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
Mon Mar 05 1990
Journal Name
وقائع المؤتمر العلمي الخامس لمجلس البحث العلمي في المجلة العراقية
INACTIVATION OF SELECTED ANTIBIOTICS AGAINST ESCHERICHIA COLI BY VAMIN NUTRITIO- NAL SUPPLEMENTATION
...Show More Authors

Posible interference of vamin with the activity of several antibiotics against E. coli was evaluated in vitro. In MBS- glucose medium, significant growth delay was induced by 8 ug/ml of terramycin (oxytetracycline- polymyxin B) and bactrim (trimethoprim-sulphamethoxazole), and by 16 ug/ml of refocin, lincomycin, and chloramphenicol. Rapid growth inhibition was induced by 32 ug/ml of all an- tibiotic tested separately. Significant inactivation of up to 64 ug/ml of licomycin and bactrim was in- duced by the addition of vamin at a concentration of 1:20 v/v of the medium. This effect was found to be due to the presence of specific amino acids in vamin. Among them is valine, leucine, isoleucine tyrosine, tryptophan, phenylalanine, cysteine, meth

... Show More
Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
Synthesis and Characterization of New Mannich Bases Derived from 7-hydroxy-4-methyl Coumarin
...Show More Authors

Coumarin is a natural substance isolated from different plants. It belonges to a group of benzobyrones which consists of a benzene ring joined to a pyrone nucleus. In the present research, a new series of coumarin derivatives were formed. Compound (1) (7-hydroxy-4-methyl Coumarin) was converted into 4-methylquinolin-2(H) derivative (2) by reaction with acetamide, and then reaction of (2) with thiosemicarbazide in ethanol leads to the synthesize of hydrazincarbothioamide derivative (3).The reaction of (3) with ethylchloroacetate in presence of sodium acetate leads to closure ring to get [(1-(5-oxo-2-thioxoimidazolidin-1-ylimino) ethyl)]quinolin-2(1H)-one (4). Mannich bases were prepared through the reaction of (4) with primary

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Jan 19 2014
Journal Name
Romanian Biotechnological Letters
Optimization conditions for bioemulsifier production by local Streptomyces sp. SS20 isolated from hydrocarbon contaminated soil
...Show More Authors

Publication Date
Wed Aug 30 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Relationship between Alpha-toxin production and biofiJm for1nation by Staphylococcus aureus isolated from Eye's infections
...Show More Authors

Staphylococcus aureus is a common pathogen associated  with eye·s

infections.  S. aureus is capable of biofilm fonnation, which increases its persistence and boots its levels of antimicrobial resistance . A total of 50

  1. aureus isolated from eyes <>f patientwith eye's infection : 41( 82%)

isolates  were positive - alpha tox in production and 37 (74 %)  isolates were  posilive  - biofilm formation .Where as  32 (64%)    isolates were positive - alpha toxin production .and biotilm formation, 11 (22%) Lsolatcs were negative- alpha toxin production and biofilm formation and 7(14%) isolates  were showed &nbs

... Show More
View Publication Preview PDF
Publication Date
Thu Apr 01 2021
Journal Name
Biochemical And Cellular Archives
Evaluation the Effect of Allium Sativum (garlic) oil on The Expression of Maz E and Maz F Genes in Escherichia Coli Clinical Isolates
...Show More Authors

Scopus (2)
Scopus
Publication Date
Sun Mar 02 2014
Journal Name
Baghdad Science Journal
Production of Silicon Metal From Iraqi Sand
...Show More Authors

In this work, production of silicon metal at high purity of 99% by using Iraqi–starting materials (Iraqi sand and plant coal)was reported, electric arc–furnaces assembly was manufactured inside, the graphite electrodes were made from graphite scrap, this system is operate to produce about 800 gm /6hr of silicon metal to meet the need for manufacturing silicon oils, resins, solar cells, and electronic parts. The procedure, equipments and analysis data were described as well.

View Publication Preview PDF
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
J. Pharm. Sci. & Res
Production of peroxidase from Providencia spp. bacteria
...Show More Authors

Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
Production of Protease Enzyme from Wheat Straw
...Show More Authors

      Protease enzyme production was studied and optimized as  a first step to collect information about solid state fermenter) to produce protease enzyme. A local isolated Aspergillus niger was used for this study with constant spores feeding in every experiment at (105/g). Experiments carried out in conical flasks with (250 ml) containing (10 g) of wheat straw as a substrate with different conditions included temperature, pH, hydration ratio, and fermentation time, the results comprised by measuring protease activity (u). The results showed that the best activity can be obtained at (T = 32°C, t= 100 hrs, pH= 2.5 and hydration ratio is 1:3). On the other hand the results is courage to p

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 31 2022
Journal Name
Wasit Journal Of Computer And Mathematics Science
Cheating in E-learning from the perspective of lecturers within Iraqi universities
...Show More Authors

Online examination is an integral and vital component of online learning. Student authentication is going to be widely seen when one of these major challenges within the online assessment. This study aims to investigate potential threats to student authentication in the online examinations. Adopting cheating in E-learning in a university of Iraq brings essential security issues for e-exam . In this document, these analysts suggested  a model making use of a quantitative research style to confirm the suggested aspects and create this relationship between these. The major elements that might impact universities to adopt cheating electronics were declared as Educational methods, Organizational methods, Teaching methods, Technical meth

... Show More
View Publication
Crossref (1)
Crossref
Publication Date
Sun Apr 06 2025
Journal Name
University Of Anbar Sport And Physical Education Science Journal
That the child is aged 7 years, surrounded by information, knowledge and skillsvaried,
...Show More Authors

Abstract That the child is aged 7 years, surrounded by information, knowledge and skillsvaried, which constitute the raw material of experience teaching and is in the rule of inputlearning, if received by the student of these data are positive, these data require research and audit, the style becomes more positive, effective, and then becomes the explorer, butnot done exploration efficiency without the visual, auditory and sensory owned by thechildren. So study aimed to identify the values of the optical track and explore mathematical and find the relationship between them. And use the descriptive approach in a manner the linkon the children of the first year of primary school age (6-7) years in my school Waziriya and Karkh, during the peri

... Show More
View Publication