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Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.
Sanaz Salehi; Kourosh Abdollahi; Reza Panahi; Nejat Rahmanian; Mozaffar Shakeri; Babak Mokhtarani. Applications of Biocatalysts for Sustainable Oxidation of Phenolic Pollutants: A Review. Sustainability 2021, 13, 8620 .
AMA StyleSanaz Salehi, Kourosh Abdollahi, Reza Panahi, Nejat Rahmanian, Mozaffar Shakeri, Babak Mokhtarani. Applications of Biocatalysts for Sustainable Oxidation of Phenolic Pollutants: A Review. Sustainability. 2021; 13 (15):8620.
Chicago/Turabian StyleSanaz Salehi; Kourosh Abdollahi; Reza Panahi; Nejat Rahmanian; Mozaffar Shakeri; Babak Mokhtarani. 2021. "Applications of Biocatalysts for Sustainable Oxidation of Phenolic Pollutants: A Review." Sustainability 13, no. 15: 8620.
In the present study, the production of cellulase by Trichoderma reesei under solid-state fermentation of nettle biomass was promoted through supplementation of the culture media using carbonaceous additives and comprehensive optimization of the cultivation via the Taguchi method. CMCase activities about 5.5–6.1 U/gds were obtained by fermentation of the autoclave-pretreated biomass, among various chemical and physical pretreatments. Then, several additives including Tween 80, betaine, carboxymethyl cellulose, and lactose were individually or in combination added to the culture media to induce the enzyme production. The results proved that such additives could act as either inducers or inhibitors. Furthermore, CMCase activity surprisingly increased to 14.0 U/gds by supplementing the fermentation medium with the optimal mixture of additives including 0.08 mg/gds Tween 80, 0.4 mg/gds betaine, and 0.2 mg/gds carboxymethyl cellulose. Factor screening according to Plackett–Burman design confirmed that the levels of Urea and MgSO4 among basal medium constituents as well as pH of the medium were significantly affected CMCase production. By optimizing the levels of these factors, CMCase activity of 18.8 U/gds was obtained, which was noticeably higher than that of fermentation of the raw nettle. The applied procedure can be promisingly used to convert the nettle biomass into valuable products.
Maryam Taherzadeh-Ghahfarokhi; Reza Panahi; Babak Mokhtarani. Medium supplementation and thorough optimization to induce carboxymethyl cellulase production by Trichoderma reesei under solid state fermentation of nettle biomass. Preparative Biochemistry and Biotechnology 2021, 1 -8.
AMA StyleMaryam Taherzadeh-Ghahfarokhi, Reza Panahi, Babak Mokhtarani. Medium supplementation and thorough optimization to induce carboxymethyl cellulase production by Trichoderma reesei under solid state fermentation of nettle biomass. Preparative Biochemistry and Biotechnology. 2021; ():1-8.
Chicago/Turabian StyleMaryam Taherzadeh-Ghahfarokhi; Reza Panahi; Babak Mokhtarani. 2021. "Medium supplementation and thorough optimization to induce carboxymethyl cellulase production by Trichoderma reesei under solid state fermentation of nettle biomass." Preparative Biochemistry and Biotechnology , no. : 1-8.
Development of cationic flocculants from lignocellulosic wastes not only eliminates the health and environmental concerns associated with the use of conventional chemicals but also is the way of waste valorization. In the present study, cellulose fibers extracted from rice husk were cationized through an optimization method based on Response Surface Methodology. The fibers cationized at the optimal conditions had a zeta potential of 15.2±1.0 mV, which was 1.73-fold higher than that of the preliminary experiments. FTIR analysis proved the presence of the corresponding functional groups. The functionalized fibers were biodegradable and had absolutely positive surface charges at a broad pH range. The cationized fibers were employed as a flocculant to remove turbidity from the synthetic wastewaters at various pHs and initial turbidities. The cationic fibers showed the excellent turbidity removals up to 98.5% from the synthetic wastewater without the need for conventional coagulants. In contrast to traditionally cationized fibers, the synthesized flocculants did not affect the effluent color during coagulation-flocculation. The charge neutralization and bridging through adsorption were the governing mechanisms of flocculation. The procedure can be applied on lignocellulosic wastes to develop cationic fibers with the excellent flocculation ability and suitable operational characteristics.
Elham Jahedi; Reza Panahi. Conversion of Lignocellulosic Waste Into Effective Flocculants: Synthesis, Characterization, and Performance. 2021, 1 .
AMA StyleElham Jahedi, Reza Panahi. Conversion of Lignocellulosic Waste Into Effective Flocculants: Synthesis, Characterization, and Performance. . 2021; ():1.
Chicago/Turabian StyleElham Jahedi; Reza Panahi. 2021. "Conversion of Lignocellulosic Waste Into Effective Flocculants: Synthesis, Characterization, and Performance." , no. : 1.
Hydrogels are highly attracted for their high swelling and adsorption capacity for pollutants. This chapter introduces hydrogels structure and highlights their adsorption properties. Structural identification methods of hydrogels are described, with investigation of usual methods such as swelling, adsorption capacity, and removal pollutants efficiency. Moreover, adsorption isotherms and kinetic models are presented, discussing adsorption mechanism for pollutants and related thermodynamics parameters of modified hydrogels that guarantee accomplishment of adsorption process. The following sections provide an insight on parameters affecting hydrogels adsorption process and their swelling. To investigate viscoelastic behavior and to ensure formation of 3D hydrogel structure and investigating their structural strength and predicting their performance in adsorption process, rheological, thermal, and morphological tests are explained. This chapter establishes a step forward in hydrogels adsorbents potential in designing, manufacturing, and identification of controlling heavy metal pollution in water.
Mahsa Baghban Salehi; Asefe Mousavi Moghadam; Reza Panahi. Sorbent hydrogels to control heavy metal pollution in water. Sorbents Materials for Controlling Environmental Pollution 2021, 247 -283.
AMA StyleMahsa Baghban Salehi, Asefe Mousavi Moghadam, Reza Panahi. Sorbent hydrogels to control heavy metal pollution in water. Sorbents Materials for Controlling Environmental Pollution. 2021; ():247-283.
Chicago/Turabian StyleMahsa Baghban Salehi; Asefe Mousavi Moghadam; Reza Panahi. 2021. "Sorbent hydrogels to control heavy metal pollution in water." Sorbents Materials for Controlling Environmental Pollution , no. : 247-283.
Conventional flocculants bear environmental and health concerns which could be avoided by applying natural materials, particularly polysaccharide and glycoprotein-containing ones. In the present study, yeast cell wall (YCW), a natural polymer matrix, was used as natural flocculant. To prepare YCW, Saccharomyces cerevisiae was cultivated in bench scale fermenter. After characterization, YCW was employed as anionic flocculant in jar tests to remove turbidity from kaolin suspensions at different conditions where either alum or poly aluminum chloride (PAC) was coagulant. Generally, the lower coagulant consumption, higher turbidity removal or faster sedimentation was observed by using YCW as flocculant. The developed flocculant was more effective in the presence of PAC compared to alum. At best, by applying 300 mg/L YCW, the highest turbidity removals of 98 and 97% were achieved using 10 ppm PAC at pH 6.5 and 50 ppm alum at pH 7.5, respectively. The presence of the flocculant in the structure of the flocs was proved by FTIR analysis. The final pH of the treated suspensions was suitable for discharge purpose without the need for neutralization. The excess positive charge neutralization and bridging were the governing mechanism in coagulation-flocculation process. YCW with proper performance, GRAS designation and readily availability can be considered as natural alternative to chemical anionic flocculants where the process needs safe compounds.
Zahra Ferasat; Reza Panahi; Babak Mokhtarani. Natural polymer matrix as safe flocculant to remove turbidity from kaolin suspension: Performance and governing mechanism. Journal of Environmental Management 2020, 255, 109939 .
AMA StyleZahra Ferasat, Reza Panahi, Babak Mokhtarani. Natural polymer matrix as safe flocculant to remove turbidity from kaolin suspension: Performance and governing mechanism. Journal of Environmental Management. 2020; 255 ():109939.
Chicago/Turabian StyleZahra Ferasat; Reza Panahi; Babak Mokhtarani. 2020. "Natural polymer matrix as safe flocculant to remove turbidity from kaolin suspension: Performance and governing mechanism." Journal of Environmental Management 255, no. : 109939.
Immobilized tyrosinase onto the functionalized nanoparticles with the ability to be reused easily in different reaction cycles to degrade phenolic compounds is known as a substantial challenge, which can be overcome through surface modification of the particles via proper chemical groups. Herein, the synthesis and silica coating of superparamagnetic nanoparticles using a simple procedure as well as their potential for tyrosinase immobilization were demonstrated. Therefore, N-[3-(trimethoxysilyl)propyl]ethylenediamine was used to functionalize the silica-coated nanoparticles with amine groups. Then, the ethylenediamine functionalized magnetic nanoparticles (EMNPs) were suspended in a solution containing tetrahydrofuran and cyanuric chloride (as an activating agent) to modify nanocarriers. To immobilize enzyme, a mixture of tyrosinase and cyanuric chloride functionalized magnetic nanoparticle (Cyc/EMNPs) was shaken at room temperature. The particles were characterized by EDX, TGA, SEM, FTIR, and TEM. As a result, the successful functionalization of the magnetic nanoparticles and covalent attachment of tyrosinase onto the Cyc/EMNPs were confirmed. The fabricated nano-biocatalyst particles were semi-spherical in shape. The immobilized tyrosinase (Ty-Cyc/EMNPs) exhibited remarkable reusability of six consecutive reaction cycles while no considerable loss of activity was observed for the first three cycles. Moreover, the excellent stability of the biocatalyst at different temperatures and pHs was proved. The Ty-Cyc/EMNPs with interesting features are promising for practical applications in biosensor development and wastewater treatment.
Kourosh Abdollahi; Farshad Yazdani; Reza Panahi. Fabrication of the robust and recyclable tyrosinase-harboring biocatalyst using ethylenediamine functionalized superparamagnetic nanoparticles: nanocarrier characterization and immobilized enzyme properties. JBIC Journal of Biological Inorganic Chemistry 2019, 24, 943 -959.
AMA StyleKourosh Abdollahi, Farshad Yazdani, Reza Panahi. Fabrication of the robust and recyclable tyrosinase-harboring biocatalyst using ethylenediamine functionalized superparamagnetic nanoparticles: nanocarrier characterization and immobilized enzyme properties. JBIC Journal of Biological Inorganic Chemistry. 2019; 24 (7):943-959.
Chicago/Turabian StyleKourosh Abdollahi; Farshad Yazdani; Reza Panahi. 2019. "Fabrication of the robust and recyclable tyrosinase-harboring biocatalyst using ethylenediamine functionalized superparamagnetic nanoparticles: nanocarrier characterization and immobilized enzyme properties." JBIC Journal of Biological Inorganic Chemistry 24, no. 7: 943-959.
Hydrogels have the capability to absorb large amounts of water or biological fluids into their three-dimensional hydrophilic polymer networks. These attractive materials are used to develop food additives, superabsorbents, wound dressing compounds, pharmaceuticals, and biomedical implants and also applied in tissue engineering, regenerative medicines, and controlled-release process. Hydrogels can be obtained from synthetic and/or natural resources. Synthetic hydrogels exhibit high water absorption capacities and proper mechanical strength, although their applications are being limited because of low biocompatibility and biodegradability as well as the toxicity arisen from unreacted monomers remained in the gel structure. Natural hydrogels are often derived from polysaccharides and proteins. Protein-based hydrogels have substantial advantages such as biocompatibility, biodegradability, tunable mechanical properties, molecular binding abilities, and intelligent responses to external stimuli such as pH, ionic strength, and temperature. Therefore, this kind of hydrogels is known as smart biomaterials for controlled release, tissue engineering, regenerative medicine, and other applications. Protein can be converted to hydrogel using physical, chemical, or enzymatic treatments. To improve their mechanical properties, hybrid hydrogels are synthesized by combining natural polymers with synthetic ones. The main approach to obtain hybrid hydrogels is grafting natural polymers with synthetic one and vice versa. This chapter intends to look over protein-based hydrogels. After brief introduction of protein and its structure, the properties of proteins and peptides used to develop hydrogels, as well as their preparation methods are discussed. The potential applications of these polypeptide-based hydrogels in the fields of superabsorbent development, tissue engineering, and controlled release are reported. Characterization methods for protein-based hydrogels are covered in the final section to determine rheological properties, morphology, and thermal stability.
Reza Panahi; Mahsa Baghban-Salehi. Protein-Based Hydrogels. Polymers and Polymeric Composites: A Reference Series 2019, 1561 -1600.
AMA StyleReza Panahi, Mahsa Baghban-Salehi. Protein-Based Hydrogels. Polymers and Polymeric Composites: A Reference Series. 2019; ():1561-1600.
Chicago/Turabian StyleReza Panahi; Mahsa Baghban-Salehi. 2019. "Protein-Based Hydrogels." Polymers and Polymeric Composites: A Reference Series , no. : 1561-1600.
Rhamnolipids are one of the most well-known classes of biosurfactants having wide applications in various industries due to low toxicity, high biodegradability, and environmentally friendly. Dissolved oxygen (DO) concentration has the crucial effect on rhamnolipids production, particularly through fed-batch cultivation. In this study, the effect of different levels of DO concentrations on rhamnolipid production by Pseudomonas aeruginosa in both batch and fed-batch fermentation was investigated in a lab-scale fermenter under precise DO control. A maximal rhamnolipid production of 22.5 g/l was obtained at a DO concentration of 40% in batch fermentation. In order to achieve the high rhamnolipid production, a fed-batch operation under tight DO control of 40% was conducted. As a result, the overall rhamnolipid production and productivity reached to 240 g/l and 0.9 (g/l h), corresponding to a 10.7 and 4.8-fold improvement compared to the batch experiments. The high level of rhamnolipid production via the fed-batch cultivation can be attributed to both DO concentration and the feeding strategy. This achievement is promising for the production of rhamnolipid in industrial scale.
Shayesteh Bazsefidpar; Babak Mokhtarani; Reza Panahi; Hamidreza Hajfarajollah. Overproduction of rhamnolipid by fed-batch cultivation of Pseudomonas aeruginosa in a lab-scale fermenter under tight DO control. Biogeochemistry 2019, 30, 59 -69.
AMA StyleShayesteh Bazsefidpar, Babak Mokhtarani, Reza Panahi, Hamidreza Hajfarajollah. Overproduction of rhamnolipid by fed-batch cultivation of Pseudomonas aeruginosa in a lab-scale fermenter under tight DO control. Biogeochemistry. 2019; 30 (1):59-69.
Chicago/Turabian StyleShayesteh Bazsefidpar; Babak Mokhtarani; Reza Panahi; Hamidreza Hajfarajollah. 2019. "Overproduction of rhamnolipid by fed-batch cultivation of Pseudomonas aeruginosa in a lab-scale fermenter under tight DO control." Biogeochemistry 30, no. 1: 59-69.
Low conversion efficiency and long-processing time are some of the major problems associated with the use of biocatalysts in industrial processes. In this study, modified magnetic iron oxide nanoparticles bearing tyrosinase (tyrosinase-MNPs) were employed as a magnetic nano-biocatalyst to treat phenol-containing wastewater. Different factors affecting the phenol removal efficiency of the fabricated nano-biocatalyst such as catalyst dosage, pH, temperature, initial phenol concentration, and reusability were investigated. The results proved that the precise dosage of nano-biocatalyst was able to degrade phenol at the wide range of pHs and temperatures. The immobilized tyrosinase showed proper phenol degradation more than 70%, where the substrate with a high concentration of 2500 mg/L was subjected to phenol removal. The nano-biocatalyst was highly efficient and reusable, since it displayed phenol degradation yields of 100% after the third reuse cycle and about 58% after the seventh cycle. Moreover, the immobilized tyrosinase was able to degrade phenol dissolved in real water samples up to 78% after incubation for 60 min. It was also reusable at least seven cycles in the real water sample. The results proved the effectiveness and applicability of the fabricated nano-biocatalyst to treat phenol-containing wastewaters in a shorter time and higher efficiency even at high phenol concentration. The developed nano-biocatalyst can be promising for the micropollutants removal and an alternative for the catalysts used in traditional treatment processes.
Kourosh Abdollahi; Farshad Yazdani; Reza Panahi; Babak Mokhtarani. Biotransformation of phenol in synthetic wastewater using the functionalized magnetic nano-biocatalyst particles carrying tyrosinase. 3 Biotech 2018, 8, 419 .
AMA StyleKourosh Abdollahi, Farshad Yazdani, Reza Panahi, Babak Mokhtarani. Biotransformation of phenol in synthetic wastewater using the functionalized magnetic nano-biocatalyst particles carrying tyrosinase. 3 Biotech. 2018; 8 (10):419.
Chicago/Turabian StyleKourosh Abdollahi; Farshad Yazdani; Reza Panahi; Babak Mokhtarani. 2018. "Biotransformation of phenol in synthetic wastewater using the functionalized magnetic nano-biocatalyst particles carrying tyrosinase." 3 Biotech 8, no. 10: 419.
Improving the production of lignocellulose-degrading enzyme such as cellulase and xylanase substantially increases the chance for cost-competitive production of cellulosic biofuel and other chemicals from such a biomass. In this study, the possible effects of carbonaceous additives including Tween 80, betaine, carboxymethyl cellulose (CMC) and lactose on cellulases and xylanase production were investigated individually or in combination. The enzymes were produced by Trichoderma reesei in solid state fermentation of wheat straw, wheat bran, rice straw and rice husk. The results proved that an individual additive could be an inducer or inhibitor based on the type of carbon source and targeted enzyme. For applying additives in combination, their roles depended on not only the type of carbon source and targeted enzyme but also their concentrations. Furthermore, a single additive with inhibitory role could be an inducer in combination with the other additives. For the best induction, the xylanase activity was about 469 U/gds with betaine as a single inducer. It increased to 218% with the mixture of Tween 80, betaine and CMC, supporting the combination of additives is more inducing. Applying the mixture of inducers can highly improve the process efficiency in lignocellulose-based biorefineries for both fuel and chemicals production.
Maryam Taherzadeh-Ghahfarokhi; Reza Panahi; Babak Mokhtarani. Optimizing the combination of conventional carbonaceous additives of culture media to produce lignocellulose-degrading enzymes by Trichoderma reesei in solid state fermentation of agricultural residues. Renewable Energy 2018, 131, 946 -955.
AMA StyleMaryam Taherzadeh-Ghahfarokhi, Reza Panahi, Babak Mokhtarani. Optimizing the combination of conventional carbonaceous additives of culture media to produce lignocellulose-degrading enzymes by Trichoderma reesei in solid state fermentation of agricultural residues. Renewable Energy. 2018; 131 ():946-955.
Chicago/Turabian StyleMaryam Taherzadeh-Ghahfarokhi; Reza Panahi; Babak Mokhtarani. 2018. "Optimizing the combination of conventional carbonaceous additives of culture media to produce lignocellulose-degrading enzymes by Trichoderma reesei in solid state fermentation of agricultural residues." Renewable Energy 131, no. : 946-955.
Hydrogels have the capability to absorb large amounts of water or biological fluids into their three-dimensional hydrophilic polymer networks. These attractive materials are used to develop food additives, superabsorbents, wound dressing compounds, pharmaceuticals, and biomedical implants and also applied in tissue engineering, regenerative medicines, and controlled-release process. Hydrogels can be obtained from synthetic and/or natural resources. Synthetic hydrogels exhibit high water absorption capacities and proper mechanical strength, although their applications are being limited because of low biocompatibility and biodegradability as well as the toxicity arisen from unreacted monomers remained in the gel structure. Natural hydrogels are often derived from polysaccharides and proteins. Protein-based hydrogels have substantial advantages such as biocompatibility, biodegradability, tunable mechanical properties, molecular binding abilities, and intelligent responses to external stimuli such as pH, ionic strength, and temperature. Therefore, this kind of hydrogels is known as smart biomaterials for controlled release, tissue engineering, regenerative medicine, and other applications. Protein can be converted to hydrogel using physical, chemical, or enzymatic treatments. To improve their mechanical properties, hybrid hydrogels are synthesized by combining natural polymers with synthetic ones. The main approach to obtain hybrid hydrogels is grafting natural polymers with synthetic one and vice versa. This chapter intends to look over protein-based hydrogels. After brief introduction of protein and its structure, the properties of proteins and peptides used to develop hydrogels, as well as their preparation methods are discussed. The potential applications of these polypeptide-based hydrogels in the fields of superabsorbent development, tissue engineering, and controlled release are reported. Characterization methods for protein-based hydrogels are covered in the final section to determine rheological properties, morphology, and thermal stability.
Reza Panahi; Mahsa Baghban-Salehi. Protein-Based Hydrogels. Encyclopedia of Polymers and Composites 2018, 1 -40.
AMA StyleReza Panahi, Mahsa Baghban-Salehi. Protein-Based Hydrogels. Encyclopedia of Polymers and Composites. 2018; ():1-40.
Chicago/Turabian StyleReza Panahi; Mahsa Baghban-Salehi. 2018. "Protein-Based Hydrogels." Encyclopedia of Polymers and Composites , no. : 1-40.
Nahid Soltani Firooz; Reza Panahi; Babak Mokhtarani; Farshad Yazdani. Direct introduction of amine groups into cellulosic paper for covalent immobilization of tyrosinase: support characterization and enzyme properties. Cellulose 2017, 24, 1407 -1416.
AMA StyleNahid Soltani Firooz, Reza Panahi, Babak Mokhtarani, Farshad Yazdani. Direct introduction of amine groups into cellulosic paper for covalent immobilization of tyrosinase: support characterization and enzyme properties. Cellulose. 2017; 24 (3):1407-1416.
Chicago/Turabian StyleNahid Soltani Firooz; Reza Panahi; Babak Mokhtarani; Farshad Yazdani. 2017. "Direct introduction of amine groups into cellulosic paper for covalent immobilization of tyrosinase: support characterization and enzyme properties." Cellulose 24, no. 3: 1407-1416.
Magnetic nanoparticles (MNPs) were synthesized using the chemical co-precipitation method. Then the nanoparticles were coated with silica via hydrolysis of tetraethyl orthosilicate using the sol-gel process. The silica coated magnetic nanoparticles were amine-functionalized with 3-aminopropyltriethoxysilane/ethanol solution. Subsequently, the nanoparticles were added to a solution of cyanuric chloride in tetrahydrofuran to synthesize cyanuric chloride-functionalized magnetic nanoparticles (Cy-MNPs). For covalent immobilization of tyrosinase, Cy-MNPs were added to a freshly prepared tyrosinase solution and the mixture was shaken. The FTIR spectra, as well as EDX, analysis proved the covalent immobilization of tyrosinase on the nanoparticles. The magnetic properties of tyrosinase-immobilized magnetic nanoparticles (tyrosinase-MNPs) were specified by VSM analysis. TEM images indicated that the most of the tyrosinase-MNPs had a semi-spherical shape with an average size of 17nm. The synthesized nanoparticles had a high loading capacity of 194mg tyrosinase/g nanoparticles with an immobilization yield of 69%. The optimum condition for both free and immobilized tyrosinase was found at pH 7.0 and 35°C. The immobilized enzyme was active after treatment of the particles at various pHs and temperatures for 100min. In addition, reusability of the immobilized enzyme was investigated and it was proved its suitability to be used for more than 7 cycles. Also, tyrosinase-MNPs remained about 70% of its initial activity after storing at 4°C for 40days. This nanobiocatalyst with interesting properties is promising for practical application in wastewater treatment and biosensor development.
Kourosh Abdollahi; Farshad Yazdani; Reza Panahi. Covalent immobilization of tyrosinase onto cyanuric chloride crosslinked amine-functionalized superparamagnetic nanoparticles: Synthesis and characterization of the recyclable nanobiocatalyst. International Journal of Biological Macromolecules 2017, 94, 396 -405.
AMA StyleKourosh Abdollahi, Farshad Yazdani, Reza Panahi. Covalent immobilization of tyrosinase onto cyanuric chloride crosslinked amine-functionalized superparamagnetic nanoparticles: Synthesis and characterization of the recyclable nanobiocatalyst. International Journal of Biological Macromolecules. 2017; 94 ():396-405.
Chicago/Turabian StyleKourosh Abdollahi; Farshad Yazdani; Reza Panahi. 2017. "Covalent immobilization of tyrosinase onto cyanuric chloride crosslinked amine-functionalized superparamagnetic nanoparticles: Synthesis and characterization of the recyclable nanobiocatalyst." International Journal of Biological Macromolecules 94, no. : 396-405.
Preparation and characterization of cross linked amine-functionalized magnetic nanoparticles as an appropriate support for covalent immobilization on tyrosinase was presented in the study "Covalent immobilization of tyrosinase onto cyanuric chloride crosslinked amine-functionalized superparamagnetic nanoparticles: synthesis and characterization of the recyclable nanobiocatalyst" (Abdollahi et al., 2016 ) [1]. Herein, complementary data regarding X-ray powder diffraction (XRD) to characterize the synthesized magnetic nanoparticles, and transmission electron microscopy (TEM) to determine the size and morphology of tyrosinase immobilized magnetic nanoparticles (tyrosinase-MNPs) were reported. The purification results of the extracted tyrosinase from mushroom Agaricus bisporus were provided in a purification table. The covalent immobilization of tyrosinase onto cyanuric chloride functionalized magnetic nanoparticles was proved by performing thermo-gravimetric and energy-dispersive X-ray spectroscopy analyses. The operational stability of immobilized tyrosinase was investigated by incubating tyrosinase-MNPs at different pH and temperatures.
Kourosh Abdollahi; Farshad Yazdani; Reza Panahi. Data in support of covalent attachment of tyrosinase onto cyanuric chloride crosslinked magnetic nanoparticles. Data in Brief 2016, 9, 1098 -1104.
AMA StyleKourosh Abdollahi, Farshad Yazdani, Reza Panahi. Data in support of covalent attachment of tyrosinase onto cyanuric chloride crosslinked magnetic nanoparticles. Data in Brief. 2016; 9 ():1098-1104.
Chicago/Turabian StyleKourosh Abdollahi; Farshad Yazdani; Reza Panahi. 2016. "Data in support of covalent attachment of tyrosinase onto cyanuric chloride crosslinked magnetic nanoparticles." Data in Brief 9, no. : 1098-1104.
A reliable production of heterologous proteins is important in the field of industrial biotechnology. This can be achieved by applying auto-inducible gene expression systems. Development of a Bacillus subtilis expression plasmid harboring SigB-dependent ohrB promoter was reported. The expression system was subjected to high cell density cultivation to produce xylanase as a stable model protein. The recombinant strain was cultured in a synthetic medium containing glucose as the carbon source. The exponential fed-batch feeding strategy was applied to prevent substrate inhibition. A sharp increase of xylanase activity (about 6-fold) at the end of fermentation was observed as a result of sigma factor B (SigB) protein activation, supporting autoinducibility of the expression system. For the control strain a specific induction of the xylanase activity was not observed. The recombinant strain showed a 5-fold increase in xylanase activity in comparison with the control strain. In addition, the constructed system displayed the catabolite repression resistance ability. This SigB-dependent expression system can be considered as a biotechnological tool and an alternative to the high costing conventional inducers, e.g. isopropyl-β-galactopyranoside.
Reza Panahi; E. Vasheghani-Farahani; Seyed Abbas Shojaosadati; Bijan Bambai. Auto-inducible expression system based on the SigB-dependent ohrB promoter in Bacillus subtilis. Molecular Biology 2014, 48, 852 -857.
AMA StyleReza Panahi, E. Vasheghani-Farahani, Seyed Abbas Shojaosadati, Bijan Bambai. Auto-inducible expression system based on the SigB-dependent ohrB promoter in Bacillus subtilis. Molecular Biology. 2014; 48 (6):852-857.
Chicago/Turabian StyleReza Panahi; E. Vasheghani-Farahani; Seyed Abbas Shojaosadati; Bijan Bambai. 2014. "Auto-inducible expression system based on the SigB-dependent ohrB promoter in Bacillus subtilis." Molecular Biology 48, no. 6: 852-857.
Natural and Mg2+ modified pumice were used for the removal of phosphorous. The adsorbents were characterized using XRF, XRD, SEM and FTIR instrumental techniques. In the optimal conditions, namely at equilibrium time (30 min), for a phosphorus concentration of 15 mg/L and pH 6, 69 and 97% phosphorus removals were achieved using 10 g/L of natural and modified pumice adsorbents, respectively. Maximum adsorption capacities were 11.88 and 17.71 mg/g by natural and modified pumice, respectively. Pseudo-second order kinetic model was the most relevant to describe the kinetic of phosphorus adsorption. External mass transfer coefficient decreased for increasing phosphorous concentration and film diffusion was found to be the rate-controlling step. Only a very low dissolution of the adsorbent was observed, leading to a low increase in conductivity and turbidity. Removal efficiency decreased for increasing ionic strength. It also decreased in the presence of competing ions; however modified pumice remained effective, since 67% of phosphorus was removed, versus only 17% for the natural pumice. The efficiency of the modified pumice was confirmed during the regeneration tests, since 96% regeneration yield was obtained after 510 min experiment, while only 22% was observed for the raw pumice.
Kamal Aldin Karimaian; Abdeltif Amrane; Hossein Kazemian; Reza Panahi; Mansur Zarrabi. Retention of phosphorous ions on natural and engineered waste pumice: Characterization, equilibrium, competing ions, regeneration, kinetic, equilibrium and thermodynamic study. Applied Surface Science 2013, 284, 419 -431.
AMA StyleKamal Aldin Karimaian, Abdeltif Amrane, Hossein Kazemian, Reza Panahi, Mansur Zarrabi. Retention of phosphorous ions on natural and engineered waste pumice: Characterization, equilibrium, competing ions, regeneration, kinetic, equilibrium and thermodynamic study. Applied Surface Science. 2013; 284 ():419-431.
Chicago/Turabian StyleKamal Aldin Karimaian; Abdeltif Amrane; Hossein Kazemian; Reza Panahi; Mansur Zarrabi. 2013. "Retention of phosphorous ions on natural and engineered waste pumice: Characterization, equilibrium, competing ions, regeneration, kinetic, equilibrium and thermodynamic study." Applied Surface Science 284, no. : 419-431.
The application of safe and cheap inducers is important in the field of fermentation technology, which persuades employing new expression systems. In this study, a Bacillus subtilis expression system was induced by applying starvation and environmental stresses to produce xylanase. The expression plasmid harbors SigB-dependent ohrB promoter. The target gene was expressed by inoculating the recombinant strain into glucose-limited synthetic medium resulting in a sharp increase of xylanase activity at the end of logarithmic growth phase. The recombinant strain was able to express the xylanase enzyme 14-fold higher than that of the control one. The induction was also performed by exposing the recombinant strain to NaCl and ethanol stresses, and heat shock; the strain growing in LB showed 5-, 15- and 6-fold increases in xylanase activity, respectively. The best induction using environmental stresses was achieved by applying the salt stress in the synthetic medium. The maximum expression for NaCl and ethanol stresses occurred after 40 min of induction. All observed inductions were related to activation of SigB protein causing expression of the SigB-dependent xylanase gene. This SigB-dependent expression system can be considered as a biotechnology tool and an alternative to eliminate the cost of conventional inducers.
Reza Panahi; Ebrahim Vasheghani-Farahani; Seyed Abbas Shojaosadati; Bijan Bambai. Induction of Bacillus subtilis expression system using environmental stresses and glucose starvation. Annals of Microbiology 2013, 64, 879 -882.
AMA StyleReza Panahi, Ebrahim Vasheghani-Farahani, Seyed Abbas Shojaosadati, Bijan Bambai. Induction of Bacillus subtilis expression system using environmental stresses and glucose starvation. Annals of Microbiology. 2013; 64 (2):879-882.
Chicago/Turabian StyleReza Panahi; Ebrahim Vasheghani-Farahani; Seyed Abbas Shojaosadati; Bijan Bambai. 2013. "Induction of Bacillus subtilis expression system using environmental stresses and glucose starvation." Annals of Microbiology 64, no. 2: 879-882.
In the present study, biosorption of stable cobalt was studied in an up-flow fixed-bed column using the brown alga Sargassum glaucescens treated with formaldehyde (FA) or MgCl2. Notable increase in cobalt removal was observed for FA-treated biosorbent with 2.7 and 1.4 times higher dynamic capacity (DC) and uptake capacity (UC) than native alga, respectively. Consequently, FA-treated S. glaucescens was selected for further investigations. In particle size experiments, the DCs of 0.5–1 and 1–2 mm particles were both equal to 27.6 mg/g, and corresponding UCs were 34 and 38 mg/g, respectively. The maximum DC was obtained at residence time of 2.5 min. Studying the effect of additional ions indicated partial effect of Na+ and K+ ions on DC and UC, Mg2+ reduced highly the DC and slightly the UC while heavy metal ions (Ni2+, Cd2+, Cu2+, Zn2+, Pb2+ and Cr3+) caused decrease in both DC and UC about 1.5–4.7 and 1.8–3.2 times, respectively. Moreover, the column regeneration studies were carried out for four sorption–desorption cycles. The DC and the UC highly decreased in the second cycle, partially decreased or remained constant in the third and in the fourth one.
Mina Ebrahimi; Reza Panahi; Reza Dabbagh. Evaluation of Native and Chemically Modified Sargassum glaucescens for Continuous Biosorption of Co(II). Applied Biochemistry and Biotechnology 2008, 158, 736 -746.
AMA StyleMina Ebrahimi, Reza Panahi, Reza Dabbagh. Evaluation of Native and Chemically Modified Sargassum glaucescens for Continuous Biosorption of Co(II). Applied Biochemistry and Biotechnology. 2008; 158 (3):736-746.
Chicago/Turabian StyleMina Ebrahimi; Reza Panahi; Reza Dabbagh. 2008. "Evaluation of Native and Chemically Modified Sargassum glaucescens for Continuous Biosorption of Co(II)." Applied Biochemistry and Biotechnology 158, no. 3: 736-746.
In the present study, separation of l -lysine from dilute aqueous solution by solid-phase extraction based on molecular imprinting technique using a polar porogen was investigated. l -Lysine imprinted polymer (LLIP) was prepared by free radical solution polymerization of methacrylic acid and ethylene glycol dimethacrylate as functional and cross-linking monomers, in the presence of l -lysine as an imprint molecule, mixture of water and methanol as solvent and AIBN as an initiator. Non-imprinted polymer (NIP) as control was also prepared by the same procedure in the absence of template molecules. LLIP particles were applied to determine the optimum operational condition for l -lysine separation from dilute aqueous solution. In adsorption step, optimum pH and retention time were 7.8 and 90 min, while corresponding values in extraction step were 12 and 50 min, respectively. l and d -Lysine recovery by LLIP at optimum condition were found to be 96 and 58% with corresponding distribution coefficients of 8000 and 460, respectively. The retention capacity of LLIP was 27.26 mg l -lys/g of polymer at optimum condition. Keywords Molecular imprinting Lysine Separation Adsorption Optimum condition Retention capacity 1 Introduction Molecular imprinting of cross-linked polymers is now widely used for the design of recognition materials for various chiral analytical and preparative separations. The method consists of polymerizing a functional monomer, mixed with a template, in the presence of a cross-linking agent. Removal of the template leaves an imprinted cavity in the polymer, providing a selective binding site for this template [1] . Numerous authors studied the preparation and performance of dedicated imprinted polymers for the separation of various mixtures of amino acids [1–3] , peptides [4] and proteins [4,5] . Lee and Hong applied a chiral selectivity of adsorbent based upon ligand exchange of coordinated copper(II) complexes of d or l -amino acids and a molecular imprinting technique by modifying the resin surface with polypyrrole coating. A pH-controlled mixture of d , l -lysine and d , l -aspartic acid was resolved displaying enantioselectivity values of 1.19 and 2.08, respectively [6] . In most of the previous studies, molecularly imprinted polymers were generally prepared in the presence of a non-polar organic solvent as porogen when the non-covalent imprinting approach was used. It was shown that a polymer prepared in a relatively non-polar organic solvent performed better than the one prepared in a polar organic solvent because the use of more polar solvents will inevitably weaken the interaction forces formed between the print species and the functional monomers resulting in poorer selectivity [3,7] . However, some amino acids, such as lysine, do not dissolve in non-polar solvent. In the present study, separation of l -lysine from a dilute aqueous solution by solid-phase extraction based on molecular imprinting technique using a polar porogen was investigated. 2 Material and methods 2.1 Material l -Lysine monohydrate (LLM), methacrylic acid (MAA) and ninhydrin were from Merck and d -lysine from Aldrich. Ethylene glycol dimethacrylate (EGDMA) and 2,2-azobisisobutyronitrile (AIBN) were obtained from Fluka. Other chemicals were analytical grade and obtained from well-known companies. 2.2 Equipment A Cary50 UV–vis spectrophotometer (VARIAN, Australia) was used to determine lysine concentration. Vacuum rotary evaporator (Heidolph, Germany) was used to concentrate the lysine solution. Scanning electron microscope (Philips XL30, The Netherlands) was used to study the morphology of polymer particles. 2.3 Preparation of l -lysine imprinted polymer (LLIP) LLIP was prepared by the non-covalent approach. The molar ratio of template:functional monomer:cross-linker was (1:6:30) in which LLM (0.715 mmol) is the template molecule, MAA (4.29 mmol) selected as the functional monomer, EGDMA (21.45 mmol) as the cross-linking agent and AIBN (0.5 mg) is the initiator. Due to the high polarity of the template, a mixture of methanol–water (4.5:1, v/v) (5.5 mL) was used as porogen. Other solvents were also evaluated as possible porogens to avoid the presence of water during the polymerization ( note: water can disrupt hydrogen bonding or ionic interactions between templates and the functional monomers), but the template was not completely soluble in any of them. All the components were mixed in a 25 mL glass vessel by adding them in the following order: LLM, water, methanol, MAA, EGDMA and AIBN. This solution was mixed for 60 min, purged with oxygen-free nitrogen for 10 min, thermally polymerized under the nitrogen atmosphere in a water-bath for 24 h at 60 °C [8,9] . The synthesized polymer was ground in a mortar, dried and sieved to get particles with a size less than 25 μm. Non-imprinted polymer (NIP) was prepared by the same procedure in the absence of template molecules and treated in the same manner. To prepare the desired adsorbent for lysine separation from dilute aqueous solutions, the imprint molecule ( l -lysine) was leached out by stirring 3 g of LLIP particles in 1000 mL of NaOH solution at pH > 13.5, for 24 h. This step was repeated for five times to assure maximum extraction of imprint molecule which avoids its leaching in subsequent adsorption and extraction experiments. 2.4 Adsorption and extraction steps In adsorption step, 0.3 g of imprinted polymer particles were added into a 100 mL aqueous solution containing 0.1827 μmol of l -lysine (0.03 mg of LLM), the pH was adjusted to a known value and stirred for a specified time. The solution was filtered and remaining particles on the filter were washed with a 50 mL aqueous solution at the same pH to remove the solution, trapped within the polymer particles and non-specifically adsorbed solute. Extraction step was performed by putting washed polymer particles into a 100 mL NaOH solution with an adjusted pH, stirred...
Reza Panahi; Ebrahim Vasheghani-Farahani; Seyed Abbas Shojaosadati. Separation of l-lysine from dilute aqueous solution using molecular imprinting technique. Biochemical Engineering Journal 2007, 35, 352 -356.
AMA StyleReza Panahi, Ebrahim Vasheghani-Farahani, Seyed Abbas Shojaosadati. Separation of l-lysine from dilute aqueous solution using molecular imprinting technique. Biochemical Engineering Journal. 2007; 35 (3):352-356.
Chicago/Turabian StyleReza Panahi; Ebrahim Vasheghani-Farahani; Seyed Abbas Shojaosadati. 2007. "Separation of l-lysine from dilute aqueous solution using molecular imprinting technique." Biochemical Engineering Journal 35, no. 3: 352-356.