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Damascus, United States

Daoud R.,National Commission for Biotechnology | Tahla M.K.,Damascus University | Azmeh M.F.,Damascus University
International Journal of ChemTech Research | Year: 2016

The effect of fermentation condition on polygalacturonase production by Trichoderma harzianumwas studied using Response Surface Methodology (RSM) design. RSM revealed that the highest production of polygalacturonase reached a maximum of 145.6 U/ml. The optimum conditions for the production of the enzyme by submerged fermentation were achieved using broth medium containing 3% orange peels powder as sole carbon source. The initial pH was 6 during fermentation period of 5day at 30°C in shaking flask 150rpm. Applying the optimum conditions obtained 145.6 U./mL enzyme activity. © 2016, Sphinx Knowledge House. All rights reserved.

Nema N.,Damascus University | Alamir L.,National Commission for Biotechnology | Mohammad M.,Damascus University
International Food Research Journal | Year: 2016

This work describes the partial purification and molecular weight determination of cellulase enzymes produced by submerged fermentation using Bacillus cereus. The enzyme was purified using phenyl-sepharose and sephadex G-100 columns up to 34.6 fold with a specific activity reaching 0.104 IU/mg. The molecular weight of the purified enzyme was determined to be 16.9 kDa by means of SDS-PAGE. This molecular weight is comparable with that of other low molecular mass cellulases produced by Bacillus spp. This finding emphasizes that cellulase produced from Bacillus cereus through submerged fermentation using corn husks belongs to a group of low molecular cellulases. © 2008 IFRJ.

Issa S.,Damascus University | Alhajali A.,Damascus University | Alamir L.,National Commission for Biotechnology
International Food Research Journal | Year: 2016

Rhodotorula yeasts were isolated from various local sources in Damascus, Syria, during 2012 and 2013. Fifty isolates (23 from leaves trees, 13 from different soils, 6 from different meats, 6 from dairy products, 1 pickle and 1 traditional sweet) were identified using API 20C AUX system. Isolated yeasts were classified into three Rhodotorula species: R. mucilaginosa, R. glutinis and R. minuta representing 76%, 20% and 4% of total isolates tested respectively. All isolates were able to produce carotenoid pigments that varied in their quantities ranging from 13.61 μg/g dry biomass for isolate A28 to 658.23 μg/g for isolate A23. The wild strain A23 of R. mucilaginosa was subjected to mutagenesis using UV irradiation at a wavelength of 254 nm. Highest carotenoid production within isolated mutants reached a value of 734.58 μg/g dry biomass after an irradiation period of 4.5 minutes. Overall, UV irradiation. © 2008 IFRJ.

Bredy S.,Damascus University | Najla S.,Damascus University | Albiski F.,National Commission for Biotechnology
International Journal of ChemTech Research | Year: 2015

Abiotic stress factors are the main limitation to plant growth and yield in agriculture. Six genotypes of tomato (Lycopersicon esculentum Mill.) were screened for water stress tolerance by measuring growth parameters and biochemical characteristics in vitro. Three treatments of water stress was evaluated by adding 20, 40 and 60g/l of PEG to Murashige- Skoog (MS) medium and compared to MS medium without PEG for the control. Osmotic pressure (MPa) of media ranged from −0.181 to −0.037 MPa. Genotypes differed for their responses. Plant length and plant diameter, leafs number and area, roots number, length and diameter and plant fresh and dry weights were measured, plus to the content of chlorophyll a and b, content of carotenoid and prolin in plants. Overall, the growth and most of biochemical parameters decreased with PEG concentrations increasing. Grouping genotypes by cluster analysis, based on the studied parameters response to water stress, resulted in three distinct groups: : (1) drought tolerant group consisting of one genotype: G3; a moderately drought tolerant group consisting of three genotypes: G2, G4 and G5; (3) a drought susceptible group consisting of two genotypes: G1 and G6 (Fig. 1). The variation in germplasm indicated that tomato genotypes can be developed for production under some levels of PEG. © 2015, Sphinx Knowledge House. All rights reserved.

The role of previous treatment in the dynamics of tuberculosis transmission has not been adequately investigated. Mycobacterium tuberculosis isolates from previously treated patients (n = 88) from all regions of Syrian Arab Republic were characterized in terms of antibiotic sensitivity and genotyping using double-repetitiveelement polymerase chain reaction (DRE-PCR) method for the proximity of the repetitive DNA elements IS6110 (a mobile genetic element) and PGRS. The 88 isolates resulted in 59 different DRE-PCR patterns. Correlations related to age, sex, region, sensitivity and genotype were examined. All regions of the country showed high levels of genotype diversity, suggesting a low level of transmission of M. tuberculosis strains in previously treated patients.

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