Showing 14 results for Bioreactor
Volume 6, Issue 3 (12-2022)
Abstract
Research subject: Osmosis membrane bioreactor is one of the best industrial wastewater treatment methods. The main advantage of using osmosis process is its operation at low hydraulic pressures which has a better performance in removing pollutants and low energy consumption than other methods
Research approach: In this research, Nano porous Titanium dioxide powder with a specific surface area and anatase wall was synthesized through a thermal process using cetyltrimethylammonium bromide (CTAB) as a surfactant directing agent and a pore-creating agent.Ultrafiltration nanocomposite membranes were made using modified titanium dioxide (TiO2) (MT) and polysulfone (PSf) by phase the inversion method. The morphology and structure of the prepared membranes and nanoparticles were investigated using by atomic fourier transforms infrared spectroscopy(FESEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). In this research, bovine serum albumin (BSA) was used as simulated wastewater for the feed solution. The fabricated ultrafiltration membranes were tested in osmosis membrane bioreactor (OMBR) system due to lower energy and fouling. 0.6 % solution of poly (sodium 4-styrene sulfonate) was used as an osmotic solution. Comparative separation performance and antifouling properties of both nanocomposites in several analyzes such as water contact angle measurement, pure water flux and filtration of different concentrations of bovine serum albumin solution. BSA and fouling resistance have been investigated
Main results: TThe results that Due to the addition of MT nanoparticles to the polymer matrix, the hydrophilicity and surface energy of the membrane increased, which led to the improvement of the membrane performance. The membrane containing 1% titanium oxide nanoparticles showed the best result. For example, for feeding with a concentration of 200 ppm, the water flux increased from 20 to 38.5 L/ m2 h, and the percentage of returning lethal solution decreased from 19.6 to 30 g/ m2 h. The flux recovery in this membrane was 96%, which indicates the antifouling property of the modified nanocomposite membrane.
S. Ghobadian , H. Ganjidoust , B. Ayati , N. Soltani ,
Volume 9, Issue 3 (9-2018)
Abstract
Z. Hajihassan, S.m. Sadat, P. Gholami Tilko ,
Volume 10, Issue 1 (3-2019)
Abstract
Aims: Nerve growth factor (β-NGF) is an important therapeutic agent for the treatment of neurodegenerative diseases such as Alzheimer’s disease; so, recombinant production of it in industrial scale is of high importance. The aim of this study is to optimize the effective factors in achieving the highest rate of β-NGF protein production in the bioreactor.
Materials & Methods: As E. coli is a suitable host for industrial production of recombinant proteins, E. coli DE3 strain was used for production of recombinant β-NGF. Also, fermentation was performed in a 5-L bioreactor and % dissolved oxygen (%DO) and post-induction temperature values were optimized by response surface methodology (RSM). At first, the effects of these two variables on the level of total protein were studied. So, in every experiment, bacterial proteins were isolated and total protein concentration was determined by Bradford assay.
Findings: The results indicated that %DO and post-induction temperature of 30% and 28.5ºC were the best values for increased production of total protein; in these circumstances, total protein concentration was 9.6±0.61 mg/ml. Finally, the effects of these variables on recombinant β-NGF production were surveyed by dot blot analysis, indicating the maximum β-NGF expression level on the optimized condition.
Conclusion: In conclusion, %DO and post-induction temperature not only affect cell growth of recombinant E. coli, but also have a direct impact on recombinant protein expression and production, such as β-NGF.
M. Jafarsalehi, R.a. Dianati Tilaki, Y. Esfandyari,
Volume 10, Issue 2 (7-2019)
Abstract
Conventional wastewater treatment systems are not capable of removing phosphorus effectively. The entry of phosphorus into water resources leads to the formation of an Eutrophication phenomenon. One of the methods for phosphorus removal is the use of microalgae. In this way, besides helping with advanced sewage treatment, it can produce algae with many applications. The purpose of this study was to determine the simultaneous and to compare the phosphorus removal (rate of phosphorus) and Spirulina biomass production in a photobioreactor, using two kinds of treated sewage. The experiments were carried out with the manufacture of a photobioreactor and air injection by means of a fine bubble diffuser into sewage-containing reactors. The light source in this test was designed as fluorescent light bulbs and alternating radiation. Urban wastewater effluent and refined sewage were used as a culture medium in a photobioreactor. The amount of phosphorus in the purified sewage was measured by spectrophotometry at a wavelength of 690nm. The phosphorus removal and algal biomass production were measured in different culture medium containing wastewater with various concentrations of phosphorus. The initial concentrations of phosphorus in refined urban sewage and sanitary sewage were 1.96 and 0.4mg L-1, respectively. Phosphorus removal during microalgae cultivation with municipal wastewater and sanitary sewerage (removal of phosphorus) for 8 days, was 71.9% and 37%, respectively. Biomass production in this time were 0.18 and 0.025g/l, respectively. By decreasing the concentration of phosphorus in the wastewater, the amount of biomass production and (removal of) phosphorus removal decreased. Treated domestic and sanitary sewage can be injected directly, without prior treatment, in photobioreactor and it is possible to remove phosphorus and to produce algal biomass.
Z. Montazer, M.b. Habibi-Najafi , M. Mohebbi, A.r. Oromieyee ,
Volume 10, Issue 2 (7-2019)
Abstract
Accumulation of polyethylene (PE) wastes has become a major environmental problem. The objective of this research was to assess the potential for microbial degradation of sun-treated low-density PE as a natural way to eliminate PE wastes in semi-industrial condition. Low-density polyethylene (LDPE) films were exposed to one month of sun radiation treatment and then cultured with two PE-degrading bacteria (Sphigobacterium moltivorum IRN11 and Delftia tsuruhatensis IRN27) in aerobic bioreactors over 100 days. Weight loss percentage of the PE and the culture pH were measured. Also, Changes in the chemical structure of the LDPE were assessed by FT-IR and surface erosion and microbial layer formation by bacterial activity was observed by Scanning Electron Microscopy. Partial increases in the culture pH were recorded during the incubation period. The weight loss percentage for T-LDPE samples cultured with Sphigobacterium moltivorum IRN11 and Delftia tsuruhatensis IRN27 was 3.31%±0.013 and 3.98%±0.025 in TLDPE samples, respectively, and functional carbonyl-groups in the TLDPE samples decreased significantly due to bacterial hydrolysis. SEM images showed the different microbial layer formation on sun-treated low-density polyethylene (T-LDPE) for both bacteria. Our results suggest that exposure of LDPE to sun radiation had a significant effect on biodegradation of Ld-PE films and that the two bacteria tested were able to enhance the biodegradation the T-LDPE.
Sanaz Noori, Parisa Hejazi,
Volume 12, Issue 1 (12-2020)
Abstract
In this study, cellulase enzyme production by Trichoderma reesei on three lignocellulosic substrates (corn bran, sawdust and wheat bran) and percentage of different combinations of sawdust and wheat bran by solid-state fermentation method for 6 days in scale checked out. Then, under optimal substrate component proportions obtained from Erlenmeyer-scale, the effect of aeration at three levels of 0.5, 1 and 1.5 liters per hour of initial dry substrate (l/(h.gds)) on the production of this enzyme in 0.5-Liter packed-bed bioreactor was studied. The initial substrate moisture and pH were 70 %(w/w) and 5 respectively, and the heating temperature was set at Erlenmeyer-scale and bioreactor at 30 and 28 °C, respectively. Cellulase enzyme production was evaluated based on the activity of endoglucanase and exoglucanase enzymes. The highest amount of endoglucanase and exoglucanase activity at substrate combination of 75% wheat bran and 25% sawdust in Erlenmeyer-scale at day 6 and 3 were obtained 13 and 6.4 U/gds, respectively, and in bioreactor at aeration of 1.5 (l/(h.gds)) at day 3 were attained 36 and 10 U/gds, respectively.
Hadis Kordzangeneh, Fereshteh Jookar Kashi,
Volume 13, Issue 4 (1-2023)
Abstract
This study aimed to isolate and identify bacteria from soils contaminated with copper and have access to a capable bacterial strain for producing copper nanoparticles (CuNPs). The present study showed the extracellular production of copper nanoparticles using strain Ta-31. The effect of various factors such as substrate, supernatant volume, enzyme inducer, and electron donor was investigated on the production process. The properties of synthesized nanoparticles were identified by using UV-Vis, FTIR, XRD, SEM, and EDS analysis.
Moreover, the growth curve of strain Ta-31 was plotted in the presence and absence of an enzyme inducer (concentration of 0.1 mM copper sulfate). After the phylogenetic analysis, 16S rDNA gene sequences were determined, and their phylogenetic tree of the selected strain was plotted. The results showed that the best conditions for producing CuNPs, glucose 1% as an electron donor, 2 mM copper sulfate, and 20 ml supernatant had the best production. Strain Ta-31 arrived at the end of the log phase and the beginning of the stationary phase after 15 h. CuNPs were spherical and irregular, and the size of CuNPs was more in the range of 30-40 nm. According to the results, strain Ta-31 belonged to Staphylococcus pasteuri sp. with 99.88% similarity.
Seyedeh Hajar Hassani, Hassan Firoozi Bereshneh, Valiollah Babaeipour,
Volume 14, Issue 1 (3-2023)
Abstract
In this study, the wheat germ was fermented with industrial bakery yeast powder to produce FWGE with high 2,6-DMBQ content in a Bench-scale bioreactor by scale-up approach. The 2,6-DMBQ content of FWGE was increased by optimizing the three initial variables of pH, fermentation temperature, and agitation rate at two levels using the Taguchi method. The 2,6-DMBQ content of the samples was determined at 14, 16, and 18 hours of the fermentation process. Then, the results were analyzed by Qualitek software. The effect of centrifugation speed on turbidity and the yeast's number in the final supernatant was then investigated. Finally, the supernatant was dried by spray dryer with an inlet temperature of 120 °C and outlet temperature of 70°C, and the amount of active 2,6-DMBQ, pH, moisture, and ash was determined. Under optimal conditions: initial pH of 6, fermentation temperature of 32 °C, and agitation rate of 80 rpm, maximum 1.527 mg of 2,6-DMBQ per gram of FWGE obtained. The separation results showed that the centrifugation rate doesn't have a significant effect on the final turbidity and the number of yeasts left, and thus 3000 g was selected as the optimal speed. However, because of the high content of yeast in the supernatant, filtration was required after centrifugation. Due to the high speed of sample drying, the low moisture of the final product, and high efficiency on an industrial scale, the samples were dried using a spray dryer. Finally, the moisture, protein, ash, and pH of the final product were measured.
Parvaneh Esmaeilnejad-Ahranjani, Azadeh Zahmatkesh,
Volume 14, Issue 2 (5-2023)
Abstract
The process of diphtheria toxoid production was designed by using SuperPro Designer and the effect of the applied changes in process on the yield and costs of the manufacturing was investigated. First, giving the information of the real process of the toxoid production, a bioreactor with improved operational conditions and a disc stack centrifuge instead of the filter press, which is applied for the bacterial debris separation, were utilized. Such alterations followed the addition of a pump between the bioreactor and centrifuge. The results indicated that improvement of the bioreactor operational conditions can lead to the 25% increase in the toxin production, i.e., the increase of toxoid production from 7,000,000 doses to 8,750,000 doses. The toxin waste through filter press (14%) may be remarkably reduced by using the centrifuge, which in turn resulted in the 44% enhancement in the toxoid production. Such alterations can result in the 16% reduction in the separation operation time, 29% reduction in water consumption and 32% increase in the energy consumption. Overall, the simulation results showed that the costs of the new equipment suggested to be used in the improved process can be recoverable through running two batches.
Volume 16, Issue 3 (12-2013)
Abstract
The provision of an adequate quantity of cells with proper function and purity is one of the main challenges of tissue engineering studies. Stem cells, with their self-renewal and differentiation capacity, are considered one of the main cell sources in the field of tissue engineering. Previously, the use of chemical factors seemed to be the only possible way for stem cell differentiation. However, scientists have recently realized that physiological processes of the human body are composed of chemical, mechanical and electrical signals. Mechanical stimulation is one of the current methods that produce cells with proper morphology and alignment in the scaffold. Specific differentiation, a higher rate of cell growth, proliferation and differentiation, and lower experiment costs can be achieved using mechanical stimulation. Different parameters such as the chemical environment, physical environment that surrounds the cell (including geometry, stiffness and topology of scaffold surface), amplitude, frequency, and duration of mechanical stimulation can affect the stem cell fate. In this study we have investigated the impact of all types of mechanical stimulations under different loading regimes on the fate of stem cells with respect to the target tissue. The result has been reflected in the design of a proper bioreactor.
Volume 19, Issue 1 (5-2016)
Abstract
Objective: In the present study we investigated the effect of a dynamic culture in a shake flask bioreactor (SFB) on the proliferation and differentiation to osteoblasts for human mesenchymal stem cells (hMSCs) cultured on multilayered electrospun PCL-nHA scaffolds.
Methods: First, we prepared PCL-nHA scaffolds by electrospinning. After culturing the hMSCs on the scaffolds in a static state, the seeded scaffolds were divided into two groups (static and SFB culture) and incubated up to 21 days. We assessed biocompatibility and cell differentiation by the MTT, calcium, and alkaline phosphatase (ALP) assays on days 7, 14, and 21.
Results: The MTT assay evaluated hMSCs proliferation rate on the scaffold layers. There was greater cell proliferation (optical density values) on the layers in the bioreactor (OD=2.18) compared to the static state condition (OD=1.68) on day 21. In order to study osteogenic differentiation, we determined the amount of calcium deposition and ALP activity. We observed a 1.6-fold greater level of calcium deposition for the dynamic culture compared to the static culture, which showed increased cell differentiation within the bioreactor on day 21. The ALP results showed that during 14 days, ALP activity within the bioreactor was 1.55-fold higher than the static culture.
Conclusion: The SFB culture displayed a higher proliferation and differentiation of stem cells on PCL-nHA multilayered scaffolds compared to the static state condition.
Volume 20, Issue 1 (4-2020)
Abstract
In this study, petrochemical complex wastewater was investigated by submerged membrane bioreactor (MBR). Initial sludge was prepared from returned sludge of petrochemical complex wastewater treatment plant. Applied membrane is of micro-filtration type made of polyvinylidene fluoride with effective surface of 0.004 m2, porosity of 73% and nominal pore diameter of 0.1 μm. Particle size distribution (PSD), soluble microbial products (SMP), and extracellular polymeric substance (EPS) for sludge were measured. In addition Fourier-transform infrared spectroscopy (FTIR), and EPS analysis were performed for determining the properties of the formed cake. Also was measured critical pressure for membrane in the MBR. The critical pressure value was 0.2 kPa. Therefore, the operating pressure was selected 0.12 kPa. This research was conducted in two phases. In the first phase, the pilot worked for 35 days. The results showed that despite the membrane fouling in initial days, the permission of the membrane still had a good efficiency, and after each 7 days, the membrane was cleaned physically and chemically, which showed a recovery of permeate more than 90%. The COD removal efficiency was achieved more than 85% in MLSS=3000±300 mg / L and HRT=14-16 hours. In addition, the TSS and turbidity in the output were below 1 mg/L and 12 NTU, respectively. In the second phase, for reducing fouling, the granule activated carbon was added in the sludge. In the reactor containing activated carbon (R2), membrane fouling was carried out with lower rate and also flux drop was lower about 22% compared to reactor without activated carbon. This phenomenon was due to increasing sludge particle size, SMP reduction.
Volume 24, Issue 2 (6-2024)
Abstract
Rapid growth of population is leading to high water consumption and producing large amount of waste water which needs to be treated and being reutilized for reusing purposes. Among sewage treatment methods, the use of integrated activated sludge and membrane separation is increasing due to advantages such as higher quality effluents, lower ecological footprint, less sludge production, and lower operational costs. Despite the many benefits, the problem of membrane fouling due to deposition and adsorption of colloidal and soluble material on the surface of membrane has limited the use of this method. There are several methods for eliminating and mitigating membrane fouling, each with disadvantages such as increasing costs, producing secondary pollutants, increasing sludge production, reducing the membrane life and durability, etc. In recent years, the use of electrical coagulation as a method to reduce membrane fouling in the MBR system has been taken into account. Submerged Membrane Electro Bioreactors (SMEBR) is a new approach that reduces clogging of the membrane by combining the MBR system with the electric field. In the forthcoming research, the effects of electric field on the system were investigated by applying a low voltage electric field (1.5 volts per cm) in the MBR reactor. The results of the experiments showed that applying the electric field in this case improves the characteristics of the wastewater (reducing the concentration of COD, nitrate and phosphate) and reducing the concentration of external polymeric substance (EPS) and soluble material product (SMP) protein. Also, the application of an electric field in MBR reactors reduces fouling and improves the output flux more than the conventional membrane.
Key words: Membrane bioreactor, Electric Field, Biofouling
Volume 25, Issue 2 (2-2022)
Abstract
Introduction: Decellularizing testis tissue and recellularizing with spermatogonial stem cells (SSCs) seems to be a promising approach to restore fertility in prepubertal boys who undergoes cytotoxic therapies.
Method: Testis tissue decellularization was performed by adding 1% SDS and confirmed by histological analysis and DNA quantification. The MTT assay was performed for biocompatibility analyses. SSCs were derived from male mice and cultured in αMEM medium for two weeks. Expanded SSCs were seeded onto the DTM scaffold. The recellularized DTM scaffold disc was cultured in a static cultivation system for one week, then transferred in a dynamic mini-perfusion bioreactor for two weeks. The expression of Id4, Plzf, Gfrα, Prm, Sycp3, ABP, Ki67, Bax, and Bcl2 genes were assessed in SSCs and recellularized DTM after static and dynamic cultivations.
Result: DNA qualification indicated that approximately 99% of the DNA components were removed from DTMs. Hematoxylin-eosin, Masson's trichrome, and DAPI staining confirmed the effective recellularization. Dynamic cultivation of recellularized DTMs at the flow rate of 10 ml/h provided optimum conditions. The expression of SSCs-specific genes of Id4, Plzf, and Gfrα-1 and post-meiosis genes of Scp3, prm1, and ABP was insignificantly higher in the DTMs group than in the control group. Ki67 expression was shown no difference between groups. An insignificant lower expression of the Bax and higher expression of Bcl2 genes was detected in the DTMs group compared to the control.
Conclusion: Our results indicated that SSCs could successfully be attached to the DTMs and effectively proliferate in the mini-perfusion bioreactor.
