Browsing by Author "Nassar, Hussein N."

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Biodesulfurization of refractory sulfur compounds in petro-diesel by a novel hydrocarbon tolerable strain Paenibacillus glucanolyticus HN4
(Springer, 44105) Nassar, Hussein N.; Abu Amr, Salem S.; El-Gendy, Nour Sh.
One of the main precursors of air pollution and acid rains is the presence of the recalcitrant thiophenic compounds, for example dibenzothiophene (DBT) and its derivatives in transportation fuels. In an attempt to achieve the worldwide regulations of ultra- low sulfur transportation fuels without affecting its hydrocarbon skeleton, a biphasic medium containing 100 mg/L DBT dissolved in n-hexadecane (1/4 oil/water v/v) used for enrichment and isolation of selective biodesulfurizing bacterium from an oil-polluted sediment sample collected from Egyptian Red Sea shoreline. The isolated bacterium is facultative anaerobe, motile, spore-former, and mesophile. It is genetically identified as Paenibacillus glucanolyticus strain HN4 (NCBI Gene Bank Accession No. MT645230). HN4 desulfurized DBT as a model of the recalcitrant thiophenic compounds without affecting its hydrocarbon skeleton via the 4S-pathway producing 2-hydroxybiphenyl (2-HBP) as a dead end product. HN4 substantiated to be a hydrocarbon tolerant, biosurfactants(s) producer, and endorsed unique enzymatic system capable of desulfurizing broad range of thiophenic compounds and expressed an efficient desulfurization activity against the recalcitrant alkylated DBTs. As far our knowledge, it is the first reported BDS study using P. glucanolyticus. Statistical optimization based on One-Factor-At-A-Time (OFAT) technique and response surface methodology (RSM) applied for elucidation of mathematical model correlations de- scribing and optimizing the effect of different physicochemical parameters on batch biphasic BDS process. That illustrated an approximate increase in BDS efficiency by 1.34 fold and recorded 94% sulfur removal in biphasic batch process at optimum operation conditions of 120 h, 0.14 wt% S-content model oil (DBT dissolved in n-hexadecane), 33.5 °C, pH7 and 1/1 oil/water phase ratio, and 147 rpm. Resting cells of HN4 in a biphasic reactor (1/1 v/v) decreased the sulfur content of a refractory thiophenic model oil (thiophene, benzothiophene, DBT, and alkylated DBT dissolved in n-hexadecane) from 0.14 to 0.027 wt%, and petro-diesel from 0.2 to 0.04 wt%, within 120 h, keeping the calorific value of the treated fuel intact. Consequently, that novel strain could be recommended as a promising candidate for BDS as complementary to hydrodesulfurization process in oil refinery.
Biosynthesized magnetite nanoparticles as an environmental opulence and sustainable wastewater treatment
(Elsevier, 2021-02) El-Gendy, Nour Sh.; Nassar, Hussein N.
This review emphasizes the win-win one-pot valorization process of different waste biomass that composed of many biological macromolecules (e.g. polysaccharides, polyphenols, carbohydrates, lipids, enzymes, proteins, etc.) and other biomolecules (e.g. alkaloids, terpenoids, tannins, phenolics, carotenoids, amino acids, sugars, vitamins, etc.) into biofunctionalized magnetite (Fe3O4) nanoparticles (BMNPs). It illustrates the sustainable recruitment of microbial intra- and extra-cellular metabolites, proteins, and/or enzymes in the biosynthesis of BMNPs. It elucidates the environmental affluence of such sustainable, cost-effective, and ecofriendly BMNPs as an antimicrobial agent for water disinfection, photo-degrader, and adsorbent for different xenobiotics, organic and inorganic water pollutants. It confers the future environmental aspects of BMNPs in biofuels production from lipids and lignocellulosic wastes, biosensors manufacturing and bio-upgrading of petroleum fractions, etc. It discusses the circular economy, challenges, and opportunities for scaling up the zero-waste green synthesis of MNPs. Nevertheless, imminent investigations are still needed to elucidate the exact rule of biological macro- and micro- molecules in BMNPs synthesis and mechanisms involved in its microbicidal and photodegradation activities. Accentuated researches are more required on the toxicity and/or biosafety of the green synthesized BMNPs to humans and other non-target organisms to ensure its eco-safety upon environmental applications.
Sustainable Photo- and Bio-Catalysts for Wastewater Treatment
(onlinelibrary.wiley, 2020-05) El-Gendy, Nour Sh.; Nassar, Hussein N.
Millions of tons of agro-industrial wastes are produced annually all over the world. These wastes are not economically reused, create air, soil, and water pollution. That has negative impact on human health, tourism, economy, and environment. This comes with the increase of the worldwide population and the climate change that have affected the sustainability of the water resources causing the degrada- tion of several renewable and non-renewable resources. Consequently, there is a great demand for applying non-conventional and developed cost effective tech- niques for wastewater reuse. This chapter will focus on the integrated valorization process for reaching to the point of zero-waste and fashioned valuable insights on the upcycling of apatite as one of the readily available and cost effective agro- industrial wastes into sustainable photo- and/bio-catalysts that can be applied in wastewater treatment.
Sustainable Phycoremediation of Xenobiotics Polluted Water
(Springer, 44119) El-Gendy, Nour Sh.; Nassar, Hussein N.; El-Tarabily, Khaled A.; Synan F., AbuQamar
Xenobiotics pose serious risks to the environment and human health because of their carcinogenic, teratogenic, mutagenic, and other toxic properties. Biodegradation of different xenobiotics has been widely covered using bacteria, yeast, and filamentous fungi. Because of the efficient capabilities of microalgae in remediation of polluted water via potential enzymatic system and production of biosurfactants, relatively little attention has been paid to the phycodegradation of xenobiotics by microalgae. This chapter summarizes the opportunities and challenges of integrated sustainable application of microalgae in the remediation of xenobiotics polluted water.