is to study different iterations algorithms types three_steps called, new iteration, <italic>M</italic> <sup>∗</sup> −iteration, <italic>k</italic> −iteration, and Noor-iteration, for approximation of fixed points. We show that the new iteration process is faster than the existing leading iteration processes like <italic>M</italic> <sup>∗</sup> −iteration, <italic>k</italic> −iteration, and Noor-iteration process, for like contraction mappings. We support our analytic proof with a numerical example.</p>
View Publication
Scopus (3)
Crossref (2)
Scopus Crossref
Publication Date
Wed Dec 15 2010
Journal Name
Iraqi Journal Of Laser
Photodynamic Inactivation of Candida Albicans Sensitized by Malachite Green
...Show More Authors

The aim of this study is to investigate the ability of malachite green (MG) combined with 650nm diode laser to kill Candida albicans and to spectrally study the MG photodegradation after photodynamic therapy (PDT) spectrally. Cultures of Candida albicans were exposed to 40mW, 650 nm diode laser in the absence of MG. In PDT group, the MG was added to the Candida suspension for 5 min then exposed to diode laser for (5, 10, 15, 20) min at power density of 0.59W/cm2. The absorption spectrum of the photosensitized fungal suspension was obtained. The data were submitted to T-test (p<0.05). A 650nm diode laser in the presence of MG reduced the number of CFU/ml in 98.4%. Laser with 650nm alone and MG alone did not reduce significantly the num

... Show More
View Publication Preview PDF
Publication Date
Fri Apr 01 2022
Journal Name
Journal Of Engineering
Improvement of Diesel Fuel Engine Performance by Nanoparticles Additives
...Show More Authors

This study was done to investigate the impact of different nanoparticles on diesel fuel characteristics, Iraqi diesel fuel was supplied from al-Dura refinery and was treated to enhance performance by improving its characteristics. Two types of nanoparticles were mixed with Iraqi diesel fuel at various weight fractions of 30, 60, 90, and 120 ppm. The diesel engine was tested and run at a constant speed of 1600 rpm to examine and evaluate the engine's performance and determine emissions. In general, ZnO additives' performance analysis showed they are more efficient for diesel fuel engines than CeO. The performance of engine diesel fuel tests showed that the weight fraction of nanoparticles at 90 and 120 ppm give a similar

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Colloid And Interface Science
Wettability alteration of oil-wet carbonate by silica nanofluid
...Show More Authors

Changing oil-wet surfaces toward higher water wettability is of key importance in subsurface engineering applications. This includes petroleum recovery from fractured limestone reservoirs, which are typically mixed or oil-wet, resulting in poor productivity as conventional waterflooding techniques are inefficient. A wettability change toward more water-wet would significantly improve oil displacement efficiency, and thus productivity. Another area where such a wettability shift would be highly beneficial is carbon geo-sequestration, where compressed CO2 is pumped underground for storage. It has recently been identified that more water-wet formations can store more CO2. We thus examined how silica based nanofluids can induce such a wettabil

... Show More
View Publication Preview PDF
Crossref (403)
Crossref