Ahmed E. Al-Sabri

Biodegradation of diesel fuel hydrocarbons by mangrove fungi from Red Sea Coast of Saudi Arabia.

Mangrove sediments were collected from major mangrove stands on the Red Sea Coast of Saudi Arabia. Forty five isolates belonging to 12 genera were purified and five isolates as well as their consortium were found to be able to grow in association with petroleum oil as sole carbon source under in vitro conditions. The isolated strains were identified based on internal transcribed spacer (ITS) rDNA sequence analysis. The fungal strains with the greatest potentiality to degrade diesel oil, without developing antagonistic activity, were identified as Alternaria alternata, Aspergillus terreus, Cladosporium sphaerospermum, Eupenicillium hirayamae and Paecilomyces variotii. As compared to the controls, these fungi accumulated significantly higher biomass, produced extracellular enzymes and liberated larger volumes of CO2. These observations with GC–MS data confirm that these isolates displayed rapid diesel oil bioremoval and when used together as a consortium, there was no antagonistic activity.

Micro-anatomical changes in major blood vessel caused by dengue virus (serotype 2) infection

Dengue virus (DENV) has emerged as a major economic concern in developing countries, with 2.5 billion people believed to be at risk. Vascular endothelial cells (ECs) lining the circulatory system from heart to end vessels perform crucial functions in the human body, by aiding gas exchange in lungs, gaseous, nutritional and its waste exchange in all tissues, including the blood brain barrier, filtration of fluid in the glomeruli, neutrophil recruitment, hormone trafficking, as well as maintenance of blood vessel tone and hemostasis. These functions can be deregulated during DENV infection. In this study, BALB/c mice infected with DENV serotype 2 were analyzed histologically for changes in major blood vessels in response to DENV infection. In the uninfected mouse model, blood vessels showed normal architecture with intact endothelial monolayer, tunica media, and tunica adventitia. In the infected mouse model, DENV distorted the endothelium lining and disturbed the smooth muscle, elastic laminae and their supporting tissues causing vascular structural disarrangement. This may explain the severe pathological illness in DENV-infected individuals. The overall DENV-induced damages on the endothelial and its supporting tissues and the dysregulated immune reactions initiated by the host were discussed.

Biodegradation of Low Density Polyethylene (Ldpe) by Mangrove Fungi from the Red Sea Coast

Forty five fungal isolates belonging to 13 genera were derived from tidal water, floating debris, and sediment collected from mangrove stands on the Red Sea coast of Saudi Arabia. Six of these isolates and their consortium were found to be able to grow in association with low density polyethylene (LDPE) film under in vitro conditions in the absence of dextrose or any other carbon source. These isolates were further tested for their potential to degrade LDPE by co-cultivation under aeration on a rotary shaker. Examination under light and scanning electron microscope revealed that the fungi attached themselves to the surface of the film and grew profusely. As compared to the controls, these fungi accumulated significantly higher biomass, produced more ligninolytic enzymes, and released larger volumes of CO2 during co-cultivation with LDPE. These observations indicated that the selected isolates were able to breakdown and consume the LDPE film.

Surfactant assisted zinc doped tin oxide nanoparticles for supercapacitor applications

AbstractZinc doped tin oxide nanoparticles were synthesized by employing sol–gel method assisted with different surfactants namely cetyl trimethyl ammonium bromide (CTAB), hexamine and polyethylene glycol 400 (PEG-400). The synthesis of uniform distribution of spherical Zn-SnO2 nanoparticles in presence of PEG-400 was optimized. The synthesized Zn-SnO2 nanoparticles were characterized by employing standard characterization techniques. X-ray diffraction results confirmed the product high-quality crystalline formation. The photoluminescence peaks appeared at 360 nm revealed the recombination of electron and hole from band to band emission of SnO2 optical properties. The vibrational properties of Zn-SnO2 nanoparticles were confirmed by both Raman and infra red spectra. The spherical morphology and nano sized product was evident in 200 nm scale SEM images. The cyclic voltammetry result of the product Zn-SnO2 assisted PEG-400 exhibited the specific capacitance value of 312.7 F/g at scan rate of 10 mV/s and revealed the superior electrochemical properties. Moreover, the EIS and GCD studies also revealed the good supercapacitor nature with specific capacitance of 132.1 F/g at current density of 1 A/g for the product Zn-SnO2 (PEG-400). Diagrammatic representation of Zn doped SnO2 synthesis by sol-gel method with enhanced specific capacitance of 132.1 F/g at 1 A/g for Zn-SnO2 (PEG-400).HighlightsZn-SnO2 nanoparticles in presence of PEG-400 was optimizedZn-SnO2 (PEG-400) nanoparticles exhibits superior electrochemical propertiesProduct exhibits good capacitance (132.1 F/g) at 1 A/g current density

Structural, morphological, optical and antibacterial properties of pentagon CuO nanoplatelets

AbstractPentagon copper oxide (CuO) nanoplatelets formation employing Nephelium lappaceum L. extract was successfully developed. Characteristic X-ray diffraction peaks revealed a monoclinic and end-centered lattice structure of copper oxide belonging to 1C62h (c2/c) space group. Three characteristic Raman peaks, Ag, Bg(1) and Bg(2), confirmed the monoclinic CuO structure. The pentagon CuO nanoplatelets formation increased proportionally with increase in calcination temperature from 600 to 800 °C and the particle size was noticeably increased from 30 to 250 nm. Strong photoluminescence emission peak was noticed in the UV region between 377 and 393 nm. The metal–oxygen Cu2+–O2− vibration of the synthesized product in the range between 300 and 700 cm−1 was confirmed using infrared studies. The CuO product obtained at 600 °C showed best antibacterial action due to its small particle size (30–60 nm) against both Gram-positive and Gram-negative bacteria. The obtained product cell morphology, proliferation and viability test were investigated with respect to control and 10, 50, 100, and 500 μg/ml. Cell viability of the product were respectively 74, 55.3, 50, and 27.3% and found suitable for biomedical applications. HighlightsBiologic-mediated pentagon CuO nanoplatelets developed.Mechanism of copper-ellagate complex formation was proposed.10, 50, 100 and 500 μg/ml cell viability were 74, 55.3, 50 and 27.3%.

Fungal Contamination of Non-Renewable Groundwater in the Arabian Peninsula: Assessing the Harmfulness to Humans

ABSTRACT Most of the studies about the groundwater quality have been focused on chemical and bacterial contamination. However, fungal contamination of drinking water has been suggested as an underestimated problem. We studied 20 wells in the Arabian Peninsula, identified their fungal contamination and assessed the potential harmfulness of the fungi to humans. We identified 28 fungal species, many of them commonly known to occur in drinking water. To assess the potential role of fungi in water, we selected 15 species for a bioassay with a model bacterium Bacillus subtilis. All fungal species inhibited the growth of B. subtilis, thus showing antibacterial activity. These fungi were interpreted to secrete toxins and thus, be possibly harmful to humans. Nine of the species retained their antibacterial activity in a boiling treatment. Therefore, they cannot be disinfected by boiling. This study raises new aspects and questions about the harmfulness of the fungal contamination in drinking water to humans.

Biodegradation of engine oil by fungi from mangrove habitat

The pollution of land and water by petroleum compounds is a matter of growing concern necessitating the development of methodologies, including microbial biodegradation, to minimize the impending impacts. It has been extensively reported that fungi from polluted habitats have the potential to degrade pollutants, including petroleum compounds. The Red Sea is used extensively for the transport of oil and is substantially polluted, due to leaks, spills, and occasional accidents. Tidal water, floating debris, and soil sediment were collected from mangrove stands on three polluted sites along the Red Sea coast of Saudi Arabia and forty-five fungal isolates belonging to 13 genera were recovered from these samples. The isolates were identified on the basis of a sequence analysis of the 18S rRNA gene fragment. Nine of these isolates were found to be able to grow in association with engine oil, as the sole carbon source, under in vitro conditions. These selected isolates and their consortium accumulated greater biomass, liberated more CO2, and produced higher levels of extracellular enzymes, during cultivation with engine oil as compared with the controls. These observations were authenticated by gas chromatography-mass spectrophotometry (GC-MS) analysis, which indicated that many high mass compounds present in the oil before treatment either disappeared or showed diminished levels.