54 research outputs found

    Molecular characterization of two microalgal strains in Egypt and investigation of the antimicrobial activity of their extracts

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    The emergence of new pathogens and the increasing drug-resistance of recognized ones pose a difficult challenge. One way that this challenge is being addressed is through the discovery of new cost-effective drug resources in the form of bioactive compounds. Algae represent a promising source of bioactive compounds in this regard. In the present research, we used molecular and phylogenetic analysis to isolate and identify two microalgal strains. We found that one strain belonged to the phylum chrysophyta and the other to the cyanobacteria. We also investigated the antimicrobial activity of some of the lipophilic extracts of the two microalgal strains. Several fractions showed high individual antimicrobial bioactivity against multidrug-resistant Salmonella sp., Citrobacter sp., Aspergillus niger and Aspergillus flavus. Fraction III from Poterioochromonas malhamensis showed the highest level of activity against two multidrug-resistant bacterial pathogens. The inhibition zone diameter was 1.4 cm for Salmonella and 1.4 cm for Citrobacter. Meanwhile, another lipophilic fraction from the cyanobacterium Synechocystis salina showed broad-spectrum bioactivity (inhibition zone diameter of 0.9 cm for Aspergillus niger, 1 cm for Citrobacter and 0.9 cm for Salmonella). One lipophilic fraction from Aphanizomenon showed antifungal bioactivity against Aspergillus niger and Aspergillus flavus, where the inhibition zone diameter was 1.1 cm and 1.0 cm, respectively. The study highlights the antimicrobial bioactivity of extracts from local microalgae and emphasizes the importance of carrying out screening programs for those microorganisms

    Anticancer activity of Cyanothece sp. strain extracts from Egypt: First record

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    AbstractObjectiveTo assess the anticancer activity of eight cyanobacterial hydrophilic extracts on Ehrlich ascites carcinoma cell line.MethodsThe cyanobacterial strains used in the investigation were collected from diverse habitats in Egypt. The initial cytotoxicity test of cyanobacterial hydrophilic extracts was carried out by MTT assay. The in vitro anticancer activity of the four most active extracts was performed on MCF-7 cells using sulforhodamine B assay. Morphological and molecular techniques were used to characterise identity of the isolate from which the most potent cytotoxic extract was obtained.ResultsExtracts from four cyanobacterial strains had higher cytotoxic activities scoring 76.68%, 77.70%, 76.70% and 74.45%, respectively. A considerable anticancer effect was only detected when the concentrated extracts were used. One cyanobacterial extract gave the highest anticancer activity on human breast adenocarcinoma cell line (57.6% of inhibition) as compared to control. The isolate was best-matched to Cyanothece sp. with sequence resemblance 98% to Cyanothece sp. strain PCC7564 and the phylogenetic analysis confirmed its close identity to the Cyanothece genus.ConclusionsThis is the first study to report the anticancer effect of aqueous extracts derived from the unicellular Cyanothece sp. from Egypt and its potential as a plausible candidate for future mass biotechnological applications

    Microalgal culture in photo-bioreactor for biodiesel production: case studies from Egypt

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    Biodiesel production from three local microalgae from Egypt was investigated. These microalgae strains differ in their growth pattern as one of the cyanobacterial strainsis filamentous mat-forming  Phormidium sp. whereas the other strain is coccoid colony-forming  Microcystis sp. The third is coccoid yellow-green Botrydiopsis sp. The mass productivity for the strains in a photobioreactor usingsemi-continuous culture was arranged as: Microcystissp.>  Botrydiopsis sp.> Phormidium sp. The mass productivity can be increased by increasing the illumination periodin case of  Botrydiopsis sp. and Microcystis sp. The lipid content was determined by using different solvents for lipid extraction. The  Botrydiopsis sp. gave the highest lipidcontent (48%) for  Botrydiopsis sp. cultured in Oscillatoria medium. Microcystis sp. had (28%) lipid content while the Phormidium  sp. had the lowest lipid content (15%). The major components of the fatty acid compositions in different algal species studied were linoleic, palmitic, oleicand stearic. In conclusion, the cultivation of microalgae inphoto-bioreactor has given high biomass productivity by applying semi-continuous feeding technique. The highest mass productivity doesn’t mean the highest lipid content. The Gas chromatography analysis showed that the algae oils have the suitable fatty acid composition for biodiesel production

    Evaluation of Mapping Accuracy of High-Resolution Stereoscopic Satellite Images

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    High resolution satellite images is still used in large scale mapping due to the need to produce fast products. High resolution stereoscopic satellite images present good enough 3d products that include the benefits of large-scale coverage and low-cost products. A stereopair of IKONOS satellite is used in this research that covers a part of North Sudan country. The study handles the 3d mapping accuracy of using stereoscopic satellite images. The study gives a spotlight on the accuracy in X, Y, Z and the space vector R. Another view of this study the N, E and elevation is indicated. The research environment is mainly ENVI software due to its capabilities of topographic processing module. Some distributed set of ground points (control and tie) was determined on the images and then observed using GPS surveying. Several experiments have been performed to evaluate the resulted mapping product

    Variables Affecting the Mothers Access to Quality Care during Childbirth using the Neural Networks and Logistic Regression Models

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    Quality pregnancy and birth care is crucial in reducing maternal and child mortality in Egypt, requiring both supply and demand interventions. Using data from the Egypt Demographic Health Survey 2014, a neural networks and logistic regression models were built to determine demographic, social, and economic determinants affecting mothers access to care during childbirth. The study found that mothers working status had a significant impact on access to care, with an inverse relationship. Logistic regression outperformed neural networks in analyzing the relationship between explanatory variables and mothers access to care during childbirth

    Optimized electroporation-induced transformation in Microcystis aeruginosa PCC7806

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    Gene disruption in cyanobacteria is difficult and comprises an obstacle for genetic manipulation. Very few reports tackled this problem but the methods used are usually obscure and hardly reproducible. Here we describe an optimized electroporation-induced transformation in Microcystis aeruginosa PCC7806 where conditions for successful electroporation and transformation are investigated

    Benthic dinoflagellates from Red Sea, Egypt: Early records

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    Dinoflagellates from Red Sea are hardly studied, in particular the benthic forms. Samples collected from shallow intertidal zone, Ain Sokhna, Egypt were microscopically examined. Three genera with seven species were recorded. The most frequently-encountered was Katodinium sp., a small mushroom-like with epitheca being consistently larger than hypotheca. Light micrographs revealed the presence of a nucleus in the hyposome and descending cingulum. Scanning electromicrographs (SEM) confirmed this orientation and revealed the presence of apical pore system. Another species showed similarity to the mushroom-like morphology but with large conical episome and small hyposome. Heterotrophic, naked Gyrodinium cf dominans and Gyrodinium sp. were also observed where in the former, there were conspicuous longitudinal striations. A frequently-observed species had naked Gyrodinium-like morphology but with much smaller size. One photosynthetic species had a characteristic stigma similar to type B eyespot in “dinotoms” and episome being slightly larger than hyposome. Gymnodinium sp. with sulcus extending slightly in the episome but deeply to the end of hyposome was also recorded. This genus is reported to be mostly toxic and its presence should be monitored. Finally, this study presents some early records for benthic dinophytes from rather underexplored locality and raises alerts about genus with reported toxicity

    Modern Mashrabiyas with High-tech Daylight Responsive Systems

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    The environmental and social role of closed oriental balconies (Mashrabiyas) remains a significant vernacular aspect of Middle Eastern architecture. However, nowadays this traditional Islamic window element with its characteristic latticework is used to cover entire buildings as an oriental ornament, providing local identity and a sun-shading device for cooling. In fact, designers have reinvented this vernacular Islamic wooden structure into high-tech responsive daylight systems – often on a massive scale and using computer technology – not only to cover tall buildings as an oriental ornament, but also as a major responsive daylight system.It is possible to use the traditional architectural Islamic elements of the Middle East for problem solving design solutions in present-day architecture. The potential for achieving these solutions lies in the effective combination of the design concepts of the traditional elements with new smart materials and technologies. Hence, modern mashrabiyas could be a major responsive daylight system. Contextual information drawn from relevant theory, ethnography and practice is used to form a methodological framework for the modern mashrabiyas with high-tech responsive daylight systems. The main results set boundaries for the viability of computer technology to produce mashrabiyas and promote a sustainable way of reviving their  use within Middle Eastern buildings

    Iron-Marine Algal Interactions and Impacts: Decreasing Global Warming by Increasing Algal Biomass

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    Iron limitation in vast water bodies has been linked to decreased algal productivity, despite different iron-acquiring mechanisms, and the presence of ferritin in many algal species that act as an iron internal reservoir. Therefore, iron fertilization has been proposed to increase algal biomass and photosynthesis. This, in turn, will reduce carbon dioxide in the atmosphere and increase oxygen, thereby decreasing global warming, and achieving ecological balance. In addition, algal proliferation will hopefully lead to enhancement in biodiversity, Biological pump, fish productivity and, subsequently marine food industry. Many climate geoengineering experiments in the form of ocean iron fertilization have been conducted globally in order to achieve such a purpose. However, reservations remain as the outcomes are not as promising as were previously expected. As the temporal and spatial scales of iron fertilization experiments are limited, the effects on fish productivity remain speculative. On the other hand, side effects were also recorded. The main purpose of iron fertilization, for carbon dioxide sequestration and global warming mitigation, still remains to be fully realized and verified. Several improvements and future modifications are suggested, and legal issues are discussed in this review
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