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
Wed Jan 01 2020
Journal Name
Indian Journal Of Ecology
Study on major constraints and problems in transfer of technology by agricultural extension organization
...Show More Authors

Scopus (6)
Scopus
Publication Date
Sun Jun 12 2011
Journal Name
Baghdad Science Journal
Estimation the Radioactive Pollution by Uranium in the Soil of Al-Kut City/ Iraq
...Show More Authors

The aim of the present work, was measuring of uranium concentrations in 25 soil samples from five locations of Al-Kut city. The samples taken from different depths ranged from soil surface to 60cm step 15 cm, for this measurement of uranium concentrations .The most widely used technique SSNTDs was chosen to be the measurement technique. Results showed that the higher concentrations were in Hai Al- Kafaat which recorded 1.49 ± 0.054 ppm . The uranium content in soil samples were less than permissible limit of UNSCEAR(11.7ppm).

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Jan 01 2013
Journal Name
Iraqi Journal Of Cancer And Medical Genetics
Cytotoxicity of purified methionine γ- lyase produced by Pseudomonas putida on several cell lines
...Show More Authors

The cytotoxicity of different concentrations of purified methionine γ- lyase from Pseudomonas putida on cancer cell lines (RD, AMN3 and AMGM) at 96 hr was studied. The bacterial enzyme with concentration 1000µg/ml was revealed highly cytotoxicity against cancer cell lines in comparison with other concentrations whereas slight cytotoxicity was observed on normal cell (REF).

Publication Date
Sun Dec 03 2017
Journal Name
Sci. Int.(lahore)
IMPROVING NO2 SENSITIVITY OF POROUS SILICON BY FUNCTIONALIZATION ITS SURFACE WITH COPPER AS CATALYST
...Show More Authors

In this work, porous silicon gas sensor hs been fabricated on n-type crystalline silicon (c-Si) wafers of (100) orientation denoted by n-PS using electrochemical etching (ECE) process at etching time 10 min and etching current density 40 mA/cm2. Deposition of the catalyst (Cu) is done by immersing porous silicon (PS) layer in solution consists of 3ml from (Cu) chloride with 4ml (HF) and 12ml (ethanol) and 1 ml (H2O2). The structural, morphological and gas sensing behavior of porous silicon has been studied. The formation of nanostructured silicon is confirmed by using X-ray diffraction (XRD) measurement as well as it shows the formation of an oxide silicon layer due to chemical reaction. Atomic force microscope for PS illustrates that the p

... Show More
Publication Date
Tue Apr 05 2022
Journal Name
Nano Hybrids And Composites
Structural and Optical Properties of ZnO Nanostructures Synthesized by Hydrothermal Method at Different Conditions
...Show More Authors

Zinc oxide (ZnO) nanoparticles were synthesized using a modified hydrothermal approach at different reaction temperatures and growth times. Moreover, a thorough morphological, structural and optical investigation was demonstrated using scanning electron microscopy (SEM), x-ray diffraction (XRD), ultra-violate visible light spectroscopy (UV-Vis.), and photoluminescence (PL) techniques. Notably, SEM analysis revealed the occurrence of nanorods-shaped surface morphology with a wide range of length and diameter. Meanwhile, a hexagonal crystal structure of the ZnO nanoparticles was perceived using XRD analysis and crystallite size ranging from 14.7 to 23.8 nm at 7 and 8 ℎ𝑟𝑠., respectively. The prepared ZnO samples showed good abso

... Show More
Publication Date
Tue Mar 01 2016
Journal Name
Journal Of Engineering
Some Mechanical Properties of Concrete by using Manufactured Blended Cement with Grinded Local Rocks
...Show More Authors

The use of blended cement in concrete provides economic, energy savings, and ecological benefits, and also provides. Improvement in the properties of materials incorporating blended cements. The major aim of this investigation is to develop blended cement technology using grinded local rocks . The research includes information on constituent materials, manufacturing processes and performance characteristics of blended cements made with replacement (10 and 20) % of grinded local rocks (limestone, quartzite and porcelinite) from cement. The main conclusion of this study was that all types of manufactured blended cement conformed to the specification according to ASTM C595-12 (chemical and physical requirements). The percentage of the compress

... Show More
Preview PDF
Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Structural and Optical Properties of SnS2:Cu Thin films prepared by chemical Spbay Pyrolysis
...Show More Authors

Thin filis have been prepared from the tin disulphide (SnS2 ), the pure and the doped with copper (SnS2:Cu) with a percentages (1,2,3,4)% by using ahemical spray pyrolysis techniqee on substrate of glass heated up to(603K)and sith thicknesses (0.7±0.02)?m ,after that the films were treated thermally with a low pressure (10-3mb) and at a temperature of (473K) for one hour. The influence of both doping with copper and the thermal treatment on some of the physical characteristics of the prepared films(structural and optical) was studied. The X-ray analysis showed that the prepared films were polycrystalline Hexagonal type. The optical study that included the absorptance and transmitance spectra in the weavelength range (300-900)nm

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Aug 31 2022
Journal Name
Al-kindy College Medical Journal
A comparison of cross sections for Selenium -73 radioisotopes produced by accelerators and reactors
...Show More Authors

Background: Selenium-73 with half- life of 7.15 hour emits β+ in nature and has six stable isotopes which are ( 74Se,76Se,77Se,78Se,80Se and 82Se ). Selenium-73 has many applications in technology and radioselenium compounds of metallic have found various applications in medicine. Objective:  To make a comparison between different reactions that produced cross sections of Se-73 radioisotopes. Subjects and methods: The feasibility of the production of Selenium -73 via various nuclear reactions was investigated. Excitation functions of 73Se production by the reactions of 75As (p,3n), 169Tm( d,x), 74Se, natSe, natBr (p,x) , 75As (d,4n), natGe (3He,x), 70Ge (α, n), and 72Ge (α, 3n) and neutron capture were calculated using the avail

... Show More
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Indian Journal Of Ecology
Horizontal variability of some soil properties in wasit governorate by using time series analysis
...Show More Authors

Scopus (2)
Scopus
Publication Date
Thu Jun 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Assessment of mandibular third molar position by using computed tomography and reconstructed lateral radiograph
...Show More Authors

Background: Consideration of mandibular third molar is important from orthodontic perspective due to several factors such as, lower anterior arch crowding, relapse in lower anterior region, interference with uprighting of mandibular first and second molars during anchorage preparation and molar distalization. The aims of this study were to assess of gender differences in the mandibular third molar position and compare and evaluate whether there is any differences in the results provided by CT scan and lateral reconstructed radiograph. Materials and Methods: The sample of present study consisted of 39 patients (18 males and 21 females) with age range 11-15 years. CT images for patients who were attending at Al Suwayra General Hospital/the C

... Show More
View Publication Preview PDF
Crossref