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Response surface optimization of a single‑step castor oil–based biodiesel production process using a stator‑rotor hydrodynamic cavitation reactor
(Springer Nature, 2024-10-10) Aya Soliman; Abdallah R. Ismail; Mohamed Khater; Salem A. Abu Amr; Nour Sh. El‑Gendy; Abbas Anwar Ezzat
In order to combat environmental pollution and the depletion of non-renewable fuels, feasible, eco-friendly, and sustainable biodiesel production from non-edible oil crops must be augmented. This study is the first to intensify biodiesel production from castor oil using a self-manufactured cylindrical stator-rotor hydrodynamic cavitation reactor. In order to model and optimize the biodiesel yield, a response surface methodology based on a 1/2 fraction-three-level face center composite design of three levels and five experimental factors was used. The predicted ideal operating parameters were found to be 52.51°C, 1164.8 rpm rotor speed, 27.43 min, 8.4:1 methanol-to-oil molar ratio, and 0.89% KOH concentration. That yielded 95.51% biodiesel with a 99% fatty acid methyl ester content. It recorded a relatively low energy consumption and high cavitation yield of 6.09 × 105 J and 12 × 10−3 g/J, respectively. The generated biodiesel and bio-/petro-diesel blends had good fuel qualities that were on par with global norms and commercially available Egyptian petro-diesel. The preliminary cost analysis assured the feasibility of the applied process.
A Study on the Potential of Valorizing Sargassum latifolium into Biofuels and Sustainable Value-Added Products
(International Journal of Biomaterials : wiley, 2024) Nour Sh. El-Gendy; Mohamed Hosny; Abdallah R. Ismail; Ahmad A. Radwan; Basma A. Ali; Hager R. Ali; Radwa A. El-Salamony; Khaled M. Abdelsalam; Manal Mubarak
To increase the limited commercial utility and lessen the negative environmental effects of the massive growth of brown macroalgae, this work illustrates the feasibility of valorizing the invasively proliferated Sargassum latifolium into different value-added products. The proximate analysis recommends its applicability as a solid biofuel with a sufficient calorific value (14.82 ± 0.5 MJ/kg). It contains 6.00 ± 0.07% N + P2O5 + K2O and 29.61 ± 0.05% organic C. Its nutritional analysis proved notable carbohydrate, ash, protein, and fiber contents with a rational amount of lipid and a considerable amount of beneficial macronutrients and micronutrients, with a low concentration of undesirable heavy metals. That recommends its application in the organic fertilizer, food, medicine, and animal fodder industries. A proposed eco-friendly sequential integrated process valorized its biomass into 77.6 ± 0.5 mg/g chlorophyll, 180 ± 0.5 mg/g carotenoids, 5.86 ± 0.5 mg/g fucoxanthin, 0.93 ± 0.5 mg/g β-carotene, 21.97 ± 0.5% (w/w) alginate, and 16.40 ± 0.5% (w/w) cellulose, with different industrial and bioprocess applications. Furthermore, Aspergillus galapagensis SBWF1, Mucor hiemalis SBWF2, and Penicillium oxalicum SBWF3 (GenBank accession numbers OR636487, OR636488, and OR636489) have been isolated from its fresh biomass. Those showed wide versatility for hydrolyzing and saccharifying its polysaccharides. A Gram-negative Stutzerimonas stutzeri SBB1(GenBank accession number OR764547) has also been isolated with good capabilities to ferment the produced pentoses, hexoses, and mannitol from the fungal saccharification, yielding 0.25 ± 0.014, 0.26 ± 0.018, and 0.37 ± 0.020 g ethanol/g algal biomass, respectively. Furthermore, in a pioneering step for valuing the suggested sequential biomass hydrolysis and bioethanol fermentation processes, the spent waste S. latifolium disposed of from the saccharification process has been valorized into C-dots with potent biocidal activity against pathogenic microorganisms.
Investigation of Antiviral Effects of Essential Oils
(wiley, 2024-01) Mustafa, Ahmad; El-Kashef, Dina H; Abdelwahab, Miada F; Gomaa, Alshymaa Abdel-Rahman; Mustafa, Muhamad; Abdel-Wahab, Nada M; Ibrahim, Alyaa H
Essential oils (EOs) represent one of the most interesting natural products obtained from various aromatic plants. Their effective use in many industries including pharmaceuticals, agriculture, perfumes and food is predominantly attributed to their distinctive aroma and intriguing bioactivities. The chemical profile of these agents exhibited the presence of a variety of volatile constituents that are mainly classified into terpenes and oxygenated compounds. In fact, most of the EOs and essential oil components (EOCs) have received considerable attention in the last years, owing to their promising biological activities, for instance antioxidant, antibacterial, antifungal, antiviral, antispasmodic, insecticidal, anti-inflammatory and cytotoxic activities. This chapter emphasizes particularly the potential antiviral effect of EOs by reviewing some recent literature. It illustrates the different methods implemented to investigate the in vitro antiviral activity of both EOs and EOCs, as well as their mechanisms of action. In addition, the efficacy of EOs against several viral infections affecting human body systems, some plants and animals is also highlighted. Besides, this chapter gives insights into the application of nanoencapsulation technology to improve EOs bioavailability and hence their antiviral efficacy.
Rotor–stator hydrodynamic cavitation reactor for intensifcation of castor oil biodiesel production
(Springer, 2024-08) Khater, M; Aboelazayem, O; Ismail, A.R; Soliman, A; Abu Amr, S. A; El‑Gendy, N. Sh; Ezzat, A. A
Nowadays, the intensifcation of the production of biodiesel from non-edible oil crops is mandatory to overcome petrol-fuel depletion and environmental pollution. For the frst time, enhanced biodiesel production from castor oil via rotor–stator hydrodynamic cavitation has been studied in this work. Response surface methodology based on one-factor-at-a-time design of experiments was employed for modelling and optimizing the biodiesel yield and the decrease in feedstock viscosity, density, and total acid number (TAN). The predicted optimum parameters of 8.15:1 methanol:oil (M:O), 1499 rpm, 29.38 min, 48.43 °C, and a KOH catalyst concentration of 0.74 wt.% resulted in a 96% biodiesel yield with a concomitant decrease in viscosity, density, and TAN of approximately 95%, 5.12%, and 90.02%, respectively. According to the results of the breakthrough kinetic calculations, the reaction is pseudo-second order, with the activation energy, frequency factor, and reaction rate constant being 0.23 M−1 min−1, 18.77 kJ/mol, and 6.32 M−1 min−1, respectively. The fuel properties of the produced biodiesel and bio-petro-diesel blends were good, comparable to international standards and the marketed Egyptian petro-diesel.
Nano-Magnetic Sugarcane Bagasse Cellulosic Composite as a Sustainable Photocatalyst for Textile Industrial Effluent Remediation
(Multidisciplinary Digital Publishing Institute (MDPI), 2024-05) Tony, Maha A; El-Gendy, Nour Sh; Hussien, Mohamed; Ahmed, Abdullah A. S; Xin, Jiayu; Lu, Xingmei; El-Sayed, Ibrahim El Tantawy
Researchers have focused on deriving environmentally benign materials from biomass waste and converting them into value-added materials. In this study, cellulosic crystals derived from sugarcane bagasse (SCB) are augmented with magnetite (M) nanoparticles. Following the co-precipitation route, the composite was prepared, and then the mixture was subjected to a green microwave solvent-less technique. Various mass ratios of SCB:M (1:1, 2:1, 3:1, 5:1, and 1:2) were prepared and efficiently utilized as photocatalysts. To look at the structural and morphological properties of the prepared samples, X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), and elemental analysis were used to describe the composite fibers. SCB:M augmented with H2O2 as a Fenton reaction was used to eliminate Reactive blue 19 (RB19) from polluted water and was compared with pristine SCB and M. Additionally, the response surface methodology (RSM) statistically located and assessed the optimized parameters. The optimal operating conditions were recorded at pH 2.0 and 3:1 SCB: M with 40 mg/L and 100 mg/L of hydrogen peroxide. However, the temperature increase inhibits the oxidation reaction. The kinetic modeling fit showed the reaction following the second-order kinetic model with an energy barrier of 98.66 kJ/mol. The results show that such photocatalyst behavior is a promising candidate for treating textile effluent in practical applications.
para‑Nitrophenol nano‑biodegradation using Turbinaria triquetra‑synthesized magnetic nanoparticles‑coated novel bacteria: a sustainable approach for refnery wastewater treatment
(Springer, 2024-05) Nassar, H. N; Abd El Salam, H. M; Al‑Sadek, A. F; Abu Amr, S. A; El‑Gendy, N. Sh
Recently, nano-biodegradation is considered promising for environmental reclamation. In this study, selective enrichment technique was applied for isolating a novel bacterium, Bacillus nealsonii strain HN9 (NCBI Gene Bank Accession No. MZ081627) capable of degrading high concentrations of para-nitrophenol (pNP) via the hydroquinone pathway. Sustainable Turbinaria triquetra hot aqueous extract (TAE) was successfully used as a revolutionary reducing, stabilizing, and capping agent in a one-pot mild operating process for the green synthesis of ecofriendly, crystalline, non-toxic, polydispersed, multishaped, highly stable Fe3O4 NPs with average size, specifc surface area, and magnetic saturation of 26.31 nm, 82.48 m2 /g, and 57.57 emu/g, respectively. In a cutting-edge approach, response surface methodology and artifcial neural network were applied for modeling and optimizing the pNP nano-biodegradation batch process using the TAE-synthesized MNPs-coated HN9. Approximately complete removal of pNP was achieved at the predicted optimum operating conditions of 12,900 mg/L salinity, 30 °C, pH7, 0.38 g/g MNPs to biomass ratio (M/B), 170 RPM, and 400 mg/L pNP concentrations within 48 h. Relative to free cells, the MNPs-coated cells expressed a fve-times higher pNP biodegradation rate, higher storage and operational stability, and could be used for fve successive times without losing its activity, besides the advantage of magnetic separation. Upon the pioneering application of TAE-synthesized MNPs-coated HN9 for the nanobioremediation of refnery wastewater, the removal rate of BOD, COD, TPH, PAHs, and phenols recorded 12.15 mg/L/h, 12.10 mg/L/h, 1.68 mg/L/h, 4.27 mg/L/h, and 8.84 mg/L/h, respectively. That was approximately three-times higher than that recorded in batch bioreactor inoculated by free HN9.
A Study on the Valorization of Rice Straw into Different Value-Added Products and Biofuels
(Hindawi Publishing Corporation, 2024-04) Ali, Basma A; Hosny, Mohamed; Nassar, Hussein N; Elhakim, Heba K. A; El-Gendy, Nour Sh
Tis work depicts that rice straw (RS), which is one of the major lignocellulosic wastes all over the world and causing many environmental problems, has considerable amounts of protein, ash, macronutrients, and micronutrients of approximately 11.38%, 16.77%, 2.27 mg/kg, and 771.9 mg/kg, respectively; besides, a C/N ratio of 15.18, a total N, P2O5, and K2O content of 1.85%, and a considerably low concentration of undesirable heavy metals and silica of approximately 77.69 mg/kg and 109 mg/kg are also present, which recommends its applicability as a precursor feedstock for the production of organic fertilizer and animal fodder. Te batch solid-state fermentation (SSF) of RS by Trichoderma longibrachiatum DSMZ 16517 produced considerable amount of total reducing sugars (TRS) of approximately 339.2 mg TRS/g RS under the optimum operatic conditions of 20% (w:v) substrate concentration, pH 7, 1% inoculum size, a 9-day incubation period, and 30°C incubation temperature. Te readily available and cost-efective agroindustrial waste, sugarcane molasses, proved to enhance the fungal biomass growth and (hemi) cellulolytic enzymes activities. Te inoculated RS-SSF batch process with T. longibrachiatum precultured on 10% molasses enhanced the (hemi) cellulolytic enzymatic activities and TRS production rate by approximately 5.82 and 3.8 folds, respectively, relative to that inoculated by T. longibrachiatum precultured in the conventional potato dextrose broth medium. Te separate hydrolysis and fermentation processes by diferent yeast strains Candida tropicalis DSM 70156, C. shehatae ATCC 58779, and Saccharomyces cerevisiae ATCC 64712 revealed an efcient bioethanol yield and productivity that ranged between 0.36 and 0.38 g/g sugars and 0.22 and 0.23 g/L/h, respectively, with concomitant competent fermentation efciencies that ranged between 48.35% and 51.25%. Te proximate analysis of rice straw before and after fungal hydrolysis proved calorifc values of approximately 15.8 MJ/kg and 16.05 MJ/kg, respectively, recommending their applicability as primary and secondary solid biofuels. Tus, this study proved the waste prosperity of RS for environmental opulence and sustainability.
Investigating the Combined Impact of Water–Diesel Emulsion and Al2O3 Nanoparticles on the Performance and the Emissions from a Diesel Engine via the Design of Experiment
(MDPI AG, 2024-02) Mostafa, A; Mourad, M; Mustafa, Ahmad; Youssef, I
This study aims to assess the impact of the water ratio and nanoparticle concentration of neat diesel fuel on the performance characteristics of and exhaust gas emissions from diesel engines. The experimental tests were conducted in two stages. In the first stage, the effects of adding water to neat diesel fuel in ratios of 2.5% and 5% on engine performance and emissions characteristics were examined and compared to those of neat diesel at a constant engine speed of 3000 rpm under three different engine loads. A response surface methodology (RSM) based on a central composite design (CCD) was utilized to simulate the design of the experiment. According to the test results, adding water to neat diesel fuel increased the brake-specific fuel consumption and reduced the brake thermal efficiency compared to neat diesel fuel. In the examination of exhaust emissions, hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) in the tested fuel containing 2.5% of water were decreased in comparison to pure diesel fuel by 16.62%, 21.56%, and 60.18%, respectively, on average, through engine loading. In the second stage, due to the trade-off between emissions and performance, the emulsion fuel containing 2.5% of water is chosen as the best emulsion from the previous stage and mixed with aluminum oxide nanoparticles at two dose levels (50 and 100 ppm). With the same engine conditions, the emulsion fuel mixed with 50 ppm of aluminum oxide nanoparticles exhibited the best performance and the lowest emissions compared to the other evaluated fuels. The outcomes of the investigations showed that a low concentration of 50 ppm with a small amount of 11 nm of aluminum oxide nanoparticles combined with a water diesel emulsion is a successful method for improving diesel engine performance while lowering emissions. Additionally, it was found that the mathematical model could accurately predict engine performance parameters and pollution characteristics. © 2023 by the authors.
Clean production of isopropyl myristate: A cutting-edge enzymatic approach with a holistic techno-economic evaluation
(Elsevier Ltd, 2024-03) ., M. Shaaban Sadek a , Ahmad Mustafa b,c,* , N.A. Mostafa a,* , Luigi di Bitonto d , Muhamad Mustafa e ,f , Carlo Pastore d
This work aims to develop a simple, clean, and energy-efficient lipase-catalyzed method for the synthesis of isopropyl myristate (IPM). The enzymatic esterification between isopropyl alcohol and myristic acid was catalyzed using immobilized Candida Antarctica lipase. Response Surface Methodology (RSM) was applied to study the interactive effect of reaction conditions on IPM yield. The maximum experimental and predicted conversions were 92.4 % and 92.0 %, respectively. The optimized conditions were as follows: molar ratio of isopropyl alcohol to myristic acid molar ratio of 8:1, molecular sieves of 12.5 % w/w, a catalyst load of 4 % w/w, at a temperature of 60 ◦C and a reaction time of 2.5 h. Isopropyl myristate synthesized was isolated and fully characterized by GC–MS, FTIR, 1 H and 13C NMR. Finally, to support the applicability perspective of this proposed method, a process diagram (PSD) was created using ASPEN PLUS software to simulate the production of IPM under the optimized conditions. The economic assessment of the whole process produced a positive net present value (NPV) of $44,797,732, return on investment (ROI) of 716.17 %, internal rate of return (IRR) of 110 %, payback period of 1.61, and a levelized cost of production (LCOP) of $1,777 per ton over a 14-year project lifespan. These results strongly suggest low-risk and high-profitability benefits to investing in this green route. Finally, the environmental impact was also assessed by calculating the quantity of CO2 generated from the proposed enzymatic process. The results showed a reduced emission rate of 0.25 ton CO2 eq. per ton of IPM produced. This underscores the lower environmental impact of this technology compared to traditional methods. Importantly, this study stands out as the first to conduct a comprehensive techno-economic assessment of the enzymatic synthesis of IPM, providing valuable insights into the economic viability and potential benefits of adopting this innovative and sustainable approach in the chemical manufacturing industry.
Comparison of the Techno-Economic and Environmental Assessment of Hydrodynamic Cavitation and Mechanical Stirring Reactors for the Production of Sustainable Hevea brasiliensis Ethyl Ester
(MDPI AG, 2023-12) Samuel, Olusegun David; Aigba, Peter A; Tran, Thien Khanh; Fayaz, H; Pastore, Carlo; Der, Oguzhan; Erçetin, Ali; Enweremadu, Christopher C; Mustafa, Ahmad
Even though the hydrodynamic cavitation reactor (HCR) performs better than the mechanical stirring reactor (MSR) at producing biodiesel, and the ethylic process of biodiesel production is entirely bio-based and environmentally friendly, non-homogeneous ethanol with the triglyceride of underutilized oil, despite the many technical advantages, has discouraged the biodiesel industry and stakeholders from producing ethylic biodiesel in HCRs. This study examines the generation of biodiesel from rubber seed oil (RSO) by comparing the ethyl-based HCR and MSR. Despite ethyl’s technical advantages and environmental friendliness, a lack of scalable protocols for various feedstocks hinders its global adoption. The research employs Aspen HYSYS simulations to investigate the ethanolysis process for RSO in both HCRs and MSRs. The HCR proves more productive, converting 99.01% of RSO compared to the MSR’s 94.85%. The HCR’s exergetic efficiency is 89.56% vs. the MSR’s 54.92%, with significantly lower energy usage. Removing catalytic and glycerin purification stages impacts both processes, with HC showing lower exergy destruction. Economic analysis reveals the HCR’s lower investment cost and higher net present value (USD 57.2 million) and return on investment (176%) compared to the MSR’s. The HCR also has a much smaller carbon footprint, emitting 7.2 t CO2 eq./year, while the MSR emits 172 t CO2 eq./year. This study provides database information for quickly scaling up the production of ethanolic biodiesel from non-edible and third-generation feedstocks in the HCR and MSR.
Development and Evaluation of an Eco-Friendly Hand Sanitizer Formulation Valorized from Fruit Peels
(Hindawi Publishing Corporation, 2023-12) Verma, J; Mishra, R; Mazumdar, A; Singh, R; El-Gendy, N. Sh
Hand sanitizer usage has proven to be a common and practical method for reducing the spread of infectious diseases which can be caused by many harmful pathogens. Tere is a need for alcohol-free hand sanitizers because most hand sanitizers on the market are alcohol-based, and regular use of them can damage the skin and can be hazardous. India is the world’s largest producer of fruits and one of the major problems after fruit consumption is their peels, causing waste management problems and contributing to the formation of greenhouse gases leading to air pollution and adding to the problem of climate change. Valorization of such wastes into other value-added products and their incorporation into formulations of eco-friendly alcohol-free hand sanitizers would solve these issues, save the environment, beneft the society, and help in achieving the sustainable development goals. Tus, this research focuses on formulating an efective natural alcohol-free hand sanitizer that harnesses the antimicrobial properties of the various types of bioactive components found in fruit peels of pomegranate, sweet lime, and lemon. Te peel extracts and the formulated sanitizer proved considerable antimicrobial activity against the pathogenic Escherichia coli and hand microfora. Molecular docking was also applied to examine ligand-protein interaction patterns and predict binding conformers and afnity of the sanitizer phytocompounds towards target proteins in COVID-19, infuenza, and pneumonia viruses. Te binding afnities and the protein-ligand interactions virtual studies revealed that the sanitizer phytocompounds bind with the amino acids in the target proteins’ active sites via hydrogen bonding interactions. As a result, it is possible to formulate a natural, alcohol-free hand sanitizer from fruit peels that is efective against pathogenic germs and viruses using the basic structure of these potential fndings.
Highly efficient one-pot bioethanol production from corn stalk with biocompatible ionic liquids
(Elsevier Ltd., 2023-05) Zhu, Qingqing; Gao, Die; Yan, Dongxia; Tang, Jing; Cheng, Xiujie; El Sayed, Ibrahim El Tantawy; El-Gendy, Nour Sh; Lu, Xingmei; Xin, Jiayu
Efficient utilization of ionic liquids (ILs) for transforming lignocellulose into biofuel and alleviating concerns over shortages of nonrenewable resources is still an urgent issue. Herein, a highly efficient one-pot bioethanol production with biocompatible ILs was designed. XRD, TGA, and DSC analysis showed that pre-treatment of corn stalk with [Ch][Gly] trend to become easier to depolymerize than the untreated sample. Under one-pot process, the efficiency of [Ch][Gly] pretreated method could achieve a 9-fold sugar yield, i.e., 324.7 mg glucose/PU and 131.8 mg xylose/PU (1 PU = 10 g, 3 wt% [Ch][Gly] aqueous). The conditions for the whole process were optimized and the maximum yield% were achieved 80 % for glucose, 79 % for xylose, and 84 % for bioethanol. Besides, we found that increasing surface area and pore size could enhance accessibility for enzymes to attack cellulose and hemicellulose. The proposed study offers an efficient one-pot bioethanol production strategy with sustainable ILs.
Highly selective synthesis of glyceryl monostearate via lipase catalyzed esterification of triple pressed stearic acid and glycerin
(Elsevier Ltd., 2023-04) Mustafa, Ahmad; Ramadan, Rehab; Niikura, Fumiya; Inayat, Abrar; Hafez, H
The synthesis of value-added products from glycerin is an attractive research area that aims to valorize this abundant by-product of the biodiesel industry. Thus, raising the economic feasibility and mitigating the envi- ronmental consequences. In this work, an alternative green, energy-efficient, and selective enzymatic (ENZ) esterification of triple-pressed stearic acid (TPSA) and glycerin was carried out to produce glyceryl monostearate (GMS). Response surface methodology (RSM) was used to optimize the reaction conditions; the optimum con- ditions were a 6:1 glycerin to TPSA molar ratio, 8% w/w Lipozyme 435 amount, and 350% w/w solvent amount. It is worth mentioning that the solvent addition greatly enhanced the yield of GMS compared to the conventional autocatalytic esterification (AUT) process. The proposed ENZ approach was also economically assessed, and the findings were compared to those of the AUT method. Considering a plant capacity of 4,950 t year− 1 and an interest of 11%, the total capital investment of the ENZ GMS production was 1.8 times cheaper than the AUT process, suggesting a favorable investment opportunity. In addition, the positively obtained net present value (NPV) and return on investment (ROI) for the ENZ process’s total production costs reveal the proposed method’s economic feasibility. The suggested approach for synthesizing GMS can be seen as a baseline for a cleaner large- scale monoglycerides synthesis
A Mini Review on Flotation Techniques and Reagents Used in Graphite Beneficiation
(Hindawi Publishing Corporation, 2023-03) Vasumathi, N.; Sarjekar, Anshuli; Chandrayan, Hrishikesh; Chennakesavulu, K; Reddy, G Ramanjaneya; Kumar, T. V. Vijaya; El-Gendy, Nour Sh; Gopalkrishna, S. J
Due to its numerous and major industrial uses, graphite is one of the significant carbon allotropes. Refractories and batteries are only a couple of the many uses for graphite. A growing market wants high-purity graphite with big flakes. Since there are fewer naturally occurring high-grade graphite ores, low-grade ores must be processed to increase their value to meet the rising demand, which is predicted to increase by >700% by 2025 due to the adoption of electric vehicles. Since graphite is inherently hydrophobic, flotation is frequently used to beneficiate low-grade ores. The pretreatment process, both conventional and unconventional; liberation/grinding methods; flotation methods like mechanical froth flotation, column flotation, ultrasound-assisted flotation, and electroflotation; and more emphasis on various flotation reagents are all covered in this review of beneficiation techniques. This review also focuses on the different types of flotation reagents that are used to separate graphite, such as conventional reagents and possible nonconventional environmentally friendly reagents.
Valorization of Waste Cooking Oil into Biodiesel via Bacillus stratosphericus Lipase Amine-Functionalized Mesoporous SBA-15 Nanobiocatalyst
(Hindawi Publishing Corporation, 2022-11) Ismail, Abdallah R; Kashtoh, Hamdy; Betiha, Mohamed A; Abu Amr, Salem A; Baek, Kwang-Hyun; El-Gendy, Nour Sh
In this study, evaporation-induced self-assembly was applied to prepare amine-functionalized nano-silica (NH2-Pr-SBA-15). Tat was simply used to immobilize Bacillus stratosphericus PSP8 lipase (E–NH2–Pr-SBA-15), producing a nanobiocatalyst with good stability under vigorous shaking and a maximum lipase activity of 45 ± 2 U/mL. High-resolution X-ray dif- fractometer, Fourier transform infrared spectroscopy, N2 adsorption-desorption, feld-emission scanning electron, and high- resolution transmission electron microscopic analyses proved the successful SBA-15 functionalization and enzyme im- mobilization. Response surface methodology based on a 1/2 fraction-three-levels face center composite design was applied to optimize the biodiesel transesterifcation process. Tis expressed efcient percentage conversion (97.85%) and biodiesel yield (97.01%) under relatively mild operating conditions: 3.12 : 1 methanol to oil ratio, 3.08 wt.% E–NH2–Pr-SBA-15 loading, 48.6°C, 3.19 h at a mixing rate of 495.53 rpm. E–NH2–Pr-SBA-15 proved to have a long lifetime, operational stability, and reusability.
Glycolipid biosurfactants: Biosynthesis and related potential applications in food industry
(Elsevier, 2022-10) Ashby, Richard D; Zulkifli, Wan Nur Fatihah Wan Muhammad; Yatim, Abdul Rashid M; Ren, Kangzi; Mustafa, Ahmad
Applications of Next Generation Biosurfactants in the Food Sector 2023, Pages 307-334 Chapter 15 - Glycolipid biosurfactants: Biosynthesis and related potential applications in food industry☆ Author links open overlay panelRichard D.AshbyaWan Nur Fatihah Wan MuhammadZulkiflibAbdul Rashid M.YatimcKangziRendAhmadMustafae,f a United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, United States b Advanced Oleochemical Technology Division, Malaysian Palm Oil Board, Bandar Baru Bangi, Malaysia c Bioprocessing & Biotechnology Division, Eman Biodiscoveries Sdn Bhd, Sungai Petani, Malaysia d College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan, China e General Systems Engineering, October University for Modern Sciences and Arts (MSA), 6th of October, Egypt f Center of Excellence, October University for Modern Sciences and Arts (MSA), 6th of October, Egypt Available online 21 October 2022, Version of Record 21 October 2022. https://doi.org/10.1016/B978-0-12-824283-4.00006-X Get rights and content Abstract Glycolipids are microbial surface-active molecules that are composed of a carbohydrate unit linked to a single or multiple fatty acid(s). They are receiving increased research interest due to their green production pathways and their environmental and application benefits. Rhamnolipids, trehalolipids, sophorolipids, and mannosylerythritol lipids are among the most well-characterized glycolipids. Their antibacterial and emulsifying properties impart great potential to glycolipids in areas such as cleaning, cosmetic, and food preservation and can serve as sustainable substitutes for many synthetic surfactants. In addition, the valorization of food wastes through their use as fermentation feedstocks to produce glycolipid biosurfactants has received considerable attention because the process allows the bioconversion of inexpensive renewable by-products to value-added compounds, which may help to decrease production costs. This chapter focuses on the status and future perspectives related to the economical production of glycolipid biosurfactants and their potential application in foods.
Green synthesis of isopropyl palmitate using immobilized Candida antarctica lipase: Process optimization using response surface methodology
(Elsevier, 2022-06) Mustafa, Ahmad; Niikura, Fumiya
This work aims to produce isopropyl palmitate (IPP), a common emollient ester in a solvent-free system. An esterification reaction between isopropyl alcohol (IPA) and palmitic acid (PA) was performed in a closed batch reactor using immobilized Candida antarctica lipase as a biocatalyst. Reaction conditions were optimized using response surface methodology based on a five-level, three-variable composite design. The interactive effects of conditions on the IPP yield were investigated in the following ranges: IPA-to-PA molar ratio of 3:1–15:1, 1%–4% (w/w) Novozym 435, and 1%–10% (w/w) molecular sieves. The optimum conditions were IPA-to-PA molar ratio of 15:1, 4% w/w of Novozym 435, and 10% w/w of molecular sieves at 60◦C and 150 RPM for 2.5 h. The maximum experimental and predicted conversion values were 90.00% and 90.92%, respectively. Moreover, Novozym 435 exhibited remarkable operational stability because it was used for 15 cycles without considerably losing its original activity. In studying the feasibility of the proposed method, a process flow diagram was suggested to perform the semicontinuous production of IPP in a solvent-free medium
Selective synthesis of alpha monoglycerides by a clean method: Techno-economic and environmental assessment
(Elsevier, 2022-04-12) Mustafa, Ahmad; Niikura, Fumiya; Pastore, Carlo; Allam, Hoda A; Hassan, Omnia Bassam; Mustafa, Muhamad; Inayat, Abrar; Salah, Sameh A; Abdel Salam, Ahmed; Mohsen, Reham
This work proposes an alternative green and selective biocatalytic route for Glycerin Mono- stearate (α-monostearin) production. The conventional method of production uses an elevated temperature. Apart from the high energy consumption, such high temperatures darken the final product’s color, lead to random reactions, and produce high orders of diglycerides and tri- glycerides instead of monoglycerides. The proposed production process was performed by esterifying stearic acid with glycerin in an organic medium using Candida antarctica lipase (Novozym 435) at a mild temperature. The reaction conditions were optimized using the response surface methodology (RSM): optimum conditions were a temperature of 60 ◦C, glycerin to stearic acid molar ratio of 8:1, and Novozym 435 amount of 6% w/w. The solvent addition remarkably improved the α-monostearin yield to nearly 80% without the need for the energy-intensive distillation step. The conventional autocatalytic esterification (AUT) process was also per- formed to investigate the comparative monoglyceride yield, and it was found to be 22.5%. Proton nuclear magnetic resonance and gas-chromatography confirmed that α-monostearin could be produced with the highest purity using the proposed enzymatic method (ENZ). Economic and environmental analyses were also conducted for the proposed ENZ process, and the results were compared with those of the AUT process. The total capital investment of α-monostearin pro- duction, considering a projected capacity of 4950 t year− 1 and 11% interest for the proposed ENZ process, was favorably 2.5 times lower than that of the AUT process, suggesting a promising investment opportunity. However, the total production costs showed unfavorable negative net present value (NPV) and return on investment (ROI) for the ENZ process and favorable positive NPV and ROI for the AUT process, indicating that the proposed venture is not profitable for α-monostearin production. However, the process can be profitable at improved operational sta- bility of Novozym 435 up to 1 kg per 3-ton product. The carbon footprint was calculated on the basis of the given capacity and conditions of 50 and 656 t CO2 eq./year for the ENZ and AUT processes, respectively. The synthesis of α-monostearin using the proposed route can be consid- ered a building block toward a cleaner large-scale production of α-monoglycerides.
Synthesis and characterization of new bifunctional SnZrSi oxide catalysts for biodiesel production
(Elsevier, 2022-03-01) Ibrahim, Shaimaa M; Mustafa, Ahmad
A set of unprecedented (mesoporous SnO2/ZrSiO4) solids has been synthesized via the ultrasound-assisted co-precipitation path. The impact of silica dopant content (ranged between 0.05 and 0.4 mol %) on the characterization evolution of the sonicated ZrSnO4 interface and their biodiesel production efficiency were examined. Physio-chemical characteristics of the synthesized catalysts were analyzed by XRD, SEM-EDS, TEM, TGA-DTG, N2 adsorption–desorption analysis, NH3-TPD, UV-Visible/ DR, and FT-IR before and after pyridine adsorption. The obtained results revealed the formation of reconstructed rutile-SnO2 and zircon as new active phases by calcination at 500 ͦC, good morphology with mesoporous structure, and significant increase in the SBET, pore volume, interesting optical behavior, and exhibited different acidic properties. The impacts of reaction temperature, silica dopant content, fatty acid type and calcination temperature on the biodiesel % were examined. The tertiary oxide catalysts were gainful for the biodiesel production. The optimum catalyst (0.2 % SiO2 / ZrSnO4) had the biggest number of both strong Brönsted and Lewis acid sites compared to the doped and undoped catalysts, so, its maximum yield at optimum conditions for esterification of palmitic acid reaction was 90.2 % and can be reused until the fifth run with giving excellent yield for biodiesel production. But, for the transesterification of soybean oil reaction with methanol was maxima at 88% for (0.4 % SiO2/ZrSnO4) sample. The kinetic, mechanism studies and thermodynamic parameters were estimated. The important role of the doped silica molecules in the mechanism of the esterification process was emphasized by the computational chemistry study.
Kinetic and statistical perspectives on the interactive effects of recalcitrant polyaromatic and sulfur heterocyclic compounds and in-vitro nanobioremediation of oily marine sediment at microcosm level
(Elsevier, 2022-01-24) Nassar, Hussein N; Rabie, Abdelrahman M; Abu Amr, Salem A; El-Gendy, Nour Sh
A halotolerant biosurfactant producer Pseudomonas aeruginosa strain NSH3 (NCBI Gene Bank Accession No. MN149622) was isolated to degrade high concentrations of recalcitrant polyaromatic hydrocarbons (PAHs) and polyaromatic heterocyclic sulfur compounds (PASHs). In biphasic batch bioreactors, the biodegradation and biosurfactant-production activities of NSH3 have been significantly enhanced (p < 0.0001) by its decoration with eco-friendly prepared magnetite nanoparticles (MNPs). On an artificially contaminated sediment microcosm level, regression modeling and statistical analysis based on a 23 full factorial design of experiments were trendily applied to provide insights into the interactive impacts of such pollutants. MNPs-coated NSH3 were also innovatively applied for nanobioremediation (NBR) of in-vitro diesel oil-polluted sediment microcosms. Gravimetric, chromatographic, and microbial respiratory analyses proved the significantly enhanced biodegradation capabilities of MNPs-coated NSH3 (p < 0.001) and the complete mineralization of various recalcitrant diesel oil components. Kinetic analyses showed that the biodegradation of iso- and n-alkanes was best fitted with a second-order kinetic model equation. Nevertheless, PAHs and PASHs in biphasic batch bioreactors and sediment microcosms followed the first-order kinetic model equation. Sustainable NBR overcome the toxicity of low molecular weight hydrocarbons, mass transfer limitation, and steric hindrance of hydrophobic recalcitrant high molecular weight hydrocarbons and alkylated polyaromatic compounds

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