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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Water,metal nanoparticles,Biological Denitrification,Nano Scale Zero Valent Iron
- چکیده:
- چکیده انگلیسی: Globally, increasing nitrate concentrations have become a serious environmental problem and a potential risk to public health. The World Health Organization (WHO) has set a limit of (10 mg/ (L)) NO3- for human consumption and (100 mg/ (L)) NO3- for animals. Water above these limits requires denitrification. Nitrate causes cancer, blue-baby syndrome, hypertension and thyroid hypertrophy. Several treatment processes can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation. Among these processes chemical denitrification and biological denitrification are useful processes considering efficiency cost and maintenance. Denitrifying microorganisms are able to reduce nitrate to
innocuous nitrogen gas using suitable source of electron. Oxides of metal nanoparticles, hydrogen gas, and sulfur reduced compounds; pyrite and arsenate have been used as electron donors for biological nitrate reduction. Among these electron
donors H2 and oxides of metal nanoparticles have better performance in the removal of nitrate. Bio-denitrification coupled to metal nanoparticle oxidation is an inexpensive and advantageous process for nitrate removal from source of water. In this review article the biological denitrification efficiency was studied between free cell and cell amended metal nanoparticle such as nano scale zero valent iron (nZVI). This study investigated the potential applicability of employing metal nanoparticle as source of electron for biological nitrate reduction. Temperature, pH, nitrate concentration and dissolve oxygen concentration are the major factors affecting nitrate removal, with or without the presence of metal nanoparticles that studied in this article.- انتشار مقاله: 21-10-1394
- نویسندگان: Mahdieh Rajab Beiki,Fatemeh Yazdian,Behnam Rasekh,Hamid Rashedi,Arash Darzian Rostami
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Aloe vera,Cellulase,Temperature,viscosity,Enzymatic Process
- چکیده:
- چکیده انگلیسی: Aloe vera is a plant of the Liliaceae family with a brilliant history in disease treatment. In addition to the pharmaceutical, cosmetic, and health care industries, this plant is used in food industry due to having various nutrients such as amino acids and various vitamins or anti-bacterial compounds. The purpose of this study was to investigate the effects of variables such as temperature, time, and cellulase concentration to reduce the gel viscosity of edible Aloe vera. Lowering the gel viscosity increases the gel condensation rate and spray dryer efficiency. So, In this study, the effects of different variables, including temperature, enzymatic process time and cellulase concentration was investigated on Aloe vera gel viscosity using a commercial cellulase enzyme. According to the results, temperature, process time and enzyme concentration are the affecting parameters on the gel viscosity. By increasing the temperature, without incorporating the enzyme, a sharp decrease in viscosity was observed so that in 55°C the viscosity decreased to 9.2 cP. By addition of constant amount of enzyme, the gel viscosity reached to 5.1 cP after 34 minutes, with 9.5 g E/100 g SG enzyme concentration, viscosity reached to the minimum value 4.2 cP. The results were statistically significant at the 5% probability level and indicate that the model was significant. Finally, the use of enzymatic processing for the production of Aloe vera concentrate or powder is appropriate because by reducing the gel viscosity, gel condensation rate will
increase and it’s drying is economically efficient.- انتشار مقاله: 24-06-1394
- نویسندگان: Ali Izadi,Hamid Rashedi,Reza Ghafarzadegan,Reza Hajiaghaee
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Response surface methodology,Biosurfactant,Rhamnolipid,Pseudomonas aeruginosa MM1011
- چکیده:
- چکیده انگلیسی: A rhamnolipid–type biosurfactant production by Pseudomonas aeruginosa MM1011 was studied in a miniaturized shaken bioreactor. The operational parameters, affecting the biosurfactant production in shaken bioreactors, such as shaking frequency (200, 250, 300 rpm), filling volume (50, 75, 100 ml), and aeration rate (0.2, 0.6, 1 vvm), were optimized using response surface methodology. The optimization process conducted based on three different response variables (surface tension, rhamnolipid concentration, and emulsification activity). The best results were achieved at agitation rate of 292 rpm, filling volume of 50 ml, and aeration rate of 1 vvm. Also, the results indicated that all of the three factors were effective parameters in biosurfactant production and the surface tension, rhamnolipid production and emulsification activity under optimum conditions, were measured 31.00 mN/m, 1.89 g/L and 80.23 %, respectively.
- انتشار مقاله: 24-06-1394
- نویسندگان: Hamid Rashedi,Ali Izadi,Mehdi Esmaeili Bidhendi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: LSM,Nitrosomonas europaea,Nitrobacter agilis,Substrate Concentration
- چکیده:
- چکیده انگلیسی: In this study, the substrate diffusion in an immobilized spherical cell-support aggregate is studied and effects of various parameters are investigated on substrates profile. Analyses are performed by using of an analytical solution called the Least Square Method (LSM) and results are compared with numerical solution. The effects of effective diffusion coefficient (De), maximum specific growth rate (µm) and type of limiting substrate are studied on substrate concentration profile in immobilized Nitrosomonas europaea and Nitrobacter agilis microorganisms. Outcomes reveal that LSM is an appropriate method for analyze of biological non-linear equations. In the center of the spherical microbial support, the substrates concentration is minimums and with reducing µm or increasing De, substrate concentration profile gradient reduces.
- انتشار مقاله: 26-01-1394
- نویسندگان: Ali Izadi,Sobhan Mosayebi Dorcheh,Hamid Rashedi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Aggregation,Interferon beta 1-b,Autocatalytic Model,Polysorbate 20
- چکیده:
- چکیده انگلیسی: The aggregation of protein is the most prevalent and the most disturbing kind of instability and this challenge exists in almost every stage of the development of protein drug. The presence of insoluble aggregations in protein drugs will make the supply of the product a tough job. This study identifies the inhibition of the folded Interferon beta 1-b’s aggregation with the assistance of some excipients. It uses some thermal stress and mechanical methods to accelerate the aggregation, and also the spectroscopic method to identify the protein aggregation and its growth. Experimental data of the tests show compliance with the autocatalytic model. This model has been used to obtain the Kinetic constants of aggregation in different states and to make comparison with one another in the presence of some excipients. The kinetic constants were obtained by fitting the Autocatalytic model on data. Among these excipients, Polysorbate 20 of 0.01% (w/v) showed the best result in decreasing the aggregation. Using this excipient of 0.01% (w/v) in thermal stress causes dramatic reduction of nucleation constant from 8.3× 10-3 (min-1) to 4.14× 10-6 (min-1), which indicates the reduction of protein aggregation in the solution.
- انتشار مقاله: 26-11-1392
- نویسندگان: Zahra Ebrahimi,Hamid Rashedi,Ahmad Fazeli
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Immobilization,Cellulose,LFA System,Nitrocellulose,Nylon,PVDF
- چکیده:
- چکیده انگلیسی: Lateral flow assay, a simple and rapid test to detect various agents; have found many applications in different fields. One of the most important issues in the construction of a Lateral Flow assay is the increasing of its sensitivity and efficiency by processing of analytical layer. This study, aimed to investigate the performance of, Nellulose, Nitrocellulose, Nylon and PVD as different analytical layer in morphine Lateral flow strip as a model. Cyanogens bromide, acetonitrile, methanol and specific polymers were used to activate cellulose, nitrocellulose, PVDF and nylon respectively. BSA-morphine and anti morphine polyclonal antibodies were immobilized orderly in test and control bands different concentrations of morphine were prepared as sample solution. Results showed that activated supports have better detection level in comparison with control strips. Among activated supports nitrocellulose showed more reliable results rather than others and introduced as a suitable support for construction of analytical layer and antibody immobilization. Nylon and PVDF supports due to its hydrophobic nature and cellulose due to high capillary property and non-uniform texture showed inappropriate results. Using proper supports for design of lateral flow strips can improve the sensitivity and detection level of this system.
- انتشار مقاله: 25-10-1393
- نویسندگان: Housna Shamloo Ahmadi,Mohammad Heiat,Hamid Rashedi,Ali Mohammad Latifi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Mechanism,Aggregation,Nucleation,Reteplase,Monomer-Loss Model,Thermal Stimulation
- چکیده:
- چکیده انگلیسی: Aggregation of pharmaceutical proteins reduces the efficiency and increases the cost of production. It can also lead to the reduced efficacy of drug or cause side effects on the patient’s body. Investigating how to create them plays an important role to find agents that prevents the aggregation. This study was allocated for understanding the mechanism of formation of the reteplase protein using thermal stimulation. Aggregation was studied by ultraviolet spectrometry, and observation at 4, 25, 50 and 70°C, the concentration of protein monomer was measured by using a spectrum of 360 nm and 280 nm. At 4°C, there was no significant change in monomer concentration for a month. By increasing the temperature to 25˚C, aggregation process was slow, but at 70°C, the reaction was carried out at a rapid rate less than 2 hours. In order to investigate the mechanism of reteplase aggregation, some kinetics that was presented in of monomer-loss models were used. Experimental data was fitted in three “pre balance core”, “self-catalytic” and “slow start” models using MATLAB. The best fit was obtained using optimization methods. Best fit for self-catalytic model is (R2> 0.98). For other two models (R2 <0.9) occurred. The best fit for the pre balance core and a slow start model was occurred in n = 2. These results could indicate that the core is formed by connecting two reteplase monomers together. The reaction rate constants were calculated too. The results showed that increasing the temperature increases the reaction rate constant. With increasing temperature from 25 ˚C up to 70˚C, both of K1 and K2 increased from 4.7±0.1*10-11K1(min-1) to 1.6±0.2*10-7K1(min-1) and from 1.04±0.2*10-5 K2(M -1 min-1) to 1.5± 0.3*10-4 K2(M -1min-1), respectively for autocatalytic model. Limitation step of the reaction is the nucleation. K1
2 demonstrates this fact. In addition, an existence of disulfide bonds in aggregate protein was guessed. These bonds are strong covalent that cannot be easily broken. - انتشار مقاله: 25-10-1393
- نویسندگان: Soheyla Ershadi,Hamid Rashedi,Ahmad Fazeli
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Applied Biotechnology Reports
- نوع مقاله: Journal Article
- کلمات کلیدی: Aspergillus niger,Textile effluent,Biodecolorization,Carcinogen
- چکیده:
- چکیده انگلیسی: Textile effluents contain different kinds of chemical dyes and many mutagenic and carcinogenic substances. Discharge of these effluents into terrestrial and aquatic ecosystems causes harmful effects. In this research, decolorization of a textile effluent by nineteen different strains of fungi was investigated. Removal activity of dyes was in order of Aspergillus > Rhizopus > Fuzarium > Penicillium > Saccharomyces. The selected fungal strain was capable of decolorizing textile effluent at original pH of effluent (8.5- 9) by adding 0.6 and 0.2 g/L of sucrose and NH4Cl as additional carbon and nitrogen sources respectively at 30ᵒC. 98 % of dyes were absorbed from effluent during the exponential growth phase in the presence of a biodegradable substrate such as sucrose under shake flask conditions. Dyes strongly bound to the fungal biomass required extraction with methanol for their removal. The dyes pigment yellow (PY 74) and reactive blue (RB 38) were totally decolorized after 6 days at initial concentration of 250 ppm by terrestrial Aspergillus niger.
- انتشار مقاله: 24-06-1393
- نویسندگان: Maryam Mazaheri Tehrani,Mahnaz Mazaheri Assadi,Hamid Rashedi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Biotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: Xylanase,Ceriporiopsis subvermispora,Fungal enzyme,Brightness,Dimethyl formamide pulping
- چکیده:
- چکیده انگلیسی: A study was carried out on totally chlorine-free (TCF) bleachability of dimethyl formamide (DMF) treated bagasse pulps exposed to CZ-3 and FP 90031-sp strains of white-rot fungus Ceriporiopsis subvermispora. This process involved an oxygen and peroxide stage bleaching sequence. The effect of enzymatic stage on bleachability properties was studied and compared with control pulps, processed without enzyme addition. Final brightness of 79-80% ISO was achieved after complete bleaching. The effects of direct bleaching caused pulp brightening (1.7-1.3% ISO) and delignification (<10%) immediately after the enzymatic stage. Under a peroxide charge of 3% to 9%, the brightness improvement and the bleachability of these pulps were found to be superior to those of the control during all peroxide stages. The selective bleaching of each process was assessed by changes of intrinsic viscosity. Generally higher bleachability and bleaching selectivity of xylanase-treated pulps and the inevitable maximal gain in pulp brightness (or bleach boosting, as a main objective of xylanase application) could be achieved only after the first and second peroxide bleaching stages which then substantially diminished by the end of the sequence.
- انتشار مقاله: 02-02-1394
- نویسندگان: Amir Sheikhi,Ghasem Amoabediny,Hamid Rashedi,Yaser Ziaie-Shirkolaee,Saeed Soltanali,Zahra Shams-Haghani
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Streptomyces,Ectoine,Molecular Dynamic,Thermodynamic principles
- چکیده:
- چکیده انگلیسی: In this study, ectoine is produced by Streptomyces. sp IBRC-M PTCC 10615. Fermentation parameters such as flow regime, gas hold up, mass transfer coefficient, and mixing time were optimized by statistical analysis. Streptomyces. sp produced a maximal ectoine concentration of 270 mmol/kg at optimal conditions of ectoine and L-aspartic acid. Also, the amount of mass transfer, gas hold up, and mixing time were determined 0,41/s ,0.3, and 40 s, respectively. The amount of ectoine was measured by HPLC. Furthermore, Molecular Dynamics (MD) simulation was used for studying the solubility of ectoine in aqueous media. Equilibrium data such as temperature, potential energy, and volume graphs showed that the solubility of ectoine is 25%more than glycerol. Also, all the achieving graphs from the equilibrium of simulation were confirmed the appropriate structure of the system.
- انتشار مقاله: 15-02-1398
- نویسندگان: Soheil Rezazadeh Mofradnia,Reihaneh Ashouri,Najmeh Abtahi,Fatemeh Yazdian,Hamid Rashedi,Mojgan Sheikhpour,Fatemeh Ashrafi
- مشاهده