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Sample records for sulfidogenic bioreactor fed

  1. Arsenic removal in a sulfidogenic fixed-bed column bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Altun, Muslum, E-mail: muslumaltun@hotmail.com [Hacettepe University, Department of Chemistry, Beytepe, Ankara (Turkey); Sahinkaya, Erkan [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey); Durukan, Ilknur; Bektas, Sema [Hacettepe University, Department of Chemistry, Beytepe, Ankara (Turkey); Komnitsas, Kostas [Technical University of Crete, Department of Mineral Resources Engineering, Chania (Greece)

    2014-03-01

    Highlights: • Sulfidogenic treatment of As-containing AMD was investigated. • High rate simultaneous removal of As and Fe was achieved. • As was removed without adding alkalinity or adjusting pH. • As and Fe removal mechanisms were elucidated. - Abstract: In the present study, the bioremoval of arsenic from synthetic acidic wastewater containing arsenate (As{sup 5+}) (0.5–20 mg/L), ferrous iron (Fe{sup 2+}) (100–200 mg/L) and sulfate (2000 mg/L) was investigated in an ethanol fed (780–1560 mg/L chemical oxygen demand (COD)) anaerobic up-flow fixed bed column bioreactor at constant hydraulic retention time (HRT) of 9.6 h. Arsenic removal efficiency was low and averaged 8% in case iron was not supplemented to the synthetic wastewater. Neutral to slightly alkaline pH and high sulfide concentration in the bioreactor retarded the precipitation of arsenic. Addition of 100 mg/L Fe{sup 2+} increased arsenic removal efficiency to 63%. Further increase of influent Fe{sup 2+} concentration to 200 mg/L improved arsenic removal to 85%. Decrease of influent COD concentration to its half, 780 mg/L, resulted in further increase of As removal to 96% when Fe{sup 2+} and As{sup 5+} concentrations remained at 200 mg/L and 20 mg/L, respectively. As a result of the sulfidogenic activity in the bioreactor the effluent pH and alkalinity concentration averaged 7.4 ± 0.2 and 1736 ± 239 mg CaCO{sub 3}/L respectively. Electron flow from ethanol to sulfate averaged 72 ± 10%. X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses were carried out to identify the nature of the precipitate generated by sulfate reducing bacteria (SRB) activity. Precipitation of arsenic in the form of As{sub 2}S{sub 3} (orpiment) and co-precipitation with ferrous sulfide (FeS), pyrite (FeS{sub 2}) or arsenopyrite (FeAsS) were the main arsenic removal mechanisms.

  2. Effect of sulfate absence and nitrate addition on bacterial community in a sulfidogenic bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Yangguo [College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100 (China); State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Wang Aijie, E-mail: waj0578@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Ren Nanqi [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China)

    2009-12-30

    The characteristics and behavior of sulfate-reducing bacteria (SRB), methane-producing bacteria (MPB) and denitrifying bacteria (DB) were investigated by polymerase chain reaction (PCR) based methods under the transitory sulfate absence or nitrate addition conditions in a sulfidogenic continuously stirred tank reactor. The bioreactor started-up feeding with 4000 mg l{sup -1} COD (lactate) and 2000 mg l{sup -1} sulfate (SO{sub 4}{sup 2-}). The sulfate removal efficiency reached 3.84 g l{sup -1} d{sup -1} when the activated sludge formed a stable bacterial community comprising of some members of genera Desulfobulbus, Desulfovibrio, Clostridium and Pseudomonas after 20 days' operation. And about 79% of reduced sulfate captured electrons from the oxidization of propionate. Sulfate absence influenced little on quantity and population structure of SRB and DB, while much on MPB and metabolic typing. And the acetate (up to 86% (w/w) of total end-products) in end-product profiles was replaced by the propionate (75% (w/w)). The addition of nitrate to sulfidogenic system suppressed the sulfidogenesis mainly by capturing the electron flow. These results suggested that sulfate absence or nitrate addition would not inhibit SRB permanently in a stable sulfidogenic community.

  3. Isolation and characterization of two novel alkalitolerant sulfidogens from a Thiopaq bioreactor, Desulfonatronum alkalitolerans sp. nov., and Sulfurospirillum alkalitolerans sp. nov.

    NARCIS (Netherlands)

    Sorokin, D.Y.; Tourova, T.P.; Muyzer, G.

    2013-01-01

    wo obligately anaerobic sulfidogenic bacterial strains were isolated from the full-scale Thiopaq bioreactor in Lelystad (The Netherlands) removing H2S from biogas under oxygen-limiting and moderately haloalkaline conditions. Strain HSRB-L represents a dominant culturable sulfate-reducing bacterium

  4. Synthesis of Copper Sulfide Nanoparticles Using Biogenic H2S Produced by a Low-pH Sulfidogenic Bioreactor

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    Camila Colipai

    2018-01-01

    Full Text Available The application of acidophilic sulfate-reducing bacteria (SRB for the treatment of acidic mine water has been recently developed to integrate mine water remediation and selective biomineralization. The use of biogenic hydrogen sulfide (H2S produced from the dissimilatory reduction of sulfate to fabricate valuable products such as metallic sulfide nanoparticles has potential applications in green chemistry. Here we report on the operation of a low-pH sulfidogenic bioreactor, inoculated with an anaerobic sediment obtained from an acid river in northern Chile, to recover copper via the production of copper sulfide nanoparticles using biogenic H2S. The laboratory-scale system was operated as a continuous flow mode for up to 100 days and the bioreactor pH was maintained by the automatic addition of a pH 2.2 influent liquor to compensate for protons consumed by biosulfidogenesis. The “clean” copper sulfide nanoparticles, produced in a two-step process using bacterially generated sulfide, were examined using transmission electron microscopy, dynamic light scattering, energy dispersive (X-ray spectroscopy and UV-Vis spectroscopy. The results demonstrated a uniform nanoparticle size distribution with an average diameter of less than 50 nm. Overall, we demonstrated the production of biogenic H2S using a system designed for the treatment of acid mine water that holds potential for large-scale abiotic synthesis of copper sulfide nanoparticles.

  5. Zinc deprivation of methanol fed anaerobic granular sludge bioreactors

    Science.gov (United States)

    Fermoso, Fernando G.; Collins, Gavin; Bartacek, Jan

    2008-01-01

    The effect of omitting zinc from the influent of mesophilic (30 °C) methanol fed upflow anaerobic sludge bed (UASB) reactors, and latter zinc supplementation to the influent to counteract the deprivation, was investigated by coupling the UASB reactor performance to the microbial ecology of the bioreactor sludge. Limitation of the specific methanogenic activity (SMA) on methanol due to the absence of zinc from the influent developed after 137 days of operation. At that day, the SMA in medium with a complete trace metal solution except Zn was 3.4 g CH4-COD g VSS−1 day−1, compared to 4.2 g CH4-COD g VSS−1 day−1 in a medium with a complete (including zinc) trace metal solution. The methanol removal capacity during these 137 days was 99% and no volatile fatty acids accumulated. Two UASB reactors, inoculated with the zinc-deprived sludge, were operated to study restoration of the zinc limitation by zinc supplementation to the bioreactor influent. In a first reactor, no changes to the operational conditions were made. This resulted in methanol accumulation in the reactor effluent after 12 days of operation, which subsequently induced acetogenic activity 5 days after the methanol accumulation started. Methanogenesis could not be recovered by the continuous addition of 0.5 μM ZnCl2 to the reactor for 13 days. In the second reactor, 0.5 μM ZnCl2 was added from its start-up. Although the reactor stayed 10 days longer methanogenically than the reactor operated without zinc, methanol accumulation was observed in this reactor (up to 1.1 g COD-MeOH L−1) as well. This study shows that zinc limitation can induce failure of methanol fed UASB reactors due to acidification, which cannot be restored by resuming the continuous supply of the deprived metal. PMID:18283507

  6. Recent Developments for Remediating Acidic Mine Waters Using Sulfidogenic Bacteria

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    Ivan Nancucheo

    2017-01-01

    Full Text Available Acidic mine drainage (AMD is regarded as a pollutant and considered as potential source of valuable metals. With diminishing metal resources and ever-increasing demand on industry, recovering AMD metals is a sustainable initiative, despite facing major challenges. AMD refers to effluents draining from abandoned mines and mine wastes usually highly acidic that contain a variety of dissolved metals (Fe, Mn, Cu, Ni, and Zn in much greater concentration than what is found in natural water bodies. There are numerous remediation treatments including chemical (lime treatment or biological methods (aerobic wetlands and compost bioreactors used for metal precipitation and removal from AMD. However, controlled biomineralization and selective recovering of metals using sulfidogenic bacteria are advantageous, reducing costs and environmental risks of sludge disposal. The increased understanding of the microbiology of acid-tolerant sulfidogenic bacteria will lead to the development of novel approaches to AMD treatment. We present and discuss several important recent approaches using low sulfidogenic bioreactors to both remediate and selectively recover metal sulfides from AMD. This work also highlights the efficiency and drawbacks of these types of treatments for metal recovery and points to future research for enhancing the use of novel acidophilic and acid-tolerant sulfidogenic microorganisms in AMD treatment.

  7. Thiosulphate conversion in a methane and acetate fed membrane bioreactor

    NARCIS (Netherlands)

    Suarez Zuluaga, D.A.; Timmers, P.H.A.; Plugge, C.M.; Stams, A.J.M.; Buisman, C.J.N.; Weijma, J.

    2016-01-01

    The use of methane and acetate as electron donors for biological reduction of thiosulphate in a 5-L laboratory membrane bioreactor was studied and compared to disproportionation of thiosulphate as competing biological reaction. The reactor was operated for 454 days in semi-batch mode; 30 % of its

  8. Microbial aspects of synthesis gas fed bioreactors treating sulfate and metal rich wastewaters

    NARCIS (Netherlands)

    Houten, van B.H.G.W.

    2006-01-01

    The use of synthesis gas fed sulfate-reducing bioreactors to simultaneously remove both oxidized sulfur compounds and metals shows great potential to treat wastewaters generated as a result of flue gas scrubbing, mining activities and galvanic processes. Detailed information about the phylogenetic

  9. Zinc deprivation of methanol fed anaerobic granular sludge bioreactors

    NARCIS (Netherlands)

    Fermoso, F.G.; Collins, G.; Bartacek, J.; Lens, P.N.L.

    2008-01-01

    The effect of omitting zinc from the influent of mesophilic (30 degrees C) methanol fed upflow anaerobic sludge bed (UASB) reactors, and latter zinc supplementation to the influent to counteract the deprivation, was investigated by coupling the UASB reactor performance to the microbial ecology of

  10. Estimation of the Maximum Theoretical Productivity of Fed-Batch Bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Bomble, Yannick J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); St. John, Peter C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Crowley, Michael F [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-18

    A key step towards the development of an integrated biorefinery is the screening of economically viable processes, which depends sharply on the yields and productivities that can be achieved by an engineered microorganism. In this study, we extend an earlier method which used dynamic optimization to find the maximum theoretical productivity of batch cultures to explicitly include fed-batch bioreactors. In addition to optimizing the intracellular distribution of metabolites between cell growth and product formation, we calculate the optimal control trajectory of feed rate versus time. We further analyze how sensitive the productivity is to substrate uptake and growth parameters.

  11. Effect of Sulfide Removal on Sulfate Reduction at pH 5 in a Hydrogen fed Gas-Lift Bioreactor

    NARCIS (Netherlands)

    Bijmans, M.F.M.; Dopson, M.; Lens, P.N.L.; Buisman, C.J.N.

    2008-01-01

    UNCORRECTED PROOF J. Microbiol. Biotechnol. (2007), 17(4), ¿ Effect of Sulfide Removal on Sulfate Reduction at pH 5 in a Hydrogen fed Gas-Lift Bioreactor Bijmans, Martijn F. M.1*, Mark Dopson2, Frederick Ennin1, Piet N. L. Lens1, and Cees J. N. Buisman1 1Sub Department of Environmental Technology,

  12. Genetic Algorithmic Optimization of PHB Production by a Mixed Culture in an Optimally Dispersed Fed-batch Bioreactor

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    Pratap R. Patnaik

    2009-10-01

    Full Text Available Poly-β-hydroxybutyrate (PHB is an energy-storage polymer whose properties are similar to those of chemical polymers such as polyethylene and polypropylene. Moreover, PHB is biodegradable, absorbed by human tissues and less energy-consuming than synthetic polymers. Although Ralstonia eutropha is widely used to synthesize PHB, it is inefficient in utilizing glucose and similar sugars. Therefore a co-culture of R. eutropha and Lactobacillus delbrueckii is preferred since the latter can convert glucose to lactate, which R. eutropha can metabolize easily. Tohyama et al. [24] maximized PHB production in a well-mixed fed-batch bioreactor with glucose and (NH42SO4 as the primary substrates. Since production-scale bioreactors often deviate from ideal laboratory-scale reactors, a large bioreactor was simulated by means of a dispersion model with the kinetics determined by Tohyama et al. [24] and dispersion set at an optimum Peclet number of 20 [32]. The time-dependent feed rates of the two substrates were determined through a genetic algorithm (GA to maximize PHB production. This bioreactor produced 22.2% more PHB per liter and 12.8% more cell mass than achieved by Tohyama et al. [24]. These results, and similar observations with other fermentations, indicate the feasibility of enhancing the efficiency of large nonideal bioreactors through GA optimizations.

  13. Effects of hydraulic retention time on anaerobic hydrogenation performance and microbial ecology of bioreactors fed with glucose-peptone and starch-peptone

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shiue-Lin; Chao, Yu-Chieh; Wang, Yu-Hsuan; Hsiao, Chia-Jung; Bai, Ming-Der [Department of Environmental Engineering, National Cheng-Kung University, No. 1, University Road, Tainan 701 (China); Whang, Liang-Ming; Wang, Yung-Fu; Cheng, Sheng-Shung [Department of Environmental Engineering, National Cheng-Kung University, No. 1, University Road, Tainan 701 (China); Sustainable Environment Research Center (SERC), National Cheng-Kung University, No. 1, University Road, Tainan 701 (China); Tseng, I.-Cheng [Sustainable Environment Research Center (SERC), National Cheng-Kung University, No. 1, University Road, Tainan 701 (China); Department of Life Science, National Cheng-Kung University, No. 1, University Road, Tainan 701 (China)

    2010-01-15

    This study evaluated anaerobic hydrogenation performance and microbial ecology in bioreactors operated at different hydraulic retention time (HRT) conditions and fed with glucose-peptone (GP) and starch-peptone (SP). The maximum hydrogen production rates for GP- and SP-fed bioreactors were found to be 1247 and 412 mmol-H{sub 2}/L/d at HRT of 2 and 3 h, respectively. At HRT > 8 h, hydrogen consumption due to peptone fermentation could occur and thus reduced hydrogen yield from carbohydrate fermentation. Results of cloning/sequencing and denaturant gradient gel electrophoresis (DGGE) indicated that Clostridium sporogenes and Clostridium celerecrescens were dominant hydrogen-producing bacteria in the GP-fed bioreactor, presumably due to their capability on protein hydrolysis. In the SP-fed bioreactor, Lactobacillus plantarum, Propionispira arboris, and Clostridium butyricum were found to be dominant populations, but the presence of P. arboris at HRT > 3 h might be responsible for a lower hydrogen yield from starch fermentation. As a result, optimizing HRT operation for bioreactors was considered an important asset in order to minimize hydrogen-consuming activities and thus maximize net hydrogen production. The limitation of simple parameters such as butyrate to acetate ratio (B/A ratio) in predicting hydrogen production was recognized in this study for bioreactors fed with multiple substrates. It is suggested that microbial ecology analysis, in addition to chemical analysis, should be performed when complex substrates and mixed cultures are used in hydrogen-producing bioreactors. (author)

  14. Bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Jamaleddine, E. [McGill Univ., Montreal, PQ (Canada). Dept. of Bioresource Engineering

    2010-07-01

    Composting is once again gaining interest among ecological engineers in view of greener industrial and residential activities. Uniform composting is needed to ensure decomposition and to keep the whole system at the same composting stage. A homogeneous temperature must be maintained throughout the media. A bioreactor design consisting of a heater core made of copper tubing was designed and tested. Two four-inch holes were made at the top and bottom of the barrel to allow air to flow through the system and promote aerobic composting. Once composting began and temperature increased, the water began to flow through the copper piping and the core heat was distributed throughout the medium. Three thermocouples were inserted at different heights on a 200 litre plastic barrel fitted with the aforementioned apparatus. Temperature variations were found to be considerably lower when the apparatus was operated with the heat redistribution system, enabling uniform composting, accelerating the process and reducing the risks of pathogenic or other contaminants remaining active in the barrels.

  15. THE EFFECT OF THE ADDITION OF INVERT SUGAR ON THE PRODUCTION OF CEPHALOSPORIN C IN A FED-BATCH BIOREACTOR

    Directory of Open Access Journals (Sweden)

    A.S. Silva

    1998-12-01

    Full Text Available Cephalosporin C, a b -lactam antibiotic, is the starting molecule for industrial production of semi-synthetic cephalosporins. The bioprocess for its production is carried out in batch stirred and aerated tank reactors utilizing strains of the filamentous fungus Cephalosporium acremonium. In this work a comparison was made between the processes of production of cephalosporin C in a conventional batch bioreactor, with synthetic medium containing glucose and sucrose, and in a fed-batch reactor at several flowrates of supplementary medium containing invert sucrose. In general, the fed-batch process was shown to be more efficient than the conventional batch one, and the process in which the lowest supplementation flowrate was used presented an antibiotic production significantly higher than those obtained under the other conditions.

  16. Methanol utilizing Desulfotomaculum species utilizes hydrogen in a methanol-fed sulfate-reducing bioreactor

    NARCIS (Netherlands)

    Balk, M.; Weijma, J.; Goorissen, H.P.; Ronteltap, M.; Hansen, T.A.; Stams, A.J.M.

    2007-01-01

    A sulfate-reducing bacterium, strain WW1, was isolated from a thermophilic bioreactor operated at 65 degrees C with methanol as sole energy source in the presence of sulfate. Growth of strain WW1 on methanol or acetate was inhibited at a sulfide concentration of 200 mg l(-1), while on H-2/CO2, no

  17. Comparative study of production of Bio-Indigo by Pandoraea sp. in a two phase - fed batch and continuous bioreactor

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    Vaishnavi Unde

    2016-03-01

    Full Text Available Indigo, is blue of blue jeans, a synthetic dye used on large scale all over the world. Chemical production of the dye is taking a new route towards bacterial production to overcome the environmental effects that are posed by the synthetic blue powder (Indigo. In the present work a strain Pandoraea sp. isolated from the oil contaminated soil is found to produce blue pigment which is analyzed qualitatively as indigo using UV-visible scan and Thin Layer Chromatography (TLC. The strain is used for indigo production at lab scale in two different bioreactor configurations first the fed batch mode and second continuous mode using two phases. The two phases consisting of medium carrying biomass and the second phase of silicone oil carrying substrate indole. The use of second phase allows higher concentration of substrate injection reducing the inhibition effects of the substrate as well as act as a partitioning agent for removal of the product. In two phase study, the maximum indigo produced was seen to be 0.068 g/L after 22 hours of substrate injection into the Fermentor in a fed batch mode. The maximum yield obtained in this configuration was 19%. For commercial production of bio-indigo a continuous operation is required, which was studied in a bioreactor with 2.5 liter capacity under the optimized conditions. The maximum indigo produced was found to be 0.052 g/L after about 72 hours of operation. The results showed decrease in the production of indigo in continuous mode as compared to fed batch operation, which may be due to the insufficient time available for the bacteria to bio-transform indole into indigo.

  18. Neural Network-Based State Estimation for a Closed-Loop Control Strategy Applied to a Fed-Batch Bioreactor

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    Santiago Rómoli

    2017-01-01

    Full Text Available The lack of online information on some bioprocess variables and the presence of model and parametric uncertainties pose significant challenges to the design of efficient closed-loop control strategies. To address this issue, this work proposes an online state estimator based on a Radial Basis Function (RBF neural network that operates in closed loop together with a control law derived on a linear algebra-based design strategy. The proposed methodology is applied to a class of nonlinear systems with three types of uncertainties: (i time-varying parameters, (ii uncertain nonlinearities, and (iii unmodeled dynamics. To reduce the effect of uncertainties on the bioreactor, some integrators of the tracking error are introduced, which in turn allow the derivation of the proper control actions. This new control scheme guarantees that all signals are uniformly and ultimately bounded, and the tracking error converges to small values. The effectiveness of the proposed approach is illustrated on the basis of simulated experiments on a fed-batch bioreactor, and its performance is compared with two controllers available in the literature.

  19. Glycoprofiling effects of media additives on IgG produced by CHO cells in fed-batch bioreactors

    DEFF Research Database (Denmark)

    Kildegaard, Helene Faustrup; Fan, Yuzhou; Wagtberg Sen, Jette

    2016-01-01

    Therapeutic monoclonal antibodies (mAbs) are mainly produced by heterogonous expression in Chinese hamster ovary (CHO) cells. The glycosylation profile of the mAbs has major impact on the efficacy and safety of the drug and is therefore an important parameter to control during production. In this......Therapeutic monoclonal antibodies (mAbs) are mainly produced by heterogonous expression in Chinese hamster ovary (CHO) cells. The glycosylation profile of the mAbs has major impact on the efficacy and safety of the drug and is therefore an important parameter to control during production....... In this study, the effect on IgG N-glycosylation from feeding CHO cells with eight glycosylation precursors during cultivation was investigated. The study was conducted in fed-batch mode in bioreactors with biological replicates to obtain highly controlled and comparable conditions. We assessed charge...

  20. Methanol utilizing Desulfotomaculum species utilizes hydrogen in a methanol-fed sulfate-reducing bioreactor.

    Science.gov (United States)

    Balk, Melike; Weijma, Jan; Goorissen, Heleen P; Ronteltap, Mariska; Hansen, Theo A; Stams, Alfons J M

    2007-01-01

    A sulfate-reducing bacterium, strain WW1, was isolated from a thermophilic bioreactor operated at 65 degrees C with methanol as sole energy source in the presence of sulfate. Growth of strain WW1 on methanol or acetate was inhibited at a sulfide concentration of 200 mg l(-1), while on H2/CO2, no apparent inhibition occurred up to a concentration of 500 mg l(-1). When strain WW1 was co-cultured under the same conditions with the methanol-utilizing, non-sulfate-reducing bacteria, Thermotoga lettingae and Moorella mulderi, both originating from the same bioreactor, growth and sulfide formation were observed up to 430 mg l(-1). These results indicated that in the co-cultures, a major part of the electron flow was directed from methanol via H2/CO2 to the reduction of sulfate to sulfide. Besides methanol, acetate, and hydrogen, strain WW1 was also able to use formate, malate, fumarate, propionate, succinate, butyrate, ethanol, propanol, butanol, isobutanol, with concomitant reduction of sulfate to sulfide. In the absence of sulfate, strain WW1 grew only on pyruvate and lactate. On the basis of 16S rRNA analysis, strain WW1 was most closely related to Desulfotomaculum thermocisternum and Desulfotomaculum australicum. However, physiological properties of strain WW1 differed in some aspects from those of the two related bacteria.

  1. Transformation of ferulic acid to vanillin using a fed-batch solid-liquid two-phase partitioning bioreactor.

    Science.gov (United States)

    Ma, Xiao-kui; Daugulis, Andrew J

    2014-01-01

    Amycolatopsis sp. ATCC 39116 (formerly Streptomyces setonii) has shown promising results in converting ferulic acid (trans-4-hydroxy-3-methoxycinnamic acid; substrate), which can be derived from natural plant wastes, to vanillin (4-hydroxy-3-methoxybenzaldehyde). After exploring the influence of adding vanillin at different times during the growth cycle on cell growth and transformation performance of this strain and demonstrating the inhibitory effect of vanillin, a solid-liquid two-phase partitioning bioreactor (TPPB) system was used as an in situ product removal technique to enhance transformation productivity by this strain. The thermoplastic polymer Hytrel(®) G4078W was found to have superior partitioning capacity for vanillin with a partition coefficient of 12 and a low affinity for the substrate. A 3-L working volume solid-liquid fed-batch TPPB mode, using 300 g Hytrel G4078W as the sequestering phase, produced a final vanillin concentration of 19.5 g/L. The overall productivity of this reactor system was 450 mg/L. h, among the highest reported in literature. Vanillin was easily and quantitatively recovered from the polymers mostly by single stage extraction into methanol or other organic solvents used in food industry, simultaneously regenerating polymer beads for reuse. A polymer-liquid two phase bioreactor was again confirmed to easily outperform single phase systems that feature inhibitory or easily further degraded substrates/products. This enhancement strategy might reasonably be expected in the production of other flavor and fragrance compounds obtained by biotransformations. © 2013 American Institute of Chemical Engineers.

  2. Microfaunal indicators, Ciliophora phylogeny and protozoan population shifts in an intermittently aerated and fed bioreactor

    International Nuclear Information System (INIS)

    Ntougias, Spyridon; Tanasidis, Spartakos; Melidis, Paraschos

    2011-01-01

    Microfauna community structure was examined in the mixed liquor of a bench-scale bioreactor equipped with an intermittent aeration and feeding system. The reactor was operated under an intermittent aeration of 25 min in every 1 h and varying feeding conditions (0.264, 0.403 and 0.773 kg BOD 5 /m 3 d). A total of 14 protozoan and metazoan taxa were identified by microscopic examination. Sessile ciliates, followed by crawling ciliates, were the major protozoan groups under 0.403 kg BOD 5 /m 3 d organic loading conditions, while sessile ciliate population was remarkably increased under an organic loading of 0.773 kg BOD 5 /m 3 d. Principal Component Analysis and Pearson correlation coefficient tests were performed in order to reveal relationships between microfauna community and operational parameters. Ciliophora specific-18S rRNA gene clone library was constructed to identify ciliate diversity under 0.773 kg BOD 5 /m 3 d organic loading conditions. Ciliophora diversity consisted of members of Aspidiscidae, Epistylidae, Opisthonectidae and Vorticellidae, with the majority of the clones being associated with the species Vorticella fusca. At least one novel phylogenetic linkage among Ciliophora was identified. Comparisons made after molecular characterization and microscopic examination of Ciliophora community showed that the estimation of broad ciliate groups is useful for ecological considerations and evaluation of the operational conditions in wastewater treatment plants.

  3. Microfaunal indicators, Ciliophora phylogeny and protozoan population shifts in an intermittently aerated and fed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Ntougias, Spyridon, E-mail: sntougia@env.duth.gr [Democritus University of Thrace, Department of Environmental Engineering, Laboratory of Wastewater Management and Treatment Technologies, Vas. Sofias 12, 67100 Xanthi (Greece); Tanasidis, Spartakos; Melidis, Paraschos [Democritus University of Thrace, Department of Environmental Engineering, Laboratory of Wastewater Management and Treatment Technologies, Vas. Sofias 12, 67100 Xanthi (Greece)

    2011-02-28

    Microfauna community structure was examined in the mixed liquor of a bench-scale bioreactor equipped with an intermittent aeration and feeding system. The reactor was operated under an intermittent aeration of 25 min in every 1 h and varying feeding conditions (0.264, 0.403 and 0.773 kg BOD{sub 5}/m{sup 3} d). A total of 14 protozoan and metazoan taxa were identified by microscopic examination. Sessile ciliates, followed by crawling ciliates, were the major protozoan groups under 0.403 kg BOD{sub 5}/m{sup 3} d organic loading conditions, while sessile ciliate population was remarkably increased under an organic loading of 0.773 kg BOD{sub 5}/m{sup 3} d. Principal Component Analysis and Pearson correlation coefficient tests were performed in order to reveal relationships between microfauna community and operational parameters. Ciliophora specific-18S rRNA gene clone library was constructed to identify ciliate diversity under 0.773 kg BOD{sub 5}/m{sup 3} d organic loading conditions. Ciliophora diversity consisted of members of Aspidiscidae, Epistylidae, Opisthonectidae and Vorticellidae, with the majority of the clones being associated with the species Vorticella fusca. At least one novel phylogenetic linkage among Ciliophora was identified. Comparisons made after molecular characterization and microscopic examination of Ciliophora community showed that the estimation of broad ciliate groups is useful for ecological considerations and evaluation of the operational conditions in wastewater treatment plants.

  4. Dextran Utilization During Its Synthesis by Weissella cibaria RBA12 Can Be Overcome by Fed-Batch Fermentation in a Bioreactor.

    Science.gov (United States)

    Baruah, Rwivoo; Deka, Barsha; Kashyap, Niharika; Goyal, Arun

    2018-01-01

    Weissella cibaria RBA12 produced a maximum of 9 mg/ml dextran (with 90% efficiency) using shake flask culture under the optimized concentration of medium components viz. 2% (w/v) of each sucrose, yeast extract, and K 2 HPO 4 after incubation at optimized conditions of 20 °C and 180 rpm for 24 h. The optimized medium and conditions were used for scale-up of dextran production from Weissella cibaria RBA12 in 2.5-l working volume under batch fermentation in a bioreactor that yielded a maximum of 9.3 mg/ml dextran (with 93% efficiency) at 14 h. After 14 h, dextran produced was utilized by the bacterium till 18 h in its stationary phase under sucrose depleted conditions. Dextran utilization was further studied by fed-batch fermentation using sucrose feed. Dextran on production under fed-batch fermentation in bioreactor gave 35.8 mg/ml after 32 h. In fed-batch mode, there was no decrease in dextran concentration as observed in the batch mode. This showed that the utilization of dextran by Weissella cibaria RBA12 is initiated when there is sucrose depletion and therefore the presence of sucrose can possibly overcome the dextran hydrolysis. This is the first report of utilization of dextran, post-sucrose depletion by Weissella sp. studied in bioreactor.

  5. Fed-batch bioreactor performance and cell line stability evaluation of the artificial chromosome expression technology expressing an IgG1 in Chinese hamster ovary cells.

    Science.gov (United States)

    Combs, Rodney G; Yu, Erwin; Roe, Susanna; Piatchek, Michele Bailey; Jones, Heather L; Mott, John; Kennard, Malcolm L; Goosney, Danika L; Monteith, Diane

    2011-01-01

    The artificial chromosome expression (ACE) technology system uses an engineered artificial chromosome containing multiple site-specific recombination acceptor sites for the rapid and efficient construction of stable cell lines. The construction of Chinese hamster ovary(CHO) cell lines expressing an IgG1 monoclonal antibody (MAb) using the ACE system has been previously described (Kennard et al., Biotechnol Bioeng. 2009;104:540-553). To further demonstrate the manufacturing feasibility of the ACE system, four CHO cell lines expressing the human IgG1 MAb 4A1 were evaluated in batch and fed-batch shake flasks and in a 2-L fed-batch bioreactor. The batch shake flasks achieved titers between 0.7 and 1.1 g/L, whereas the fed-batch shake flask process improved titers to 2.5–3.0 g/L. The lead 4A1 ACE cell line achieved titers of 4.0 g/L with an average specific productivity of 40 pg/(cell day) when cultured in a non optimized 2-L fed-batch bioreactor using a completely chemically defined process. Generational stability characterization of the lead 4A1-expressing cell line demonstrated that the cell line was stable for up to 75 days in culture. Product quality attributes of the 4A1 MAb produced by the ACE system during the stability evaluation period were unchanged and also comparable to existing expression technologies such as the CHO-dhfr system. The results of this evaluation demonstrate that a clonal, stable MAb-expressing CHO cell line can be produced using ACE technology that performs competitively using a chemically defined fed-batch bioreactor process with comparable product quality attributes to cell lines generated by existing technologies.

  6. Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor

    Science.gov (United States)

    Guerrero-Barajas, Claudia; Ordaz, Alberto; García-Solares, Selene Montserrat; Garibay-Orijel, Claudio; Bastida-González, Fernando; Zárate-Segura, Paola Berenice

    2015-01-01

    The importance of microbial sulfate reduction relies on the various applications that it offers in environmental biotechnology. Engineered sulfate reduction is used in industrial wastewater treatment to remove large concentrations of sulfate along with the chemical oxygen demand (COD) and heavy metals. The most common approach to the process is with anaerobic bioreactors in which sulfidogenic sludge is obtained through adaptation of predominantly methanogenic granular sludge to sulfidogenesis. This process may take a long time and does not always eliminate the competition for substrate due to the presence of methanogens in the sludge. In this work, we propose a novel approach to obtain sulfidogenic sludge in which hydrothermal vents sediments are the original source of microorganisms. The microbial community developed in the presence of sulfate and volatile fatty acids is wide enough to sustain sulfate reduction over a long period of time without exhibiting inhibition due to sulfide. This protocol describes the procedure to generate the sludge from the sediments in an upflow anaerobic sludge blanket (UASB) type of reactor. Furthermore, the protocol presents the procedure to demonstrate the capability of the sludge to remove by reductive dechlorination a model of a highly toxic organic pollutant such as trichloroethylene (TCE). The protocol is divided in three stages: (1) the formation of the sludge and the determination of its sulfate reducing activity in the UASB, (2) the experiment to remove the TCE by the sludge, and (3) the identification of microorganisms in the sludge after the TCE reduction. Although in this case the sediments were taken from a site located in Mexico, the generation of a sulfidogenic sludge by using this procedure may work if a different source of sediments is taken since marine sediments are a natural pool of microorganisms that may be enriched in sulfate reducing bacteria. PMID:26555802

  7. Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor.

    Science.gov (United States)

    Guerrero-Barajas, Claudia; Ordaz, Alberto; García-Solares, Selene Montserrat; Garibay-Orijel, Claudio; Bastida-González, Fernando; Zárate-Segura, Paola Berenice

    2015-10-15

    The importance of microbial sulfate reduction relies on the various applications that it offers in environmental biotechnology. Engineered sulfate reduction is used in industrial wastewater treatment to remove large concentrations of sulfate along with the chemical oxygen demand (COD) and heavy metals. The most common approach to the process is with anaerobic bioreactors in which sulfidogenic sludge is obtained through adaptation of predominantly methanogenic granular sludge to sulfidogenesis. This process may take a long time and does not always eliminate the competition for substrate due to the presence of methanogens in the sludge. In this work, we propose a novel approach to obtain sulfidogenic sludge in which hydrothermal vents sediments are the original source of microorganisms. The microbial community developed in the presence of sulfate and volatile fatty acids is wide enough to sustain sulfate reduction over a long period of time without exhibiting inhibition due to sulfide. This protocol describes the procedure to generate the sludge from the sediments in an upflow anaerobic sludge blanket (UASB) type of reactor. Furthermore, the protocol presents the procedure to demonstrate the capability of the sludge to remove by reductive dechlorination a model of a highly toxic organic pollutant such as trichloroethylene (TCE). The protocol is divided in three stages: (1) the formation of the sludge and the determination of its sulfate reducing activity in the UASB, (2) the experiment to remove the TCE by the sludge, and (3) the identification of microorganisms in the sludge after the TCE reduction. Although in this case the sediments were taken from a site located in Mexico, the generation of a sulfidogenic sludge by using this procedure may work if a different source of sediments is taken since marine sediments are a natural pool of microorganisms that may be enriched in sulfate reducing bacteria.

  8. Microbial Community Structure and Functions in Ethanol-Fed Sulfate Removal Bioreactors for Treatment of Mine Water

    Directory of Open Access Journals (Sweden)

    Malin Bomberg

    2017-09-01

    Full Text Available Sulfate-rich mine water must be treated before it is released into natural water bodies. We tested ethanol as substrate in bioreactors designed for biological sulfate removal from mine water containing up to 9 g L−1 sulfate, using granular sludge from an industrial waste water treatment plant as inoculum. The pH, redox potential, and sulfate and sulfide concentrations were measured twice a week over a maximum of 171 days. The microbial communities in the bioreactors were characterized by qPCR and high throughput amplicon sequencing. The pH in the bioreactors fluctuated between 5.0 and 7.7 with the highest amount of up to 50% sulfate removed measured around pH 6. Dissimilatory sulfate reducing bacteria (SRB constituted only between 1% and 15% of the bacterial communities. Predicted bacterial metagenomes indicated a high prevalence of assimilatory sulfate reduction proceeding to formation of l-cystein and acetate, assimilatory and dissimilatory nitrate reduction, denitrification, and oxidation of ethanol to acetaldehyde with further conversion to ethanolamine, but not to acetate. Despite efforts to maintain optimal conditions for biological sulfate reduction in the bioreactors, only a small part of the microorganisms were SRB. The microbial communities were highly diverse, containing bacteria, archaea, and fungi, all of which affected the overall microbial processes in the bioreactors. While it is important to monitor specific physicochemical parameters in bioreactors, molecular assessment of the microbial communities may serve as a tool to identify biological factors affecting bioreactor functions and to optimize physicochemical attributes for ideal bioreactor performance.

  9. High rate sulfate reduction at pH 6 in a Ph-auxostat submerged membrane bioreactor fed with formate

    NARCIS (Netherlands)

    Bijmans, M.F.M.; Peeters, T.W.T.; Lens, P.N.L.; Buisman, C.J.N.

    2008-01-01

    Many industrial waste and process waters contain high concentrations of sulfate, which can be removed by sulfate-reducing bacteria (SRB). This paper reports on mesophilic (30 °C) sulfate reduction at pH 6 with formate as electron donor in a membrane bioreactor with a pH-auxostat dosing system. A

  10. FEDS

    DEFF Research Database (Denmark)

    Venable, John; Pries-Heje, Jan; Baskerville, Richard

    2016-01-01

    Evaluation of design artefacts and design theories is a key activity in Design Science Research (DSR), as it provides feedback for further development and (if done correctly) assures the rigour of the research. However, the extant DSR literature provides insufficient guidance on evaluation...... to enable Design Science Researchers to effectively design and incorporate evaluation activities into a DSR project that can achieve DSR goals and objectives. To address this research gap, this research paper develops, explicates, and provides evidence for the utility of a Framework for Evaluation in Design...... Science (FEDS) together with a process to guide design science researchers in developing a strategy for evaluating the artefacts they develop within a DSR project. A FEDS strategy considers why, when, how, and what to evaluate. FEDS includes a two-dimensional characterisation of DSR evaluation episodes...

  11. Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production

    Directory of Open Access Journals (Sweden)

    Patnaik Pratap R

    2008-03-01

    Full Text Available Abstract Background Although the production of poly-β-hydroxybutyrate (PHB has many biological, energetic and environmental advantages over chemically synthesized polymers, synthetic polymers continue to be produced industrially since the productivities of fermentation processes fr PHB are not yet economically competitive. Improvement of a PHB fermentation requires good understanding and optimization under the realistic conditions of large bioreactors. Laboratory-scale studies have shown that co-cultures of Ralstonia eutropha and Lactobacillus delbrueckii generate better fermentation efficiencies than R. eutropha alone. In large bioreactors, incomplete dispersioin and perturbations in the dissolved oxygen (DO concentration, both of which affect the fermentation, have to be considered. This study analyzes the effect of DO fluctuations on bioreactor performance for both ideal and optimally dispersed broths. Results Response coefficient analysis was employed to obtain quantitative information on the effect of DO perturbations on different variables. Three values of the Peclet number (Pe cheracterized three levels of dispersion: Pe = 0.01 for nearly complete dispersion, Pe = 20 for optimum dispersion and Pe = 60 for insufficient dispersion. The response coefficients (RCs of the pairs of bacterial concentrations and the main substrates, glucose and ammonium chloride, showed contrasting variations with time. Lactate, a critical intermediate, and PHB had similar RC profiles but those of lactate were one to two orders of magnitude larger than other RCs. Significantly, the optimum Pe also resulted in the largest RCs, suggesting a balance between productivity and reactor stability. Conclusion Since R. eutropha requires oxygen for its growth whereas L. delbrueckii does not, fluctuations in the DO concentartion have a strong influence on the fermentation. Apart from this, the mechanism of PHB biosynthesis indicates that control of lactate is a critical

  12. A fed-batch strategy to produce high poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) terpolymer yield with enhanced mechanical properties in bioreactor.

    Science.gov (United States)

    Aziz, Nursolehah Abd; Huong, Kai-Hee; Sipaut, Coswald Stephen; Amirul, A A

    2017-11-01

    This study reports an efficient fed-batch strategy to improve poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) [P(3HB-co-3HV-co-4HB)] terpolymer production by Cupriavidus sp. USMAA2-4 with enhanced mechanical properties in bioreactor. The cultivations have been performed by combining oleic acid with γ-butyrolactone at different concentration ratios with 1-pentanol at a fixed concentration. The batch and fed-batch fermentations have resulted in P(3HB-co-3HV-co-4HB) with compositions of 9-35 mol% 3HV and 4-24 mol% 4HB monomers. The DO-stat fed-batch fermentation strategies have significantly improved the production with a maximum 4.4-fold increment of cell dry weight (CDW). Besides, appropriate feeding of the substrates has resulted in an increment of terpolymer productivity from 0.086-0.347 g/L/h, with a significantly shortened cultivation time. The bacterial growth and terpolymer formation have been found to be affected by the concentration of carbon sources supplied. Characterization of P(3HB-co-3HV-co-4HB) has demonstrated that incorporation of 3HV and 4HB monomer has significantly improved the physical and thermodynamic properties of the polymers, by reducing the polymer's crystallinity. The tensile strength, Young's modulus of the terpolymer has been discovered to increase with the increase of M w . The fed-batch fermentation strategies employed in this study have resulted in terpolymers with a range of flexible materials having improved tensile strength and Young's modulus as compared to the terpolymer produced from batch fermentation. Possession of lower melting temperature indicates an enhanced thermal stability which broadens the polymer processing window.

  13. Continuous sulfidogenic wastewater treatment with iron sulfide sludge oxidation and recycle.

    Science.gov (United States)

    Deng, Dongyang; Lin, Lian-Shin

    2017-05-01

    This study evaluated the technical feasibility of packed-bed sulfidogenic bioreactors dosed with ferrous chloride for continuous wastewater treatment over a 450-day period. In phase I, the bioreactors were operated under different combinations of carbon, iron, and sulfate mass loads without sludge recycling to identify optimal treatment conditions. A COD/sulfate mass ratio of 2 and a Fe/S molar ratio of 1 yielded the best treatment performance with COD oxidation rate of 786 ± 82 mg/(L⋅d), which resulted in 84 ± 9% COD removal, 94 ± 6% sulfate reduction, and good iron retention (99 ± 1%) under favorable pH conditions (6.2-7.0). In phase II, the bioreactors were operated under this chemical load combination over a 62-day period, during which 7 events of sludge collection, oxidation, and recycling were performed. The collected sludge materials contained both inorganic and organic matter with FeS and FeS 2 as the main inorganic constituents. In each event, the sludge materials were oxidized in an oxidizing basin before recycling to mix with the wastewater influent. Sludge recycling yielded enhanced COD removal (90 ± 6% vs. 75 ± 7%), and better effluent quality in terms of pH (6.8 ± 0.1 vs. 6.5 ± 0.2), iron (0.7 ± 0.5 vs. 1.9 ± 1.7 mg/L), and sulfide-S (0.3 ± 0.1 vs. 0.4 ± 0.1 mg/L) removal compared to the baseline operation without sludge recycling during phase II. This process exhibited treatment stability with reasonable variations, and fairly consistent sludge content over long periods of operation under a range of COD/sulfate and Fe/S ratios without sludge recycling. The bioreactors were found to absorb recycling-induced changes efficiently without causing elevated suspended solids in the effluents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Monitoring the bacterial community dynamics in a petroleum refinery wastewater membrane bioreactor fed with a high phenolic load.

    Science.gov (United States)

    Silva, Cynthia C; Viero, Aline F; Dias, Ana Carolina F; Andreote, Fernando D; Jesus, Ederson C; De Paula, Sergio O; Torres, Ana Paula R; Santiago, Vania M J; Oliveira, Valeria M

    2010-01-01

    The phenolic compounds are a major contaminant class often found in industrial wastewaters and the biological treatment is an alternative tool commonly employed for their removal. In this sense, monitoring microbial community dynamics is crucial for a successful wastewater treatment. This work aimed to monitor the structure and activity of the bacterial community during the operation of a laboratory-scale continuous submerged membrane bioreactor (SMBR), using PCR and RT-PCR followed by Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rRNA libraries. Multivariate analyses carried out using DGGE profiles showed significant changes in the total and metabolically active dominant community members during the 4-week treatment period, explained mainly by phenol and ammonium input. Gene libraries were assembled using 16S rDNA and 16S rRNA PCR products from the fourth week of treatment. Sequencing and phylogenetic analyses of clones from 16S rDNA library revealed a high diversity of taxa for the total bacterial community, with predominance of Thauera genus (ca. 50%). On the other hand, a lower diversity was found for metabolically active bacteria, which were mostly represented by members of Betaproteobacteria (Thauera and Comamonas), suggesting that these groups have a relevant role in the phenol degradation during the final phase of the SMBR operation.

  15. Biodegradable poly-ε-caprolactone microcarriers for efficient production of human mesenchymal stromal cells and secreted cytokines in batch and fed-batch bioreactors.

    Science.gov (United States)

    Lam, Alan Tin-Lun; Li, Jian; Toh, Jessica Pei-Wen; Sim, Eileen Jia-Hui; Chen, Allen Kuan-Liang; Chan, Jerry Kok-Yen; Choolani, Mahesh; Reuveny, Shaul; Birch, William R; Oh, Steve Kah-Weng

    2017-03-01

    Large numbers of human mesenchymal stromal cells (MSCs) used for a variety of applications in tissue engineering and cell therapy can be generated by scalable expansion in a bioreactor using microcarriers (MCs) systems. However, the enzymatic digestion process needed to detach cells from the growth surface can affect cell viability and potentially the potency and differentiation efficiency. Thus, the main aim of our study was to develop biocompatible and biodegradable MCs that can support high MSC yields while maintaining their differentiation capability and potency. After cell expansion, the cells that covered MCs can be directly implanted in vivo without the need for cell harvesting or use of scaffold. Poly-ε-caprolactone (PCL) is known as a biocompatible and biodegradable material. However, it cannot be used for generation of MCs because its high density (1.14 g/cm 3 ) would exclude its applicability for suspension MCs in stirred reactors. In this article, we describe expansion and potency of MSCs propagated on low-density (1.06 g/cm 3 ) porous PCL MCs coated with extracellular matrices (LPCLs) in suspended stirred reactors. Using these LPCLs, cell yields of about 4 × 10 4 cells/cm 2 and 7- to 10-fold increases were obtained using four different MSC lines (bone marrow, cord blood, fetal and Wharton's jelly). These yields were comparable with those obtained using non-degradable MCs (Cytodex 3) and higher than two-dimensional monolayer (MNL) cultures. A fed-batch process, which demonstrated faster cell expansion (4.5 × 10 4 cells/cm 2 in 5 days as compared with 7 days in batch culture) and about 70% reduction in growth media usage, was developed and scaled up from 100-mL spinner flask to 1-L controlled bioreactor. Surface marker expression, trilineage differentiation and clonogenic potential of the MSCs expanded on LPCL were not affected. Cytokine secretion kinetics, which occurred mostly during late logarithmic phase, was usually comparable with

  16. Sulfidogenic biotreatment of synthetic acid mine drainage and sulfide oxidation in anaerobic baffled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bekmezci, Ozan K.; Ucar, Deniz [Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa (Turkey); Kaksonen, Anna H. [CSIRO Land and Water, Underwood Avenue, Floreat, WA 6014 (Australia); Sahinkaya, Erkan, E-mail: erkansahinkaya@yahoo.com [Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa (Turkey)

    2011-05-30

    The treatment of synthetic acid mine drainage (AMD) water (pH 3.0-6.5) containing sulfate (3.0-3.5 g L{sup -1}) and various metals (Co, Cu, Fe, Mn, Ni, and Zn) was studied in an ethanol-fed sulfate-reducing 4-compartment anaerobic baffled reactor (ABR) at 32 {sup o}C. The reactor was operated for 160 days at different chemical oxygen demand (COD)/sulfate ratios, hydraulic retention times (HRT), pH, and metal concentrations to study the robustness of the process. The last compartment of the reactor was aerated at different rates to study the bio-oxidation of sulfide to elemental sulfur. The highest sulfate reduction efficiency (88%) was obtained with a feed sulfate concentration of 3.5 g L{sup -1}, COD/sulfate mass ratio of 0.737, feed pH of 3.0 and HRT of 2 days without aeration in the 4th compartment. The corresponding COD removal efficiency was about 92%. The alkalinity produced in the sulfidogenic ethanol oxidation neutralized the acidic mine water from pH 3.0-4.5 to pH 7.0-8.0. Effluent soluble and total heavy metal concentrations were substantially reduced with removal efficiencies generally higher than 99%, except for Mn (25-77%). Limited aeration in the 4th compartment of ABR promoted incomplete oxidation of sulfide to elemental sulfur rather than complete oxidation to sulfate. Depending on the aeration rate and HRT, 32-74% of produced sulfide was oxidized to elemental sulfur. This study demonstrates that by optimizing operating conditions, sulfate reduction, metal removal, alkalinity generation, and excess sulfide oxidation can be achieved in a single ABR treating AMD.

  17. Following an Optimal Batch Bioreactor Operations Model

    DEFF Research Database (Denmark)

    Ibarra-Junquera, V.; Jørgensen, Sten Bay; Virgen-Ortíz, J.J.

    2012-01-01

    The problem of following an optimal batch operation model for a bioreactor in the presence of uncertainties is studied. The optimal batch bioreactor operation model (OBBOM) refers to the bioreactor trajectory for nominal cultivation to be optimal. A multiple-variable dynamic optimization of fed...... as the master system which includes the optimal cultivation trajectory for the feed flow rate and the substrate concentration. The “real” bioreactor, the one with unknown dynamics and perturbations, is considered as the slave system. Finally, the controller is designed such that the real bioreactor...

  18. Bioreactor principles

    Science.gov (United States)

    2001-01-01

    Cells cultured on Earth (left) typically settle quickly on the bottom of culture vessels due to gravity. In microgravity (right), cells remain suspended and aggregate to form three-dimensional tissue. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  19. Immobilized yeast in bioreactor for alcohol fermentation

    International Nuclear Information System (INIS)

    Handy, M.K.; Kim, K.

    1986-01-01

    Mutant of Saccharomyces cerevisiae was developed using a Co-60 source. Cells were immobilized onto sterile, channeled alumina beads and packed into bioreactor column under controlled temperature. Feedstocks containing substrate and nutrients were fed into the bioreactor at specific rates. Beads with greatest porosity and surface area produced the most ethanol. Factors affecting ethanol productivity included: temperature, pH, flow rate, nutrients and substrate in the feedstock

  20. Characteristics, kinetics and thermodynamics of Congo Red bio sorption by activated sulfidogenic sludge from an aqueous solution

    International Nuclear Information System (INIS)

    Rasool, K.; Lee, D. S.

    2015-01-01

    The kinetics and thermodynamics of the bio sorption of textile dye Congo Red on anaerobic activated sulfidogenic sludge were examined. The influence of different adsorption parameters such as p H, temperature, contact time and initial dye concentrations on the bio sorption capacity was also investigated. The sulfidogenic sludge showed a maximum bio sorption density of 238.90 mg dye/g cell for Congo Red at an initial dye concentration of 1,000 mg/L, p H 3.5 and 22 C, which is higher than that of many other adsorbents reported in the literature. The bio sorption processes obeyed the Langmuir isotherm and exhibited pseudo-second-order rate kinetics. The thermodynamic parameters indicated the spontaneous and exothermic nature of Congo Red bio sorption. The Fourier transform infrared spectra revealed the dye interaction with the biomass. Scanning electron microscopy showed significant changes in the surface morphology of the sludge after dye bio sorption. These results showed that sulfidogenic sludge biomass is an attractive alternative low-cost bio sorbent for the removal of the dye from aqueous media.

  1. An innovative membrane bioreactor for methane biohydroxylation.

    Science.gov (United States)

    Pen, N; Soussan, L; Belleville, M-P; Sanchez, J; Charmette, C; Paolucci-Jeanjean, D

    2014-12-01

    In this study, a membrane bioreactor (MBR) was developed for efficient, safe microbial methane hydroxylation with Methylosinus trichosporium OB3b. This innovative MBR, which couples a bioreactor with two gas/liquid macroporous membrane contactors supplying the two gaseous substrates (methane and oxygen) was operated in fed-batch mode. The feasibility and the reproducibility of this new biohydroxylation process were first demonstrated. The mass transfer within this MBR was twice that observed in a batch reactor in similar conditions. The productivity reached with this MBR was 75±25mgmethanol(gdrycell)(-1)h(-1). Compared to the literature, this value is 35times higher than that obtained with the only other fed-batch membrane bioreactor reported, which was run with dense membranes, and is comparable to those obtained with bioreactors fed by bubble-spargers. However, in the latter case, an explosive gas mixture can be formed, a problem that is avoided with the MBR. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Mechanism of MnS-mediated pit initiation and propagation in carbon steel in an anaerobic sulfidogenic media

    International Nuclear Information System (INIS)

    Avci, R.; Davis, B.H.; Wolfenden, M.L.; Beech, I.B.; Lucas, K.; Paul, D.

    2013-01-01

    Highlights: •In carbon steel, pits are initiated in the immediate surroundings of MnS inclusions. •Unlike stainless steel, MnS inclusions do not dissolve during pit initiation. •The presence of biofilms accelerates pit growth and development. -- Abstract: In a saline anaerobic sulfidogenic environment, pitting on 1018 carbon steel was initiated within a 20–30 nm zone at the MnS inclusion boundary. Nanoscale analysis was performed using scanning electron microscopy and a scanning Auger nanoprobe. The pitting was more pronounced in the presence of a biofilm of sulfate-reducing bacteria than in abiotic sulfide medium. It is proposed that initiation of an anodic reaction leading to dissolution of Fe matrix and subsequent pitting of steel in MnS inclusion boundary regions is due to disorder and strain exerted on the Fe matrix by MnS contamination of the interface from metallurgical processes

  3. Cascades of bioreactors

    NARCIS (Netherlands)

    Gooijer, de C.D.

    1995-01-01

    In this thesis a common phenomenon in bioprocess engineering is described : the execution of a certain bioprocess in more than one bioreactor. Chapter 1, a review, classifies bioprocesses by means of a number of characteristics :
    i) processes with a variable

  4. Biotreatment of zinc-containing wastewater in a sulfidogenic CSTR: Performance and artificial neural network (ANN) modelling studies

    International Nuclear Information System (INIS)

    Sahinkaya, Erkan

    2009-01-01

    Sulfidogenic treatment of sulfate (2-10 g/L) and zinc (65-677 mg/L) containing simulated wastewater was studied in a mesophilic (35 deg. C) CSTR. Ethanol was supplemented (COD/sulfate = 0.67) as carbon and energy source for sulfate-reducing bacteria (SRB). The robustness of the system was studied by increasing Zn, COD and sulfate loadings. Sulfate removal efficiency, which was 70% at 2 g/L feed sulfate concentration, steadily decreased with increasing feed sulfate concentration and reached 40% at 10 g/L. Over 99% Zn removal was attained due to the formation of zinc-sulfide precipitate. COD removal efficiency at 2 g/L feed sulfate concentration was over 94%, whereas, it steadily decreased due to the accumulation of acetate at higher loadings. Alkalinity produced from acetate oxidation increased wastewater pH remarkably when feed sulfate concentration was 5 g/L or lower. Electron flow from carbon oxidation to sulfate reduction averaged 83 ± 13%. The rest of the electrons were most likely coupled with fermentative reactions as the amount of methane production was insignificant. The developed ANN model was very successful as an excellent to reasonable match was obtained between the measured and the predicted concentrations of sulfate (R = 0.998), COD (R = 0.993), acetate (R = 0.976) and zinc (R = 0.827) in the CSTR effluent

  5. Oscillating Cell Culture Bioreactor

    Science.gov (United States)

    Freed, Lisa E.; Cheng, Mingyu; Moretti, Matteo G.

    2010-01-01

    To better exploit the principles of gas transport and mass transport during the processes of cell seeding of 3D scaffolds and in vitro culture of 3D tissue engineered constructs, the oscillatory cell culture bioreactor provides a flow of cell suspensions and culture media directly through a porous 3D scaffold (during cell seeding) and a 3D construct (during subsequent cultivation) within a highly gas-permeable closed-loop tube. This design is simple, modular, and flexible, and its component parts are easy to assemble and operate, and are inexpensive. Chamber volume can be very low, but can be easily scaled up. This innovation is well suited to work with different biological specimens, particularly with cells having high oxygen requirements and/or shear sensitivity, and different scaffold structures and dimensions. The closed-loop changer is highly gas permeable to allow efficient gas exchange during the cell seeding/culturing process. A porous scaffold, which may be seeded with cells, is fixed by means of a scaffold holder to the chamber wall with scaffold/construct orientation with respect to the chamber determined by the geometry of the scaffold holder. A fluid, with/without biological specimens, is added to the chamber such that all, or most, of the air is displaced (i.e., with or without an enclosed air bubble). Motion is applied to the chamber within a controlled environment (e.g., oscillatory motion within a humidified 37 C incubator). Movement of the chamber induces relative motion of the scaffold/construct with respect to the fluid. In case the fluid is a cell suspension, cells will come into contact with the scaffold and eventually adhere to it. Alternatively, cells can be seeded on scaffolds by gel entrapment prior to bioreactor cultivation. Subsequently, the oscillatory cell culture bioreactor will provide efficient gas exchange (i.e., of oxygen and carbon dioxide, as required for viability of metabolically active cells) and controlled levels of fluid

  6. Development of an equipment for the detection and measurement of localized corrosion of carbon steel induced by sulfidogenic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cotiche, C. [CFG Services, 3 avenue Claude Guillemin, BP 6429, 45064 Orleans Cedex (France); Dauma, S. [CFG Services, 117 avenue de Luminy, 13009 Marseille (France)

    2004-07-01

    Most of the geothermal installations exploiting the Dogger aquifer of the Paris basin are faced to corrosion and scaling problems. Localized corrosion phenomena due to the presence of sulfate reducing bacteria which have been identified in the geothermal water and in scales deposited on corrosion coupons is the most insidious being able to induce rapid failures of the casings of production and injection wells and surface pipelines. In order to evaluate and prevent the occurrence of such corrosion risks that are similar to those encountered in oil and gas industry, a specific equipment has been developed by CFG Services, engineering company specialized in the exploitation and maintenance of geothermal plants. This equipment which includes a probe and an electronic device has to be installed on the pipeline transporting the corrosive medium through a nipple secured to it. The principle is based on the generation of a pit on a circular electrode in carbon steel by anodic polarization and on the measurement of the corrosion current between this electrode and the pipeline or the probe body used as cathodic pole. Then, the current freely flowing between the anode and cathode is monitored and used to estimate if the pitting corrosion artificially created by an electric pulse may be maintained or not by the activity of sulfidogenic bacteria which may have developed on the surface of the electrode. This equipment has been tested on a geothermal exploitation where the risk of microbial corrosion has been identified and the sensibility of the signal of the probe to the injection of biocide products proved. (authors)

  7. Sensing in tissue bioreactors

    Science.gov (United States)

    Rolfe, P.

    2006-03-01

    Specialized sensing and measurement instruments are under development to aid the controlled culture of cells in bioreactors for the fabrication of biological tissues. Precisely defined physical and chemical conditions are needed for the correct culture of the many cell-tissue types now being studied, including chondrocytes (cartilage), vascular endothelial cells and smooth muscle cells (blood vessels), fibroblasts, hepatocytes (liver) and receptor neurones. Cell and tissue culture processes are dynamic and therefore, optimal control requires monitoring of the key process variables. Chemical and physical sensing is approached in this paper with the aim of enabling automatic optimal control, based on classical cell growth models, to be achieved. Non-invasive sensing is performed via the bioreactor wall, invasive sensing with probes placed inside the cell culture chamber and indirect monitoring using analysis within a shunt or a sampling chamber. Electroanalytical and photonics-based systems are described. Chemical sensing for gases, ions, metabolites, certain hormones and proteins, is under development. Spectroscopic analysis of the culture medium is used for measurement of glucose and for proteins that are markers of cell biosynthetic behaviour. Optical interrogation of cells and tissues is also investigated for structural analysis based on scatter.

  8. Use of sulfate reducing cell suspension bioreactors for the treatment of SO2 rich flue gases

    NARCIS (Netherlands)

    Lens, P.N.L.; Gastesi, R.; Lettinga, G.

    2003-01-01

    This paper describes a novel bioscrubber concept for biological flue gas desulfurization, based on the recycling of a cell suspension of sulfite/sulfate reducing bacteria between a scrubber and a sulfite/sulfate reducing hydrogen fed bioreactor. Hydrogen metabolism in sulfite/sulfate reducing cell

  9. Role of nickel in high rate methanol degradation in anaerobic granular sludge bioreactors

    NARCIS (Netherlands)

    Fermoso, F.G.; Collins, G.; Bartacek, J.; O'Flaherty, V.; Lens, P.N.L.

    2008-01-01

    The effect of nickel deprivation from the influent of a mesophilic (30 degrees C) methanol fed upflow anaerobic sludge bed (UASB) reactor was investigated by coupling the reactor performance to the evolution of the Methanosarcina population of the bioreactor sludge. The reactor was operated at pH

  10. USE OF MEMBRANE BIOREACTOR FOR BIODEGRADATION OF MTBE IN CONTAMINATED WATER1

    Science.gov (United States)

    An ultrafiltration membrane bioreactor was evaluated for biodegradation of methyl tert-butyl ether (MTBE) in contaminated water. The system was fed 5 mg/L MTBE in granular activated carbon (GAC) treated Cincinnati tap water containing ample buffer and nutrients. Within 120...

  11. Filtration characteristics in membrane bioreactors

    NARCIS (Netherlands)

    Evenblij, H.

    2006-01-01

    Causes of and remedies for membrane fouling in Membrane Bioreactors for wastewater treatment are only poorly understood and described in scientific literature. A Filtration Characterisation Installation and a measurement protocol were developed with the aim of a) unequivocally determination and

  12. Anaerobic membrane bioreactor under extreme conditions (poster)

    NARCIS (Netherlands)

    Munoz Sierra, J.D.; De Kreuk, M.K.; Spanjers, H.; Van Lier, J.B.

    2013-01-01

    Membrane bioreactors ensure biomass retention by the application of micro or ultrafiltration processes. This allows operation at high sludge concentrations. Previous studies have shown that anaerobic membrane bioreactors is an efficient way to retain specialist microorganisms for treating

  13. The effect of hydroxylamine on the activity and aggregate structure of autotrophic nitrifying bioreactor cultures

    DEFF Research Database (Denmark)

    Harper, W.F.; Terada, Akihiko; Poly, F.

    2009-01-01

    Addition of hydroxylamine (NH2OH) to autotrophic biomass in nitrifying bioreactors affected the activity, physical structure, and microbial ecology of nitrifying aggregates. When NH2OH is added to nitrifying cultures in 6-h batch experiments, the initial NH3-N uptake rates were physiologically...... accelerated by a factor of 1.4-13. NH2OH addition caused a 20-40% decrease in the median aggregate size, broadened the shape of the aggregate size distribution by up to 230%, and caused some of the microcolonies to appear slightly more dispersed. Longer term NH2OH addition in fed batch bioreactors decreased...

  14. Bacterial communities in haloalkaliphilic sulfate-reducing bioreactors under different electron donors revealed by 16S rRNA MiSeq sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jiemin [National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhou, Xuemei; Li, Yuguang [101 Institute, Ministry of Civil Affairs, Beijing 100070 (China); Xing, Jianmin, E-mail: jmxing@ipe.ac.cn [National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100190 (China)

    2015-09-15

    Highlights: • Bacterial communities of haloalkaliphilic bioreactors were investigated. • MiSeq was first used in analysis of communities of haloalkaliphilic bioreactors. • Electron donors had significant effect on bacterial communities. - Abstract: Biological technology used to treat flue gas is useful to replace conventional treatment, but there is sulfide inhibition. However, no sulfide toxicity effect was observed in haloalkaliphilic bioreactors. The performance of the ethanol-fed bioreactor was better than that of lactate-, glucose-, and formate-fed bioreactor, respectively. To support this result strongly, Illumina MiSeq paired-end sequencing of 16S rRNA gene was applied to investigate the bacterial communities. A total of 389,971 effective sequences were obtained and all of them were assigned to 10,220 operational taxonomic units (OTUs) at a 97% similarity. Bacterial communities in the glucose-fed bioreactor showed the greatest richness and evenness. The highest relative abundance of sulfate-reducing bacteria (SRB) was found in the ethanol-fed bioreactor, which can explain why the performance of the ethanol-fed bioreactor was the best. Different types of SRB, sulfur-oxidizing bacteria, and sulfur-reducing bacteria were detected, indicating that sulfur may be cycled among these microorganisms. Because high-throughput 16S rRNA gene paired-end sequencing has improved resolution of bacterial community analysis, many rare microorganisms were detected, such as Halanaerobium, Halothiobacillus, Desulfonatronum, Syntrophobacter, and Fusibacter. 16S rRNA gene sequencing of these bacteria would provide more functional and phylogenetic information about the bacterial communities.

  15. Bioreactor technology for herbal plants

    International Nuclear Information System (INIS)

    Sobri Hussein; Rusli Ibrahim; Abdul Rahim Harun; Azhar Mohamad; Hawa Abdul Aziz; Wan Nazirah Wan Ali

    2010-01-01

    Plants have been an important source of medicine for thousands of years and herbs are hot currency in the world today. During the last decade, popularity of alternative medicine increased significantly worldwide with noticeable trend. This in turn accelerated the global trade of herbal raw materials and herbal products and created greater scope for Asian countries that possess the major supply of herbal raw materials within their highly diversified tropical rain forest. As such, advanced bioreactor culture system possesses a great potential for large scale production than the traditional tissue culture system. Bioreactor cultures have many advantages over conventional cultures. Plant cells in bioreactors can grow fast and vigorously in shorter period as the culture conditions in bioreactor such as temperature, pH, concentrations of dissolved oxygen, carbon dioxide and nutrients can be optimised by on-line manipulation. Nutrient uptake can also be enhanced by continuous medium circulation, which ultimately increased cell proliferation rate. Consequently, production period and cost are substantially reduced, product quality is controlled and standardized as well as free of pesticide contamination and production of raw material can be conducted all year round. Taking all these into consideration, current research efforts were focused on varying several parameters such as inoculation density, air flow, medium formulation, PGRs etc. for increased production of cell and organ cultures of high market demand herbal and medicinal plants, particularly Eurycoma longifolia, Panax ginseng and Labisia pumila. At present, the production of cell and organ culture of these medicinal plants have also been applied in airlift bioreactor with different working volumes. It is hope that the investment of research efforts into this advanced bioreactor technology will open up a bright future for the modernization of agriculture and commercialisation of natural product. (author)

  16. Application of semifluidized bed bioreactor as novel bioreactor ...

    African Journals Online (AJOL)

    The conventional bioreactors such as pond digester, anaerobic filtration, up-flow anaerobic sludge blanket (UASB), up-flow anaerobic sludge fixed-film (UASFF), continuous stirred tank reactor (CSTR), anaerobic contact digestion and fluidized bed, used over the past decades are largely operated anaerobically. They have ...

  17. Bioreactor production of recombinant herpes simplex virus vectors.

    Science.gov (United States)

    Knop, David R; Harrell, Heather

    2007-01-01

    Serotypical application of herpes simplex virus (HSV) vectors to gene therapy (type 1) and prophylactic vaccines (types 1 and 2) has garnered substantial clinical interest recently. HSV vectors and amplicons have also been employed as helper virus constructs for manufacture of the dependovirus adeno-associated virus (AAV). Large quantities of infectious HSV stocks are requisite for these therapeutic applications, requiring a scalable vector manufacturing and processing platform comprised of unit operations which accommodate the fragility of HSV. In this study, production of a replication deficient rHSV-1 vector bearing the rep and cap genes of AAV-2 (denoted rHSV-rep2/cap2) was investigated. Adaptation of rHSV production from T225 flasks to a packed bed, fed-batch bioreactor permitted an 1100-fold increment in total vector production without a decrease in specific vector yield (pfu/cell). The fed-batch bioreactor system afforded a rHSV-rep2/cap2 vector recovery of 2.8 x 10(12) pfu. The recovered vector was concentrated by tangential flow filtration (TFF), permitting vector stocks to be formulated at greater than 1.5 x 10(9) pfu/mL.

  18. Effect of vitamin B12 pulse addition on the performance of cobalt deprived anaerobic granular sludge bioreactors

    KAUST Repository

    Fermoso, Fernando G.; Bartacek, Jan; Lens, Piet N.L.

    2010-01-01

    The effect of a pulse addition of vitamin B12 as cobalt source to restore the performance of cobalt depleted methanol-fed bioreactors was investigated. One upflow anaerobic sludge bed (UASB) reactor was supplied with a pulse of vitamin B12, and its

  19. Rôle des bactéries sulfurogènes dans la corrosion du fer Involvment of Sulfidogenic Bacteria in Iron Corrosion

    Directory of Open Access Journals (Sweden)

    Marchal R.

    2006-12-01

    Full Text Available Cet article fait le point sur les connaissances concernant l'implication des bactéries sulfurogènes dans la corrosion des aciers au carbone. Après la description de quelques cas récents tirés de l'industrie pétrolière, la physiologie des bactéries sulfurogènes qui jouent le rôle principal dans le mécanisme de la corrosion anaérobie d'origine bactérienne est examinée. La participation des bactéries productrices d'H2S à la constitution de biofilms est une condition importante à la manifestation des phénomènes de corrosion. Les différentes hypothèses de mécanismes décrites par la littérature sont passées en revue. Indépendamment du rôle physicochirnique joué par les sulfures de fer, non couvrants, bons conducteurs électriques, il en ressort que l'acidification résultant du métabolisme cellulaire est un facteur crucial, non seulement en termes d'électrochimie, mais également en termes de croissance microbienne. L'acidification métabolique explique vraisemblablement la fourniture des ions ferreux pour le micro-organisme dans un environnement chargé d'ions sulfures et finalement la persistance de son activité physiologique dans un micro environnement riche en H2S. The involvement of sulfidogenic bacteria in the corrosion of carbon steel is reviewed. After a brief description of some recent cases drawn from the petroleum industry, the physiology of the sulfidogenic bacteria which plays the most important role in the mechanism of anaerobic bacterial corrosion is examined. The involvement of H2S-producing bacteria to the biofilm formation is a prerequisite for biocorrosion. The hypothetical mechanisms described in the literature are reviewed. Regardless of the physicochemical role played by iron sulfides, which have been shown to be non-covering and to have good properties of electric conductivity, the acidification arising from cellular metabolism has been found to be an important parameter, not only in terms of

  20. Bioreactor design and optimization – a future perspective

    DEFF Research Database (Denmark)

    Gernaey, Krist

    2011-01-01

    Bioreactor design and optimisation are essential in translating the experience gained from lab or pilot scale experiments to efficient production processes in industrial scale bioreactors. This article gives a future perspective on bioreactor design and optimisation, where it is foreseen...

  1. Review of nonconventional bioreactor technology

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C.E.; Mcllwain, M.E.

    1993-09-01

    Biotechnology will significantly affect many industrial sectors in the future. Industrial sectors that will be affected include pharmaceutical, chemical, fuel, agricultural, and environmental remediation. Future research is needed to improve bioprocessing efficiency and cost-effectiveness in order to compete with traditional technologies. This report describes recent advances in bioprocess technologies and bioreactor designs and relates them to problems encountered in many industrial bioprocessing operations. The primary focus is directed towards increasing gas and vapor transfer for enhanced bioprocess kinetics as well as unproved by-product separation and removal. The advantages and disadvantages of various conceptual designs such as hollow-fiber, gas-phase, hyperbaric/hypobaric, and electrochemical bioreactors are also discussed. Specific applications that are intended for improved bioprocesses include coal desulfurization, coal liquefaction, soil bioremediation, biomass conversion to marketable chemicals, biomining, and biohydrometallurgy as well as bioprocessing of gases and vapors.

  2. Membrane bioreactors for waste gas treatment.

    NARCIS (Netherlands)

    Reij, M.W.; Keurentjes, J.T.F.; Hartmans, S.

    1998-01-01

    This review describes the recent development of membrane reactors for biological treatment of waste gases. In this type of bioreactor gaseous pollutants are transferred through a membrane to the liquid phase, where micro-organisms degrade the pollutants. The membrane bioreactor combines the

  3. Membrane bioreactors for waste gas treatment

    NARCIS (Netherlands)

    Reij, M.W.; Keurentjes, J.T.F.; Hartmans, S.

    1998-01-01

    This review describes the recent development of membrane reactors for biological treatment of waste gases. In this type of bioreactor gaseous pollutants are transferred through a membrane to the liquid phase, where micro-organisms degrade the pollutants. The membrane bioreactor combines the

  4. Comparison of membrane bioreactor technology and conventional ...

    African Journals Online (AJOL)

    The purpose of this paper was to review the use of membrane bioreactor technology as an alternative for treating the discharged effluent from a bleached kraft mill by comparing and contrasting membrane bioreactors with conventional activated sludge systems for wastewater treatment. There are many water shortage ...

  5. Determination of the kinetic and stoichiometric constant in a conventional bioreactor of activated sludge, to scale

    International Nuclear Information System (INIS)

    Rodriguez Chaparro, Tatiana; Perez Navarrete, Eddie Albert; Vivas Mora, Eneydi

    2003-01-01

    The activated sludge process is the one of the most efficient process, when it comes to removal of organic matter. Implementing in the lab is quite easy, economic technically feasible, and simultaneously offers the possibility of using the results obtained in the lab to be applied in field by determining the kinetic and stoichiometric constants. The activated sludge system was designed, built and operated in the water quality lab, at the Military University in Bogota, Colombia. The bioreactor has an aeration chamber, a sedimentation tank and a feeding source with wastewater taken from a meat packing plant in Bogota. The research was carried out for 3 months, in two stages as follows: in the first stage and in order to obtain a high concentration of biomass the acclimatizing process was carried out. This step allows the bioreactor to run in a continuous flow. In the second stage, the bioreactor was taken in to operation and fed with the acclimated sludge at different sludge ages. This would allow us to determine the kinetics, and the stoichiometric constants. The bioreactor was run with a hydraulic retention time of 8 hours and for different sludge ages (5, 10, and 15 days). The system was monitored with a daily grab samples, and pH, temperature as well as the DBO 5 and suspended volatile solids were terminated

  6. Tubular membrane bioreactors for biotechnological processes.

    Science.gov (United States)

    Wolff, Christoph; Beutel, Sascha; Scheper, Thomas

    2013-02-01

    This article is an overview of bioreactors using tubular membranes such as hollow fibers or ceramic capillaries for cultivation processes. This diverse group of bioreactor is described here in regard to the membrane materials used, operational modes, and configurations. The typical advantages of this kind of system such as environments with low shear stress together with high cell densities and also disadvantages like poor oxygen supply are summed up. As the usage of tubular membrane bioreactors is not restricted to a certain organism, a brief overview of various applications covering nearly all types of cells from prokaryotic to eukaryotic cells is also given here.

  7. Bioreactor design for tendon/ligament engineering.

    Science.gov (United States)

    Wang, Tao; Gardiner, Bruce S; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B; Wang, Allan; Xu, Jiake; Smith, David W; Lloyd, David G; Zheng, Ming H

    2013-04-01

    Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments.

  8. Aujeszky's disease virus production in disposable bioreactor

    Indian Academy of Sciences (India)

    Madhu

    1Laboratory for Cell Culture Technology and Biotransformations, 2Laboratory for ... A novel, disposable-bag bioreactor system that uses wave action for mixing and transferring ... consisted of 95% of air + 5% of CO2 using gas mixing module.

  9. Oxygen transfer in slurry bioreactors.

    Science.gov (United States)

    Kawase, Y; Moo-Young, M

    1991-04-25

    The oxygen transfer in bioreactors with slurries having a yield stress was investigated. The volumetric mass transfer coefficients in a 40-L bubble column with simulated fermentation broths, the Theological properties of which were represented by the Casson model, were measured. Experimental data were compared with a theoretical correlation developed on the basis of a combination of Higbie's penetration theory and Kolmogoroff's theory of isotropic turbulence. Comparisons between the proposed correlation and data for the simulated broths show good agreement. The mass transfer data for actual mycelial fermentation broths reported previously by the authors were re-examined. Their Theological data was correlated by the Bingham plastic model. The oxygen transfer rate data in the mycelial fermentation broths fit the predictions of the proposed theoretical correlation.

  10. Bioreactor Design for Tendon/Ligament Engineering

    OpenAIRE

    Wang, Tao; Gardiner, Bruce S.; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B.; Wang, Allan; Xu, Jiake; Smith, David W.; Lloyd, David G.; Zheng, Ming H.

    2012-01-01

    Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a s...

  11. Enzymatic hydrolysis of rice straw and glucose fermentation using a Vertical Ball Mill Bioreactor (VBMB): Impact of operational conditions

    DEFF Research Database (Denmark)

    Castro, Rafael C.A.; Mussatto, Solange I.; Roberto, Inês C.

    ). This bioreactor was equipped with adjustable flat round plate impellers, allowing its operation with glass spheres as shear agent. For enzymatic hydrolysis, the spheres were the only variable with significant impact on the results, being achieved 87% cellulose conversion after 24 h when using the highest level...... saccharification and fermentation, in batch or fed-batch configurations, and with possibilities of operating at high solids content. Acknowledgments: FAPESP (2013/13953-6 and 2015/24813-6) and CNPq....

  12. Degradation of toluene and trichloroethylene by Burkholderia cepacia G4 in growth-limited fed-batch culture

    NARCIS (Netherlands)

    Mars, Astrid E.; Houwing, Joukje; Dolfing, Jan; Janssen, Dick B.

    Burkholderia (Pseudomonas) cepacia G4 was cultivated in a fed-batch bioreactor on either toluene or toluene plus trichloroethylene (TCE), The culture was allowed to reach a constant cell density under conditions in which the amount of toluene supplied equals the maintenance energy demand of the

  13. Tubular bioreactor and its application; Tubular bioreactor to sono tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Endo, I.; Nagamune, T. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yuki, K. [Nikka Whisky Distilling Co. Ltd. Tokyo (Japan); Inaba, H. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1994-09-05

    The loop type tubular bioreactor (TBR) was developed where biocatalysts are trapped in the reactor by membrane module. A UF membrane or MF membrane and crossflow filtration were adopted for the membrane module, and the reactor loop was composed of four membrane modules. The reactor was operated at 2-4 m/s in membrane surface velocity and 300-400 kPa in filtration pressure. As the result of the high-density culture of lactic acid bacteria and yeast, a biomass concentration was more than 10 times that in batch culture, suggesting the remarkable enhancement of a production efficiency. As the result of the continuous fermentation of cider, the fast fermentation more than 60 times that in conventional ones was obtained together with the same quality as conventional ones. Such a fast fermentation was probably achieved by yeast suspended in the fermenter of TBR, by yeast hardly affected physico-chemically as compared with immobilized reactors, and by small effect of mass transfer on reaction systems. 4 refs., 6 figs.

  14. Construction of a Simple Multipurpose Airlift Bioreactor and its ...

    African Journals Online (AJOL)

    BSN

    The aim of the present research is to develop a simple airlift bioreactor which can be operated even ... compression metal. The bioreactor is mixed ... the method developed by (Bailey and Olis, .... (Ed) Concise Encyclopedia of Bio-resources.

  15. 40 CFR 258.41 - Project XL Bioreactor Landfill Projects.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Project XL Bioreactor Landfill... WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Design Criteria § 258.41 Project XL Bioreactor Landfill Projects. (a) Buncombe County, North Carolina Project XL Bioreactor Landfill Requirements...

  16. Woodchip bioreactors effectively treat aquaculture effluent

    Science.gov (United States)

    Nutrients, in particular nitrogen and phosphorus, can create eutrophication problems in any watershed. Preventing water quality impairment requires controlling nutrients from both point-source and non-point source discharges. Woodchip bioreactors are one relatively new approach that can be utilized ...

  17. Sulfate-reducing bacteria in anaerobic bioreactors

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.

    1998-01-01

    The treatment of industrial wastewaters containing high amounts of easily degradable organic compounds in anaerobic bioreactors is a well-established process. Similarly, wastewaters which in addition to organic compounds also contain sulfate can be treated in this way. For a long time, the

  18. LANDFILL BIOREACTOR PERFORMANCE, SECOND INTERIM REPORT

    Science.gov (United States)

    A bioreactor landfill is a landfill that is operated in a manner that is expected to increase the rate and extent of waste decomposition, gas generation, and settlement compared to a traditional landfill. This Second Interim Report was prepared to provide an interpretation of fie...

  19. Role of nickel in high rate methanol degradation in anaerobic granular sludge bioreactors

    Science.gov (United States)

    Fermoso, Fernando G.; Collins, Gavin; Bartacek, Jan; O’Flaherty, Vincent

    2008-01-01

    The effect of nickel deprivation from the influent of a mesophilic (30°C) methanol fed upflow anaerobic sludge bed (UASB) reactor was investigated by coupling the reactor performance to the evolution of the Methanosarcina population of the bioreactor sludge. The reactor was operated at pH 7.0 and an organic loading rate (OLR) of 5–15 g COD l−1 day−1 for 191 days. A clear limitation of the specific methanogenic activity (SMA) on methanol due to the absence of nickel was observed after 129 days of bioreactor operation: the SMA of the sludge in medium with the complete trace metal solution except nickel amounted to 1.164 (±0.167) g CH4-COD g VSS−1 day−1 compared to 2.027 (±0.111) g CH4-COD g VSS−1 day−1 in a medium with the complete (including nickel) trace metal solution. The methanol removal efficiency during these 129 days was 99%, no volatile fatty acid (VFA) accumulation was observed and the size of the Methanosarcina population increased compared to the seed sludge. Continuation of the UASB reactor operation with the nickel limited sludge lead to incomplete methanol removal, and thus methanol accumulation in the reactor effluent from day 142 onwards. This methanol accumulation subsequently induced an increase of the acetogenic activity in the UASB reactor on day 160. On day 165, 77% of the methanol fed to the system was converted to acetate and the Methanosarcina population size had substantially decreased. Inclusion of 0.5 μM Ni (dosed as NiCl2) to the influent from day 165 onwards lead to the recovery of the methanol removal efficiency to 99% without VFA accumulation within 2 days of bioreactor operation. PMID:18247139

  20. Fermentative hydrogen production from anaerobic bacteria using a membrane bioreactor

    International Nuclear Information System (INIS)

    Mi-Sun Kim; You-Kwan Oh; Young-Su Yun; Dong-Yeol Lee

    2006-01-01

    Continuous H 2 production from glucose was studied at short hydraulic retention times (HRT) of 4.69 - 0.79 h using a membrane bioreactor (MBR) with a hollow-fiber filtration unit and mixed cells as inoculum. The reactor was inoculated with sewage sludge, which were heat-treated at 90 C for harvesting spore-forming, H 2 -producing bacteria, and fed with synthetic wastewater containing 1% (w/v) glucose. With decreasing HRT, volumetric H 2 production rate increased but the H 2 production yield to glucose decreased gradually. The H 2 content in biogas was maintained at 50 - 70% (v/v) and no appreciable CH 4 was detected during the operation. The maximal volumetric H 2 production rate and H 2 yield to glucose were 1714 mmol H 2 /L.d and 1.1 mol H 2 /mol glucose, respectively. These results indicate that the MBR should be considered as one of the most promising systems for fermentative H 2 production. (authors)

  1. Bioreactors in tissue engineering - principles, applications and commercial constraints.

    Science.gov (United States)

    Hansmann, Jan; Groeber, Florian; Kahlig, Alexander; Kleinhans, Claudia; Walles, Heike

    2013-03-01

    Bioreactor technology is vital for tissue engineering. Usually, bioreactors are used to provide a tissue-specific physiological in vitro environment during tissue maturation. In addition to this most obvious application, bioreactors have the potential to improve the efficiency of the overall tissue-engineering concept. To date, a variety of bioreactor systems for tissue-specific applications have been developed. Of these, some systems are already commercially available. With bioreactor technology, various functional tissues of different types were generated and cultured in vitro. Nevertheless, these efforts and achievements alone have not yet led to many clinically successful tissue-engineered implants. We review possible applications for bioreactor systems within a tissue-engineering process and present basic principles and requirements for bioreactor development. Moreover, the use of bioreactor systems for the expansion of clinically relevant cell types is addressed. In contrast to cell expansion, for the generation of functional three-dimensional tissue equivalents, additional physical cues must be provided. Therefore, bioreactors for musculoskeletal tissue engineering are discussed. Finally, bioreactor technology is reviewed in the context of commercial constraints. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Designing electrical stimulated bioreactors for nerve tissue engineering

    Science.gov (United States)

    Sagita, Ignasius Dwi; Whulanza, Yudan; Dhelika, Radon; Nurhadi, Ibrahim

    2018-02-01

    Bioreactor provides a biomimetic ecosystem that is able to culture cells in a physically controlled system. In general, the controlled-parameters are temperature, pH, fluid flow, nutrition flow, etc. In this study, we develop a bioreactor that specifically targeted to culture neural stem cells. This bioreactor could overcome some limitations of conventional culture technology, such as petri dish, by providing specific range of observation area and a uniform treatment. Moreover, the microfluidic bioreactor, which is a small-controlled environment, is able to observe as small number of cells as possible. A perfusion flow is applied to mimic the physiological environment in human body. Additionally, this bioreactor also provides an electrical stimulation which is needed by neural stem cells. In conclusion, we found the correlation between the induced shear stress with geometric parameters of the bioreactor. Ultimately, this system shall be used to observe the interaction between stimulation and cell growth.

  3. Role of Bioreactors in Microbial Biomass and Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liang [Chongqing University, Chongqing, China; Zhang, Biao [Chongqing University, Chongqing, China; Zhu, Xun [Chongqing University, Chongqing, China; Chang, Haixing [Chongqing University of Technology; Ou, Shawn [ORNL; Wang, HONG [Chongqing University, Chongqing, China

    2018-04-01

    Bioenergy is the world’s largest contributor to the renewable and sustainable energy sector, and it plays a significant role in various energy industries. A large amount of research has contributed to the rapidly evolving field of bioenergy and one of the most important topics is the use of the bioreactor. Bioreactors play a critical role in the successful development of technologies for microbial biomass cultivation and energy conversion. In this chapter, after a brief introduction to bioreactors (basic concepts, configurations, functions, and influencing factors), the applications of the bioreactor in microbial biomass, microbial biofuel conversion, and microbial electrochemical systems are described. Importantly, the role and significance of the bioreactor in the bioenergy process are discussed to provide a better understanding of the use of bioreactors in managing microbial biomass and energy conversion.

  4. Comparison between a conventional membrane bioreactor (C-MBR and a biofilm membrane bioreactor (BF-MBR for domestic wastewater treatment

    Directory of Open Access Journals (Sweden)

    E. L. Subtil

    2014-09-01

    Full Text Available In this paper, the influence of biofilm carriers in a MBR on the performance of organic matter and nitrogen removal and the influence on membrane fouling were evaluated. The configurations studied included a Conventional Membrane Bioreactor (C-MBR and a Biofilm Membrane Bioreactor (BF-MBR operated in parallel, both fed with domestic wastewater. Regarding organic matter removal, no statistically significant differences were observed between C-MBR and BF-MBR, producing an effluent with a Soluble COD concentration of 27 ± 9.0 mgO2/L and 26 ±1.0 mgO2/L and BOD concentration of 6.0 ± 2.5 mgO2/L and 6.2 ± 2.1 mgO2/L, respectively. On the other hand, the BF-MBR produced a permeate with lower ammonia and total nitrogen concentrations, which resulted in a removal efficiency of 98% and 73%, respectively. It was also observed that the fouling rate was about 35% higher in the C-MBR than that for the BF-MBR, which also presented a reduction of total membrane resistance, about 29%, and increased operational cycle length around 7 days, compared to C-MBR.

  5. Modeling of a membrane bioreactor for production of biodiesel

    International Nuclear Information System (INIS)

    Solano, Paola Andrea; Moncada, Jorge Andres; Cardona, Carlos Ariel; Ruiz, Orlando Simon

    2008-01-01

    Through the use of an enzymatic catalyst lipase, produced by Candida Antarctica a membrane bioreactor was modeled and simulated to obtain biodiesel from palm oil and ethanol. A conversion of 0.97 was reached for a residence time of 10.64 min. The membrane bioreactor was compared to a CSTR reactor, where a conversion of 0.76 was obtained. It was concluded that the membrane bioreactor is a better way of producing biodiesel than the CSTR

  6. Catalytic bioreactors and methods of using same

    Science.gov (United States)

    Worden, Robert Mark; Liu, Yangmu Chloe

    2017-07-25

    Various embodiments provide a bioreactor for producing a bioproduct comprising one or more catalytically active zones located in a housing and adapted to keep two incompatible gaseous reactants separated when in a gas phase, wherein each of the one or more catalytically active zones may comprise a catalytic component retainer and a catalytic component retained within and/or thereon. Each of the catalytically active zones may additionally or alternatively comprise a liquid medium located on either side of the catalytic component retainer. Catalytic component may include a microbial cell culture located within and/or on the catalytic component retainer, a suspended catalytic component suspended in the liquid medium, or a combination thereof. Methods of using various embodiments of the bioreactor to produce a bioproduct, such as isobutanol, are also provided.

  7. Engineering stem cell niches in bioreactors

    OpenAIRE

    Liu, Meimei; Liu, Ning; Zang, Ru; Li, Yan; Yang, Shang-Tian

    2013-01-01

    Stem cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells and amniotic fluid stem cells have the potential to be expanded and differentiated into various cell types in the body. Efficient differentiation of stem cells with the desired tissue-specific function is critical for stem cell-based cell therapy, tissue engineering, drug discovery and disease modeling. Bioreactors provide a great platform to regulate the stem cell microenvironment, known as “ni...

  8. Disposable bioreactors: maturation into pharmaceutical glycoprotein manufacturing.

    Science.gov (United States)

    Brecht, René

    2009-01-01

    Modern biopharmaceutical development is characterised by deep understanding of the structure activity relationship of biological drugs. Therefore, the production process has to be tailored more to the product requirements than to the existing equipment in a certain facility. In addition, the major challenges for the industry are to lower the high production costs of biologics and to shorten the overall development time. The flexibility for providing different modes of operation using disposable bioreactors in the same facility can fulfil these demands and support tailor-made processes.Over the last 10 years, a huge and still increasing number of disposable bioreactors have entered the market. Bioreactor volumes of up to 2,000 L can be handled by using disposable bag systems. Each individual technology has been made available for different purposes up to the GMP compliant production of therapeutic drugs, even for market supply. This chapter summarises disposable technology development over the last decade by comparing the different technologies and showing trends and concepts for the future.

  9. Tracking control of concentration profiles in a fed-batch bioreactor using a linear algebra methodology.

    Science.gov (United States)

    Rómoli, Santiago; Serrano, Mario Emanuel; Ortiz, Oscar Alberto; Vega, Jorge Rubén; Eduardo Scaglia, Gustavo Juan

    2015-07-01

    Based on a linear algebra approach, this paper aims at developing a novel control law able to track reference profiles that were previously-determined in the literature. A main advantage of the proposed strategy is that the control actions are obtained by solving a system of linear equations. The optimal controller parameters are selected through Monte Carlo Randomized Algorithm in order to minimize a proposed cost index. The controller performance is evaluated through several tests, and compared with other controller reported in the literature. Finally, a Monte Carlo Randomized Algorithm is conducted to assess the performance of the proposed controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Modelling the competition between sulphate reducers and methanogens in a thermophilic methanol-fed bioreactor

    NARCIS (Netherlands)

    Spanjers, H.; Weijma, J.; Abusam, A.

    2002-01-01

    Sulphate can be removed from wastewater by means of biological anaerobic reduction to sulphide. The reduction requires the presence of a substrate that can serve as an electron donor. Methanol a suitable electron donor for sulphate reduction under thermophilic conditions. In an anaerobic system

  11. Pharmaceutical proteins produced in plant bioreactor in recent years ...

    African Journals Online (AJOL)

    Plant bioreactor, also called molecular farming, has enormous potential to produce recombinant proteins infinitely. Products expressed in plants have natural physico-chemical properties and bioactivities. Plant bioreactor could be a safe, economic and convenient production system, and can been widely applied in ...

  12. Schisandra lignans production regulated by different bioreactor type.

    Science.gov (United States)

    Szopa, Agnieszka; Kokotkiewicz, Adam; Luczkiewicz, Maria; Ekiert, Halina

    2017-04-10

    Schisandra chinensis (Chinese magnolia vine) is a rich source of therapeutically relevant dibenzocyclooctadiene lignans with anticancer, immunostimulant and hepatoprotective activities. In this work, shoot cultures of S. chinensis were grown in different types of bioreactors with the aim to select a system suitable for the large scale in vitro production of schisandra lignans. The cultures were maintained in Murashige-Skoog (MS) medium supplemented with 3mg/l 6-benzylaminopurine (BA) and 1mg/l 1-naphthaleneacetic acid (NAA). Five bioreactors differing with respect to cultivation mode were tested: two liquid-phase systems (baloon-type bioreactor and bubble-column bioreactor with biomass immobilization), the gas-phase spray bioreactor and two commercially available temporary immersion systems: RITA ® and Plantform. The experiments were run for 30 and 60 days in batch mode. The harvested shoots were evaluated for growth and lignan content determined by LC-DAD and LC-DAD-ESI-MS. Of the tested bioreactors, temporary immersion systems provided the best results with respect to biomass production and lignan accumulation: RITA ® bioreactor yielded 17.86g/l (dry weight) during 60 day growth period whereas shoots grown for 30 days in Plantform bioreactor contained the highest amount of lignans (546.98mg/100g dry weight), with schisandrin, deoxyschisandrin and gomisin A as the major constituents (118.59, 77.66 and 67.86mg/100g dry weight, respectively). Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Wastewater treatments by membrane bioreactors (MBR); Bioreactores de membrana (MBR) para la depuracion de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Guardino Ferre, R.

    2001-07-01

    Wastewater treatments by membrane bioreactors (MBR), are a good alternative of treatment to the conventional processes when wish to obtain very high quality of the treated water or to try high load contaminants in low flow. Simultaneously, the article explains the significant reduction of the wastewater treatment plant space, eliminating the secondary septic tank. (Author) 7 refs.

  14. Tissue grown in space in NASA Bioreactor

    Science.gov (United States)

    2001-01-01

    Dr. Lisa E. Freed of the Massachusetts Institute of Technology and her colleagues have reported that initially disc-like specimens tend to become spherical in space, demonstrating that tissues can grow and differentiate into distinct structures in microgravity. The Mir Increment 3 (Sept. 16, 1996 - Jan. 22, 1997) samples were smaller, more spherical, and mechanically weaker than Earth-grown control samples. These results demonstrate the feasibility of microgravity tissue engineering and may have implications for long human space voyages and for treating musculoskeletal disorders on earth. Final samples from Mir and Earth appeared histologically cartilaginous throughout their entire cross sections (5-8 mm thick), with the exception of fibrous outer capsules. Constructs grown on Earth (A) appeared to have a more organized extracellular matrix with more uniform collagen orientation as compared with constructs grown on Mir (B), but the average collagen fiber diameter was similar in the two groups (22 +- 2 nm) and comparable to that previously reported for developing articular cartilage. Randomly oriented collagen in Mir samples would be consistent with previous reports that microgravity disrupts fibrillogenesis. These are transmission electron micrographs of constructs from Mir (A) and Earth (B) groups at magnifications of x3,500 and x120,000 (Inset). The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Credit: Proceedings of the National Academy of Sciences.

  15. Use of a Packed-Column Bioreactor for Isolation of Diverse Protease-Producing Bacteria from Antarctic Soil

    Science.gov (United States)

    Wery, Nathalie; Gerike, Ursula; Sharman, Ajay; Chaudhuri, Julian B.; Hough, David W.; Danson, Michael J.

    2003-01-01

    Seventy-five aerobic heterotrophs have been isolated from a packed-column bioreactor inoculated with soil from Antarctica. The column was maintained at 10°C and continuously fed with a casein-containing medium to enrich protease producers. Twenty-eight isolates were selected for further characterization on the basis of morphology and production of clearing zones on skim milk plates. Phenotypic tests indicated that the strains were mainly psychrotrophs and presented a high morphological and metabolical diversity. The extracellular protease activities tested were optimal at neutral pH and between 30 and 45°C. 16S ribosomal DNA sequence analyses showed that the bioreactor was colonized by a wide variety of taxons, belonging to various bacterial divisions: α-, β-, and γ-Proteobacteria; the Flexibacter-Cytophaga-Bacteroides group; and high G+C gram-positive bacteria and low G+C gram-positive bacteria. Some strains represent candidates for new species of the genera Chryseobacterium and Massilia. This diversity demonstrates that the bioreactor is an efficient enrichment tool compared to traditional isolation strategies. PMID:12620829

  16. Bioreactor engineering of stem cell environments.

    Science.gov (United States)

    Tandon, Nina; Marolt, Darja; Cimetta, Elisa; Vunjak-Novakovic, Gordana

    2013-11-15

    Stem cells hold promise to revolutionize modern medicine by the development of new therapies, disease models and drug screening systems. Standard cell culture systems have limited biological relevance because they do not recapitulate the complex 3-dimensional interactions and biophysical cues that characterize the in vivo environment. In this review, we discuss the current advances in engineering stem cell environments using novel biomaterials and bioreactor technologies. We also reflect on the challenges the field is currently facing with regard to the translation of stem cell based therapies into the clinic. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Critical Review of Membrane Bioreactor Models

    DEFF Research Database (Denmark)

    Naessens, W.; Maere, T.; Ratkovich, Nicolas Rios

    2012-01-01

    Membrane bioreactor technology exists for a couple of decades, but has not yet overwhelmed the market due to some serious drawbacks of which operational cost due to fouling is the major contributor. Knowledge buildup and optimisation for such complex systems can heavily benefit from mathematical...... modelling. In this paper, the vast literature on hydrodynamic and integrated modelling in MBR is critically reviewed. Hydrodynamic models are used at different scales and focus mainly on fouling and only little on system design/optimisation. Integrated models also focus on fouling although the ones...

  18. Biodegradation studies of selected priority acidic pesticides and diclofenac in different bioreactors

    International Nuclear Information System (INIS)

    Gonzalez, Susana; Mueller, Jutta; Petrovic, Mira; Barcelo, Damia; Knepper, Thomas P.

    2006-01-01

    The biodegradation of selected priority acidic pesticides MCPP, MCPA, 2,4-D, 2,4-DP and bentazone and the acidic pharmaceutical diclofenac was investigated using a membrane bioreactor (MBR) and a fixed-bed bioreactor (FBBR). A pilot plant MBR was fed with raw water spiked with the selected compounds. The experiment was repeated every week during four weeks to enhance the adaptation of microorganisms. In order to further study the biodegradability of these compounds, degradation studies in a FBBR were carried out. All the samples were analysed by solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS). The results indicate that in the MBR compounds except for bentazone were eliminated within the first day of the experiment at rates ranging from 44% to 85%. Comparing these results with the degradation rates in the FBBR showed that in the latter only MCPP, MCPA 2,4-D and 2,4-DP were degraded after a much longer adaptation phase of microorganisms. - Biodegradation rate of selected acidic pesticides and pharmaceuticals depends on adaptation

  19. Exploitation of Trametes versicolor for bioremediation of endocrine disrupting chemicals in bioreactors.

    Directory of Open Access Journals (Sweden)

    Cinzia Pezzella

    Full Text Available Endocrine disrupting chemicals (EDCs are environmental contaminants causing increasing concerns due to their toxicity, persistence and ubiquity. In the present study, degradative capabilities of Trametes versicolor, Pleurotus ostreatus and Phanerochaete chrysosporium to act on five EDCs, which represent different classes of chemicals (phenols, parabens and phthalate and were first applied as single compounds, were assessed. T. versicolor was selected due to its efficiency against target EDCs and its potentialities were exploited against a mixture of EDCs in a cost-effective bioremediation process. A fed-batch approach as well as a starvation strategy were applied in order to reduce the need for input of 'fresh' biomass, and avoid the requirement for external nutrients. The fungus was successfully operated in two different bioreactors over one week. Semi-batch cultures were carried out by daily adding a mixture of EDCs to the bioreactors in a total of five consecutive degradation cycles. T. versicolor was able to efficiently remove all compounds during each cycle converting up to 21 mg L-1 day-1 of the tested EDCs. The maintained ability of T. versicolor to remove EDCs without any additional nutrients represents the main outcome of this study, which enables to forecast its application in a water treatment process.

  20. Experiments as to the influence of heat recovery from a bioreactor on sewage sludge disinfecting

    Energy Technology Data Exchange (ETDEWEB)

    Tarjanyi, J.; Strauch, D.; Philipp, W.

    The influence of heat recovery on the disinfecting effect of composting of sewage sludge in a bio-reactor (in-vessel-composting) was investigated in a reactor type Weiss-system Kneer. As test agents 3 different serovars of salmonella, Parvo- and Poliovirus and eggs of Ascaris suum were used. The experiments were done in a reactor which was fed with dewatered municipal sewage sludge mixed with waste-paper as C-carrier for better composting. Even under winter conditions the test agents were inactivated within the time which is characteristic for the passage of the composting material through the plug-flow reactor. These results cannot simply be applied without further investigation to other reactors of the same type but with different ways of operation. (orig.)

  1. Continuous Ethanol Production Using Immobilized-Cell/Enzyme Biocatalysts in Fluidized-Bed Bioreactor (FBR)

    Energy Technology Data Exchange (ETDEWEB)

    Nghiem, NP

    2003-11-16

    The immobilized-cell fluidized-bed bioreactor (FBR) was developed at Oak Ridge National Laboratory (ORNL). Previous studies at ORNL using immobilized Zymomonas mobilis in FBR at both laboratory and demonstration scale (4-in-ID by 20-ft-tall) have shown that the system was more than 50 times as productive as industrial benchmarks (batch and fed-batch free cell fermentations for ethanol production from glucose). Economic analysis showed that a continuous process employing the FBR technology to produce ethanol from corn-derived glucose would offer savings of three to six cents per gallon of ethanol compared to a typical batch process. The application of the FBR technology for ethanol production was extended to investigate more complex feedstocks, which included starch and lignocellulosic-derived mixed sugars. Economic analysis and mathematical modeling of the reactor were included in the investigation. This report summarizes the results of these extensive studies.

  2. MEMBRANE BIOREACTOR FOR TREATMENT OF RECALCITRANT WASTEWATERS

    Directory of Open Access Journals (Sweden)

    Suprihatin Suprihatin

    2012-02-01

    Full Text Available The low biodegradable wastewaters remain a challenge in wastewater treatment technology. The performance of membrane bioreactor systems with submerged hollow fiber micro- and ultrafiltration membrane modules were examined for purifying recalcitrant wastewaters of leachate of a municipal solid waste open dumping site and effluent of pulp and paper mill. The use of MF and UF membrane bioreactor systems showed an efficient treatment for both types wastewaters with COD reduction of 80-90%. The membrane process achieved the desirable effects of maintaining reasonably high biomass concentration and long sludge retention time, while producing a colloid or particle free effluent. For pulp and paper mill effluent a specific sludge production of 0.11 kg MLSS/kg COD removed was achieved. A permeate flux of about 5 L/m²h could be achieved with the submerged microfiltration membrane. Experiments using ultrafiltration membrane produced relatively low permeate fluxes of 2 L/m²h. By applying periodical backwash, the flux could be improved significantly. It was indicated that the particle or colloid deposition on membrane surface was suppressed by backwash, but reformation of deposit was not effectively be prevented by shear-rate effect of aeration. Particle and colloid started to accumulate soon after backwash. Construction of membrane module and operation mode played a critical role in achieving the effectiveness of aeration in minimizing deposit formation on the membrane surface.

  3. Spaceflight bioreactor studies of cells and tissues.

    Science.gov (United States)

    Freed, Lisa E; Vunjak-Novakovic, Gordana

    2002-01-01

    Studies of the fundamental role of gravity in the development and function of biological organisms are a central component of the human exploration of space. Microgravity affects numerous physical phenomena relevant to biological research, including the hydrostatic pressure in fluid filled vesicles, sedimentation of organelles, and buoyancy-driven convection of flow and heat. These physical phenomena can in turn directly and indirectly affect cellular morphology, metabolism, locomotion, secretion of extracellular matrix and soluble signals, and assembly into functional tissues. Studies aimed at distinguishing specific effects of gravity on biological systems require the ability to: (i) control and systematically vary gravity, e.g. by utilizing the microgravity environment of space in conjunction with an in-flight centrifuge; and (ii) maintain constant all other factors in the immediate environment, including in particular concentrations and exchange rates of biochemical species and hydrodynamic shear. The latter criteria imply the need for gravity-independent mechanisms to provide for mass transport between the cells and their environment. Available flight hardware has largely determined the experimental design and scientific objectives of spaceflight cell and tissue culture studies carried out to date. Simple culture vessels have yielded important quantitative data, and helped establish in vitro models of cell locomotion, growth and differentiation in various mammalian cell types including embryonic lung cells [6], lymphocytes [2,8], and renal cells [7,31]. Studies done using bacterial cells established the first correlations between gravity-dependent factors such as cell settling velocity and diffusional distance and the respective cell responses [12]. The development of advanced bioreactors for microgravity cell and tissue culture and for tissue engineering has benefited both research areas and provided relevant in vitro model systems for studies of astronaut

  4. Disposable Bioreactors for Plant Micropropagation and Mass Plant Cell Culture

    Science.gov (United States)

    Ducos, Jean-Paul; Terrier, Bénédicte; Courtois, Didier

    Different types of bioreactors are used at Nestlé R&D Centre - Tours for mass propagation of selected plant varieties by somatic embryogenesis and for large scale culture of plants cells to produce metabolites or recombinant proteins. Recent studies have been directed to cut down the production costs of these two processes by developing disposable cell culture systems. Vegetative propagation of elite plant varieties is achieved through somatic embryogenesis in liquid medium. A pilot scale process has recently been set up for the industrial propagation of Coffea canephora (Robusta coffee). The current production capacity is 3.0 million embryos per year. The pre-germination of the embryos was previously conducted by temporary immersion in liquid medium in 10-L glass bioreactors. An improved process has been developed using a 10-L disposable bioreactor consisting of a bag containing a rigid plastic box ('Box-in-Bag' bioreactor), insuring, amongst other advantages, a higher light transmittance to the biomass due to its horizontal design. For large scale cell culture, two novel flexible plastic-based disposable bioreactors have been developed from 10 to 100 L working volumes, validated with several plant species ('Wave and Undertow' and 'Slug Bubble' bioreactors). The advantages and the limits of these new types of bioreactor are discussed, based mainly on our own experience on coffee somatic embryogenesis and mass cell culture of soya and tobacco.

  5. Process technology of luwak coffee through bioreactor utilization

    Science.gov (United States)

    Hadipernata, M.; Nugraha, S.

    2018-01-01

    Indonesia has an advantage in producing exotic coffee that is Luwak coffee. Luwak coffee is produced from the fermentation process in digestion of civet. Luwak coffee production is still limited due to the difficulty level in the use of civet animals as the only medium of Luwak coffee making. The research was conducted by developing technology of luwak coffee production through bioreactor utilization and addition the bacteria isolate from gastric of civet. The process conditions in the bioreactor which include temperature, pH, and bacteria isolate of civet are adjusted to the process that occurs in civet digestion, including peristaltic movement on the stomach and small intestine of the civet will be replaced by the use of propellers that rotate on the bioreactor. The result of research showed that proximat analysis data of artificial/bioreactor luwak coffee did not significant different with original luwak coffee. However, the original luwak coffee has higher content of caffeine compared to bioreactor luwak coffee. Based on the cuping test the bioreactor luwak coffee has a value of 84.375, while the original luwak coffee is 84.875. As the result, bioreactor luwak coffee has excellent taste that similiar with original luwak coffee taste.

  6. Biodegradation of phenolic waste liquors in stirred-tank, packed-bed, and fluidized-bed bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, D W; Hancher, G W; Chilcote, D D; Scott, C D

    1978-11-01

    The biological degradation of phenolic scrub liquors similar to those that arise in coal conversion processes was studied for symbiotic bacterial populations contained in a continuously stirred tank bioreactor, a three-phase packed-bed bioreactor, and a three-phase, fluidized-bed bioreactor. The conversions of phenol compounds were comparable in the three-phase, packed-bed bioreactor and the continuously stirred tank bioreactor; however, the packed-bed bioreactor degradation rates were as much as twice those in the continuously stirred tank bioreactor, and packed-bed bioreactor retention times were as low as one- tenth those of the continuously stirred tank bioreactors (minimum time was 12 hours).

  7. The Role of Bioreactors in Ligament and Tendon Tissue Engineering.

    Science.gov (United States)

    Mace, James; Wheelton, Andy; Khan, Wasim S; Anand, Sanj

    2016-01-01

    Bioreactors are pivotal to the emerging field of tissue engineering. The formation of neotissue from pluripotent cell lineages potentially offers a source of tissue for clinical use without the significant donor site morbidity associated with many contemporary surgical reconstructive procedures. Modern bioreactor design is becoming increasingly complex to provide a both an expandable source of readily available pluripotent cells and to facilitate their controlled differentiation into a clinically applicable ligament or tendon like neotissue. This review presents the need for such a method, challenges in the processes to engineer neotissue and the current designs and results of modern bioreactors in the pursuit of engineered tendon and ligament.

  8. Fundamentals of membrane bioreactors materials, systems and membrane fouling

    CERN Document Server

    Ladewig, Bradley

    2017-01-01

    This book provides a critical, carefully researched, up-to-date summary of membranes for membrane bioreactors. It presents a comprehensive and self-contained outline of the fundamentals of membrane bioreactors, especially their relevance as an advanced water treatment technology. This outline helps to bring the technology to the readers’ attention, and positions the critical topic of membrane fouling as one of the key impediments to its more widescale adoption. The target readership includes researchers and industrial practitioners with an interest in membrane bioreactors.

  9. Modelling across bioreactor scales: methods, challenges and limitations

    DEFF Research Database (Denmark)

    Gernaey, Krist

    that it is challenging and expensive to acquire experimental data of good quality that can be used for characterizing gradients occurring inside a large industrial scale bioreactor. But which model building methods are available? And how can one ensure that the parameters in such a model are properly estimated? And what......Scale-up and scale-down of bioreactors are very important in industrial biotechnology, especially with the currently available knowledge on the occurrence of gradients in industrial-scale bioreactors. Moreover, it becomes increasingly appealing to model such industrial scale systems, considering...

  10. Effect of vitamin B12 pulse addition on the performance of cobalt deprived anaerobic granular sludge bioreactors

    KAUST Repository

    Fermoso, Fernando G.

    2010-07-01

    The effect of a pulse addition of vitamin B12 as cobalt source to restore the performance of cobalt depleted methanol-fed bioreactors was investigated. One upflow anaerobic sludge bed (UASB) reactor was supplied with a pulse of vitamin B12, and its operation was compared to that of another cobalt depleted UASB reactor to which a pulse of CoCl2 was given. The addition of cobalt in the form of CoCl2 supplies enough cobalt to restore methanogenesis and maintain full methanol degradation coupled to methane production during more than 35 days after the CoCl2 pulse. Similar to CoCl2, pulse addition of vitamin B12 supplies enough cobalt to maintain full methanol degradation during more than 35 days after the pulse. However, the specific methanogenic activities (SMAs) of the sludge in the vitamin B12 supplied reactor were around 3 times higher than the SMA of the sludge from the CoCl2 supplied reactor at the same sampling times. An appropriate dosing strategy (repeated pulse dosing) combined with the choice of vitamin B12 as the cobalt species is suggested as a promising dosing strategy for methanol-fed anaerobic bioreactors limited by the micronutrient cobalt. © 2010 Elsevier Ltd. All rights reserved.

  11. Mechanobiologic Research in a Microgravity Environment Bioreactor

    Science.gov (United States)

    Guidi, A.; Dubini, G.; Tominetti, F.; Raimondi, M.

    A current problem in tissue culturing technology is the unavailability of an effective Bioreactor for the in vitro cultivation of cells and explants. It has, in fact, proved extremely difficult to promote the high-density three-dimensional in vitro growth of human tissues that have been removed from the body and deprived of their normal in vivo vascular sources of nutrients and gas exchange. A variety of tissue explants can be maintained for a short period of time on a supportive collagen matrix surrounded by culture medium. But this system provides only limited mass transfer of nutrients and wastes through the tissue, and gravity-induced sedimentation prevents complete three- dimensional cell-cell and cell-matrix interactions. Several devices presently on the market have been used with only limited success since each has limitations, which restrict usefulness and versatility. Further, no Bioreactor or culture vessel is known that will allow for unimpeded growth of three dimensional cellular aggregates or tissue. Extensive research on the effect of mechanical stimuli on cell metabolism suggests that tissues may respond to mechanical stimulation via loading-induced flow of the interstitial fluids. During the culture, cells are subject to a flow of culture medium. Flow properties such as flow field, flow regime (e.g. turbulent or laminar), flow pattern (e.g. circular), entity and distribution of the shear stress acting on the cells greatly influence fundamental aspects of cell function, such as regulation and gene expression. This has been demonstrated for endothelial cells and significant research efforts are underway to elucidate these mechanisms in various other biological systems. Local fluid dynamics is also responsible of the mass transfer of nutrients and catabolites as well as oxygenation through the tissue. Most of the attempts to culture tissue-engineered constructs in vitro have utilized either stationary cultures or systems generating relatively small

  12. Gel layer formation on membranes in Membrane Bioreactors

    NARCIS (Netherlands)

    Van den Brink, P.F.H.

    2014-01-01

    The widespread application of membrane bioreactors (MBRs) for municipal wastewater treatment is hampered by membrane fouling. Fouling increases energy demand, reduces process performance and creates the need for more frequent (chemical) membrane cleaning or replacement. Membrane fouling in MBRs is

  13. Thermophillic Sidestream Anaerobic Membrane Bioreactors: The Shear Rate Dilemma

    NARCIS (Netherlands)

    Jeison, D.A.; Telkamp, P.; Lier, van J.B.

    2009-01-01

    Anaerobic biomass retention under thermophilic conditions has proven difficult. Membrane filtration can be used as alternative way to achieve high sludge concentrations. This research studied the feasibility of anaerobic membrane bioreactors (AnMBRs) under thermophilic conditions. A sidestream MBR

  14. Water reuse by membrane bioreactors (MBR)

    International Nuclear Information System (INIS)

    Garcia, G.; Huete, E.; Martinez, L. C.; Torres, A.

    2010-01-01

    This paper shows an up-to date overview of the use of membrane bioreactor (MBR) to obtain water treated for reusing it. Considering the existing rules. it has been presented a summary of published studies in which the quality of the effluent is analyzed in terms on physico-chemical and biological parameters. Furthermore, MBR results are compared with the conventional treatment ones. Due to the suitability of MBR technology for removing pathogens, particular attention has been paid to disinfection process and the mechanism that govern it. Results from reviewed studies of MBR have showed equal or better quality of water treated than conventional treatments (activated sludge plus disinfection tertiary treatment by the addition of antibacterial agents). (Author) 32 refs.

  15. Microbial Bioreactor Development in the ALS NSCORT

    Science.gov (United States)

    Mitchell, Cary; Whitaker, Dawn; Banks, M. Katherine; Heber, Albert J.; Turco, Ronald F.; Nies, Loring F.; Alleman, James E.; Sharvelle, Sybil E.; Li, Congna; Heller, Megan

    The NASA Specialized Center of Research and Training in Advanced Life Support (the ALS NSCORT), a partnership of Alabama A & M, Howard, and Purdue Universities, was established by NASA in 2002 to develop technologies that will reduce the Equivalent System Mass (ESM) of regenerative processes within future space life-support systems. A key focus area of NSCORT research has been the development of efficient microbial bioreactors for treatment of human, crop, and food-process wastes while enabling resource recovery. The approach emphasizes optimizing the energy-saving advantages of hydrolytic enzymes for biomass degradation, with focus on treatment of solid wastes including crop residue, paper, food, and human metabolic wastes, treatment of greywater, cabin air, off-gases from other treatment systems, and habitat condensate. This summary includes important findings from those projects, status of technology development, and recommendations for next steps. The Plant-based Anaerobic-Aerobic Bioreactor-Linked Operation (PAABLO) system was developed to reduce crop residue while generating energy and/or food. Plant residues initially were added directly to the bioreactor, and recalcitrant residue was used as a substrate for growing plants or mushrooms. Subsequently, crop residue was first pretreated with fungi to hydrolyze polymers recalcitrant to bacteria, and leachate from the fungal beds was directed to the anaerobic digester. Exoenzymes from the fungi pre-soften fibrous plant materials, improving recovery of materials that are more easily biodegraded to methane that can be used for energy reclamation. An Autothermal Thermophilic Aerobic Digestion (ATAD) system was developed for biodegradable solid wastes. Objectives were to increase water and nutrient recovery, reduce waste volume, and inactivate pathogens. Operational parameters of the reactor were optimized for degradation and resource recovery while minimizing system requirements and footprint. The start-up behavior

  16. The status of membrane bioreactor technology.

    Science.gov (United States)

    Judd, Simon

    2008-02-01

    In this article, the current status of membrane bioreactor (MBR) technology for wastewater treatment is reviewed. Fundamental facets of the MBR process and membrane and process configurations are outlined and the advantages and disadvantages over conventional suspended growth-based biotreatment are briefly identified. Key process design and operating parameters are defined and their significance explained. The inter-relationships between these parameters are identified and their implications discussed, with particular reference to impacts on membrane surface fouling and channel clogging. In addition, current understanding of membrane surface fouling and identification of candidate foulants is appraised. Although much interest in this technology exists and its penetration of the market will probably increase significantly, there remains a lack of understanding of key process constraints such as membrane channel clogging, and of the science of membrane cleaning.

  17. Start-up Strategy for Continuous Bioreactors

    Directory of Open Access Journals (Sweden)

    A.C. da Costa

    1997-06-01

    Full Text Available Abstract - The start-up of continuous bioreactors is solved as an optimal control problem. The choice of the dilution rate as the control variable reduces the dimension of the system by making the use of the global balance equation unnecessary for the solution of the optimization problem. Therefore, for systems described by four or less mass balance equations, it is always possible to obtain an analytical expression for the singular arc as a function of only the state variables. The steady state conditions are shown to satisfy the singular arc expression and, based on this knowledge, a feeding strategy is proposed which leads the reactor from an initial state to the steady state of maximum productivity

  18. Cardiac tissue engineering using perfusion bioreactor systems

    Science.gov (United States)

    Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

    2009-01-01

    This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

  19. Nitrate Removal Rates in Denitrifying Bioreactors During Storm Flows

    Science.gov (United States)

    Pluer, W.; Walter, T.

    2017-12-01

    Field denitrifying bioreactors are designed to reduce excess nitrate (NO3-) pollution in runoff from agricultural fields. Field bioreactors saturate organic matter to create conditions that facilitate microbial denitrification. Prior studies using steady flow in lab-scale bioreactors showed that a hydraulic retention time (HRT) between 4 and 10 hours was optimal for reducing NO3- loads. However, during storm-induced events, flow rate and actual HRT fluctuate. These fluctuations have the potential to disrupt the system in significant ways that are not captured by the idealized steady-flow HRT models. The goal of this study was to investigate removal rate during dynamic storm flows of variable rates and durations. Our results indicate that storm peak flow and duration were not significant controlling variables. Instead, we found high correlations (p=0.004) in average removal rates between bioreactors displaying a predominantly uniform flow pattern compared with bioreactors that exhibited preferential flow (24.4 and 21.4 g N m-3 d-1, respectively). This suggests that the internal flow patterns are a more significant driver of removal rate than external factors of the storm hydrograph. Designing for flow patterns in addition to theoretical HRT will facilitate complete mixing within the bioreactors. This will help maximize excess NO3- removal during large storm-induced runoff events.

  20. A novel process-based model of microbial growth: self-inhibition in Saccharomyces cerevisiae aerobic fed-batch cultures.

    Science.gov (United States)

    Mazzoleni, Stefano; Landi, Carmine; Cartenì, Fabrizio; de Alteriis, Elisabetta; Giannino, Francesco; Paciello, Lucia; Parascandola, Palma

    2015-07-30

    Microbial population dynamics in bioreactors depend on both nutrients availability and changes in the growth environment. Research is still ongoing on the optimization of bioreactor yields focusing on the increase of the maximum achievable cell density. A new process-based model is proposed to describe the aerobic growth of Saccharomyces cerevisiae cultured on glucose as carbon and energy source. The model considers the main metabolic routes of glucose assimilation (fermentation to ethanol and respiration) and the occurrence of inhibition due to the accumulation of both ethanol and other self-produced toxic compounds in the medium. Model simulations reproduced data from classic and new experiments of yeast growth in batch and fed-batch cultures. Model and experimental results showed that the growth decline observed in prolonged fed-batch cultures had to be ascribed to self-produced inhibitory compounds other than ethanol. The presented results clarify the dynamics of microbial growth under different feeding conditions and highlight the relevance of the negative feedback by self-produced inhibitory compounds on the maximum cell densities achieved in a bioreactor.

  1. Impact of acclimation methods on microbial communities and performance of anaerobic fluidized bed membrane bioreactors

    KAUST Repository

    Labarge, Nicole

    2016-10-17

    An anaerobic fluidized bed membrane bioreactor (AFMBR) is a new and effective method for energy-efficient treatment of low strength wastewater, but the factors that affect performance are not well known. Different inocula and acclimation methods of the granular activated carbon (GAC) used in the reactor were examined here to determine their impact on chemical oxygen demand (COD) removal and microbial community composition of domestic wastewater-fed AFMBRs. AFMBRs inoculated with anaerobic digester sludge (D) or domestic wastewater (W) and fed domestic wastewater, or inoculated with a microbiologically diverse anaerobic bog sediment and acclimated using methanol (M), all produced the same COD removal of 63 ± 12% using a diluted wastewater feed (100 ± 21 mg L−1 COD). However, an AFMBR with GAC inoculated with anaerobic digester sludge and acclimated using acetate (A) showed significantly increased wastewater COD removal to 84 ± 6%. In addition, feeding the AFMBR with the M-acclimated GAC with an acetate medium for one week subsequently increased COD removal to 70 ± 6%. Microbial communities enriched on the GAC included Geobacter, sulfur-reducing bacteria, Syntrophaceae, and Chlorobiaceae, with reactor A having the highest relative abundance of Geobacter. These results showed that acetate was the most useful substrate for acclimation of GAC communities, and GAC harbors unique communities relative to those in the AFMBR influent and recirculated solution.

  2. The influence of sorbitol on the production of cellulases and xylanases in an airlift bioreactor.

    Science.gov (United States)

    Ritter, Carla Eliana Todero; Fontana, Roselei Claudete; Camassola, Marli; da Silveira, Maurício Moura; Dillon, Aldo José Pinheiro

    2013-11-01

    The production of cellulases and xylanases by Penicillium echinulatum in an airlift bioreactor was evaluated. In batch production, we tested media with isolated or associated cellulose and sorbitol. In fed-batch production, we tested cellulose addition at two different times, 30 h and 48 h. Higher liquid circulation velocities in the downcomer were observed in sorbitol 10 g L(-1) medium. In batch production, higher FPA (filter paper activity) and endoglucanase activities were obtained with cellulose (7.5 g L(-1)) and sorbitol (2.5 g L(-1)), 1.0 U mL(-1) (120 h) and 6.4 U m L(-1) (100 h), respectively. For xylanases, the best production condition was cellulose 10 g L(-1), which achieved 5.5 U mL(-1) in 64 h. The fed-batch process was favorable for obtaining xylanases, but not for FPA and endoglucanases, suggesting that in the case of cellulases, the inducer must be added early in the process. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Modeling and parameters identification of 2-keto-L-gulonic acid fed-batch fermentation.

    Science.gov (United States)

    Wang, Tao; Sun, Jibin; Yuan, Jingqi

    2015-04-01

    This article presents a modeling approach for industrial 2-keto-L-gulonic acid (2-KGA) fed-batch fermentation by the mixed culture of Ketogulonicigenium vulgare (K. vulgare) and Bacillus megaterium (B. megaterium). A macrokinetic model of K. vulgare is constructed based on the simplified metabolic pathways. The reaction rates obtained from the macrokinetic model are then coupled into a bioreactor model such that the relationship between substrate feeding rates and the main state variables, e.g., the concentrations of the biomass, substrate and product, is constructed. A differential evolution algorithm using the Lozi map as the random number generator is utilized to perform the model parameters identification, with the industrial data of 2-KGA fed-batch fermentation. Validation results demonstrate that the model simulations of substrate and product concentrations are well in coincidence with the measurements. Furthermore, the model simulations of biomass concentrations reflect principally the growth kinetics of the two microbes in the mixed culture.

  4. FedScope Employment Cubes

    Data.gov (United States)

    Office of Personnel Management — This raw data set provides Federal civilian employee population data. The scope of this raw data set includes all data elements used in the creation of the FedScope...

  5. Perfusion seed cultures improve biopharmaceutical fed-batch production capacity and product quality.

    Science.gov (United States)

    Yang, William C; Lu, Jiuyi; Kwiatkowski, Chris; Yuan, Hang; Kshirsagar, Rashmi; Ryll, Thomas; Huang, Yao-Ming

    2014-01-01

    Volumetric productivity and product quality are two key performance indicators for any biopharmaceutical cell culture process. In this work, we showed proof-of-concept for improving both through the use of alternating tangential flow perfusion seed cultures coupled with high-seed fed-batch production cultures. First, we optimized the perfusion N-1 stage, the seed train bioreactor stage immediately prior to the production bioreactor stage, to minimize the consumption of perfusion media for one CHO cell line and then successfully applied the optimized perfusion process to a different CHO cell line. Exponential growth was observed throughout the N-1 duration, reaching >40 × 10(6) vc/mL at the end of the perfusion N-1 stage. The cultures were subsequently split into high-seed (10 × 10(6) vc/mL) fed-batch production cultures. This strategy significantly shortened the culture duration. The high-seed fed-batch production processes for cell lines A and B reached 5 g/L titer in 12 days, while their respective low-seed processes reached the same titer in 17 days. The shortened production culture duration potentially generates a 30% increase in manufacturing capacity while yielding comparable product quality. When perfusion N-1 and high-seed fed-batch production were applied to cell line C, higher levels of the active protein were obtained, compared to the low-seed process. This, combined with correspondingly lower levels of the inactive species, can enhance the overall process yield for the active species. Using three different CHO cell lines, we showed that perfusion seed cultures can optimize capacity utilization and improve process efficiency by increasing volumetric productivity while maintaining or improving product quality. © 2014 American Institute of Chemical Engineers.

  6. Anaerobic membrane bio-reactors for severe industrial effluents and urban spill waters : The AMBROSIUS project

    NARCIS (Netherlands)

    Van Lier, J.B.; Ozgun, H.; Ersahin, M.E.; Dereli, R.K.

    2013-01-01

    With growing application experiences from aerobic membrane bioreactors, combination of membrane and anaerobic processes become more and more attractive and feasible. In anaerobic membrane bioreactors (AnMBRs), biomass and particulate organic matter are physically retained inside the reactor,

  7. Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

    NARCIS (Netherlands)

    Erşahin, M.E.

    2015-01-01

    Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become

  8. A dual flow bioreactor with controlled mechanical stimulation for cartilage tissue engineering

    NARCIS (Netherlands)

    Spitters, Tim; Leijten, Jeroen Christianus Hermanus; Deus, F.D.; Costa, I.B.F.; van Apeldoorn, Aart A.; van Blitterswijk, Clemens; Karperien, Hermanus Bernardus Johannes

    2013-01-01

    In cartilage tissue engineering bioreactors can create a controlled environment to study chondrocyte behavior under mechanical stimulation or produce chondrogenic grafts of clinically relevant size. Here we present a novel bioreactor, which combines mechanical stimulation with a two compartment

  9. Functional study on two artificial liver bioreactors with collagen gel

    Directory of Open Access Journals (Sweden)

    XU Bing

    2014-10-01

    Full Text Available ObjectiveTo improve the hollow fiber bioreactor of artificial liver. MethodsRat hepatocytes mixed with collagen solution were injected into the external cavity of a hollow fiber reactor to construct a bioreactor of hepatocytes suspended in collagen gel (group Ⅰ. Other rat hepatocytes suspended in solution were injected into the external cavity of a hollow fiber reactor with a layer of collagen on the wall of the external cavity to construct a bioreactor of collagen layer and hepatocytes (group Ⅱ. For each group, the culture solution circulated through the internal cavity of the hollow fiber bioreactor; the bioreactor was put in a culture box for 9 d, and the culture solution in the internal cavity was exchanged for new one every 24 h; the concentrations of albumin (Alb, urea, and lactate dehydrogenase (LDH in the culture solution samples were measured to examine the hepatocyte function of the bioreactor. Statistical analysis was performed using SPSS 130. Continuous data were expressed as mean±SD, and comparison between groups was made by paired t test. ResultsFor groups Ⅰ and Ⅱ, Alb levels reached peak values on day 3 of culture (1.41±0.08 g/L and 0.65±0.05 g/L; from day 3 to 9, group I had a significantly higher Alb level than group Ⅱ (t>7.572, P<0.01. For groups Ⅰ and Ⅱ, urea levels reached peak values on days 3 and 5 of culture (1.73±0.14 mmol/L and 1.56±0.18 mmol/L; from days 5 to 9, group I had a significantly higher urea level than group Ⅱ (t>8.418, P<0.01. For groups Ⅰ and Ⅱ, LDH levels reached peak values on day 9 of culture (32.03±9.13 U/L and 70.17±25.28 U/L; from days 1 to 9, group I had a significantly lower LDH level than group Ⅱ(t>5.633, P<0.01. Therefore, the bioreactor of hepatocytes suspended in collagen gel (group Ⅰ showed a better hepatocyte function and less hepatic enzyme leakage compared with the bioreactor of collagen layer and hepatocytes (group Ⅱ. Conclusion

  10. Vortex breakdown in a truncated conical bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Balci, Adnan; Brøns, Morten [DTU Compute, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Herrada, Miguel A [E.S.I, Universidad de Sevilla, Camino de los Descubrimientos s/n, E-41092 (Spain); Shtern, Vladimir N, E-mail: mobr@dtu.dk [Shtern Research and Consulting, Houston, TX 77096 (United States)

    2015-12-15

    This numerical study explains the eddy formation and disappearance in a slow steady axisymmetric air–water flow in a vertical truncated conical container, driven by the rotating top disk. Numerous topological metamorphoses occur as the water height, H{sub w}, and the bottom-sidewall angle, α, vary. It is found that the sidewall convergence (divergence) from the top to the bottom stimulates (suppresses) the development of vortex breakdown (VB) in both water and air. At α = 60°, the flow topology changes eighteen times as H{sub w} varies. The changes are due to (a) competing effects of AMF (the air meridional flow) and swirl, which drive meridional motions of opposite directions in water, and (b) feedback of water flow on AMF. For small H{sub w}, the AMF effect dominates. As H{sub w} increases, the swirl effect dominates and causes VB. The water flow feedback produces and modifies air eddies. The results are of fundamental interest and can be relevant for aerial bioreactors. (paper)

  11. Vortex breakdown in a truncated conical bioreactor

    International Nuclear Information System (INIS)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A; Shtern, Vladimir N

    2015-01-01

    This numerical study explains the eddy formation and disappearance in a slow steady axisymmetric air–water flow in a vertical truncated conical container, driven by the rotating top disk. Numerous topological metamorphoses occur as the water height, H w , and the bottom-sidewall angle, α, vary. It is found that the sidewall convergence (divergence) from the top to the bottom stimulates (suppresses) the development of vortex breakdown (VB) in both water and air. At α = 60°, the flow topology changes eighteen times as H w varies. The changes are due to (a) competing effects of AMF (the air meridional flow) and swirl, which drive meridional motions of opposite directions in water, and (b) feedback of water flow on AMF. For small H w , the AMF effect dominates. As H w increases, the swirl effect dominates and causes VB. The water flow feedback produces and modifies air eddies. The results are of fundamental interest and can be relevant for aerial bioreactors. (paper)

  12. Osteocytes Mechanosensing in NASA Rotating Wall Bioreactor

    Science.gov (United States)

    Spatz, Jordan; Sibonga, Jean; Wu, Honglu; Barry, Kevin; Bouxsein, Mary; Pajevic, Paola Divieti

    2010-01-01

    Osteocyte cells are the most abundant (90%) yet least understood bone cell type in the human body. Osteocytes are theorized to be the mechanosensors and transducers of mechanical load for bones, yet the biological mechanism of this action remains elusive. However, recent discoveries in osteocyte cell biology have shed light on their importance as key mechanosensing cells regulating bone remodeling and phosphate homeostasis. The aim of this project was to characterize gene expression patterns and protein levels following exposure of MLO-Y4, a very well characterized murine osteocyte-like cell line, to simulated microgravity using the NASA Rotating Wall Vessel (RWV) Bioreactor. To determine mechanistic pathways of the osteocyte's gravity sensing ability, we evaluated in vitro gene and protein expression of osteocytes exposed to simulated microgravity. Improved understanding of the fundamental mechanisms of mechano transduction at the osteocyte cellular level may lead to revolutionary treatment otions to mitigate the effects of bone loss encountered by astronauts on long duration space missions and provide tailored treatment options for maintaining bone strength of immobilized/partially paralyzed patients here on Earth.

  13. Mechanisms and Effectivity of Sulfate Reducing Bioreactors ...

    Science.gov (United States)

    Mining-influenced water (MIW) is the main environmental challenges associated with the mining industry. Passive MIW remediation can be achieved through microbial activity in sulfate-reducing bioreactors (SRBRs), but their actual removal rates depend on different factors, one of which is the substrate composition. Chitinous materials have demonstrated high metal removal rates, particularly for the two recalcitrant MIW contaminants Zn and Mn, but their removal mechanisms need further study. We studied Cd, Fe, Zn, and Mn removal in bioactive and abiotic SRBRs to elucidate the metal removal mechanisms and the differences in metal and sulfate removal rates using a chitinous material as substrate. We found that sulfate-reducing bacteria are effective in increasing metal and sulfate removal rates and duration of operation in SRBRs, and that the main mechanism involved was metal precipitation as sulfides. The solid residues provided evidence of the presence of sulfides in the bioactive column, more specifically ZnS, according to XPS analysis. The feasibility of passive treatments with a chitinous substrate could be an important option for MIW remediation. Mining influenced water (MIW) remediation is still one of the top priorities for the agency because it addresses the most important environmental problem associated with the mining industry and that affects thousands of communities in the U.S. and worldwide. In this paper, the MIW bioremediation mechanisms are studied

  14. Tylosin production by Streptomyces fradiae using raw cornmeal in airlift bioreactor.

    Science.gov (United States)

    Choi, Dubok; Choi, On You; Shin, Hyun-Jae; Chung, Dong-Ok; Shin, Dae-Yewn

    2007-07-01

    Using a 50-l airlift bioreactor, for the effective production of tylosin from Streptomyces fradiae TM-224 using raw cornmeal as the energy source, various environmental factors were studied in flask cultures. The maximum tylosin concentration was obtained at 32 degrees C and pH between 7.0 and 7.5. When seed was inoculated after 24 h of culture, the maximum tylosin concentration, 5.7 g/l, was obtained after 4 days of culture. Various concentrations of raw cornmeal were tested to investigate the optimum initial concentration for the tylosin production. An initial raw cornmeal concentration of 80 g/l gave the highest tylosin concentration, 5.8 g/l, after 5 days of culture. Of the various nitrogen sources, soybean meal and fish meal were found to be the most effective for the production of tylosin. In particular, with the optimal mixing ratio, 12 g/l of soybean meal to 14 g/l of fish meal, 7.2 g/l of tylosin was obtained after 5 days of culture. To compare raw cornmeal and glucose for the production oftylosin in the 50-1 airlift bioreactor for 10 days, fed-batch cultures were carried out under the optimum culture conditions. When raw corn meal was used as the energy source, the tylosin production increased with increasing culture time. The maximum tylosin concentration after 10 days of culture was 13.5 g/l, with a product yield from raw cornmeal of 0.123 g/g of consumed carbon source, which was about 7.2 times higher than that obtained when glucose was used as the carbon source.

  15. Coupled Inverse Fluidized Bed Bioreactor with Advanced Oxidation Processes for Treatment of Vinasse

    Directory of Open Access Journals (Sweden)

    Karla E. Campos Díaz

    2017-11-01

    Full Text Available Vinasse is the wastewater generated from ethanol distillation; it is characterized by high levels of organic and inorganic matter, high exit temperature, dissolved salts and low pH. In this work the treatment of undiluted vinasse was achieved using sequentially-coupled biological and advanced oxidation processes. The initial characterization of vinasse showed a high Chemical Oxygen Demand (COD, 32 kg m-3, high Total Organic Carbon (TOC, 24.5 kg m-3 and low pH (2.5. The first stage of the biological treatment of the vinasse was carried out in an inverse fluidized bed bioreactor with a microbial consortium using polypropylene as support material. The fluidized bed bioreactor was kept at a constant temperature (37 ± 1ºC and pH (6.0 ± 0.5 for 90 days. After the biological process, the vinasse was continuously fed to the photoreactor using a peristaltic pump 2.8 × 10-3 kg of FeSO4•7H2O were added to the vinasse and allowed to dissolve in the dark for five minutes; after this time, 15.3 m3 of hydrogen peroxide (H2O2 (30% w/w were added, and subsequently, the UV radiation was allowed to reach the photoreactor to treat the effluent for 3600 s at pH = 3. Results showed that the maximum organic matter removed using the biological process, measured as COD, was 80% after 90 days. Additionally, 88% of COD removal was achieved using the photo-assisted Fenton oxidation. The overall COD removal after the sequentially-coupled processes reached a value as low as 0.194 kg m-3, achieving over 99% of COD removal as well as complete TOC removal.

  16. Aerobic decolourization of the indigo dye-containing textile wastewater using continuous combined bioreactors

    International Nuclear Information System (INIS)

    Khelifi, Eltaief; Gannoun, Hana; Touhami, Youssef; Bouallagui, Hassib; Hamdi, Moktar

    2008-01-01

    An aerobic bioprocess was applied to Indigo dye-containing textile wastewater treatment aiming at the colour elimination and biodegradation. A combined aerobic system using continuous stirred tank reactor (CSTR) and fixed film bioreactor (FFB) was continuously operated at constant temperature and fed with the textile wastewater (pH: 7.5 and total chemical oxygen demand (COD): 1185 mg l -1 ). The CSTR is a 1 l continuous flow stirred tank reactor with a 700 ml working volume, and operated with a variable wastewater loading rate (WLR) from 0.92 to 3.7 g l -1 d -1 . The FFB is a 1.5 l continuous flow with three compartments packed with a rippled cylindrical polyethylene support, operated with a variable WLR between 0.09 and 0.73 g l -1 d -1 . The combined two bioreactors were inoculated by an acclimated microbial consortium and continuously operated with four total WLR. This system presented high COD elimination and colour removal efficiencies of 97.5% and 97.3%, respectively, obtained with a total hydraulic retention time (HRT) of 4 days and total WLR of 0.29 g l -1 d -1 . The effects of WLR on absorption phenomena on the yield of conversion of substrate on biomass (R TSS/COD ) and on the yield of conversion of substrate on active biomass (R VVS/COD ) are discussed. The increase of WLR and the decrease of HRT diminished the performances of this system in terms of decolourization and COD removal explained by the sloughing of biofilm, and the washout phenomena

  17. Staying alive! Sensors used for monitoring cell health in bioreactors.

    Science.gov (United States)

    O'Mara, P; Farrell, A; Bones, J; Twomey, K

    2018-01-01

    Current and next generation sensors such as pH, dissolved oxygen (dO) and temperature sensors that will help drive the use of single-use bioreactors in industry are reviewed. The current trend in bioreactor use is shifting from the traditional fixed bioreactors to the use of single-use bioreactors (SUBs). However as the shift in paradigm occurs there is now a greater need for sensor technology to play 'catch up' with the innovation of bioreactor technology. Many of the sensors still in use today rely on technology created in the 1960's such as the Clark-type dissolved oxygen sensor or glass pH electrodes. This is due to the strict requirements of sensors to monitor bioprocesses resulting in the use of traditional well understood methods, making it difficult to incorporate new sensor technology into industry. A number of advances in sensor technology have been achieved in recent years, a few of these advances and future research will also be discussed in this review. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Operation of a fluidized-bed bioreactor for denitrification

    International Nuclear Information System (INIS)

    Hancher, C.W.; Taylor, P.A.; Napier, J.M.

    1978-01-01

    Two denitrification fluidized-bed bioreactors of the same length (i.e., 5 m) but with different inside diameters (i.e., 5 and 10 cm) have been operated on feed ranging in nitrate concentration from 200 to 2000 g/m 3 ; thus far, good agreement has been obtained. Two 10-cm-ID bioreactors operating in series have also been tested; the results are in accordance with predicted results based on the performance of a 5-cm-ID bioreactor. The overall denitrification rate in the dual 10-cm-ID bioreactor system was found to be 23 kg N(NO 3 - )/day-m 3 using feed with a nitrate concentration of 1800 g/m 3 . Data obtained in operating-temperature tests indicate that the maximum denitrification rate is achieved between 22 and 30 0 C. These data will form the basis of the design of our mobile pilot plant which consists of dual 20-cm-ID by 7.3-m-long bioreactors

  19. Perfusion cell culture decreases process and product heterogeneity in a head-to-head comparison with fed-batch.

    Science.gov (United States)

    Walther, Jason; Lu, Jiuyi; Hollenbach, Myles; Yu, Marcella; Hwang, Chris; McLarty, Jean; Brower, Kevin

    2018-05-30

    In this study, we compared the impacts of fed-batch and perfusion platforms on process and product attributes for IgG1- and IgG4-producing cell lines. A "plug-and-play" approach was applied to both platforms at bench scale, using commercially available basal and feed media, a standard feed strategy for fed-batch, and ATF filtration for perfusion. Product concentration in fed-batch was 2.5 times greater than perfusion, while average productivity in perfusion was 7.5 times greater than fed-batch. PCA revealed more variability in the cell environment and metabolism during the fed-batch run. LDH measurements showed that exposure of product to cell lysate was 7-10 times greater in fed-batch. Product analysis shows larger abundances of neutral species in perfusion, likely due to decreased bioreactor residence times and extracellular exposure. The IgG1 perfusion product also had higher purity and lower half-antibody. Glycosylation was similar across both culture modes. The first perfusion harvest slice for both product types showed different glycosylation than subsequent harvests, suggesting that product quality lags behind metabolism. In conclusion, process and product data indicate that intra-lot heterogeneity is decreased in perfusion cultures. Additional data and discussion is required to understand the developmental, clinical and commercial implications, and in what situations increased uniformity would be beneficial. This article is protected by copyright. All rights reserved.

  20. Plantform Bioreactor for Mass Micropropagation of Date Palm.

    Science.gov (United States)

    Almusawi, Abdulminam H A; Sayegh, Abdullah J; Alshanaw, Ansam M S; Griffis, John L

    2017-01-01

    A novel protocol for the commercial production of date palm through micropropagation is presented. This protocol includes the use of a semisolid medium alternation or in combination with a temporary immersion system (TIS, Plantform bioreactor) in date palm micropropagation. The use of the Plantform bioreactor for date palm results in an improved multiplication rate, reduced micropropagation time, and improved weaning success. It also reduces the cost of saleable units and thus improves economic return for commercial micropropagation. The use of the Plantform bioreactor successfully addresses other hindrances that can occur during the scale-up of date palm micropropagation, including asynchrony of somatic embryos, limited maturation of somatic embryos, and highly variable germination frequencies of embryos.

  1. Miniature Bioreactor System for Long-Term Cell Culture

    Science.gov (United States)

    Gonda, Steve R.; Kleis, Stanley J.; Geffert, Sandara K.

    2010-01-01

    A prototype miniature bioreactor system is designed to serve as a laboratory benchtop cell-culturing system that minimizes the need for relatively expensive equipment and reagents and can be operated under computer control, thereby reducing the time and effort required of human investigators and reducing uncertainty in results. The system includes a bioreactor, a fluid-handling subsystem, a chamber wherein the bioreactor is maintained in a controlled atmosphere at a controlled temperature, and associated control subsystems. The system can be used to culture both anchorage-dependent and suspension cells, which can be either prokaryotic or eukaryotic. Cells can be cultured for extended periods of time in this system, and samples of cells can be extracted and analyzed at specified intervals. By integrating this system with one or more microanalytical instrument(s), one can construct a complete automated analytical system that can be tailored to perform one or more of a large variety of assays.

  2. Bioreactor droplets from liposome-stabilized all-aqueous emulsions

    Science.gov (United States)

    Dewey, Daniel C.; Strulson, Christopher A.; Cacace, David N.; Bevilacqua, Philip C.; Keating, Christine D.

    2014-08-01

    Artificial bioreactors are desirable for in vitro biochemical studies and as protocells. A key challenge is maintaining a favourable internal environment while allowing substrate entry and product departure. We show that semipermeable, size-controlled bioreactors with aqueous, macromolecularly crowded interiors can be assembled by liposome stabilization of an all-aqueous emulsion. Dextran-rich aqueous droplets are dispersed in a continuous polyethylene glycol (PEG)-rich aqueous phase, with coalescence inhibited by adsorbed ~130-nm diameter liposomes. Fluorescence recovery after photobleaching and dynamic light scattering data indicate that the liposomes, which are PEGylated and negatively charged, remain intact at the interface for extended time. Inter-droplet repulsion provides electrostatic stabilization of the emulsion, with droplet coalescence prevented even for submonolayer interfacial coatings. RNA and DNA can enter and exit aqueous droplets by diffusion, with final concentrations dictated by partitioning. The capacity to serve as microscale bioreactors is established by demonstrating a ribozyme cleavage reaction within the liposome-coated droplets.

  3. Streamlined bioreactor-based production of human cartilage tissues.

    Science.gov (United States)

    Tonnarelli, B; Santoro, R; Adelaide Asnaghi, M; Wendt, D

    2016-05-27

    Engineered tissue grafts have been manufactured using methods based predominantly on traditional labour-intensive manual benchtop techniques. These methods impart significant regulatory and economic challenges, hindering the successful translation of engineered tissue products to the clinic. Alternatively, bioreactor-based production systems have the potential to overcome such limitations. In this work, we present an innovative manufacturing approach to engineer cartilage tissue within a single bioreactor system, starting from freshly isolated human primary chondrocytes, through the generation of cartilaginous tissue grafts. The limited number of primary chondrocytes that can be isolated from a small clinically-sized cartilage biopsy could be seeded and extensively expanded directly within a 3D scaffold in our perfusion bioreactor (5.4 ± 0.9 doublings in 2 weeks), bypassing conventional 2D expansion in flasks. Chondrocytes expanded in 3D scaffolds better maintained a chondrogenic phenotype than chondrocytes expanded on plastic flasks (collagen type II mRNA, 18-fold; Sox-9, 11-fold). After this "3D expansion" phase, bioreactor culture conditions were changed to subsequently support chondrogenic differentiation for two weeks. Engineered tissues based on 3D-expanded chondrocytes were more cartilaginous than tissues generated from chondrocytes previously expanded in flasks. We then demonstrated that this streamlined bioreactor-based process could be adapted to effectively generate up-scaled cartilage grafts in a size with clinical relevance (50 mm diameter). Streamlined and robust tissue engineering processes, as the one described here, may be key for the future manufacturing of grafts for clinical applications, as they facilitate the establishment of compact and closed bioreactor-based production systems, with minimal automation requirements, lower operating costs, and increased compliance to regulatory guidelines.

  4. Biological reduction of nitrate wastewater using fluidized-bed bioreactors

    International Nuclear Information System (INIS)

    Walker, J.F. Jr.; Hancher, C.W.; Patton, B.D.; Kowalchuk, M.

    1981-01-01

    There are a number of nitrate-containing wastewater sources, as concentrated as 30 wt % NO 3 - and as large as 2000 m 3 /d, in the nuclear fuel cycle as well as in many commercial processes such as fertilizer production, paper manufacturing, and metal finishing. These nitrate-containing wastewater sources can be successfully biologically denitrified to meet discharge standards in the range of 10 to 20 gN(NO 3 - )/m 3 by the use of a fluidized-bed bioreactor. The major strain of denitrification bacteria is Pseudomonas which was derived from garden soil. In the fluidized-bed bioreactor the bacteria are allowed to attach to 0.25 to 0.50-mm-diam coal particles, which are fluidized by the upward flow of influent wastewater. Maintaining the bacteria-to-coal weight ratio at approximately 1:10 results in a bioreactor bacteria loading of greater than 20,000 g/m 3 . A description is given of the results of two biodenitrification R and D pilot plant programs based on the use of fluidized bioreactors capable of operating at nitrate levels up to 7000 g/m 3 and achieving denitrification rates as high as 80 gN(NO 3 - )/d per liter of empty bioreactor volume. The first of these pilot plant programs consisted of two 0.2-m-diam bioreactors, each with a height of 6.3 m and a volume of 208 liters, operating in series. The second pilot plant was used to determine the diameter dependence of the reactors by using a 0.5-m-diam reactor with a height of 6.3 m and a volume of 1200 liters. These pilot plants operated for a period of six months and two months respectively, while using both a synthetic waste and the actual waste from a gaseous diffusion plant operated by Goodyear Atomic Corporation

  5. Alcohol production from sterilized and non-sterilized molasses by Saccharomyces cerevisiae immobilized on brewer's spent grains in two types of continuous bioreactor systems

    International Nuclear Information System (INIS)

    Kopsahelis, Nikolaos; Bosnea, Loulouda; Bekatorou, Argyro; Tzia, Constantina; Kanellaki, Maria

    2012-01-01

    In this work an integrated cost effective system for continuous alcoholic fermentation of a cheap raw material (molasses) is described, involving yeast immobilized by a simple method on brewer's spent grains, able to ferment in the temperature range 30–40 °C, and two types of bioreactors, a Multistage Fixed Bed Tower (MFBT) and a Packed Bed reactor (PB). The MFBT bioreactor gave better results regarding ethanol concentration, productivity and conversion. Furthermore, the use of sterilized and non-sterilized molasses, fed in two similar MFBT bioreactors, showed that ethanol concentration (kg m −3 ) was significantly (p −3 at 35 °C and 44.2–48.2 kg m −3 at 40 °C), compared to sterilized molasses, where ethanol concentration ranged from 35.6 to 46.6 kg m −3 at 35 °C and 30.8–44.2 kg m −3 at 40 °C. During 32 days of continuous operation using non-sterilized molasses no contamination was observed. Industrialization of the proposed system seems to have a potential, mainly due to its high fermentation efficiency and the obtained high operational stability. -- Highlights: ► An integrated cost effective system for continuous alcoholic fermentation. ► Efficient conversion of non-sterilized molasses to ethanol. ► No need for additional treatments to prevent contamination. ► Results showed high fermentation efficiency and high operational stability.

  6. FED pumped limiter configuration issues

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma-edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

  7. FED pumped limiter configuration issues

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

  8. BIOREACTOR WITH LID FOR EASY ACCESS TO INCUBATION CAVITY

    DEFF Research Database (Denmark)

    2012-01-01

    There is provided a bioreactor which is provided with a lid (13) that facilitates access to the incubation cavity. Specifically the end wall of the incubation cavity is constituted by the lid (13) so that removal of the cap renders the incubation cavity fully accessible.......There is provided a bioreactor which is provided with a lid (13) that facilitates access to the incubation cavity. Specifically the end wall of the incubation cavity is constituted by the lid (13) so that removal of the cap renders the incubation cavity fully accessible....

  9. Hydraulic Behavior in The Downflow Hanging Sponge Bioreactor

    Directory of Open Access Journals (Sweden)

    Izarul Machdar

    2016-12-01

    Full Text Available Performance efficiency in a Downflow Hanging Sponge (DHS bioreactor is associated with the amount of time that a wastewater remains in the bioreactor. The bioreactor is considered as a plug flow reactor and its hydraulic residence time (HRT depends on the void volume of packing material and the flow rate. In this study, hydraulic behavior of DHS bioreactor was investigated by using tracer method. Two types of sponge module covers, cylindrical plastic frame (module-1 and plastic hair roller (module-2, were investigated and compared. A concentrated NaCl solution used as an inert tracer and input as a pulse at the inlet of DHS bioreactor. Analysis of the residence time distribution (RTD curves provided interpretation of the index distribution or holdup water (active volume, the degree of short-circuiting, number of tanks in series (the plug flow characteristic, and the dispersion number. It was found that the actual HRT was primarily shorter than theoretical HRT of each test. Holdup water of the DHS bioreactor ranged from 60% to 97% and 36% to 60% of module-1 and module-2, respectively. Eventhough module-1 has higher effective volume than module-2, result showed that the dispersion numbers of the two modules were not significant difference. Furthermore, N-values were found larger at a higher flow rate. It was concluded that a DHS bioreactor design should incorporated a combination of water distributor system, higher loading rate at startup process to generate a hydraulic behavior closer to an ideal plug flow.ABSTRAKEfisiensi unjuk kerja bioreactor Downflow Hanging Sponge (DHS berkaitan dengan lamanya waktu tinggal limbah berada di dalam bioreaktor tersebut. Bioreaktor DHS dianggap sebagai seuatu reaktor aliran sumbat (plug flow dimana waktu tinggal hidraulik (HRT tergantung pada volume pori material isian dan laju alir. Dua jenis modul digunakan dalam penelitian ini, yang diberi nama dengan module-1 dan module-2 untuk melihat pengaruh jenis modul

  10. ANAEROBIC MEMBRANE BIOREACTORS FOR DOMESTIC WASTEWATER TREATMENT. PRELIMINARY STUDY

    Directory of Open Access Journals (Sweden)

    Luisa Vera

    2014-12-01

    Full Text Available The operation of submerged anaerobic membrane bioreactors (SAnMBRs for domestic wastewaters treatment was studied in laboratory scale, with the objective to define sustainable filtration conditions of the suspensions along the process. During continuous experiments, the organic matter degradation by anaerobic way showed an average DQOT removal of 85% and 93%. Indeed, the degradation generated biogas after 12 days of operation and its relative methane composition was of 60% after 25 days of operation. Additionally, the comparison between membrane bioreactors (MBRs performance in aerobic and anaerobic conditions in filterability terms, reported that both systems behave similarly once reached the stationary state.

  11. Evaluation of a kinetic model for computer simulation of growth and fermentation by Scheffersomyces (Pichia) stipitis fed D-xylose.

    Science.gov (United States)

    Slininger, P J; Dien, B S; Lomont, J M; Bothast, R J; Ladisch, M R; Okos, M R

    2014-08-01

    Scheffersomyces (formerly Pichia) stipitis is a potential biocatalyst for converting lignocelluloses to ethanol because the yeast natively ferments xylose. An unstructured kinetic model based upon a system of linear differential equations has been formulated that describes growth and ethanol production as functions of ethanol, oxygen, and xylose concentrations for both growth and fermentation stages. The model was validated for various growth conditions including batch, cell recycle, batch with in situ ethanol removal and fed-batch. The model provides a summary of basic physiological yeast properties and is an important tool for simulating and optimizing various culture conditions and evaluating various bioreactor designs for ethanol production. © 2014 Wiley Periodicals, Inc.

  12. Acetate production from whey lactose using co-immobilized cells of homolactic and homoacetic bacteria in a fibrous-bed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y.; Yang, S.T. [Ohio State Univ., Columbus, OH (United States). Dept. of Chemical Engineering

    1998-11-20

    Acetate was produced from whey lactose in batch and fed-batch fermentations using co-immobilized cells of Clostridium formicoaceticum and Lactococcus lactis. The cells were immobilized in a spirally wound fibrous sheet packed in a 0.45-L column reactor, with liquid circulated through a 5-L stirred-tank fermentor. Industrial-grade nitrogen sources, including corn steep liquor, casein hydrolysate, and yeast hydrolysate, were studied as inexpensive nutrient supplements to whey permeate and acid whey. Supplementation with either 2.5% (v/v) corn steep liquor or 1.5 g/L casein hydrolysate was adequate for the cocultured fermentation. The overall acetic acid yield from lactose was 0.9 g/g, and the productivity was 0.25 g/(L h). Both lactate and acetate at high concentrations inhibited the homoacetic fermentation. To overcome these inhibitions, fed-batch fermentations were used to keep lactate concentration low and to adapt cells to high-concentration acetate. The final acetate concentration obtained in the fed-batch fermentations were used to keep lactate concentration low and to adapt cells to high-concentration acetate. The final acetate concentration obtained in the fed-batch fermentation was 75 g/L, which was the highest acetate concentration ever produced by C. formicoaceticum. Even at this high acetate concentration, the overall productivity was 0.18 g/(L h) based on the total medium volume and 1.23 g/(L h) based on the fibrous-bed reactor volume. The cells isolated from the fibrous-bed bioreactor at the end of this study were more tolerant to acetic acid than the original culture used to seed the bioreactor, indicating that adaptation and natural selection of acetate-tolerant strains occurred. This cocultured fermentation process could be used to produce a low-cost acetate deicer from whey permeate and acid whey.

  13. Introducing Textiles as Material of Construction of Ethanol Bioreactors

    Directory of Open Access Journals (Sweden)

    Osagie A. Osadolor

    2014-11-01

    Full Text Available The conventional materials for constructing bioreactors for ethanol production are stainless and cladded carbon steel because of the corrosive behaviour of the fermenting media. As an alternative and cheaper material of construction, a novel textile bioreactor was developed and examined. The textile, coated with several layers to withstand the pressure, resist the chemicals inside the reactor and to be gas-proof was welded to form a 30 L lab reactor. The reactor had excellent performance for fermentative production of bioethanol from sugar using baker’s yeast. Experiments with temperature and mixing as process parameters were performed. No bacterial contamination was observed. Bioethanol was produced for all conditions considered with the optimum fermentation time of 15 h and ethanol yield of 0.48 g/g sucrose. The need for mixing and temperature control can be eliminated. Using a textile bioreactor at room temperature of 22 °C without mixing required 2.5 times longer retention time to produce bioethanol than at 30 °C with mixing. This will reduce the fermentation investment cost by 26% for an ethanol plant with capacity of 100,000 m3 ethanol/y. Also, replacing one 1300 m3 stainless steel reactor with 1300 m3 of the textile bioreactor in this plant will reduce the fermentation investment cost by 19%.

  14. Numerical study of fluid motion in bioreactor with two mixers

    Energy Technology Data Exchange (ETDEWEB)

    Zheleva, I., E-mail: izheleva@uni-ruse.bg [Department of Heat Technology, Hydraulics and Ecology, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria); Lecheva, A., E-mail: alecheva@uni-ruse.bg [Department of Mathematics, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria)

    2015-10-28

    Numerical study of hydrodynamic laminar behavior of a viscous fluid in bioreactor with multiple mixers is provided in the present paper. The reactor is equipped with two disk impellers. The fluid motion is studied in stream function-vorticity formulation. The calculations are made by a computer program, written in MATLAB. The fluid structure is described and numerical results are graphically presented and commented.

  15. Membrane bioreactor biomass characteristics and microbial yield at ...

    African Journals Online (AJOL)

    In this study, a laboratory-scale MBR and SBR were operated in parallel and at very low MCRTs (3 d, 2 d, 1 d and 0.5 d) to assess the relative bioreactor performance, biomass characteristics, and microbial yield. This study confirmed that the MBR maintains higher solids levels and better overall effluent quality than ...

  16. Integrated sensor array for on-line monitoring micro bioreactors

    NARCIS (Netherlands)

    Krommenhoek, E.E.

    2007-01-01

    The “Fed��?batch on a chip��?��?project, which was carried out in close cooperation with the Technical University of Delft, aims to miniaturize and parallelize micro bioreactors suitable for on-line screening of micro-organisms. This thesis describes an electrochemical sensor array which has been

  17. Modelling and characterization of an airlift-loop bioreactor

    NARCIS (Netherlands)

    Verlaan, P.

    1987-01-01

    An airlift-loop reactor is a bioreactor for aerobic biotechnological processes. The special feature of the ALR is the recirculation of the liquid through a downcomer connecting the top and the bottom of the main bubbling section. Due to the high circulation-flow rate, efficient mixing and

  18. The kinetics of crossflow dynamic membrane bioreactor | Li | Water SA

    African Journals Online (AJOL)

    Crossflow dynamic membrane bioreactor (CDMBR) kinetics was investigated by treating caprolactam wastewater over a period of 180 d. The removal efficiencies of organic substances and nitrogen averaged over 99% and 80%, respectively. The observed sludge yield was only 0.14 g SS·g-1 COD·d-1 at an SRT of 30 d ...

  19. MODULAR FIELD-BIOREACTOR FOR ACID MINE DRAINAGE TREATMENT

    Science.gov (United States)

    The presentation focuses on the improvements to engineered features of a passive technology that has been used for remediation of acid rock drainage (ARD). This passive remedial technology, a sulfate-reducing bacteria (SRB) bioreactor, takes advantage of the ability of SRB that,...

  20. Anaerobic dynamic membrane bioreactors for high strength wastewater treatment

    NARCIS (Netherlands)

    Ersahin, M.E.; Gimenez Garcia, J.B.; Ozgun, H.; Tao, Y.; Van Lier, J.B.

    2013-01-01

    A laboratory scale external anaerobic dynamic membrane bioreactor (AnDMBR) treating high strength wastewater was operated to assess the effect of gas sparging velocity and organic loading rate on removal efficiency and dynamic membrane (DM) filtration characteristics. An increase in gas sparging

  1. Microfluidic bioreactors for culture of non-adherent cells

    DEFF Research Database (Denmark)

    Shah, Pranjul Jaykumar; Vedarethinam, Indumathi; Kwasny, Dorota

    2011-01-01

    Microfluidic bioreactors (μBR) are becoming increasingly popular for cell culture, sample preparation and analysis in case of routine genetic and clinical diagnostics. We present a novel μBR for non-adherent cells designed to mimic in vivo perfusion of cells based on diffusion of media through...

  2. Shell of Planet Earth – Global Batch Bioreactor.

    Czech Academy of Sciences Publication Activity Database

    Hanika, Jiří; Šolcová, Olga; Kaštánek, P.

    2017-01-01

    Roč. 40, č. 11 (2017), s. 1959-1965 ISSN 0930-7516 R&D Projects: GA TA ČR TE01020080 Institutional support: RVO:67985858 Keywords : critical raw materials * global batch bioreactor * planet earth Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.051, year: 2016

  3. Anaerobic Membrane Bioreactors For Cost-Effective Municipal Water Reuse

    NARCIS (Netherlands)

    Özgün, H.

    2015-01-01

    In recent years, anaerobic membrane bioreactor (AnMBR) technology has been increasingly researched for municipal wastewater treatment as a means to produce nutrient-rich, solids free effluents with low levels of pathogens, while occupying a small footprint. An AnMBR can be used not only for on-site

  4. MEASUREMENT OF FUGITIVE EMISSIONS AT A BIOREACTOR LANDFILL

    Science.gov (United States)

    This report focuses on three field campaigns performed in 2002 and 2003 to measure fugitive emissions at a bioreactor landfill in Louisville, KY, using an open-path Fourier transform infrared spectrometer. The study uses optical remote sensing-radial plume mapping. The horizontal...

  5. Cell culture experiments planned for the space bioreactor

    Science.gov (United States)

    Morrison, Dennis R.; Cross, John H.

    1987-01-01

    Culturing of cells in a pilot-scale bioreactor remains to be done in microgravity. An approach is presented based on several studies of cell culture systems. Previous and current cell culture research in microgravity which is specifically directed towards development of a space bioprocess is described. Cell culture experiments planned for a microgravity sciences mission are described in abstract form.

  6. Enhancing inhibited fermentations through a dynamic electro-membrane bioreactor

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres; Garde, Arvid; Rype, Jens-Ulrik

    produced in the bioreactor) with hydroxide ions, which maintained a pH close to optimal growing conditions. The ion-exchange was in turn regulated by a PID control unit, which adjusted the electrical current output between the REED electrodes to match the growing production speed of lactic acid, which...

  7. Quantitative analysis of microbial biomass yield in aerobic bioreactor.

    Science.gov (United States)

    Watanabe, Osamu; Isoda, Satoru

    2013-12-01

    We have studied the integrated model of reaction rate equations with thermal energy balance in aerobic bioreactor for food waste decomposition and showed that the integrated model has the capability both of monitoring microbial activity in real time and of analyzing biodegradation kinetics and thermal-hydrodynamic properties. On the other hand, concerning microbial metabolism, it was known that balancing catabolic reactions with anabolic reactions in terms of energy and electron flow provides stoichiometric metabolic reactions and enables the estimation of microbial biomass yield (stoichiometric reaction model). We have studied a method for estimating real-time microbial biomass yield in the bioreactor during food waste decomposition by combining the integrated model with the stoichiometric reaction model. As a result, it was found that the time course of microbial biomass yield in the bioreactor during decomposition can be evaluated using the operational data of the bioreactor (weight of input food waste and bed temperature) by the combined model. The combined model can be applied to manage a food waste decomposition not only for controlling system operation to keep microbial activity stable, but also for producing value-added products such as compost on optimum condition. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  8. Bioreactors for Tissue Engineering of Cartilage

    Science.gov (United States)

    Concaro, S.; Gustavson, F.; Gatenholm, P.

    The cartilage regenerative medicine field has evolved during the last decades. The first-generation technology, autologous chondrocyte transplantation (ACT) involved the transplantation of in vitro expanded chondrocytes to cartilage defects. The second generation involves the seeding of chondrocytes in a three-dimensional scaffold. The technique has several potential advantages such as the ability of arthroscopic implantation, in vitro pre-differentiation of cells and implant stability among others (Brittberg M, Lindahl A, Nilsson A, Ohlsson C, Isaksson O, Peterson L, N Engl J Med 331(14):889-895, 1994; Henderson I, Francisco R, Oakes B, Cameron J, Knee 12(3):209-216, 2005; Peterson L, Minas T, Brittberg M, Nilsson A, Sjogren-Jansson E, Lindahl A, Clin Orthop (374):212-234, 2000; Nagel-Heyer S, Goepfert C, Feyerabend F, Petersen JP, Adamietz P, Meenen NM, et al. Bioprocess Biosyst Eng 27(4):273-280, 2005; Portner R, Nagel-Heyer S, Goepfert C, Adamietz P, Meenen NM, J Biosci Bioeng 100(3):235-245, 2005; Nagel-Heyer S, Goepfert C, Adamietz P, Meenen NM, Portner R, J Biotechnol 121(4):486-497, 2006; Heyland J, Wiegandt K, Goepfert C, Nagel-Heyer S, Ilinich E, Schumacher U, et al. Biotechnol Lett 28(20):1641-1648, 2006). The nutritional requirements of cells that are synthesizing extra-cellular matrix increase along the differentiation process. The mass transfer must be increased according to the tissue properties. Bioreactors represent an attractive tool to accelerate the biochemical and mechanical properties of the engineered tissues providing adequate mass transfer and physical stimuli. Different reactor systems have been [5] developed during the last decades based on different physical stimulation concepts. Static and dynamic compression, confined and nonconfined compression-based reactors have been described in this review. Perfusion systems represent an attractive way of culturing constructs under dynamic conditions. Several groups showed increased matrix

  9. Influence of methanol/sorbitol co-feeding rate on pAOX1 induction in a Pichia pastoris Mut+ strain in bioreactor with limited oxygen transfer rate.

    Science.gov (United States)

    Carly, F; Niu, H; Delvigne, F; Fickers, P

    2016-04-01

    High Pichia pastoris biomass density could be obtained using high co-feeding rate of methanol and sorbitol in a fed-batch or continuous culture, while further higher feeding rate finally leads to oxygen limitation in bioreactor. In the literature, there is lack of report about AOX1 promoter regulation with regard to dissolved oxygen level (DO). Therefore, in this work, chemostat cultures were performed to investigate the cell growth, metabolism and regulation of the AOX1 promoter (pAOX1) regarding co-feeding rate of optimized methanol/sorbitol mixture (methanol fraction 0.60 C-mol/C-mol) using a P. pastoris Mut+/pAOX1-lacZ strain. The oxygen transfer rates (OTR) in bioreactor were kept in the range of typical values of large bioreactor, i.e., 4-8 g/(L h) if DO equals 30 % saturation or 5-10 g/(L h) if DO nears zero. For DO >0, an increase of the carbon fed led to an increase of pAOX1 induction. By contrast, when dissolved oxygen was completely depleted, methanol accumulated, causing a 30 % decrease of pAOX1 induction. However, this decrease is more likely to be lined to methanol accumulation than to low level of dissolved oxygen (sorbitol co-feeding allowed cells to adapt to oxygen transient limitations that often occur at industrial scale with reduced effect on pAOX1 induction. The optimal feeding rate tested here was 6.6 mmol C (DCW h)(-1) at an OTR of 8.28 g O2(L h)(-1) with over fivefold pAOX1 induction (probably directly associated with target protein productivity) compared with previous work.

  10. Development of a mathematical model for the growth associated Polyhydroxybutyrate fermentation by Azohydromonas australica and its use for the design of fed-batch cultivation strategies.

    Science.gov (United States)

    Gahlawat, Geeta; Srivastava, Ashok K

    2013-06-01

    In the present investigation, batch cultivation of Azohydromonas australica DSM 1124 was carried out in a bioreactor for growth associated PHB production. The observed batch PHB production kinetics data was then used for the development of a mathematical model which adequately described the substrate limitation and inhibition during the cultivation. The statistical validity test demonstrated that the proposed mathematical model predictions were significant at 99% confidence level. The model was thereafter extrapolated to fed-batch to identify various nutrients feeding regimes during the bioreactor cultivation to improve the PHB accumulation. The distinct capability of the mathematical model to predict highly dynamic fed-batch cultivation strategies was demonstrated by experimental implementation of two fed-batch cultivation strategies. A significantly high PHB concentration of 22.65 g/L & an overall PHB content of 76% was achieved during constant feed rate fed-batch cultivation which is the highest PHB content reported so far using A. australica. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Lactic acid Production with in situ Extraction in Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    Hamidreza Ghafouri Taleghani

    2017-01-01

    Full Text Available Background and Objective: Lactic acid is widely used in the food, chemical and pharmaceutical industries. The major problems associated with lactic acid production are substrate and end-product inhibition, and by-product formation. Membrane technologyrepresents one of the most effective processes for lactic acid production. The aim of this work is to increase cell density and lactic acid productivity due to reduced inhibition effect of substrate and product in membrane bioreactor.Material and Methods: In this work, lactic acid was produced from lactose in membrane bioreactor. A laboratory scale membrane bioreactor was designed and fabricated. Five types of commercial membranes were tested at the same operating conditions (transmembrane pressure: 500 KPa and temperature: 25°C. The effects of initial lactose concentration and dilution rate on biomass growth, lactic acid production and substrate utilization were evaluated.Results and Conclusion: The high lactose retention of 79% v v-1 and low lactic acid retention of 22% v v-1 were obtained with NF1 membrane; therefore, this membrane was selected for membrane bioreactor. The maximal productivity of 17.1 g l-1 h-1 was obtainedwith the lactic acid concentration of 71.5 g l-1 at the dilution rate of 0.24 h−1. The maximum concentration of lactic acid was obtained at the dilution rate of 0.04 h−1. The inhibiting effect of lactic acid was not observed at high initial lactose concentration. The critical lactose concentration at which the cell growth severely hampered was 150 g l-1. This study proved that membrane bioreactor had great advantages such as elimination of substrate and product inhibition, high concentration of process substrate, high cell density,and high lactic acid productivity.Conflict of interest: There is no conflict of interest.

  12. Biological treatment of N-nitrosodimethylamine (NDMA) and N-nitrodimethylamine (NTDMA) in a field-scale fluidized bed bioreactor.

    Science.gov (United States)

    Hatzinger, Paul B; Lewis, Celeste; Webster, Todd S

    2017-12-01

    The ex situ treatment of N-nitrosodimethylamine (NDMA) and N-nitrodimethylamine (NTDMA) in groundwater was evaluated in a field-scale fluidized bed bioreactor (FBR). Both of these compounds, which originally entered groundwater at the test site from the use of liquid rocket propellant, are suspected human carcinogens. The objective of this research was to examine the application of a novel field-scale propane-fed fluidized bed bioreactor as an alternative to ultraviolet irradiation (UV) for treating NDMA and NTDMA to low part-per-trillion (ng/L) concentrations. Previous laboratory studies have shown that the bacterium Rhodococcus ruber ENV425 can biodegrade NDMA and NTDMA during growth on propane as a primary substrate and that the strain can effectively reduce NDMA concentrations in propane-fed bench-scale bioreactors of different design. R. ruber ENV425 was used as a seed culture for the FBR, which operated at a fluidization flow of ∼19 L-per-min (LPM) and received propane, oxygen, and inorganic nutrients in the feed. The reactor effectively treated ∼1 μg/L of influent NDMA to effluent concentrations of less than 10 ng/L at a hydraulic residence time (HRT) of only 10 min. At a 20 min HRT, the FBR reduced NDMA to NDMA and NTDMA elimination capacities achieved were 2.1 mg NDMA treated/m 3 of expanded bed/hr of operation and 1.1 mg NTDMA treated/m 3 of expanded bed/hr of operation, respectively. The FBR system was highly resilient to upsets including power outages. Treatment of NDMA, but not NTDMA, was marginally affected when trace co-contaminants including trichloroethene (TCE) and trichlorofluoromethane (Freon 11) were initially added to feed groundwater, but performance recovered over a few weeks in the continued presence of these compounds. Strain ENV425 appeared to be replaced by native propanotrophs over time based on qPCR analysis, but contaminant treatment was not diminished. The results suggest that a FBR can be a viable alternative to UV

  13. A Multiple-objective Optimization of Whey Fermentation in Stirred Tank Bioreactors

    Directory of Open Access Journals (Sweden)

    Mitko Petrov

    2006-12-01

    Full Text Available A multiple-objective optimization is applied to find an optimal policy of a fed-batch fermentation process for lactose oxidation from a natural substratum of the strain Kluyveromyces marxianus var. lactis MC5. The optimal policy is consisted of feed flow rate, agitation speed, and gas flow rate. The multiple-objective problem includes: the total price of the biomass production, the second objective functions are the separation cost in downstream processing and the third objective function corresponds to the oxygen mass-transfer in the bioreactor. The multiple-objective optimization are transforming to standard problem for optimization with single-objective function. Local criteria are defined utility function with different weight for single-type vector task. A fuzzy sets method is applied to be solved the maximizing decision problem. A simple combined algorithm guideline to find a satisfactory solution to the general multiple-objective optimization problem. The obtained optimal control results have shown an increase of the process productiveness and a decrease of the residual substrate concentration.

  14. Soil infiltration bioreactor incorporated with pyrite-based (mixotrophic) denitrification for domestic wastewater treatment.

    Science.gov (United States)

    Kong, Zhe; Li, Lu; Feng, Chuanping; Chen, Nan; Dong, Shanshan; Hu, Weiwu

    2015-01-01

    In this study, an integrated two-stage soil infiltration bioreactor incorporated with pyrite-based (mixotrophic) denitrification (SIBPD) was designed for domestic wastewater treatment. Benefited from excellent adsorption ability and water-permeability, soil infiltration could avoid clogging, shorten operating time and lower maintenance cost. Respiration and nitrification were mostly engaged in aerobic stage (AES), while nitrate was majorly removed by pyrite-based mixotrophic denitrification mainly occurred in anaerobic stage (ANS). Fed with synthetic and real wastewater for 120days at 1.5h HRT, SIBPD demonstrated good removal performance showing 87.14% for COD, 92.84% for NH4(+)-N and 82.58% for TP along with 80.72% of nitrate removed by ANS. TN removal efficiency was 83.74% when conducting real wastewater. Compared with sulfur-based process, the effluent pH of SIBPD was maintained at 6.99-7.34 and the highest SO4(2-) concentration was only 64.63mgL(-1). This study revealed a promising and feasible application prospect for on-site domestic wastewater treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Performance of novel sludge-bed anaerobic membrane bioreactor (SB-AnMBR) treating prehydrolysis liquor.

    Science.gov (United States)

    Kale, Mayur M; Singh, Kripa S

    2014-01-01

    The feasibility of a novel sludge-bed anaerobic membrane bioreactor (SB-AnMBR) configuration for treating a waste stream from a dissolving pulp production industry was evaluated. The waste stream, called prehydrolysis liquor (PHL), is generated after the wood chips are subjected to high temperature steam to remove unwanted hemicelluloses. The PHL with total chemical oxygen demand (COD) of approximately 100 g/L contained mainly sugars, furfural, lignin, and acetic acid. The SB-AnMBR was fed with the PHL at organic loading rates in a range of 0.8 to10 kg-COD/(m(3)·d). The COD removal efficiency of more than 85% and an average rate of methane production of 0.35 m(3)/(kg-COD·d) were observed at each loading rate. No detectable sugars or furfural were present in the treated effluent from SB-AnMBR. Lignin removal varied from 60 to 90%. Flat-sheet membranes performed well with one fouling event during first 400 days of operation.

  16. High-rate, High Temperature Acetotrophic Methanogenesis Governed by a Three Population Consortium in Anaerobic Bioreactors.

    Directory of Open Access Journals (Sweden)

    Dang Ho

    Full Text Available A combination of acetate oxidation and acetoclastic methanogenesis has been previously identified to enable high-rate methanogenesis at high temperatures (55 to 65°C, but this capability had not been linked to any key organisms. This study combined RNA-stable isotope probing on 13C-labelled acetate and 16S amplicon sequencing to identify the active micro-organisms involved in high-rate methanogenesis. Active biomass was harvested from three bench-scale thermophilic bioreactors treating waste activated sludge at 55, 60 and 65°C, and fed with 13-C labelled and 12C-unlabelled acetate. Acetate uptake and cumulative methane production were determined and kinetic parameters were estimated using model-based analysis. Pyrosequencing performed on 13C- enriched samples indicated that organisms accumulating labelled carbon were Coprothermobacter (all temperatures between 55 and 65°C, acetoclastic Methanosarcina (55 to 60°C and hydrogenotrophic Methanothermobacter (60 to 65°C. The increased relative abundance of Coprothermobacter with increased temperature corresponding with a shift to syntrophic acetate oxidation identified this as a potentially key oxidiser. Methanosarcina likely acts as both a hydrogen utilising and acetoclastic methanogen at 55°C, and is replaced by Methanothermobacter as a hydrogen utiliser at higher temperatures.

  17. High-rate, High Temperature Acetotrophic Methanogenesis Governed by a Three Population Consortium in Anaerobic Bioreactors.

    Science.gov (United States)

    Ho, Dang; Jensen, Paul; Gutierrez-Zamora, Maria-Luisa; Beckmann, Sabrina; Manefield, Mike; Batstone, Damien

    2016-01-01

    A combination of acetate oxidation and acetoclastic methanogenesis has been previously identified to enable high-rate methanogenesis at high temperatures (55 to 65°C), but this capability had not been linked to any key organisms. This study combined RNA-stable isotope probing on 13C-labelled acetate and 16S amplicon sequencing to identify the active micro-organisms involved in high-rate methanogenesis. Active biomass was harvested from three bench-scale thermophilic bioreactors treating waste activated sludge at 55, 60 and 65°C, and fed with 13-C labelled and 12C-unlabelled acetate. Acetate uptake and cumulative methane production were determined and kinetic parameters were estimated using model-based analysis. Pyrosequencing performed on 13C- enriched samples indicated that organisms accumulating labelled carbon were Coprothermobacter (all temperatures between 55 and 65°C), acetoclastic Methanosarcina (55 to 60°C) and hydrogenotrophic Methanothermobacter (60 to 65°C). The increased relative abundance of Coprothermobacter with increased temperature corresponding with a shift to syntrophic acetate oxidation identified this as a potentially key oxidiser. Methanosarcina likely acts as both a hydrogen utilising and acetoclastic methanogen at 55°C, and is replaced by Methanothermobacter as a hydrogen utiliser at higher temperatures.

  18. Influence of membrane fouling reducers (MFRs) on filterability of disperse mixed liquor of jet loop bioreactors.

    Science.gov (United States)

    Koseoglu-Imer, Derya Yuksel; Dizge, Nadir; Karagunduz, Ahmet; Keskinler, Bulent

    2011-07-01

    The effects of membrane fouling reducers (MFRs) (the cationic polyelectrolyte (CPE) and FeCI(3)) on membrane fouling were studied in a lab-scale jet loop submerged membrane bioreactor (JL-SMBR) system. The optimum dosages of MFRs (CPE dosage=20 mg g(-1)MLSS, FeCI(3) dosage=14 mg g(-1)MLSS) were continuously fed to JL-SMBR system. The soluble and bound EPS concentrations as well as MLSS concentration in the mixed liquor of JL-SMBR were not changed substantially by the addition of MFRs. However, significant differences were observed in particle size and relative hydrophobicity. Filtration tests were performed by using different membrane types (polycarbonate (PC) and nitrocellulose mixed ester (ME)) and various pore sizes (0.45-0.22-0.1 μm). The steady state fluxes (J(ss)) of membranes increased at all membranes after MFRs addition to JL-SMBR. The filtration results showed that MFRs addition was an effective approach in terms of improvement in filtration performance for both membrane types. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Propionic acid production in a plant fibrous-bed bioreactor with immobilized Propionibacterium freudenreichii CCTCC M207015.

    Science.gov (United States)

    Chen, Fei; Feng, Xiaohai; Xu, Hong; Zhang, Dan; Ouyang, Pingkai

    2012-12-15

    A plant fibrous-bed bioreactor (PFB) was constructed for propionic acid production. Sugar cane bagasse was applied to the PFB as immobilizing material. Starting at a concentration of 80g/L of glucose, Propionibacterium freudenreichii CCTCC M207015 produced 41.20±2.03g/L of propionic acid at 108h in the PFB. The value was 21.07% higher than that produced by free cell fermentation. Intermittent and constant fed-batch fermentations were performed in the PFB to optimize the fermentation results. The highest propionic acid concentration obtained from constant fed-batch fermentation was 136.23±6.77g/L, which is 1.40 times higher than the highest concentration (97.00g/L) previously reported. Scanning electron microscopy analysis showed that cells exhibited striking changes in morphology after PFB domestication. Compared with free cell fermentation, the fluxes of propionic acid synthesis and the pentose phosphate pathway in PFB fermentation increased by 84.65% and 227.62%, respectively. On the other hand, a decrease in succinic and acetic acid fluxes was also observed. The metabolic flux distributions of the two PFB fed-batch fermentation strategies also demonstrated that constant fed-batch fermentation is a more beneficial method for the immobilized production of propionic acid. The relevant key enzyme activities and metabolic flux variations of the batch cultures showed good consistency. These results suggest that the PFB was effective in high-concentration propionic acid production. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  20. Study on Serum Lipoprotein Profile of Exclusive Breast Fed, Mixed Fed and Formula Fed Preterm Infants

    Directory of Open Access Journals (Sweden)

    Vineet Jaiswal

    2017-10-01

    Full Text Available Introduction: Breast feeding is protective for atherosclerotic cardiovascular disease, obesity, Diabetes Mellitus (DM and hypertension. Serum lipoprotein is principal risk factor for atherosclerosis. There is growing evidence that risk of Coronary Heart Disease (CHD begins to emerge from infancy. Lipoprotein level is affected by different feeding pattern during infancy. Aim: To compare serum lipoprotein profile of exclusively breast fed, mixed fed and formula fed preterm infant. Materials and Methods: A total of two fifty preterm newborn were recruited at birth and divided into three groups. Group A were Exclusively Breast Fed (EBF, Group B were Mixed Fed (MF and Group C were Formula/bovine milk Fed (FF infants. Preterm newborns with severe sepsis, hypoglycemia, Hypoxic Ischemic Encephalopathy (HIE stage II and III, meconium stained amniotic fluid, pathological jaundice, Hyaline Membrane Disease (HMD, less than 28 weeks gestation, with major congenital anomaly and infants born to mothers with DM, gestational diabetes, hypertension, pre-eclampsia, eclampsia or on long term medications were excluded from the study. Lipoprotein profile estimation was done at four weeks and again at 16 weeks of age. Results: At four weeks of age, Total Cholesterol (TC, Triglyceride (TG, Low Density Lipoprotein (LDL and Very Low Density Lipoprotein (VLDL were higher in EBF infants as compared to MF and FF infants. For TC, difference was significant between EBF vs. MF (p<0.001, EBF vs. FF (p<0.001 and MF vs. FF (p=0.005 infants. At 16 weeks also, TC and HDL were higher in EBF infants as compared to MF and FF infants. For TC, this difference was significant between EBF vs. MF (p<0.001 and EBF vs. FF (p<0.001 infants. When infants were followed up to 16 weeks of age, TC and LDL level fell significantly (p<0.001 in EBF and MF group, a significant (p<0.05 rise for TC was seen in FF group. At 16 weeks of age, there was no significant rise in HDL in EBF infants, but

  1. Scale-up bioprocess development for production of the antibiotic valinomycin in Escherichia coli based on consistent fed-batch cultivations.

    Science.gov (United States)

    Li, Jian; Jaitzig, Jennifer; Lu, Ping; Süssmuth, Roderich D; Neubauer, Peter

    2015-06-12

    Heterologous production of natural products in Escherichia coli has emerged as an attractive strategy to obtain molecules of interest. Although technically feasible most of them are still constrained to laboratory scale production. Therefore, it is necessary to develop reasonable scale-up strategies for bioprocesses aiming at the overproduction of targeted natural products under industrial scale conditions. To this end, we used the production of the antibiotic valinomycin in E. coli as a model system for scalable bioprocess development based on consistent fed-batch cultivations. In this work, the glucose limited fed-batch strategy based on pure mineral salt medium was used throughout all scales for valinomycin production. The optimal glucose feed rate was initially detected by the use of a biocatalytically controlled glucose release (EnBase® technology) in parallel cultivations in 24-well plates with continuous monitoring of pH and dissolved oxygen. These results were confirmed in shake flasks, where the accumulation of valinomycin was highest when the specific growth rate decreased below 0.1 h(-1). This correlation was also observed for high cell density fed-batch cultivations in a lab-scale bioreactor. The bioreactor fermentation produced valinomycin with titers of more than 2 mg L(-1) based on the feeding of a concentrated glucose solution. Valinomycin production was not affected by oscillating conditions (i.e. glucose and oxygen) in a scale-down two-compartment reactor, which could mimic similar situations in industrial bioreactors, suggesting that the process is very robust and a scaling of the process to a larger industrial scale appears a realistic scenario. Valinomycin production was scaled up from mL volumes to 10 L with consistent use of the fed-batch technology. This work presents a robust and reliable approach for scalable bioprocess development and represents an example for the consistent development of a process for a heterologously expressed natural

  2. Effect of sudden addition of PCE and bioreactor coupling to ZVI filters on performance of fluidized bed bioreactors operated in simultaneous electron acceptor modes.

    Science.gov (United States)

    Moreno-Medina, C U; Poggi-Varaldo, Hector M; Breton-Deval, L; Rinderknecht-Seijas, N

    2017-11-01

    The present work evaluated the effects of (i) feeding a water contaminated with 80 mg/L PCE to bioreactors seeded with inoculum not acclimated to PCE, (ii) coupling ZVI side filters to bioreactors, and (iii) working in different biological regimes, i.e., simultaneous methanogenic aeration and simultaneous methanogenic-denitrifying regimes, on fluidized bed bioreactor performance. Simultaneous electron acceptors refer to the simultaneous presence of two compounds operating as final electron acceptors in the biological respiratory chain (e.g., use of either O 2 or NO 3 - in combination with a methanogenic environment) in a bioreactor or environmental niche. Four lab-scale, mesophilic, fluidized bed bioreactors (bioreactors) were implemented. Two bioreactors were operated as simultaneous methanogenic-denitrifying (MD) units, whereas the other two were operated in partially aerated methanogenic (PAM) mode. In the first period, all bioreactors received a wastewater with 1 g chemical oxygen demand of methanol per liter (COD-methanol/L). In a second period, all the bioreactors received the wastewater plus 80 mg perchloroethylene (PCE)/L; at the start of period 2, one MD and one PAM were coupled to side sand-zero valent iron filters (ZVI). All bioreactors were inoculated with a microbial consortium not acclimated to PCE. In this work, the performance of the full period 1 and the first 60 days of period 2 is reported and discussed. The COD removal efficiency and the nitrate removal efficiency of the bioreactors essentially did not change between period 1 and period 2, i.e., upon PCE addition. On the contrary, specific methanogenic activity in PAM bioreactors (both with and without coupled ZVI filter) significantly decreased. This was consistent with a sharp fall of methane productivity in those bioreactors in period 2. During period 2, PCE removals in the range 86 to 97 % were generally observed; the highest removal corresponded to PAM bioreactors along with the

  3. Energy and greenhouse gas life cycle assessment and cost analysis of aerobic and anaerobic membrane bioreactor systems: Influence of scale, population density, climate, and methane recovery

    Science.gov (United States)

    This study calculated the energy and greenhouse gas life cycle and cost profiles of transitional aerobic membrane bioreactors (AeMBR) and anaerobic membrane bioreactors (AnMBR). Membrane bioreactors (MBR) represent a promising technology for decentralized wastewater treatment and...

  4. Construction and fed-batch cultivation of Candida famata with enhanced riboflavin production.

    Science.gov (United States)

    Dmytruk, Kostyantyn; Lyzak, Oleksy; Yatsyshyn, Valentyna; Kluz, Maciej; Sibirny, Vladimir; Puchalski, Czeslaw; Sibirny, Andriy

    2014-02-20

    Riboflavin (vitamin B2) is an essential nutrition component serving as a precursor of coenzymes FMN and FAD that are involved mostly in reactions of oxidative metabolism. Riboflavin is produced in commercial scale and is used in feed and food industries, and in medicine. The yeast Candida famata (Candida flareri) belongs to the group of so called "flavinogenic yeasts" which overproduce riboflavin under iron limitation. Three genes SEF1, RIB1 and RIB7 coding for a putative transcription factor, GTP cyclohydrolase II and riboflavin synthase, respectively were simultaneously overexpressed in the background of a non-reverting riboflavin producing mutant AF-4, obtained earlier in our laboratory using methods of classical selection (Dmytruk et al. (2011), Metabolic Engineering 13, 82-88). Cultivation conditions of the constructed strain were optimized for shake-flasks and bioreactor cultivations. The constructed strain accumulated up to 16.4g/L of riboflavin in optimized medium in a 7L laboratory bioreactor during fed-batch fermentation. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. The feasibility of nanofiltration membrane bioreactor (NF-MBR)+reverse osmosis (RO) process for water reclamation: Comparison with ultrafiltration membrane bioreactor (UF-MBR)+RO process.

    Science.gov (United States)

    Tay, Ming Feng; Liu, Chang; Cornelissen, Emile R; Wu, Bing; Chong, Tzyy Haur

    2018-02-01

    This study examines the feasibility of a novel nanofiltration membrane bioreactor (NF-MBR) followed by reverse osmosis (RO) process for water reclamation at 90% recovery and using an ultrafiltration MBR (UF-MBR)+RO as baseline for comparison. Both MBRs adopted the same external hollow fiber membrane configurations and operating conditions. The collected permeates of the MBRs were subsequently fed to the respective RO systems. The results showed that the NF-MBR (operated at a constant flux of 10 L/m 2 h) achieved superior MBR permeate quality due to enhanced biodegradation and high rejection capacity of the NF membrane, leading to lower RO fouling rates (∼3.3 times) as compared to the UF-MBR. Further analysis indicated that the cake layer fouling that caused the cake-enhanced osmotic pressure (CEOP) effect contributed predominantly to the transmembrane pressure (TMP) increase in the NF-MBR, while irreversible pore fouling was the major reason for UF membrane fouling. Furthermore, it was found that the biopolymers (i.e., organics with MW > 10 kDa) were the main components present in the foulants of the NF/UF membranes and RO membranes. The analysis indicated that the NF-MBR + RO system at recovery of 90% has comparable energy consumption as the UF-MBR + RO system at recovery of 75%. Our findings proved the feasibility of the NF-MBR + RO for water reclamation at a high recovery rate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Using a medium of free amino acids to produce penicillin g acylase in fed-batch cultivations of Bacillus megaterium ATCC 14945

    Directory of Open Access Journals (Sweden)

    R. G. Silva

    2006-03-01

    Full Text Available The production of penicillin G acylase (PGA, an important industrial enzyme from a wild strain of Bacillus megaterium using a pool of free amino acids as substrate was studied in a bench-scale bioreactor. Experiments carried out in shakers showed that the substitution of casein for free amino acids in the presence of cheese whey was the culture medium that provided the highest productivity. Several cultivations were carried out in a bioreactor operated in either batch or fed-batch mode. Batch runs showed that enzyme production is associated with microorganism growth. The following set of amino acids was preferentially consumed: Ala, Arg, Asp, Gly, Lys, Ser, Thr and Trp. On the other hand, the rates of consumption of His, Ile, Leu, Met, Phe, Pro, Tyr and Val were lower.

  7. Combination of Electrochemical Processes with Membrane Bioreactors for Wastewater Treatment and Fouling Control: A Review

    OpenAIRE

    Ensano, Benny M. B.; Borea, Laura; Naddeo, Vincenzo; Belgiorno, Vincenzo; de Luna, Mark D. G.; Ballesteros, Florencio C.

    2016-01-01

    This paper provides a critical review about the integration of electrochemical processes into membrane bioreactors (MBR) in order to understand the influence of these processes on wastewater treatment performance and membrane fouling control. The integration can be realized either in an internal or an external configuration. Electrically enhanced membrane bioreactors or electro membrane bioreactors (eMBRs) combine biodegradation, electrochemical and membrane filtration processes into one syst...

  8. Combination of electrochemical processes with membrane bioreactors for wastewater treatment and fouling control: A review

    OpenAIRE

    Benny Marie B. Ensano; Laura Borea; Vincenzo Naddeo; Vincenzo Belgiorno; Mark Daniel G. de Luna; Mark Daniel G. de Luna; Florencio C. Ballesteros, Jr.; Florencio C. Ballesteros, Jr.

    2016-01-01

    This paper provides a critical review about the integration of electrochemical processes into membrane bioreactors (MBR) in order to understand the influence of these processes on wastewater treatment performance and membrane fouling control. The integration can be realized either in an internal or an external configuration. Electrically enhanced membrane bioreactors or electro membrane bioreactors (eMBRs) combine biodegradation, electrochemical and membrane filtration processes into one syst...

  9. Nonlinear adaptive optimization of biomass productivity in continuous bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Sauvaire, P; Mellichamp, D A; Agrawal, P [California Univ., Santa Barbara, CA (United States). Dept. of Chemical and Nuclear Engineering

    1991-11-01

    A novel on-line adaptive optimization algorithm is developed and applied to continuous biological reactors. The algorithm makes use of a simple nonlinear estimation model that relates either the cell-mass productivity or the cell-mass concentration to the dilution rate. On-line estimation is used to recursively identify the parameters in the nonlinear process model and to periodically calculate and steer the bioreactor to the dilution rate that yields optimum cell-mass productivity. Thus, the algorithm does not require an accurate process model, locates the optimum dilution rate online, and maintains the bioreactors at this optimum condition at all times. The features of the proposed new algorithm are compared with those of other adaptive optimization techniques presented in the literature. A detailed simulation study using three different microbial system models was conducted to illustrate the performance of the optimization algorithms. (orig.).

  10. Optimization of biological sulfide removal in a CSTR bioreactor.

    Science.gov (United States)

    Roosta, Aliakbar; Jahanmiri, Abdolhossein; Mowla, Dariush; Niazi, Ali; Sotoodeh, Hamidreza

    2012-08-01

    In this study, biological sulfide removal from natural gas in a continuous bioreactor is investigated for estimation of the optimal operational parameters. According to the carried out reactions, sulfide can be converted to elemental sulfur, sulfate, thiosulfate, and polysulfide, of which elemental sulfur is the desired product. A mathematical model is developed and was used for investigation of the effect of various parameters on elemental sulfur selectivity. The results of the simulation show that elemental sulfur selectivity is a function of dissolved oxygen, sulfide load, pH, and concentration of bacteria. Optimal parameter values are calculated for maximum elemental sulfur selectivity by using genetic algorithm as an adaptive heuristic search. In the optimal conditions, 87.76% of sulfide loaded to the bioreactor is converted to elemental sulfur.

  11. Treatment of textile wastewater with membrane bioreactor: A critical review.

    Science.gov (United States)

    Jegatheesan, Veeriah; Pramanik, Biplob Kumar; Chen, Jingyu; Navaratna, Dimuth; Chang, Chia-Yuan; Shu, Li

    2016-03-01

    Membrane bioreactor (MBR) technology has been used widely for various industrial wastewater treatments due to its distinct advantages over conventional bioreactors. Treatment of textile wastewater using MBR has been investigated as a simple, reliable and cost-effective process with a significant removal of contaminants. However, a major drawback in the operation of MBR is membrane fouling, which leads to the decline in permeate flux and therefore requires membrane cleaning. This eventually decreases the lifespan of the membrane. In this paper, the application of aerobic and anaerobic MBR for textile wastewater treatment as well as fouling and control of fouling in MBR processes have been reviewed. It has been found that long sludge retention time increases the degradation of pollutants by allowing slow growing microorganisms to establish but also contributes to membrane fouling. Further research aspects of MBR for textile wastewater treatment are also considered for sustainable operations of the process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Bacterial study of the anaerobic bioreactor for distillery effluent

    International Nuclear Information System (INIS)

    Shah, F. A.; Pathan, M. I.

    2006-01-01

    This study relates with anaerobic bioreactors of Habib Sugar Mills, Nawabshah. Bacterial growth was studied through microscope along with its effect on the production of methane gas (Biogas) at all HRTs (Hydraulic Retention Times) between 15 and 28 days. The bacterium has the efficiency to convert 12% glucose within 24 hours to final product and cell mass. The acetogenic organisms also show their maximum growth on glucose in BGP-1 and BPG-2 at both the corks, where as Methanogenic organisms have shown their zero shown their zero growth on glucose. The efforts have been taken to determine the methanogenic, acetogenic and syntrophomonas sp. data of anaerobic bioreactors of BGP (Biogas Plant) I and II, when these samples were cultured on acetate, methanol, formate, butyrate, propionate and glucose. (author)

  13. Application of a membrane bioreactor for winery wastewater treatment.

    Science.gov (United States)

    Bolzonella, D; Fatone, F; Pavan, P; Cecchi, F

    2010-01-01

    Winery wastewaters are variable in nature and are hard to treat by means of the conventional activated sludge process because of the high organic loading associated with their production, especially during vintage. To face this situation, recently, membrane bioreactors have been widely applied to treat winery wastewaters. In this study, a full-scale membrane bioreactor treated some 110 m(3)/d of wastewater and organic loadings up to 1,600 kg COD per day. The average removal efficiency was 95% while the corresponding sludge yield was only 0.1 kg MLVSS per kg COD removed, as usual for these wastewaters. A detailed analysis of energy consumption showed specific energy demands of 2.0-3.6 kWh/m(3) of treated wastewater or 1 kWh per kg of COD removed.

  14. The stress response system of proteins: Implications for bioreactor scaleup

    Science.gov (United States)

    Goochee, Charles F.

    1988-01-01

    Animal cells face a variety of environmental stresses in large scale bioreactors, including periodic variations in shear stress and dissolved oxygen concentration. Diagnostic techniques were developed for identifying the particular sources of environmental stresses for animal cells in a given bioreactor configuration. The mechanisms by which cells cope with such stresses was examined. The individual concentrations and synthesis rates of hundreds of intracellular proteins are affected by the extracellular environment (medium composition, dissolved oxygen concentration, ph, and level of surface shear stress). Techniques are currently being developed for quantifying the synthesis rates and concentrations of the intracellular proteins which are most sensitive to environmental stress. Previous research has demonstrated that a particular set of stress response proteins are synthesized by mammalian cells in response to temperature fluctuations, dissolved oxygen deprivation, and glucose deprivation. Recently, it was demonstrated that exposure of human kidney cells to high shear stress results in expression of a completely distinct set of intracellular proteins.

  15. High-throughput miniaturized bioreactors for cell culture process development: reproducibility, scalability, and control.

    Science.gov (United States)

    Rameez, Shahid; Mostafa, Sigma S; Miller, Christopher; Shukla, Abhinav A

    2014-01-01

    Decreasing the timeframe for cell culture process development has been a key goal toward accelerating biopharmaceutical development. Advanced Microscale Bioreactors (ambr™) is an automated micro-bioreactor system with miniature single-use bioreactors with a 10-15 mL working volume controlled by an automated workstation. This system was compared to conventional bioreactor systems in terms of its performance for the production of a monoclonal antibody in a recombinant Chinese Hamster Ovary cell line. The miniaturized bioreactor system was found to produce cell culture profiles that matched across scales to 3 L, 15 L, and 200 L stirred tank bioreactors. The processes used in this article involve complex feed formulations, perturbations, and strict process control within the design space, which are in-line with processes used for commercial scale manufacturing of biopharmaceuticals. Changes to important process parameters in ambr™ resulted in predictable cell growth, viability and titer changes, which were in good agreement to data from the conventional larger scale bioreactors. ambr™ was found to successfully reproduce variations in temperature, dissolved oxygen (DO), and pH conditions similar to the larger bioreactor systems. Additionally, the miniature bioreactors were found to react well to perturbations in pH and DO through adjustments to the Proportional and Integral control loop. The data presented here demonstrates the utility of the ambr™ system as a high throughput system for cell culture process development. © 2014 American Institute of Chemical Engineers.

  16. Development of a Mechanically Versatile Bioreactor System as a Cellular Microgravity Countermeasure for Regenerative Medicine Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary objective of this research project is to develop a compact, mechanically versatile bioreactor capable of producing desired local mechanical environments...

  17. Osmotic membrane bioreactor for phenol biodegradation under continuous operation

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, Prashant; Loh, Kai-Chee, E-mail: chelohkc@nus.edu.sg

    2016-03-15

    Highlights: • Osmotic membrane bioreactor was used for phenol biodegradation in continuous mode. • Extractant impregnated membranes were used to alleviate substrate inhibition. • Phenol removal was achieved through both biodegradation and membrane rejection. • Phenol concentrations up to 2500 mg/L were treated at HRT varying in 2.8–14 h. • A biofilm removal strategy was formulated to improve bioreactor sustainability. - Abstract: Continuous phenol biodegradation was accomplished in a two-phase partitioning osmotic membrane bioreactor (TPPOMBR) system, using extractant impregnated membranes (EIM) as the partitioning phase. The EIMs alleviated substrate inhibition during prolonged operation at influent phenol concentrations of 600–2000 mg/L, and also at spiked concentrations of 2500 mg/L phenol restricted to 2 days. Filtration of the effluent through forward osmosis maintained high biomass concentration in the bioreactor and improved effluent quality. Steady state was reached in 5–6 days at removal rates varying between 2000 and 5500 mg/L-day under various conditions. Due to biofouling and salt accumulation, the permeate flux varied from 1.2–7.2 LMH during 54 days of operation, while maintaining an average hydraulic retention time of 7.4 h. A washing cycle, comprising 1 h osmotic backwashing using 0.5 M NaCl and 2 h washing with water, facilitated biofilm removal from the membranes. Characterization of the extracellular polymeric substances (EPS) through FTIR showed peaks between 1700 and 1500 cm{sup −1}, 1450–1450 cm{sup −1} and 1200–1000 cm{sup −1}, indicating the presence of proteins, phenols and polysaccharides, respectively. The carbohydrate to protein ratio in the EPS was estimated to be 0.3. These results indicate that TPPOMBR can be promising in continuous treatment of phenolic wastewater.

  18. Construction and characterization of a novel vocal fold bioreactor.

    Science.gov (United States)

    Zerdoum, Aidan B; Tong, Zhixiang; Bachman, Brendan; Jia, Xinqiao

    2014-08-01

    In vitro engineering of mechanically active tissues requires the presentation of physiologically relevant mechanical conditions to cultured cells. To emulate the dynamic environment of vocal folds, a novel vocal fold bioreactor capable of producing vibratory stimulations at fundamental phonation frequencies is constructed and characterized. The device is composed of a function generator, a power amplifier, a speaker selector and parallel vibration chambers. Individual vibration chambers are created by sandwiching a custom-made silicone membrane between a pair of acrylic blocks. The silicone membrane not only serves as the bottom of the chamber but also provides a mechanism for securing the cell-laden scaffold. Vibration signals, generated by a speaker mounted underneath the bottom acrylic block, are transmitted to the membrane aerodynamically by the oscillating air. Eight identical vibration modules, fixed on two stationary metal bars, are housed in an anti-humidity chamber for long-term operation in a cell culture incubator. The vibration characteristics of the vocal fold bioreactor are analyzed non-destructively using a Laser Doppler Vibrometer (LDV). The utility of the dynamic culture device is demonstrated by culturing cellular constructs in the presence of 200-Hz sinusoidal vibrations with a mid-membrane displacement of 40 µm. Mesenchymal stem cells cultured in the bioreactor respond to the vibratory signals by altering the synthesis and degradation of vocal fold-relevant, extracellular matrix components. The novel bioreactor system presented herein offers an excellent in vitro platform for studying vibration-induced mechanotransduction and for the engineering of functional vocal fold tissues.

  19. Waste to Energy Potential - A High Concentration Anaerobic Bioreactor

    Science.gov (United States)

    2012-05-23

    of the solids placed in the bioreactor and, generate a biogas • What do you get? • Biogas that can be...contains methane = fuel source • Biogas measured by flow meter • Biogas generated was correlated to mass of volatile solids destroyed • Biogas ...to enhance operation and biogas production Applicability to larger scale Verification of power generation using a microturbine Refinement of

  20. A review of some parameters involved in fluidized bed bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Wright, P.C. [School of Chemical Engineering and Industrial Chemistry, The Univ. of New South Wales, Sydney (Australia); Raper, J.A. [School of Chemical Engineering and Industrial Chemistry, The Univ. of New South Wales, Sydney (Australia)

    1996-02-01

    Three-phase fluidized bed bioreactors have advantages over conventional chemical reaction systems. There is a lack of agreement over most major operational conditions, and a wide range of design variables are open to question. A large body of recent work in the field has been reviewed, with a degree of historical comparison and discussion. It has been found that aspects of fluidized bed biofilm reactors of vital importance include: choice of solid media, gas and liquid loadings, bacterial type and reactor mechanical design. A large proportion of the work in the field of three-phase fluidization is non-biologically specific, or not tested on a bacterially inoculated system. The majority of three-phase fluidized bed bioreactor work is in the field of water treatment. Although this work has highlighted the potential for use of bio-fluidized beds for this application, there are still specific problems hinderin the large scale industrial acceptance of three-phase fluidized bed bioreactors. (orig.)

  1. Simulation of three-phase fluidized bioreactors for denitrification

    International Nuclear Information System (INIS)

    Hamza, A.V.; Dolan, J.F.; Wong, E.W.

    1981-03-01

    Fluidized-bed bioreactors were developed and operated at three scales (diameters of 0.1, 0.2, and 0.5 m) by the Chemical Technology Division. The performance of these reactors in denitrification was simulated using the following modified form of Monod kinetics to describe the reaction kinetics: rate = V/sub max/ (NO 3 - /K/sub s/ + NO 3 - ) (% biomass). In the fluids-movement portion of the simulation the tanks-in-series approximation to backmixing was used. This approach yielded a V/sub max/ of 3.5 g/m 3 -min (% biomass) and a K/sub s/ of 163 g/m 3 for the 0.5-m bioreactor. Values of V/sub max/ and K/sub s/ were also determined for data derived from the 0.1-m bioreactor, but inadequate RTD data reduced the confidence level in these results. A complication in denitrification is the multi-step nature of the reduction from nitrate to nitrite to hyponitrite and finally to nitrogen. An experimental study of the effect of biomass loading upon denitrification was begun. It is recommended that the experimental work be continued

  2. Biogas Production from Citrus Waste by Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    Rachma Wikandari

    2014-08-01

    Full Text Available Rapid acidification and inhibition by d-limonene are major challenges of biogas production from citrus waste. As limonene is a hydrophobic chemical, this challenge was encountered using hydrophilic polyvinylidine difluoride (PVDF membranes in a biogas reactor. The more sensitive methane-producing archaea were encapsulated in the membranes, while freely suspended digesting bacteria were present in the culture as well. In this membrane bioreactor (MBR, the free digesting bacteria digested the citrus wastes and produced soluble compounds, which could pass through the membrane and converted to biogas by the encapsulated cell. As a control experiment, similar digestions were carried out in bioreactors containing the identical amount of just free cells. The experiments were carried out in thermophilic conditions at 55 °C, and hydraulic retention time of 30 days. The organic loading rate (OLR was started with 0.3 kg VS/m3/day and gradually increased to 3 kg VS/m3/day. The results show that at the highest OLR, MBR was successful to produce methane at 0.33 Nm3/kg VS, while the traditional free cell reactor reduced its methane production to 0.05 Nm3/kg VS. Approximately 73% of the theoretical methane yield was achieved using the membrane bioreactor.

  3. A Novel bioreactor with mechanical stimulation for skeletal tissue engineering

    Directory of Open Access Journals (Sweden)

    M. Petrović

    2009-01-01

    Full Text Available The provision of mechanical stimulation is believed to be necessary for the functional assembly of skeletal tissues, which are normally exposed to a variety of biomechanical signals in vivo. In this paper, we present a development and validation of a novel bioreactor aimed for skeletal tissue engineering that provides dynamic compression and perfusion of cultivated tissues. Dynamic compression can be applied at frequencies up to 67.5 Hz and displacements down to 5 m thus suitable for the simulation of physiological conditions in a native cartilage tissue (0.1-1 Hz, 5-10 % strain. The bioreactor also includes a load sensor that was calibrated so to measure average loads imposed on tissue samples. Regimes of the mechanical stimulation and acquisition of load sensor outputs are directed by an automatic control system using applications developed within the LabView platform. In addition, perfusion of tissue samples at physiological velocities (10–100 m/s provides efficient mass transfer, as well as the possibilities to expose the cells to hydrodynamic shear and simulate the conditions in a native bone tissue. Thus, the novel bioreactor is suited for studies of the effects of different biomechanical signals on in vitro regeneration of skeletal tissues, as well as for the studies of newly formulated biomaterials and cell biomaterial interactions under in vivo-like settings.

  4. Membrane bioreactors' potential for ethanol and biogas production: a review.

    Science.gov (United States)

    Ylitervo, Päivi; Akinbomia, Julius; Taherzadeha, Mohammad J

    2013-01-01

    Companies developing and producing membranes for different separation purposes, as well as the market for these, have markedly increased in numbers over the last decade. Membrane and separation technology might well contribute to making fuel ethanol and biogas production from lignocellulosic materials more economically viable and productive. Combining biological processes with membrane separation techniques in a membrane bioreactor (MBR) increases cell concentrations extensively in the bioreactor. Such a combination furthermore reduces product inhibition during the biological process, increases product concentration and productivity, and simplifies the separation of product and/or cells. Various MBRs have been studied over the years, where the membrane is either submerged inside the liquid to be filtered, or placed in an external loop outside the bioreactor. All configurations have advantages and drawbacks, as reviewed in this paper. The current review presents an account of the membrane separation technologies, and the research performed on MBRs, focusing on ethanol and biogas production. The advantages and potentials of the technology are elucidated.

  5. FED baseline engineering studies report

    Energy Technology Data Exchange (ETDEWEB)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept.

  6. FED baseline engineering studies report

    International Nuclear Information System (INIS)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept

  7. Ultra-micro aqua bioreactor systems for modifying edible oils and fats; Shokuyo yushi kaishitsuyo chobisuikei bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Kurashige, J. [Ajinomoto Co. Inc., Tokyo (Japan)

    1995-10-20

    Practical solvent-free bioreactor systems using immobilized lipases have been constructed to convert palm oil to high quality foodstuff oil without quality deterioration through hydrolysis of triglycerides in oil. To avoid hydrolysis, moisture level of substrate oil has to be maintained at less than the solubility level of water in oil, which we call ultra-micro aqueous level. On the other hand, lipase is well known to manifest its activities mostly at the interface between oil and water phases. To make lipase manifest its activities at the ultra-micro aqueous oil phase, the novel bioreactor systems with the new immobilizing method of lipase together with activator on-to hydrophylic carriers, and without a drying procedure have been developed. These biochemical accomplishments show high promises for efficient convention of edible fats and oils to highly valuable foodstuff, which can not be attained by means of chemical or physical methods. 29 refs., 9 figs., 4 tabs.

  8. Comparison between moving bed-membrane bioreactor (MB-MBR) and membrane bioreactor (MBR) systems: influence of wastewater salinity variation.

    Science.gov (United States)

    Di Trapani, Daniele; Di Bella, Gaetano; Mannina, Giorgio; Torregrossa, Michele; Viviani, Gaspare

    2014-06-01

    Two pilot plant systems were investigated for the treatment of wastewater subject to a gradual increase of salinity. In particular, a membrane bioreactor (MBR) and a moving bed biofilm membrane bioreactor (MB-MBR) were analyzed. Carbon and ammonium removal, kinetic constants and membranes fouling rates have been assessed. Both plants showed very high efficiency in terms of carbon and ammonium removal and the gradual salinity increase led to a good acclimation of the biomass, as confirmed by the respirometric tests. Significant biofilm detachments from carriers were experienced, which contributed to increase the irreversible superficial cake deposition. However, this aspect prevented the pore fouling tendency in the membrane module of MB-MBR system. On the contrary, the MBR pilot, even showing a lower irreversible cake deposition, was characterized by a higher pore fouling tendency. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. A novel bioreactor to simulate urinary bladder mechanical properties and compliance for bladder functional tissue engineering.

    Science.gov (United States)

    Wei, Xin; Li, Dao-bing; Xu, Feng; Wang, Yan; Zhu, Yu-chun; Li, Hong; Wang, Kun-jie

    2011-02-01

    Bioreactors are pivotal tools for generating mechanical stimulation in functional tissue engineering study. This study aimed to create a bioreactor that can simulate urinary bladder mechanical properties, and to investigate the effects of a mechanically stimulated culture on urothelial cells and bladder smooth muscle cells. We designed a bioreactor to simulate the mechanical properties of bladder. A pressure-record system was used to evaluate the mechanical properties of the bioreactor by measuring the pressure in culture chambers. To test the biocompatibility of the bioreactor, viabilities of urothelial cells and smooth muscle cells cultured in the bioreactor under static and mechanically changed conditions were measured after 7-day culture. To evaluate the effect of mechanical stimulations on the vital cells, urethral cells and smooth muscle cells were cultured in the simulated mechanical conditions. After that, the viability and the distribution pattern of the cells were observed and compared with cells cultured in non-mechanical stimulated condition. The bioreactor system successfully generated waveforms similar to the intended programmed model while maintaining a cell-seeded elastic membrane between the chambers. There were no differences between viabilities of urothelial cells ((91.90 ± 1.22)% vs. (93.14 ± 1.78)%, P > 0.05) and bladder smooth muscle cells ((93.41 ± 1.49)% vs. (92.61 ± 1.34)%, P > 0.05). The viability of cells and tissue structure observation after cultured in simulated condition showed that mechanical stimulation was the only factor affected cells in the bioreactor and improved the arrangement of cells on silastic membrane. This bioreactor can effectively simulate the physiological and mechanical properties of the bladder. Mechanical stimulation is the only factor that affected the viability of cells cultured in the bioreactor. The bioreactor can change the growth behavior of urothelial cells and bladder smooth muscle cells, resulting in

  10. High throughput automated microbial bioreactor system used for clone selection and rapid scale-down process optimization.

    Science.gov (United States)

    Velez-Suberbie, M Lourdes; Betts, John P J; Walker, Kelly L; Robinson, Colin; Zoro, Barney; Keshavarz-Moore, Eli

    2018-01-01

    High throughput automated fermentation systems have become a useful tool in early bioprocess development. In this study, we investigated a 24 x 15 mL single use microbioreactor system, ambr 15f, designed for microbial culture. We compared the fed-batch growth and production capabilities of this system for two Escherichia coli strains, BL21 (DE3) and MC4100, and two industrially relevant molecules, hGH and scFv. In addition, different carbon sources were tested using bolus, linear or exponential feeding strategies, showing the capacity of the ambr 15f system to handle automated feeding. We used power per unit volume (P/V) as a scale criterion to compare the ambr 15f with 1 L stirred bioreactors which were previously scaled-up to 20 L with a different biological system, thus showing a potential 1,300 fold scale comparability in terms of both growth and product yield. By exposing the cells grown in the ambr 15f system to a level of shear expected in an industrial centrifuge, we determined that the cells are as robust as those from a bench scale bioreactor. These results provide evidence that the ambr 15f system is an efficient high throughput microbial system that can be used for strain and molecule selection as well as rapid scale-up. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 34:58-68, 2018. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers.

  11. Effects of a perfusion bioreactor activated novel bone substitute in spine fusion in sheep

    DEFF Research Database (Denmark)

    Sørensen, Jesper Roed; Koroma, Kariatta Ester; Ding, Ming

    2012-01-01

    To evaluate the effect of a large perfusion-bioreactor cell-activated bone substitute, on a two-level large posterolateral spine fusion sheep model.......To evaluate the effect of a large perfusion-bioreactor cell-activated bone substitute, on a two-level large posterolateral spine fusion sheep model....

  12. Hydrogel/poly-dimethylsiloxane hybrid bioreactor facilitating 3D cell culturing

    NARCIS (Netherlands)

    Schurink, B.; Luttge, R.

    2013-01-01

    The authors present a hydrogel/poly-dimethylsiloxane (PDMS) hybrid bioreactor. The bioreactor enables a low shear stress 3D culture by integrating a hydrogel as a barrier into a PDMS casing. The use of PDMS allows the reversible adhesion of the device to a commercially available microelectrode

  13. Dissipation of atrazine, enrofloxacin, and sulfamethazine in wood chip bioreactors and impact on denitrification

    Science.gov (United States)

    Wood chip bioreactors are receiving increasing attention as a means of reducing nitrate in subsurface tile drainage systems. Agrochemicals in tile drainage water entering wood chip bioreactors can be retained or degraded and may impact denitrification. The degradation of 5 mg L-1 atrazine, enrofloxa...

  14. Define of internal recirculation coefficient for biological wastewater treatment in anoxic and aerobic bioreactors

    Science.gov (United States)

    Rossinskyi, Volodymyr

    2018-02-01

    The biological wastewater treatment technologies in anoxic and aerobic bioreactors with recycle of sludge mixture are used for the effective removal of organic compounds from wastewater. The change rate of sludge mixture recirculation between bioreactors leads to a change and redistribution of concentrations of organic compounds in sludge mixture in bioreactors and change hydrodynamic regimes in bioreactors. Determination of the coefficient of internal recirculation of sludge mixture between bioreactors is important for the choice of technological parameters of biological treatment (wastewater treatment duration in anoxic and aerobic bioreactors, flow capacity of recirculation pumps). Determination of the coefficient of internal recirculation of sludge mixture requires integrated consideration of hydrodynamic parameter (flow rate), kinetic parameter (rate of oxidation of organic compounds) and physical-chemical parameter of wastewater (concentration of organic compounds). The conducted numerical experiment from the proposed mathematical equations allowed to obtain analytical dependences of the coefficient of internal recirculation sludge mixture between bioreactors on the concentration of organic compounds in wastewater, the duration of wastewater treatment in bioreactors.

  15. Fluid bed porosity equation for an inverse fluidized bed bioreactor with particles growing biofilm

    International Nuclear Information System (INIS)

    Campos-Diaz, K. E.; Limas-Ballesteros, R.

    2009-01-01

    Fluid Bed Bioreactor performance is strongly affected by bed void fraction or bed porosity fluctuations. Particle size enlargement due to biofilm growth is an important factor that is involved in these variations and until now there are no mathematical equations that consider biofilm growth. In this work a mathematical equation is proposed to calculate bed void fraction in an inverse fluid bed bioreactor. (Author)

  16. Pilot-scale passive bioreactors for the treatment of acid mine drainage: efficiency of mushroom compost vs. mixed substrates for metal removal.

    Science.gov (United States)

    Song, Hocheol; Yim, Gil-Jae; Ji, Sang-Woo; Neculita, Carmen Mihaela; Hwang, Taewoon

    2012-11-30

    Pilot-scale field-testing of passive bioreactors was performed to evaluate the efficiency of a mixture of four substrates (cow manure compost, mushroom compost, sawdust, and rice straw) relative to mushroom compost alone, and of the effect of the Fe/Mn ratio, during the treatment of acid mine drainage (AMD) over a 174-day period. Three 141 L columns, filled with either mushroom compost or the four substrate mixture (in duplicate), were set-up and fed with AMD from a closed mine site, in South Korea, using a 4-day hydraulic retention time. In the former bioreactor, effluent deterioration was observed over 1-2 months, despite the good efficiency predicted by the physicochemical characterization of mushroom compost. Steady state effluent quality was then noted for around 100 days before worsening in AMD source water occurred in response to seasonal variations in precipitation. Such changes in AMD quality resulted in performance deterioration in all reactors followed by a slow recovery toward the end of testing. Both substrates (mushroom compost and mixtures) gave satisfactory performance in neutralizing pH (6.1-7.8). Moreover, the system was able to consistently reduce sulfate from day 49, after the initial leaching out from organic substrates. Metal removal efficiencies were on the order of Al (∼100%) > Fe (68-92%) > Mn (49-61%). Overall, the mixed substrates showed comparable performance to mushroom compost, while yielding better effluent quality upon start-up. The results also indicated mushroom compost could release significant amounts of Mn and sulfate during bioreactor operation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Membrane bioreactors for enzymatic hydrolysis of lactose; Idrolisi enzimatica del lattosio con bioreattori a membrana

    Energy Technology Data Exchange (ETDEWEB)

    Pizzichini, M; Pilloton, R [ENEA, Casaccia (Italy). Area Energia e Innovazione; Pontecorvo, M; Mignogna, G; Fortunato, A; Beone, F

    1993-03-01

    Bioreactor systems obtained by cell or enzyme immobilization offer many advantages compared with native enzyme, intact cell systems or other biocatalysts. Thus, many attempts have been made to design and use new types of bioreactor systems in order to improve performance, enhance productivity and reduce environmental impacts. Membrane bioreactors, obtained by physical immobilization of biocatalysts, in polymeric membrane support, offer such practical advantages as: a continuous separation and transformation process with low product inhibition and suitable hydraulic configuration (backflushing recycling, ultrafiltrating). Specific membrane modules (Amicon VitaFiber), for bioreactor applications are being commercialized. Beta-galctosidase enzyme has successfully been immobilized in a hollow fiber and in ceramic modules to hydrolyze lactose in waste whey. This technical report presents the general properties and performances (permeability, washing procedures, hydraulic configurations, physical and chemical properties) of both, polymeric and ceramic supports, enzyme kinetics, physical and covalent immobilization, mathematical model of the bioreactor and on-line process monitoring.

  18. Construction and evaluation of urinary bladder bioreactor for urologic tissue-engineering purposes.

    LENUS (Irish Health Repository)

    Davis, Niall F

    2012-01-31

    OBJECTIVE: To design and construct a urinary bladder bioreactor for urologic tissue-engineering purposes and to compare the viability and proliferative activity of cell-seeded extracellular matrix scaffolds cultured in the bioreactor with conventional static growth conditions. MATERIALS AND METHODS: A urinary bladder bioreactor was designed and constructed to replicate physiologic bladder dynamics. The bioreactor mimicked the filling pressures of the human bladder by way of a cyclical low-delivery pressure regulator. In addition, cell growth was evaluated by culturing human urothelial cells (UCs) on porcine extracellular matrix scaffolds in the bioreactor and in static growth conditions for 5 consecutive days. The attachment, viability, and proliferative potential were assessed and compared with quantitative viability indicators and by fluorescent markers for intracellular esterase activity and plasma membrane integrity. Scaffold integrity was characterized with scanning electron microscopy and 4\\

  19. Computational fluid dynamics modeling of momentum transport in rotating wall perfused bioreactor for cartilage tissue engineering.

    Science.gov (United States)

    Cinbiz, Mahmut N; Tığli, R Seda; Beşkardeş, Işil Gerçek; Gümüşderelioğlu, Menemşe; Colak, Uner

    2010-11-01

    In this study, computational fluid dynamics (CFD) analysis of a rotating-wall perfused-vessel (RWPV) bioreactor is performed to characterize the complex hydrodynamic environment for the simulation of cartilage development in RWPV bioreactor in the presence of tissue-engineered cartilage constructs, i.e., cell-chitosan scaffolds. Shear stress exerted on chitosan scaffolds in bioreactor was calculated for different rotational velocities in the range of 33-38 rpm. According to the calculations, the lateral and lower surfaces were exposed to 0.07926-0.11069 dyne/cm(2) and 0.05974-0.08345 dyne/cm(2), respectively, while upper surfaces of constructs were exposed to 0.09196-0.12847 dyne/cm(2). Results validate adequate hydrodynamic environment for scaffolds in RWPV bioreactor for cartilage tissue development which concludes the suitability of operational conditions of RWPV bioreactor. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Long-term adaptation of methanol-fed thermophilic (55°C) sulfate-reducing reactors to NaCl

    NARCIS (Netherlands)

    Vallero, M.V.G.; Lettinga, G.; Lens, P.N.L.

    2003-01-01

    A laboratory-scale upflow anaerobic sludge bed (UASB) reactor was operated during 273 days at increasing NaCl concentrations (0.5-12.5 g NaCl l(-1)) to assess whether the stepwise addition of the salt NaCl results in the acclimation of that sludge. The 6.5-1 thermophilic (55 degreesC), sulfidogenic

  1. Increased kidney growth in formula-fed versus breast-fed healthy infants

    DEFF Research Database (Denmark)

    Schmidt, Ida M; Damgaard, Ida N; Boisen, Kirsten A

    2004-01-01

    versus breast feeding on kidney growth in a cohort of 631 healthy children examined at birth, and at 3 and 18 months of age. Kidney size was determined by ultrasonography and related to gender, age, body size, and feeding category (fully breast fed, partially breast fed, or fully formula fed at 3 months...

  2. L-Tryptophan depletion bioreactor, a possible cancer therapy

    Directory of Open Access Journals (Sweden)

    Rolf Bambauer

    2015-04-01

    Full Text Available The cancer therapeutic strategies knownto date are not adequate for all cancer patients. Most of them are followed by a high rate of side effects and complications. The L-tryptophan depletion bioreactor is described as a possible new method of cancer therapy. L-tryptophan is an essential amino acid which has been recognized as an important cancer nutrient and its removal can lead to destruction of the tumour. Normal human cells or tumor cells cannot synthesize L-tryptophan and therefore tumor resistance is unlikely to develop. L-tryptophan is also a constituent for different bio-molecules such as Serotonin, Melatonin, and is needed for other synthesis processes in the cell growth. L-tryptophan degrading enzymes with 3 iso-enzymes called tryptophan side chain oxydase (TSO I, II, III were isolated. The 3 iso-enzymes can be differentiated by tryptic digestion. They have different molecular weights with different effectivenesses. All the TSO enzymes have heme that can catalyze essentially similar reactions involving L-tryptophan as a substrate. The most effective TSO is the type TSO III. A column which contained TSO as a bioreactor was integrated in a plasmapheresis unit and tested it in different animals. In sheep and rabbits L-tryptophan depletion in plasma was shown at 95% and 100% rates respectively by a single pass through the bioreactor. The results in immune supprimized rats with tumors were impressive, too. In 20 different tumor cell lines there were different efficacies. Brest cancer and medulloblastoma showed the greatest efficacy of L-tryptophan degrading. The gene technology of TSO production from Pseudomonas is associated with formation of endotoxins. This disadvantage can be prevented by different washing procedures or by using fungal sources for the TSO production. TSO III is developed to treat cancer diseases successfully, and has low side effects. A combination of L-tryptophan depletion with all available cancer therapies is

  3. Scale-up of bioreactors: The concept of bioreactor number and its relation to the physiology of industrial microorganisms at different scales

    Energy Technology Data Exchange (ETDEWEB)

    De Ford, D

    1988-01-01

    The objective of this research is to provide a novel approach to the problem of scale-up of fermentations. The work subscribes the idea that two regions appear in bioreactors as the volume increases. The first is where high oxygen transfer occurs and the second is where low oxygen transfer occurs. It is assumed that organisms grown in a stirred tank fermenter travel in a cyclical manner through these two regions. A dimensionless factor is developed, the bioreactor number. Using this number the performance of any stirred tank fermenter can be described as a function of its geometry, operating conditions and physical properties of media. A mathematical model for the prediction of the physiological response of aerobic micro-organisms (specific growth rate, final cell concentration and product synthesis) as a function of the bioreactor number is also developed. It was adjusted by using the results of fermentations performed in a specially designed experimental rig allowing the simulation of fermenters with various bioreactor numbers. If the bioreactor and physiological models are linked it is possible to predict how micro-organisms respond when geometry, operating conditions or media properties are changed in a bioreactor. This approach is a tool for decision making in the design and operation of fermenters.

  4. Biomethanation of salty cheese whey using multichamber anaerobic bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Chirag; Madamwar, Datta [Sardar Patel Univ., Gujarat (India)

    1998-07-01

    To obtain enriched methane content and improve anaerobic digestion of salty cheese whey after diluting with total dairy waste water, a multichamber anaerobic bioreactor has been developed using different combination of bedding materials in different chambers. Best performance has been obtained at 37''oC under the combination of polystyrene chips, pumice stones and PVC beads as supporting materials, and operating at 2 day hydraulic retention time. Maximum gas production of 3.2 litre/litre of digester/day with methane content of 68% and 83% reduction in COD have been noticed. (Author)

  5. Bioreactor activated graft material for early implant fixation in bone

    DEFF Research Database (Denmark)

    Snoek Henriksen, Susan; Ding, Ming; Overgaard, Søren

    2011-01-01

    from the iliac crest. For both groups, mononuclear cells were isolated, and injected into a perfusion bioreactor (Millenium Biologix AG, Switzerland). Scaffold granules (Ø~900-1500 µm, ~88% porosity) in group 1, consisted of hydroxyapatite (HA, 70%) with β-tricalcium-phosphate (β-TCP, 30%) (Danish....... The superficial part was used for mechanical testing and micro-CT scanning, and the profound part for histomorphometry. Push-out tests were performed on an 858 Bionix MTS hydraulic materials testing machine (MTS Systems Corporation, USA). Shear mechanical properties between implant and newly generated bone were...

  6. Sensor equipment for quantification of spatial heterogeneity in large bioreactor

    DEFF Research Database (Denmark)

    Nørregaard, Anders; Formenti, Luca Riccardo; Stocks, Stuart M.

    of sensors and in order to apply more sensor equipment the bioreactor has to be modified which is both costly and results in production downtime. The presence of three phases (gas, liquid, and solid), and the opaque nature of the fermentation broth together with the necessity of heat sterilization further...... increases the requirements to the sensor equipment. In order to address these issues this study aims to make an investigation into freely floating, battery driven sensor particles that can follow the liquid movement in the reactor and make measurements while being distributed in the whole volume...

  7. Effect of Mixing on Microorganism Growth in Loop Bioreactors

    Directory of Open Access Journals (Sweden)

    A. M. Al Taweel

    2012-01-01

    Full Text Available The impact of mixing on the promotion of microorganism growth rate has been analyzed using a multiphase forced-circulation pipe-loop reactor model capable of identifying conditions under which it is possible to convert natural gas into Single-Cell Protein. The impact of mixing in the interphase mass transfer was found to exert a critical role in determining the overall productivity of the bioreactor, particularly at the high cell loadings needed to reduce the capital costs associated with the large-scale production needed for the production of relatively low-value SCP in a sustainable manner.

  8. Enrichment of carbon monoxide utilising microorganisms from methanogenic bioreactor sludge

    OpenAIRE

    Pereira, Ana Luísa; Stams, Alfons Johannes Maria; Alves, M. M.; Sousa, D. Z.

    2015-01-01

    Conversion of CO is the rate limiting step during anaerobic conversion of syngas (a gaseous mixture mainly composed of CO, CO2 and H2). In this work we study the microbial diversity in anaerobic sludge submitted to extended contact to syngas in a multi-orifice baffled bioreactor (MOBB). Methane was the main product resulting from syngas conversion in the MOBB. Enrichment cultures started with this sludge produced methane as final product, but also acetate. 16S rRNA gene analysis revealed a pr...

  9. Anaerobic electrochemical membrane bioreactor and process for wastewater treatment

    KAUST Repository

    Amy, Gary

    2015-07-09

    An anaerobic electrochemical membrane bioreactor (AnEMBR) can include a vessel into which wastewater can be introduced, an anode electrode in the vessel suitable for supporting electrochemically active microorganisms (EAB, also can be referred to as anode reducing bacteria, exoelectrogens, or electricigens) that oxidize organic compounds in the wastewater, and a cathode membrane electrode in the vessel, which is configured to pass a treated liquid through the membrane while retaining the electrochemically active microorganisms and the hydrogenotrophic methanogens (for example, the key functional microbial communities, including EAB, methanogens and possible synergistic fermenters) in the vessel. The cathode membrane electrode can be suitable for catalyzing the hydrogen evolution reaction to generate hydro en.

  10. A Good Neighborhood for Cells: Bioreactor Demonstration System (BDS-05)

    Science.gov (United States)

    Chung, Leland W. K.; Goodwin, Thomas J. (Technical Monitor)

    2002-01-01

    Good neighborhoods help you grow. As with a city, the lives of a cell are governed by its neighborhood connections Connections that do not work are implicated in a range of diseases. One of those connections - between prostate cancer and bone cells - will be studied on STS-107 using the Bioreactor Demonstration System (BDS-05). To improve the prospects for finding novel therapies, and to identify biomarkers that predict disease progression, scientists need tissue models that behave the same as metastatic or spreading cancer. This is one of several NASA-sponsored lines of cell science research that use the microgravity environment of orbit in an attempt to grow lifelike tissue models for health research. As cells replicate, they "self associate" to form a complex matrix of collagens, proteins, fibers, and other structures. This highly evolved microenvironment tells each cell who is next door, how it should grow arid into what shapes, and how to respond to bacteria, wounds, and other stimuli. Studying these mechanisms outside the body is difficult because cells do not easily self-associate outside a natural environment. Most cell cultures produce thin, flat specimens that offer limited insight into how cells work together. Ironically, growing cell cultures in the microgravity of space produces cell assemblies that more closely resemble what is found in bodies on Earth. NASA's Bioreactor comprises a miniature life support system and a rotating vessel containing cell specimens in a nutrient medium. Orbital BDS experiments that cultured colon and prostate cancers have been highly promising.

  11. Glyco-engineering for biopharmaceutical production in moss bioreactors

    Directory of Open Access Journals (Sweden)

    Eva L. Decker

    2014-07-01

    Full Text Available The production of recombinant biopharmaceuticals (pharmaceutical proteins is a strongly growing area in the pharmaceutical industry. While most products to date are produced in mammalian cell cultures, namely CHO cells, plant-based production systems gained increasing acceptance over the last years. Different plant systems have been established which are suitable for standardization and precise control of cultivation conditions, thus meeting the criteria for pharmaceutical production.The majority of biopharmaceuticals comprise glycoproteins. Therefore, differences in protein glycosylation between humans and plants have to be taken into account and plant-specific glycosylation has to be eliminated to avoid adverse effects on quality, safety and efficacy of the products.The basal land plant Physcomitrella patens (moss has been employed for the recombinant production of high-value therapeutic target proteins (e.g., Vascular Endothelial Growth Factor, Complement Factor H, monoclonal antibodies, Erythropoietin. Being genetically excellently characterized and exceptionally amenable for precise gene targeting via homologous recombination, essential steps for the optimization of moss as a bioreactor for the production of recombinant proteins have been undertaken.Here, we discuss the glyco-engineering approaches to avoid non-human N- and O-glycosylation on target proteins produced in moss bioreactors.

  12. Farm Deployable Microbial Bioreactor for Fuel Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Okeke, Benedict [Auburn Univ., Montgomery AL (United States)

    2016-03-30

    Research was conducted to develop a farm and field deployable microbial bioreactor for bioethanol production from biomass. Experiments were conducted to select the most efficient microorganisms for conversion of plant fiber to sugars for fermentation to ethanol. Mixtures of biomass and surface soil samples were collected from selected sites in Alabama black belt counties (Macon, Sumter, Choctaw, Dallas, Montgomery, Lowndes) and other areas within the state of Alabama. Experiments were conducted to determine the effects of culture parameters on key biomass saccharifying enzymes (cellulase, beta-glucosidase, xylanase and beta-xylosidase). A wide-scale sampling of locally-grown fruits in Central Alabama was embarked to isolate potential xylose fermenting microorganisms. Yeast isolates were evaluated for xylose fermentation. Selected microorganisms were characterized by DNA based methods. Factors affecting enzyme production and biomass saccharification were examined and optimized in the laboratory. Methods of biomass pretreatment were compared. Co-production of amylolytic enzymes with celluloytic-xylanolytic enzymes was evaluated; and co-saccharification of a combination of biomass, and starch-rich materials was examined. Simultaneous saccharification and fermentation with and without pre-saccharifcation was studied. Whole culture broth and filtered culture broth simultaneous saccahrifcation and fermentation were compared. A bioreactor system was designed and constructed to employ laboratory results for scale up of biomass saccharification.

  13. A fault diagnosis prototype for a bioreactor for bioinsecticide production

    International Nuclear Information System (INIS)

    Tarifa, Enrique E.; Scenna, Nicolas J.

    1995-01-01

    The objective of this work is to develop an algorithm for fault diagnosis in a process of animal cell cultivation, for bioinsecticide production. Generally, these processes are batch processes. It is a fact that the diagnosis for a batch process involves a division of the process evolution (time horizon) into partial processes, which are defined as pseudocontinuous blocks. Therefore, a PCB represents the evolution of the system in a time interval where it has a qualitative behavior similar to a continuous one. Thus, each PCB, in which the process is divided, can be handled in a conventional way (like continuous processes). The process model, for each PCB, is a Signed Directed Graph (SDG). To achieve generality and to allow the computational implementation, the modular approach was used in the synthesis of the bioreactor digraph. After that, the SDGs were used to carry out qualitative simulations of faults. The achieved results are the fault patterns. A special fault symptom dictionary - SM - has been adopted as data base organization for fault patterns storage. An effective algorithm is presented for the searching process of fault patterns. The system studied, as a particular application, is a bioreactor for cell cultivation for bioinsecticide production. During this work, we concentrate on the SDG construction, and 3btaining real fault patterns by the elimination of spurious patterns. The algorithm has proved to be effective in both senses, resolution and accuracy, to diagnose different kinds of simulated faults

  14. High cell density cultivation of Escherichia coli K4 in a microfiltration bioreactor: a step towards improvement of chondroitin precursor production

    Directory of Open Access Journals (Sweden)

    De Rosa Mario

    2011-02-01

    Full Text Available Abstract Background The bacteria Escherichia coli K4 produces a capsular polysaccharide (K4 CPS whose backbone is similar to the non sulphated chondroitin chain. The chondroitin sulphate is one of the major components of the extra-cellular matrix of the vertebrate connective tissues and a high value molecule, widely employed as active principle in the treatment of osteoarthritis. It is usually obtained by extraction from animal tissues, but the risk of virus contaminations, as well as the scarceness of raw material, makes this productive process unsafe and unable to satisfy the growing market demand. In previous studies a new biotechnological process to produce chondroitin from Escherichia coli K4 capsular polysaccharide was investigated and a 1.4 g·L-1 K4 CPS concentration was reached using fed-batch fermentation techniques. In this work, on the trail of these results, we exploited new fermentation strategies to further improve the capsular polysaccharide production. Results The inhibitory effect of acetate on the bacterial cells growth and K4 CPS production was studied in shake flask conditions, while a new approach, that combined the optimization of the feeding profiles, the improvement of aeration conditions and the use of a microfiltration bioreactor, was investigated in three different types of fermentation processes. High polysaccharide concentrations (4.73 ± 0.2 g·L-1, with corresponding average yields (0.13 ± 0.006 gK4 CPS·gcdw-1, were obtained; the increase of K4 CPS titre, compared to batch and fed-batch results, was of 16-fold and 3.3-fold respectively, while average yield was almost 3.5 and 1.4 fold higher. Conclusion The increase of capsular polysaccharide titre confirmed the validity of the proposed fermentation strategy and opened the way to the use of the microfiltration bioreactor for the biotechnological production of chondroitin.

  15. Scale up of diesel oil biodegradation in a baffled roller bioreactor.

    Science.gov (United States)

    Nikakhtari, Hossein; Song, Wanning; Kumar, Pardeep; Nemati, Mehdi; Hill, Gordon A

    2010-05-01

    Diesel oil is a suitable substance to represent petroleum contamination from accidental spills in operating and transportation facilities. Using a microbial culture enriched from a petroleum contaminated soil, biodegradation of diesel oil was carried out in 2.2, 55, and 220 L roller baffled bioreactors. The effects of bioreactor rotation speed (from 5 to 45 rpm) and liquid loading (from 18% to 73% of total volume) on the biodegradation of diesel oil were studied. In the small scale bioreactor (2.2L), the maximum rotation speed of 45 rpm resulted in the highest biodegradation rate with a first order biodegradation kinetic constant of 0.095 d(-1). In the larger scale bioreactors, rotation speed did not affect the biodegradation rate. Liquid loadings higher than 64% resulted in reduced biodegradation rates in the small scale bioreactor; however, in the larger roller bioreactors liquid loading did not affect the biodegradation rate. Biodegradation of diesel oil at 5 rpm and 73% loading is recommended for operating large scale roller baffled bioreactors. Under these conditions, high diesel oil concentrations up to 50 gL(-1) can be bioremediated at a rate of 1.61 gL(-1)d(-1). Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Bioreactor design for successive culture of anchorage-dependent cells operated in an automated manner.

    Science.gov (United States)

    Kino-Oka, Masahiro; Ogawa, Natsuki; Umegaki, Ryota; Taya, Masahito

    2005-01-01

    A novel bioreactor system was designed to perform a series of batchwise cultures of anchorage-dependent cells by means of automated operations of medium change and passage for cell transfer. The experimental data on contamination frequency ensured the biological cleanliness in the bioreactor system, which facilitated the operations in a closed environment, as compared with that in flask culture system with manual handlings. In addition, the tools for growth prediction (based on growth kinetics) and real-time growth monitoring by measurement of medium components (based on small-volume analyzing machinery) were installed into the bioreactor system to schedule the operations of medium change and passage and to confirm that culture proceeds as scheduled, respectively. The successive culture of anchorage-dependent cells was conducted with the bioreactor running in an automated way. The automated bioreactor gave a successful culture performance with fair accordance to preset scheduling based on the information in the latest subculture, realizing 79- fold cell expansion for 169 h. In addition, the correlation factor between experimental data and scheduled values through the bioreactor performance was 0.998. It was concluded that the proposed bioreactor with the integration of the prediction and monitoring tools could offer a feasible system for the manufacturing process of cultured tissue products.

  17. Thinking beyond the Bioreactor Box: Incorporating Stream Ecology into Edge-of-Field Nitrate Management.

    Science.gov (United States)

    Goeller, Brandon C; Febria, Catherine M; Harding, Jon S; McIntosh, Angus R

    2016-05-01

    Around the world, artificially drained agricultural lands are significant sources of reactive nitrogen to stream ecosystems, creating substantial stream health problems. One management strategy is the deployment of denitrification enhancement tools. Here, we evaluate the factors affecting the potential of denitrifying bioreactors to improve stream health and ecosystem services. The performance of bioreactors and the structure and functioning of stream biotic communities are linked by environmental parameters like dissolved oxygen and nitrate-nitrogen concentrations, dissolved organic carbon availability, flow and temperature regimes, and fine sediment accumulations. However, evidence of bioreactors' ability to improve waterway health and ecosystem services is lacking. To improve the potential of bioreactors to enhance desirable stream ecosystem functioning, future assessments of field-scale bioreactors should evaluate the influences of bioreactor performance on ecological indicators such as primary production, organic matter processing, stream metabolism, and invertebrate and fish assemblage structure and function. These stream health impact assessments should be conducted at ecologically relevant spatial and temporal scales. Bioreactors have great potential to make significant contributions to improving water quality, stream health, and ecosystem services if they are tailored to site-specific conditions and implemented strategically with land-based and stream-based mitigation tools within watersheds. This will involve combining economic, logistical, and ecological information in their implementation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. ON-LINE MONITORING OF BIOMASS CONCENTRATION BASED ON A CAPACITANCE SENSOR: ASSESSING THE METHODOLOGY FOR DIFFERENT BACTERIA AND YEAST HIGH CELL DENSITY FED-BATCH CULTURES

    Directory of Open Access Journals (Sweden)

    A. C. L. Horta

    2015-12-01

    Full Text Available Abstract The performance of an in-situ capacitance sensor for on-line monitoring of biomass concentration was evaluated for some of the most important microorganisms in the biotechnology industry: Escherichia coli, Saccharomyces cerevisiae, Pichia pastoris and Bacillus megaterium. A total of 33 batch and fed-batch cultures were carried out in a bench-scale bioreactor and biomass formation trends were followed by dielectric measurements during the growth phase as well as the induction phase, for 5 recombinant E. coli strains. Permittivity measurements and viable cellular concentrations presented a linear correlation for all the studied conditions. In addition, the permittivity signal was further used for inference of the cellular growth rate. The estimated specific growth rates mirrored the main trends of the metabolic states of the different cells and they can be further used for setting-up control strategies in fed-batch cultures.

  19. A CFD model for determining mixing and mass transfer in a high power agitated bioreactor

    DEFF Research Database (Denmark)

    Bach, Christian; Albæk, Mads O.; Stocks, Stuart M.

    performance of a high power agitated pilot scale bioreactor has been characterized using a novel combination of computational fluid dynamics (CFD) and experimental investigations. The effect of turbulence inside the vessel was found to be most efficiently described by using the k-ε model with regards...... simulations, and the overall mass transfer coefficient was found to be in accordance with experimental data. This work illustrates the possibility of predicting the hydrodynamic performance of an agitated bioreactor using validated CFD models. These models can be applied in the testing of new bioreactor...

  20. Commissioning of Research Bioreactor made in Korea with Malaysian Environment Adaptation

    International Nuclear Information System (INIS)

    Mohd Jamil Hashim; Mohd Azmi Sidid Omar

    2011-01-01

    Bioreactor is equipment used by researcher in Agrotechnology and Biosciences department (BAB) as a scientific approach to get a scale up of product. Headed by one of the senior researcher in the department, an effort has been made to upscale the project by using MTDC fund. The technology platform has been acquired from South Korea. Some modification has to be made to cater for the need of a research bioreactor to be established for Nuclear Malaysia Agency. This research bioreactor is to emulate a tissue culture product in a bigger scale bio processing, pharmaceutical biotechnology and industrial production. (author)

  1. Solvent Fermentation From Palm Oil Mill Effluent Using Clostridium acetobutylicum In Oscillatory Flow Bioreactor

    International Nuclear Information System (INIS)

    Takriff, M.S.; Masngut, N.; Kadhum, A.A.H.; Kalil, M.S.; Mohammad, A.W.

    2009-01-01

    Acetone-butanol-ethanol (ABE) fermentation from Palm Oil Mill Effluent (POME) by C. acetobutylicum NCIMB 13357 in an oscillatory flow bioreactor was investigated. Experimental works were conducted in a U-shaped stainless steel oscillatory flow bioreactor at oscillation frequency between 0.45-0.78 Hz and a constant amplitude of 12.5 mm. Fermentations were carried out for 72 hr at 35 degree Celsius using palm oil mill effluent and reinforced clostridia medium as a growth medium in batch culture. Result of this investigation showed that POME is a viable media for ABE fermentation and oscillatory flow bioreactor has an excellent potential as an alternative fermentation device. (author)

  2. Mathematical modeling of fed-batch fermentation of Schizochytrium sp. FJU-512 growth and DHA production using a shift control strategy.

    Science.gov (United States)

    Zhang, Mingliang; Wu, Weibin; Guo, Xiaolei; Weichen, You; Qi, Feng; Jiang, Xianzhang; Huang, Jianzhong

    2018-03-01

    To obtain high-cell-density cultures of Schizochytrium sp. FJU-512 for DHA production, two stages of fermentation strategy were used and carbon/nitrogen ratio, DO and temperature were controlled at different levels. The final dry cell weight, total lipid production and DHA yield in 15 l bioreactor reached 103.9, 37.2 and 16.0 g/l, respectively. For the further study of microbial growth and DHA production dynamics, we established a set of kinetic models for the fed-batch production of DHA by Schizochytrium sp. FJU-512 in 15 and 100 l fermenters and a compensatory parameter n was integrated into the model in order to find the optimal mathematical equations. A modified Logistic model was proposed to fit the cell growth data and the following kinetic parameters were obtained: µ m  = 0.0525/h, X m  = 100 g/l and n  = 4.1717 for the 15 l bioreactor, as well as µ m  = 0.0382/h, X m  = 107.4371 g/l and n  = 10 for the 100 l bioreactor. The Luedeking-Piret equations were utilized to model DHA production, yielding values of α  = 0.0648 g/g and β  = 0.0014 g/g/h for the 15 l bioreactor, while the values of α and β obtained for the 100 l fermentation were 0.0209 g/g and 0.0030 g/g/h. The predicted results compared with experimental data showed that the established models had a good fitting precision and were able to exactly depict the dynamic features of the DHA production process.

  3. Recovery of resources for advanced life support space applications: effect of retention time on biodegradation of two crop residues in a fed-batch, continuous stirred tank reactor

    Science.gov (United States)

    Strayer, R. F.; Finger, B. W.; Alazraki, M. P.; Cook, K.; Garland, J. L.

    2002-01-01

    Bioreactor retention time is a key process variable that will influence costs that are relevant to long distance space travel or long duration space habitation. However. little is known about the effects of this parameter on the microbiological treatment options that are being proposed for Advanced Life Support (ALS) systems. Two bioreactor studies were designed to examine this variable. In the first one, six retention times ranging from 1.3 to 21.3 days--were run in duplicate, 81 working-volume continuous stirred tank reactors (CSTR) that were fed ALS wheat residues. Ash-free dry weight loss, carbon mineralization, soluble TOC reduction, changes in fiber content (cellulose, hemicellulose, and lignin), bacterial numbers, and mineral recoveries were monitored. At short retention times--1.33 days--biodegradation was poor (total: 16-20%, cellulose - 12%, hemicellulose - 28%) but soluble TOC was decreased by 75-80% and recovery of major crop inorganic nutrients was adequate, except for phosphorus. A high proportion of the total bacteria (ca. 83%) was actively respiring. At the longest retention time tested, 21.3 days, biodegradation was good (total: 55-60%, cellulose ca. 70%, hemicellulose - ca. 55%) and soluble TOC was decreased by 80%. Recovery of major nutrients, except phosphorus, remained adequate. A very low proportion of total bacteria was actively respiring (ca. 16%). The second bioreactor study used potato residue to determine if even shorter retention times could be used (range 0.25-2.0 days). Although overall biodegradation deteriorated, the degradation of soluble TOC continued to be ca. 75%. We conclude that if the goal of ALS bioprocessing is maximal degradation of crop residues, including cellulose, then retention times of 10 days or longer will be needed. If the goal is to provide inorganic nutrients with the smallest volume/weight bioreactor possible, then a retention time of 1 day (or less) is sufficient.

  4. Process integration for biological sulfate reduction in a carbon monoxide fed packed bed reactor.

    Science.gov (United States)

    Kumar, Manoj; Sinharoy, Arindam; Pakshirajan, Kannan

    2018-05-09

    This study examined immobilized anaerobic biomass for sulfate reduction using carbon monoxide (CO) as the sole carbon source under batch and continuous fed conditions. The immobilized bacteria with beads made of 10% polyvinyl alcohol (PVA) showed best results in terms of sulfate reduction (84 ± 3.52%) and CO utilization (98 ± 1.67%). The effect of hydraulic retention time (HRT), sulfate loading rate and CO loading rate on sulfate and CO removal was investigated employing a 1L packed bed bioreactor containing the immobilized biomass. At 48, 24 and 12 h HRT, the sulfate removal was 94.42 ± 0.15%, 89.75 ± 0.47% and 61.08 ± 0.34%, respectively, along with a CO utilization of more than 90%. The analysis of variance (ANOVA) of the results obtained showed that only the initial CO concentration significantly affected the sulfate reduction process. The reactor effluent sulfate concentrations were 27.41 ± 0.44, 59.16 ± 1.08, 315.83 ± 7.33 mg/L for 250, 500 and 1000 mg/L of influent sulfate concentrations respectively, under the optimum operating conditions. The sulfate reduction rates matched well with low inlet sulfate loading rates, indicating stable performance of the bioreactor system. Overall, this study yielded very high sulfate reduction efficiency by the immobilized anaerobic biomass under high CO loading condition using the packed bed reactor system. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. A parametric study ot protease production in batch and fed-batch cultures of Bacillus firmus.

    Science.gov (United States)

    Moon, S H; Parulekar, S J

    1991-03-05

    Proteolytic enzymes produced by Bacillus species find a wide variety of applications in brewing, detergent, food, and leather industries. Owing to significant differences normally observed in culture conditions promoting cell growth and those promoting production of metabolites such as enzymes, for increased efficacy of bioreactor operations it is essential to identify these sets of conditions (including medium formulation). This study is focused on formulation of a semidefined medium that substantially enhances synthesis and secretion of an alkaline protease in batch cultures of Bacillus firmus NRS 783, a known superior producer of this enzyme. The series of experiments conducted to identify culture conditions that lead to improved protease production also enables investigation of the regulatory effects of important culture parameters including pH, dissolved oxygen, and concentrations of nitrogen and phosphorous sources and yeast extract in the medium on cell growth, synthesis and secretion of protease, and production of two major nonbiomass products, viz., acetic acid and ethanol. Cell growth and formation of the three nonbiomass products are hampered significantly under nitrogen, phosphorous, or oxygen limitation, with the cells being unable to grow in an oxygen-free environment. Improvement in protease production is achieved with respect to each culture parameter, leading in the process to 80% enhancement in protease activity over that attained using media reported in the literature. Results of a few fed-batch experiments with constant feed rate, conducted to examine possible enhancement in protease production and to further investigate repression of protease synthesis by excess of the principal carbon and nitrogen sources, are also discussed. The detailed investigation of stimulatory and repressory effects of simple and complex nutrients on protease production and metabolism of Bacillus firmus conducted in this study will provide useful guidelines for design

  6. Stochastic models to study the impact of mixing on a fed-batch culture of Saccharomyces cerevisiae.

    Science.gov (United States)

    Delvigne, F; Lejeune, A; Destain, J; Thonart, P

    2006-01-01

    The mechanisms of interaction between microorganisms and their environment in a stirred bioreactor can be modeled by a stochastic approach. The procedure comprises two submodels: a classical stochastic model for the microbial cell circulation and a Markov chain model for the concentration gradient calculus. The advantage lies in the fact that the core of each submodel, i.e., the transition matrix (which contains the probabilities to shift from a perfectly mixed compartment to another in the bioreactor representation), is identical for the two cases. That means that both the particle circulation and fluid mixing process can be analyzed by use of the same modeling basis. This assumption has been validated by performing inert tracer (NaCl) and stained yeast cells dispersion experiments that have shown good agreement with simulation results. The stochastic model has been used to define a characteristic concentration profile experienced by the microorganisms during a fermentation test performed in a scale-down reactor. The concentration profiles obtained in this way can explain the scale-down effect in the case of a Saccharomyces cerevisiae fed-batch process. The simulation results are analyzed in order to give some explanations about the effect of the substrate fluctuation dynamics on S. cerevisiae.

  7. High level expression of Glomerella cingulata cutinase in dense cultures of Pichia pastoris grown under fed-batch conditions.

    Science.gov (United States)

    Seman, W M K Wan; Bakar, S A; Bukhari, N A; Gaspar, S M; Othman, R; Nathan, S; Mahadi, N M; Jahim, J; Murad, A M A; Bakar, F D Abu

    2014-08-20

    A Pichia pastoris transformant carrying the cutinase cDNA of Glomerella cingulata was over-expressed in a 5L bioreactor (2.0L working volume) under fed-batch conditions. Bioreactor experiments rely on varying selected parameters in repeated rounds of optimisation: here these included duration of induction, pH and temperature. Highest cell densities (320gL(-1) wet cell weight) with a cutinase production of 3800mgL(-1) and an activity of 434UmL(-1) were achieved 24h after induction with methanol in basal salt medium (at pH 5 and 28°C). Characterisation of the cutinase showed that it was stable between pH 6 and pH 11, had an optimum pH of 8.0 and retained activity for 30min at 50°C (optimum temperature 25°C).The preferred substrates of G. cingulata cutinase were the medium- to long-chain ρ-nitrophenyl esters of ρ-nitrophenylcaprylate (C8), ρ-nitrophenyllaurate (C12) and ρ-nitrophenylmyristate (C14), with the highest catalytic efficiency, kcat/Km of 7.7±0.7mM(-1)s(-1) for ρ-nitrophenylcaprylate. Microscopic analyses showed that the G. cingulata cutinase was also capable of depolymerising the high molecular weight synthetic polyester, polyethylene terephthalate. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Submerged membrane bioreactor for domestic wastewater treatment and reuse

    International Nuclear Information System (INIS)

    Feki; Firas; Jraou, Mouna; Loukil, Slim; Kchaou, Sonia; Sayadi, Sami; Arnolt, Tom

    2009-01-01

    The Mediterranean basin (and particularly North African countries) is one of the poorest regions in the world in terms of water resources. In Tunisia, treated municipal wastewater is becoming one of the main alternative sources of water. Indeed, in 2007, 99 municipal wastewater treatment plants (WWTP) has treated a quantity of 215 millions of m 3 from which more than 30 pour cent are reused. The treated volume in 2011 is expected to be 266 millions m 3 , whereas the reused wastewaters should reach more than 50 pour cent. However, especially in the eastern and northern Mediterranean regions, wastewaters are inefficiently treated and re-used for irrigation or sanitary purposes, serving as a carrier for diseases or causing water pollution when discharged to water bodies. In the last decade, several water treatment technologies have been used in the region with little success in pathogen removal. Membrane bioreactor (MBR) technology is a very promising alternative to those conventional water treatments as membranes act as a barrier against bacteria and viruses achieving a high degree of water purification. However, most membrane bioreactors currently in use have very high running costs because of the high pressure drop and high air-flushing rate required for their operation. The objective of this PURATREAT FP 6 EU project was to study a new approach to the operation of membrane bioreactors. This study was included a comparison of three leading membrane technologies. The operating procedure to be studied is expected to yield very low energy consumption and reduced maintenance costs. After the start up period, the MBR3 was operated with a MLSS concentration of 4.5 and 9 g/L, respectively. Different fluxes as 16, 18, 20 and 22 Lh -1 m -2 were tested. When the flux increase from 16 to 22 Lh -1 m -2 , the treatment energy consumption decreased from 7 to 5 kWh/m 3 . However the increases of MLSS concentration from 4.5 and 9 g/L raise the membrane fouling frequency from 1

  9. Start-up period investigation of pilot-scale submerged membrane electro-bioreactor (SMEBR) treating raw municipal wastewater.

    Science.gov (United States)

    Hasan, Shadi W; Elektorowicz, Maria; Oleszkiewicz, Jan A

    2014-02-01

    Submerged membrane electro-bioreactor (SMEBR) is a new hybrid technology for wastewater treatment employing electrical field and microfiltration in a nutrient-removing activated sludge process. A pilot SMEBR system was located at the wastewater treatment plant in the City of l'Assomption (Quebec, Canada) with the objective of investigating the start-up period performance under variable organic loadings and environmental conditions with respect to effluent quality, membrane fouling, and sludge properties. The pilot SMEBR facility was fed with the raw de-gritted municipal wastewater. At steady state operation, the removal efficiencies of ammonia (as NH3(+)-N), phosphorus (as PO4(3-)-P), and COD were 99%, 99%, and 92%, respectively. No substantial increase in the monitored transmembrane pressure as 0.02kPad(-1) was reported. The time necessary to filter 100mL of the sludge sample has decreased by 78% after treatment whilst the sludge volume index averaged 119mLg(-1). Energy requirements were in the range of 1.1-1.6kWhm(-3) of wastewater. It was concluded that the SMEBR is a very competitive technology when compared to conventional membrane systems as it can enhance treatment performance to an appreciable extent, remove phosphorus and reduce fouling. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  10. Green and economical production of propionic acid by Propionibacterium freudenreichii CCTCC M207015 in plant fibrous-bed bioreactor.

    Science.gov (United States)

    Feng, Xiaohai; Chen, Fei; Xu, Hong; Wu, Bo; Li, Hui; Li, Sha; Ouyang, Pingkai

    2011-05-01

    Propionic acid production by Propionibacterium freudenreichii from molasses and waste propionibacterium cells was studied in plant fibrous-bed bioreactor (PFB). With non-treated molasses as carbon source, 12.69 ± 0.40 g l(-1) of propionic acid was attained at 120 h in free-cell fermentation, whereas the PFB fermentation yielded 41.22 ± 2.06 g l(-1) at 120 h and faster cells growth was observed. In order to optimize the fermentation outcomes, fed-batch fermentation was performed with hydrolyzed molasses in PFB, giving 91.89 ± 4.59 g l(-1) of propionic acid at 254 h. Further studies were carried out using hydrolyzed waste propionibacterium cells as substitute nitrogen source, resulting in a propionic acid concentration of 79.81 ± 3.99 g l(-1) at 302 h. The present study suggests that the low-cost molasses and waste propionibacterium cells can be utilized for the green and economical production of propionic acid by P. freudenreichii. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Prediction of COD and NH4+-N Concentrations in Leachate from Lab-scale Landfill Bioreactors Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Mohamad Javad Zoqi

    2010-06-01

    Full Text Available In this study, we present an Artificial Neural Network (ANN model for predicting COD and NH4+-N concentrations in landfill leachate from lab-scale landfill bioreactors. For this purpose, two different lab-scale systems were modeled. for neural network’s data obtained. In the first system, the leachate from a fresh-waste reactor was drained to a recirculation tank and recycled every two days. In the second, the leachate from a fresh waste landfill reactor was fed through a well-decomposed refuse landfill reactor, while the leachate from a well-decomposed refuse landfill reactor was simultaneously recycled to a fresh waste landfill reactor. The results indicate that leachate NH4+-N and COD concentrations accumulated to a high level in the first system, while. NH4+-N and COD removals were successfully carried out in the second. Also, average removal efficiencies in the second system reached 85% and 34% for COD and NH4+-N, respectively. Finally, the ANN’s results exhibited the success of the model as witnessed by the excellent agreement obtained between measured and predicted values.

  12. Bioreactors as Engineering Support to Treat Cardiac Muscle and Vascular Disease

    Directory of Open Access Journals (Sweden)

    Diana Massai

    2013-01-01

    Full Text Available Cardiovascular disease is the leading cause of morbidity and mortality in the Western World. The inability of fully differentiated, load-bearing cardiovascular tissues to in vivo regenerate and the limitations of the current treatment therapies greatly motivate the efforts of cardiovascular tissue engineering to become an effective clinical strategy for injured heart and vessels. For the effective production of organized and functional cardiovascular engineered constructs in vitro, a suitable dynamic environment is essential, and can be achieved and maintained within bioreactors. Bioreactors are technological devices that, while monitoring and controlling the culture environment and stimulating the construct, attempt to mimic the physiological milieu. In this study, a review of the current state of the art of bioreactor solutions for cardiovascular tissue engineering is presented, with emphasis on bioreactors and biophysical stimuli adopted for investigating the mechanisms influencing cardiovascular tissue development, and for eventually generating suitable cardiovascular tissue replacements.

  13. CULTIVATION OF HUMAN LIVER CELLS AND ADIPOSE-DERIVED MESENCHYMAL STROMAL CELLS IN PERFUSION BIOREACTOR

    Directory of Open Access Journals (Sweden)

    Yu. В. Basok

    2018-01-01

    Full Text Available Aim: to show the progress of the experiment of cultivation of human liver cells and adipose-derived mesenchymal stromal cells in perfusion bioreactor.Materials and methods. The cultivation of a cell-engineered construct, consisting of a biopolymer microstructured collagen-containing hydrogel, human liver cells, adipose-derived mesenchymal stromal cells, and William’s E Medium, was performed in a perfusion bioreactor.Results. On the 7th day large cells with hepatocyte morphology – of a polygonal shape and a centrally located round nucleus, – were present in the culture chambers of the bioreactor. The metabolic activity of hepatocytes in cell-engineered constructs was confi rmed by the presence of urea in the culture medium on the seventh day of cultivation in the bioreactor and by the resorption of a biopolymer microstructured collagen-containing hydrogel.

  14. Removal of Cyclohexane from a Contaminated Air Stream Using a Dense Phase Membrane Bioreactor

    National Research Council Canada - National Science Library

    Roberts, Michael G

    2005-01-01

    The purpose of this research was to determine the ability of a dense phase membrane bioreactor to remove cyclohexane, a volatile organic compound in JP-8 jet fuel, from a contaminated air stream using...

  15. Influence of phosphorus precipitation on permeability and soluble microbial product concentration in a membrane bioreactor

    Czech Academy of Sciences Publication Activity Database

    Gómez, M.; Dvořák, L.; Růžičková, I.; Wanner, J.; Holba, Marek; Sýkorová, E.

    2013-01-01

    Roč. 129, Feb 2013 (2013), s. 164-169 ISSN 0960-8524 Institutional support: RVO:67985939 Keywords : membrane bioreactor * coagulant adition * soluble microbial products Subject RIV: EF - Botanics Impact factor: 5.039, year: 2013

  16. Method and Apparatus for a Miniature Bioreactor System for Long-Term Cell Culture

    Science.gov (United States)

    Kleis, Stanley J. (Inventor); Geffert, Sandra K. (Inventor); Gonda, Steve R. (Inventor)

    2015-01-01

    A bioreactor and method that permits continuous and simultaneous short, moderate, or long term cell culturing of one or more cell types or tissue in a laminar flow configuration is disclosed, where the bioreactor supports at least two laminar flow zones, which are isolated by laminar flow without the need for physical barriers between the zones. The bioreactors of this invention are ideally suited for studying short, moderate and long term studies of cell cultures and the response of cell cultures to one or more stressors such as pharmaceuticals, hypoxia, pathogens, or any other stressor. The bioreactors of this invention are also ideally suited for short, moderate or long term cell culturing with periodic cell harvesting and/or medium processing for secreted cellular components.

  17. Concept of Compound Retention Time for Organic Micro Pollutants in Anaerobic Membrane Bioreactor with Nanofiltration

    KAUST Repository

    Pan, Jiangjiang

    2011-01-01

    to control OMPs wastage. An innovative hybrid process, anaerobic membrane bioreactor with nanofiltration (AnMBR-NF), in which enhanced OMPs removal is possible based on the concept of compound retention time (CRT) through coupling anaerobic biodegradation

  18. Use of G3-DHS Bioreactor for Secondary Treatment of Septic Tank Desludging Wastewater

    Directory of Open Access Journals (Sweden)

    Izarul Machdar

    2016-01-01

    Full Text Available Study was done for the use of the third-generation of downflow hanging sponge (G3-DHS bioreactor for secondary treatment of septic tank desludging wastewater. The main objective of this study was to evaluate the prospective system of G3-DHS bioreactor to be applied in Indonesia. During experiment, the G3-DHS bioreactor kept a relatively high dissolved oxygen concentration under natural aeration. At a relatively short hydraulic retention (HRT of 3 h, the G3-DHS bioreactor could remove up to 21% (SD 15% of total COD, 21% (SD = 7% of filtered-COD, 58% (SD = 24% of unfiltered-BOD, and 33% (SD = 24% of ammonium removal. The final effluent had an unfiltered-BOD of only 46 mg.L-1 (SD = 20 mg.L-1 that it was below the Indonesian standard (unfiltered-BOD = 100 mg.L-1 for thresholds of domestic wastewater treatment plants effluent.

  19. Forecasting the settlement of a bioreactor landfill based on gas pressure changes.

    Science.gov (United States)

    Qiu, Gang; Li, Liang; Sun, Hongjun

    2013-10-01

    In order to study the influence of settlement under gas pressure in bioreactor landfill, the landfill is simplified as a one-way gas seepage field, combining Darcy's Law, the gas equation of state, and the principle of effective stress and fluid dynamics of porous media theory. First assume that the bioreactor landfill leachate is fully recharged on the basis of gas mass conservation, then according to the changes in gas pressure (inside the landfill and surrounding atmosphere) during the gas leakage time and settlement in the landfill, establish a numerical model of bioreactor landfill settlement under the action of the gas pressure, and use the finite difference method to solve it. Through a case study, the model's improved prediction of the settlement of bioreactor landfill is demonstrated.

  20. Optimal Homogenization of Perfusion Flows in Microfluidic Bio-Reactors: A Numerical Study

    DEFF Research Database (Denmark)

    Okkels, Fridolin; Dufva, Martin; Bruus, Henrik

    2011-01-01

    In recent years, the interest in small-scale bio-reactors has increased dramatically. To ensure homogeneous conditions within the complete area of perfused microfluidic bio-reactors, we develop a general design of a continually feed bio-reactor with uniform perfusion flow. This is achieved...... by introducing a specific type of perfusion inlet to the reaction area. The geometry of these inlets are found using the methods of topology optimization and shape optimization. The results are compared with two different analytic models, from which a general parametric description of the design is obtained...... and tested numerically. Such a parametric description will generally be beneficial for the design of a broad range of microfluidic bioreactors used for, e. g., cell culturing and analysis and in feeding bio-arrays....

  1. Synthesis of supermacroporous cryogel for bioreactors continuous starch hydrolysis.

    Science.gov (United States)

    Guilherme, Ederson Paulo Xavier; de Oliveira, Jocilane Pereira; de Carvalho, Lorendane Millena; Brandi, Igor Viana; Santos, Sérgio Henrique Sousa; de Carvalho, Gleidson Giordano Pinto; Cota, Junio; Mara Aparecida de Carvalho, Bruna

    2017-11-01

    A bioreactor was built by means of immobilizing alpha-amylase from Aspergillus oryzae by encapsulation, through cryopolymerization of acrylamide monomers for the continuous starch hydrolysis. The starch hydrolysis was evaluated regarding pH, the concentration of immobilized amylase on cryogel, the concentration of starch solution and temperature. The maximum value for starch hydrolysis was achieved at pH 5.0, concentration of immobilized enzyme 111.44 mg amylase /g cryogel , concentration of starch solution 45 g/L and temperature of 35°C. The immobilized enzyme showed a conversion ratio ranging from 68.2 to 97.37%, depending on the pH and temperature employed. Thus, our results suggest that the alpha-amylase from A. oryzae immobilized on cryogel monoliths represents a potential process for industrial production of maltose from starch hydrolysis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Leachate pretreatment for enhancing organic matter conversion in landfill bioreactor

    International Nuclear Information System (INIS)

    He Pinjing; Qu Xian; Shao Liming; Li Guojian; Lee Duujong

    2007-01-01

    Direct recycling of leachate from refuse of high food waste content was shown to ineffectively stabilize the refuse. This work aims at evaluating the effects of three pretreatments of leachate on the refuse stabilization efficiency were investigated. Pretreatment of leachate using an anaerobic upflow filtration bioreactor (UFB) or a well-decomposed waste layer could reduce the COD and provide methanogens, both were beneficial to establish early methanogenesis status. Using an aerobic sequential batch reactor (SBR) to pretreat the leachate could reduce its COD to 1000 mg l -1 , but the fully developed methanogenesis phase would be built up in a later stage. The organic matters in the effluent leachate inhibited both the hydrolysis/acidogenesis and the methanogenesis steps in the refuse. With the dilution and acid neutralization effects by the recycled leachate, a favorable methanogenetic environment could be produced from the column's top, which moved downward along, and finally made the breakthrough of the column

  3. Model system studies with a phase separated membrane bioreactor

    Science.gov (United States)

    Petersen, G. R.; Seshan, P. K.; Dunlop, Eric H.

    1989-01-01

    The operation and evaluation of a bioreactor designed for high intensity oxygen transfer in a microgravity environment is described. The reactor itself consists of a zero headspace liquid phase separated from the air supply by a long length of silicone rubber tubing through which the oxygen diffuses in and the carbon dioxide diffuses out. Mass transfer studies show that the oxygen is film diffusion controlled both externally and internally to the tubing and not by diffusion across the tube walls. Methods of upgrading the design to eliminate these resistances are proposed. Cell growth was obtained in the fermenter using Saccharomyces cerevisiae showing that this concept is capable of sustaining cell growth in the terrestial simulation.

  4. Phase separated membrane bioreactor - Results from model system studies

    Science.gov (United States)

    Petersen, G. R.; Seshan, P. K.; Dunlop, E. H.

    1989-01-01

    The operation and evaluation of a bioreactor designed for high intensity oxygen transfer in a microgravity environment is described. The reactor itself consists of a zero headspace liquid phase separated from the air supply by a long length of silicone rubber tubing through which the oxygen diffuses in and the carbon dioxide diffuses out. Mass transfer studies show that the oxygen is film diffusion controlled both externally and internally to the tubing and not by diffusion across the tube walls. Methods of upgrading the design to eliminate these resistances are proposed. Cell growth was obtained in the fermenter using Saccharomyces cerevisiae showing that this concept is capable of sustaining cell growth in the terrestrial simulation.

  5. Application of gain scheduling to the control of batch bioreactors

    Science.gov (United States)

    Cardello, Ralph; San, Ka-Yiu

    1987-01-01

    The implementation of control algorithms to batch bioreactors is often complicated by the inherent variations in process dynamics during the course of fermentation. Such a wide operating range may render the performance of fixed gain PID controllers unsatisfactory. In this work, a detailed study on the control of batch fermentation is performed. Furthermore, a simple batch controller design is proposed which incorporates the concept of gain-scheduling, a subclass of adaptive control, with oxygen uptake rate as an auxiliary variable. The control of oxygen tension in the biorector is used as a vehicle to convey the proposed idea, analysis and results. Simulation experiments indicate significant improvement in controller performance can be achieved by the proposed approach even in the presence of measurement noise.

  6. Treatment of dairy wastewater with a membrane bioreactor

    Directory of Open Access Journals (Sweden)

    L. H. Andrade

    2013-12-01

    Full Text Available Among the food industries, the dairy industry is considered to be the most polluting one because of the large volume of wastewater generated and its high organic load. In this study, an aerobic membrane bioreactor (MBR was used for the treatment of wastewater from a large dairy industry and two hydraulic retention times (HRT, 6 and 8 hours, were evaluated. For both HRTs removal efficiencies of organic matter of 99% were obtained. Despite high permeate flux (27.5 L/h.m², the system operated fairly stablely. The molecular weight distribution of feed, permeate and mixed liquor showed that only the low molecular weight fraction is efficiently degraded by biomass and that the membrane has an essential role in producing a permeate of excellent quality.

  7. Phase separated membrane bioreactor: Results from model system studies

    Science.gov (United States)

    Petersen, G. R.; Seshan, P. K.; Dunlop, E. H.

    The operation and evaluation of a bioreactor designed for high intensity oxygen transfer in a microgravity environment is described. The reactor itself consists of a zero headspace liquid phase separated from the air supply by a long length of silicone rubber tubing through which the oxygen diffuses in and the carbon dioxide diffuses out. Mass transfer studies show that the oxygen is film diffusion controlled both externally and internally to the tubing and not by diffusion across the tube walls. Methods of upgrading the design to eliminate these resistances are proposed. Cell growth was obtained in the fermenter using Saccharomyces cerevisiae showing that this concept is capable of sustaining cell growth in the terrestial simulation.

  8. Membrane bioreactors in waste water treatment - status and trends

    Energy Technology Data Exchange (ETDEWEB)

    Kraume, M. [Technische Universitaet Berlin, Chair of Chemical and Process Engineering, Berlin (Germany); Drews, A. [HTW Berlin, FB II, Life Science Engineering, Berlin (Germany)

    2010-08-15

    Due to their unique advantages like controlled biomass retention, improved effluent quality, and decreased footprint, membrane bioreactors (MBRs) are being increasingly used in waste water treatment up to a capacity of several 100,000 p.e. This article reviews the current status of MBRs and reports trends in MBR design and operation. Typical operational and design parameters are given as well as guidelines for waste water treatment plant revamping. To further improve the biological performance, specific or hybrid process configurations are shown to lead to, e.g., enhanced nutrient removal. With regards to reducing membrane fouling, optimized modules, advanced control, and strategies like the addition of flux enhancers are currently emerging. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  9. Membrane bioreactors and their uses in wastewater treatments

    Energy Technology Data Exchange (ETDEWEB)

    Le-Clech, Pierre [New South Wales Univ., Sydney (Australia). UNESCO Centre for Membrane Science and Technology

    2010-12-15

    With the current need for more efficient and reliable processes for municipal and industrial wastewaters treatment, membrane bioreactor (MBR) technology has received considerable attention. After just a couple of decades of existence, MBR can now be considered as an established wastewater treatment system, competing directly with conventional processes like activated sludge treatment plant. However, MBR processes still suffer from major drawbacks, including high operational costs due to the use of anti-fouling strategies applied to the system to maintain sustainable filtration conditions. Moreover, this specific use of membranes has not reached full maturity yet, as MBR suppliers and users still lack experience regarding the long-term performances of the system. Still, major improvements of the MBR design and operation have been witnessed over the recent years, making MBR an option of choice for wastewater treatment and reuse. This mini-review reports recent developments and current research trends in the field. (orig.)

  10. Impact of sludge flocs on membrane fouling in membrane bioreactors

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Niessen, Wolfgang; Jørgensen, Mads Koustrup

    Membrane bioreactors (MBR) are widely used for wastewater treatment, but membrane fouling reduces membrane performance and thereby increases the cost for membranes and fouling control. Large variation in filtration properties measured as flux decline was observed for the different types of sludges....... Further, the flux could partly be reestablished after the relaxation period depending on the sludge composition. The results underline that sludge properties are important for membrane fouling and that control of floc properties, as determined by the composition of the microbial communities...... and the physico-chemical properties, is an efficient method to reduce membrane fouling in the MBR. High concentration of suspended extracellular substances (EPS) and small particles (up to 10 µm) resulted in pronounced fouling propensity. The membrane fouling resistance was reduced at high concentration...

  11. Online monitoring of cartilage tissue in a novel bioreactor

    Science.gov (United States)

    von der Burg, E.; von Buttlar, M.; Grill, W.

    2011-04-01

    Standard techniques for the analysis of biological tissues like immunohistochemical staining are typically invasive and lead to mortification of cells. Non-invasive monitoring is an important element of regenerative medicine because implants and components of implants should be 100% quality-checked with non-invasive and therefore also marker-free methods. We report on a new bioreactor for the production of collagen scaffolds seeded with Mesenchymal Stem Cells (MSCs). It contains a computer controlled mechanical activation and ultrasonic online monitoring and has been constructed for the in situ determination of ultrasonic and rheological parameters. During the cultivation period of about two weeks the scaffold is periodically compressed by two movable pistons for improved differentiation of the MSCs. This periodic compression beneficially ensures the supply with nutrition even inside the sample. During the physiological stimuli, rheological properties are measured by means of highly sensitive load cells. In addition measurements of the speed of sound in the sample and in the culture medium, with frequencies up to 16 MHz, are performed continuously. Therefore piezoceramic transducers are attached to the pistons and emit and detect ultrasonic waves, travelling through the pistons, the sample and the culture medium. The time-of-flight (TOF) of the ultrasonic signals is determined in real time with the aid of chirped excitation and correlation procedures with a resolution of at least 10 ps. The implemented ultrasonic measurement scheme allows beside the speed of sound measurements the detection of the distance between the pistons with a resolution better than 100 nm. The developed monitoring delivers information on rigidity, fluid dynamics and velocity of sound in the sample and in the culture medium. The hermetically sealed bioreactor with its life support system provides a biocompatible environment for MSCs for long time cultivation.

  12. Denitrifying Bioreactors Resist Disturbance from Fluctuating Water Levels

    Directory of Open Access Journals (Sweden)

    Sarah K. Hathaway

    2017-06-01

    Full Text Available Nitrate can be removed from wastewater streams, including subsurface agricultural drainage systems, using woodchip bioreactors to promote microbial denitrification. However, the variations in water flow in these systems could make reliable performance from this microbially-mediated process a challenge. In the current work, the effects of fluctuating water levels on nitrate removal, denitrifying activity, and microbial community composition in laboratory-scale bioreactors were investigated. The performance was sensitive to changing water level. An average of 31% nitrate was removed at high water level and 59% at low water level, despite flow adjustments to maintain a constant theoretical hydraulic retention time. The potential activity, as assessed through denitrifying enzyme assays, averaged 0.0008 mg N2O-N/h/dry g woodchip and did not show statistically significant differences between reactors, sampling depths, or operational conditions. In the denitrifying enzyme assays, nitrate removal consistently exceeded nitrous oxide production. The denitrifying bacterial communities were not significantly different from each other, regardless of water level, meaning that the denitrifying bacterial community did not change in response to disturbance. The overall bacterial communities, however, became more distinct between the two reactors when one reactor was operated with periodic disturbances of changing water height, and showed a stronger effect at the most severely disturbed location. The communities were not distinguishable, though, when comparing the same location under high and low water levels, indicating that the communities in the disturbed reactor were adapted to fluctuating conditions rather than to high or low water level. Overall, these results describe a biological treatment process and microbial community that is resistant to disturbance via water level fluctuations.

  13. Osmotic stress on nitrification in an airlift bioreactor

    International Nuclear Information System (INIS)

    Jin Rencun; Zheng Ping; Mahmood, Qaisar; Hu Baolan

    2007-01-01

    The effect of osmotic pressure on nitrification was studied in a lab-scale internal-loop airlift-nitrifying reactor. The reactor slowly adapted to the escalating osmotic pressure during 270 days operation. The conditions were reversed to the initial stage upon full inhibition of the process. Keeping influent ammonium concentration constant at 420 mg N L -1 and hydraulic retention time at 20.7 h, with gradual increase in osmotic pressure from 4.3 to 18.8 x 10 5 Pa by adding sodium sulphate, the ammonium removal efficiencies of the nitrifying bioreactor were maintained at 93-100%. Further increase in osmotic pressure up to 19.2 x 10 5 Pa resulted in drop of the ammonium conversion to 69.2%. The osmotic pressure caused abrupt inhibition of nitrification without any alarm and the critical osmotic pressure value causing inhibition remained between 18.8 and 19.2 x 10 5 Pa. Nitrite oxidizers were found more sensitive to osmotic stress as compared with ammonia oxidizers, leading to nitrite accumulation up to 61.7% in the reactor. The performance of bioreactor recovered gradually upon lowering the osmotic pressure. Scanning and transmission electron microscopy indicated that osmotic stress resulted in simplification of the nitrifying bacterial populations in the activated sludge as the cellular size reduced; the inner membrane became thinner and some unknown inclusions appeared within the cells. The microbial morphology and cellular structure restored upon relieving the osmotic pressure. Addition of potassium relieved the effect of osmotic pressure upon nitrification. Results demonstrate that the nitrifying reactor possesses the potential to treat ammonium-rich brines after acclimatization

  14. Mathematical modeling of the integrated process of mercury bioremediation in the industrial bioreactor

    OpenAIRE

    Głuszcz, Paweł; Petera, Jerzy; Ledakowicz, Stanisław

    2010-01-01

    The mathematical model of the integrated process of mercury contaminated wastewater bioremediation in a fixed-bed industrial bioreactor is presented. An activated carbon packing in the bioreactor plays the role of an adsorbent for ionic mercury and at the same time of a carrier material for immobilization of mercury-reducing bacteria. The model includes three basic stages of the bioremediation process: mass transfer in the liquid phase, adsorption of mercury onto activated carbon and ionic me...

  15. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac, E-mail: jaehacko@pkusz.edu.cn

    2015-07-15

    Highlights: • Temporary aeration shortened the initial acid inhibition phase for methanogens. • COD decreased faster in the hybrid bioreactor than that in the anaerobic control. • Methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. • MSW settlement increased with increasing the frequency of intermittent aeration. - Abstract: Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10 months. The hybrid bioreactors were operated in an aerobic–anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia–nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75 d and 60 d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

  16. Oral microbial profile discriminates breast-fed from formula-fed infants.

    Science.gov (United States)

    Holgerson, Pernilla L; Vestman, Nelly R; Claesson, Rolf; Ohman, Carina; Domellöf, Magnus; Tanner, Anne C R; Hernell, Olle; Johansson, Ingegerd

    2013-02-01

    Little is known about the effect of diet on the oral microbiota of infants, although diet is known to affect the gut microbiota. The aims of the present study were to compare the oral microbiota in breast-fed and formula-fed infants, and investigate growth inhibition of streptococci by infant-isolated lactobacilli. A total of 207 mothers consented to participation of their 3-month-old infants. A total of 146 (70.5%) infants were exclusively and 38 (18.4%) partially breast-fed, and 23 (11.1%) were exclusively formula-fed. Saliva from all of their infants was cultured for Lactobacillus species, with isolate identifications from 21 infants. Lactobacillus isolates were tested for their ability to suppress Streptococcus mutans and S sanguinis. Oral swabs from 73 infants were analysed by the Human Oral Microbe Identification Microarray (HOMIM) and by quantitative polymerase chain reaction for Lactobacillus gasseri. Lactobacilli were cultured from 27.8% of exclusively and partially breast-fed infants, but not from formula-fed infants. The prevalence of 14 HOMIM-detected taxa, and total salivary lactobacilli counts differed by feeding method. Multivariate modelling of HOMIM-detected bacteria and possible confounders clustered samples from breast-fed infants separately from formula-fed infants. The microbiota of breast-fed infants differed based on vaginal or C-section delivery. Isolates of L plantarum, L gasseri, and L vaginalis inhibited growth of the cariogenic S mutans and the commensal S sanguinis: L plantarum >L gasseri >L vaginalis. The microbiota of the mouth differs between 3-month-old breast-fed and formula-fed infants. Possible mechanisms for microbial differences observed include species suppression by lactobacilli indigenous to breast milk.

  17. Generation of Neural Progenitor Spheres from Human Pluripotent Stem Cells in a Suspension Bioreactor.

    Science.gov (United States)

    Yan, Yuanwei; Song, Liqing; Tsai, Ang-Chen; Ma, Teng; Li, Yan

    2016-01-01

    Conventional two-dimensional (2-D) culture systems cannot provide large numbers of human pluripotent stem cells (hPSCs) and their derivatives that are demanded for commercial and clinical applications in in vitro drug screening, disease modeling, and potentially cell therapy. The technologies that support three-dimensional (3-D) suspension culture, such as a stirred bioreactor, are generally considered as promising approaches to produce the required cells. Recently, suspension bioreactors have also been used to generate mini-brain-like structure from hPSCs for disease modeling, showing the important role of bioreactor in stem cell culture. This chapter describes a detailed culture protocol for neural commitment of hPSCs into neural progenitor cell (NPC) spheres using a spinner bioreactor. The basic steps to prepare hPSCs for bioreactor inoculation are illustrated from cell thawing to cell propagation. The method for generating NPCs from hPSCs in the spinner bioreactor along with the static control is then described. The protocol in this study can be applied to the generation of NPCs from hPSCs for further neural subtype specification, 3-D neural tissue development, or potential preclinical studies or clinical applications in neurological diseases.

  18. Evaluation of Productivity of Zymotis Solid-State Bioreactor Based on Total Reactor Volume

    Directory of Open Access Journals (Sweden)

    Oscar F. von Meien

    2002-01-01

    Full Text Available In this work a method of analyzing the performance of solid-state fermentation bioreactors is described. The method is used to investigate the optimal value for the spacing between the cooling plates of the Zymotis bioreactor, using simulated fermentation data supplied by a mathematical model. The Zymotis bioreactor has good potential for those solid-state fermentation processes in which the substrate bed must remain static. The current work addresses two design parameters introduced by the presence of the internal heat transfer plates: the width of the heat transfer plate, which is governed by the amount of heat to be removed and the pressure drop of the cooling water, and the spacing between these heat transfer plates. In order to analyze the performance of the bioreactor a productivity term is introduced that takes into account the volume occupied within the bioreactor by the heat transfer plates. As part of this analysis, it is shown that, for logistic growth kinetics, the time at which the biomass reaches 90 % of its maximum possible value is a good estimate of the optimum harvesting time for maximizing productivity. Application of the productivity analysis to the simulated fermentation results suggests that, with typical fast growing fungi ( = 0.324 h–1, the optimal spacing between heat transfer plates is of the order of 6 cm. The general applicability of this approach to evaluate the productivity of solid-state bioreactors is demonstrated.

  19. Intelligent Bioreactor Management Information System (IBM-IS) for Mitigation of Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Paul Imhoff; Ramin Yazdani; Don Augenstein; Harold Bentley; Pei Chiu

    2010-04-30

    Methane is an important contributor to global warming with a total climate forcing estimated to be close to 20% that of carbon dioxide (CO2) over the past two decades. The largest anthropogenic source of methane in the US is 'conventional' landfills, which account for over 30% of anthropogenic emissions. While controlling greenhouse gas emissions must necessarily focus on large CO2 sources, attention to reducing CH4 emissions from landfills can result in significant reductions in greenhouse gas emissions at low cost. For example, the use of 'controlled' or bioreactor landfilling has been estimated to reduce annual US greenhouse emissions by about 15-30 million tons of CO2 carbon (equivalent) at costs between $3-13/ton carbon. In this project we developed or advanced new management approaches, landfill designs, and landfill operating procedures for bioreactor landfills. These advances are needed to address lingering concerns about bioreactor landfills (e.g., efficient collection of increased CH4 generation) in the waste management industry, concerns that hamper bioreactor implementation and the consequent reductions in CH4 emissions. Collectively, the advances described in this report should result in better control of bioreactor landfills and reductions in CH4 emissions. Several advances are important components of an Intelligent Bioreactor Management Information System (IBM-IS).

  20. Tokamak-FED plasma-engineering assessments

    International Nuclear Information System (INIS)

    Peng, Y.K.M.; Lyon, J.F.; Rutherford, P.H.

    1981-01-01

    A wide range of plasma assumptions and scenarios has been examined for the current US tokamak FED concept, which aims to provide a controlled, long pulse (approx. 100 s) burning plasma with an energy amplification of greater than or equal to 5, a fusion power of 180 MW, and a neutron wall load of greater than or equal to 0.4 MW/m 2 . The results of the assessment suggest that the current FED baseline parameters of R = 5.0 m, B/sub t/ = 3.6 T, a = 1.3 m, b = 2.1 m (D-shape), and I/sub p/ = 5.4 MA are appropriate in reaching the above plasma performance, despite uncertainties in several plasma physics areas, such as confinement scaling, achievable beta, impurity control, etc. To enhance the probability of achieving fusion ignition and to provide some margin against a short fall in our physics projections in FED, a limited operating capability at B/sub t/ = 4.6 T and I/sub p/ = 6.5 MA is incorporated. Various other options and remedies have also been assessed aiming to alleviate the impact of the uncertainties on the FED design concept. These approaches appear promising because they can be studied within the current fusion physics program and may lead to drastically more cost-effective FED concepts

  1. FED-R2: concept and magnet design of a low-cost FED

    International Nuclear Information System (INIS)

    Williams, J.E.C.; Becker, H.; Blackfield, D.; Bobrov, E.; Bromberg, L.; Cohn, D.R.; Diatchenko, N.; LeClaire, R.

    1982-12-01

    High performance resistive magnet technology was used to develop a design for a compact, low cost version of the fusion engineering device FED. We refer to this design as FED-R2, for FED-resistive magnet design 2 to distinguish it from the larger resistive magnet design for FED which uses demountable coils (FED-R1). The main objectives of FED-R2 are: (1) to demonstrate reliable, quasi-steady state (long pulse, high duty factor) operation with Q/sub p/ approx. 5; (2) to demonstrate Q/sub p/ > 5 operation for a limited number of pulses; (3) to provide high neutron flux for irradiation of nuclear test modules with a total area greater tha 20m 2 ; (4) to utilize steady-state RF current drive if this option appears promising. Based upon the costing codes at the Fusion Engineering Design Center and upon TFTR costs, the estimated direct costs of FED-R2 would be on the range 380 to 460M, a factor of about 2 below that of the baseline FED design

  2. A symbiotic gas exchange between bioreactors enhances microalgal biomass and lipid productivities: taking advantage of complementary nutritional modes.

    Science.gov (United States)

    Santos, C A; Ferreira, M E; da Silva, T Lopes; Gouveia, L; Novais, J M; Reis, A

    2011-08-01

    This paper describes the association of two bioreactors: one photoautotrophic and the other heterotrophic, connected by the gas phase and allowing an exchange of O(2) and CO(2) gases between them, benefiting from a symbiotic effect. The association of two bioreactors was proposed with the aim of improving the microalgae oil productivity for biodiesel production. The outlet gas flow from the autotrophic (O(2) enriched) bioreactor was used as the inlet gas flow for the heterotrophic bioreactor. In parallel, the outlet gas flow from another heterotrophic (CO(2) enriched) bioreactor was used as the inlet gas flow for the autotrophic bioreactor. Aside from using the air supplied from the auto- and hetero-trophic bioreactors as controls, one mixotrophic bioreactor was also studied and used as a model, for its claimed advantage of CO(2) and organic carbon being simultaneously assimilated. The microalga Chlorella protothecoides was chosen as a model due to its ability to grow under different nutritional modes (auto, hetero, and mixotrophic), and its ability to attain a high biomass productivity and lipid content, suitable for biodiesel production. The comparison between heterotrophic, autotrophic, and mixotrophic Chlorella protothecoides growth for lipid production revealed that heterotrophic growth achieved the highest biomass productivity and lipid content (>22%), and furthermore showed that these lipids had the most suitable fatty acid profile in order to produce high quality biodiesel. Both associations showed a higher biomass productivity (10-20%), when comparing the two separately operated bioreactors (controls) which occurred on the fourth day. A more remarkable result would have been seen if in actuality the two bioreactors had been inter-connected in a closed loop. The biomass productivity gain would have been 30% and the lipid productivity gain would have been 100%, as seen by comparing the productivities of the symbiotic assemblage with the sum of the two

  3. Bioreactors for high cell density and continuous multi-stage cultivations: options for process intensification in cell culture-based viral vaccine production.

    Science.gov (United States)

    Tapia, Felipe; Vázquez-Ramírez, Daniel; Genzel, Yvonne; Reichl, Udo

    2016-03-01

    With an increasing demand for efficacious, safe, and affordable vaccines for human and animal use, process intensification in cell culture-based viral vaccine production demands advanced process strategies to overcome the limitations of conventional batch cultivations. However, the use of fed-batch, perfusion, or continuous modes to drive processes at high cell density (HCD) and overextended operating times has so far been little explored in large-scale viral vaccine manufacturing. Also, possible reductions in cell-specific virus yields for HCD cultivations have been reported frequently. Taking into account that vaccine production is one of the most heavily regulated industries in the pharmaceutical sector with tough margins to meet, it is understandable that process intensification is being considered by both academia and industry as a next step toward more efficient viral vaccine production processes only recently. Compared to conventional batch processes, fed-batch and perfusion strategies could result in ten to a hundred times higher product yields. Both cultivation strategies can be implemented to achieve cell concentrations exceeding 10(7) cells/mL or even 10(8) cells/mL, while keeping low levels of metabolites that potentially inhibit cell growth and virus replication. The trend towards HCD processes is supported by development of GMP-compliant cultivation platforms, i.e., acoustic settlers, hollow fiber bioreactors, and hollow fiber-based perfusion systems including tangential flow filtration (TFF) or alternating tangential flow (ATF) technologies. In this review, these process modes are discussed in detail and compared with conventional batch processes based on productivity indicators such as space-time yield, cell concentration, and product titers. In addition, options for the production of viral vaccines in continuous multi-stage bioreactors such as two- and three-stage systems are addressed. While such systems have shown similar virus titers compared to

  4. Proceedings of FED remote maintenance equipment workshop

    International Nuclear Information System (INIS)

    Sager, P.; Garin, J.; Hager, E.R.; Spampinato, P.T.; Tobias, D.; Young, N.

    1981-11-01

    A workshop was convened in two sessions in January and March 1981, on the remote maintenance equipment for the Fusion Engineering Device (FED). The objectives of the first session were to familiarize the participants with the status of the design of the FED and to develop a remote maintenance equipment list for the FED. The objective of the second session was to have the participants present design concepts for the equipment which had been identified in the first session. The equipment list was developed for general purpose and special purpose equipment. The general purpose equipment was categorized as manipulators and other, while the special purpose equipment was subdivided according to the reactor subsystem it serviced: electrical, magnetic, and nuclear. Both mobile and fixed base manipulators were identified. Handling machines were identified as the major requirement for special purpose equipment

  5. Tritium transport and control in the FED

    International Nuclear Information System (INIS)

    Rogers, M.L.

    1981-01-01

    The tritium systems for the FED have three primary purposes. The first is to provide tritium and deuterium fuel for the reactor. This fuel can be new tritium or deuterium delivered to the plant site, or recycled DT from the reactor that must be processed before it can be recycled. The second purpose of the FED tritium systems is to provide state-of-the-art tritium handling to limit worker radiation exposure and to minimize tritium losses to the environment. The final major objective of the FED tritium systems is to provide an integrated system test of the tritium handling technology necessary to support the fusion reactor program. Every effort is being made to incorporate available information from the Tritium System Test Assembly (TSTA) at Los Alamos National Laboratory, the Tokamak Fusion Test Reactor (TFTR) tritium systems, and the tritium handling information generated within DOE for the past 20 years

  6. Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

    Energy Technology Data Exchange (ETDEWEB)

    Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

    2004-09-11

    This report summarizes work performed on this project from April 2004 through September 2004. Our previous work demonstrated that a polyurethane foam biofilter could successfully biodegrade the BTEX contaminants found in the SMZ regeneration waste gas stream. However, establishing the biomass on the polyurethane foam packing was relatively time consuming and daily recirculation of a concentrated nutrient solution was required for efficient operation of the foam biofilter. To simplify the start up and operating requirements of the biofilter system, a simple, compost-based biofilter was investigated for its ability to treat the BTEX contaminants generated during the SMZ regeneration process. The investigation of the compost biofilter was divided into three experimental phases that spanned 180 days of biofilter operation. During Phase 1, the biofilter was continuously supplied a BTEX-contaminated waste gas stream. During Phase 2, a series of periodic shutdown tests were conducted to assess how the biofilter responded when the BTEX feed was discontinued for periods ranging from 1 day to 2.8 days. The Phase 3 experiments focused on determining how the biofilter would handle periodic spikes in inlet BTEX concentration as would be expected when it is coupled with an SMZ column. Results from the continuous feed (Phase 1) experiments demonstrated that the compost biofilter could maintain BTEX removals of greater than 98% within two weeks of startup. Results of the shutdown experiments indicated that benzene removal was the most sensitive to interruptions in the BTEX feed. Nevertheless, the BTEX removal efficiency exceeded 95% within 6 hours of reestablishing the BTEX feed to the biofilter. When the biofilter was subjected to periodic spikes in BTEX concentration (Phase 3), it was found that the total BTEX removal efficiency stabilized at approximately 75% despite the fact that the biofilter was only fed BTEX contaminants 8 hours per day. Finally, the effects of nutrient

  7. Biogeochemistry of the compost bioreactor components of a composite acid mine drainage passive remediation system

    International Nuclear Information System (INIS)

    Johnson, D. Barrie; Hallberg, Kevin B.

    2005-01-01

    The compost bioreactor ('anaerobic cell') components of three composite passive remediation systems constructed to treat acid mine drainage (AMD) at the former Wheal Jane tin mine, Cornwall, UK were studied over a period of 16 months. While there was some amelioration of the preprocessed AMD in each of the three compost bioreactors, as evidenced by pH increase and decrease in metal concentrations, only one of the cells showed effective removal of the two dominant heavy metals (iron and zinc) present. With two of the compost bioreactors, concentrations of soluble (ferrous) iron draining the cells were significantly greater than those entering the reactors, indicating that there was net mobilisation (by reductive dissolution) of colloidal and/or solid-phase ferric iron compounds within the cells. Soluble sulfide was also detected in waters draining all three compost bioreactors which was rapidly oxidised, in contrast to ferrous iron. Oxidation and hydrolysis of iron, together with sulfide oxidation, resulted in reacidification of processed AMD downstream of the compost bioreactors in two of the passive treatment systems. The dominant cultivatable microorganism in waters draining the compost bioreactors was identified, via analysis of its 16S rRNA gene, as a Thiomonas sp. and was capable of accelerating the dissimilatory oxidation of both ferrous iron and reduced sulfur compounds. Sulfate-reducing bacteria (SRB) were also detected, although only in the bioreactor that was performing well were these present in significant numbers. This particular compost bioreactor had been shut down for 10 months prior to the monitoring period due to operational problems. This unforeseen event appears to have allowed more successful development of AMD-tolerant and other microbial populations with critical roles in AMD bioremediation, including neutrophilic SRB (nSRB), in this compost bioreactor than in the other two, where the throughput of AMD was not interrupted. This study has

  8. Biogeochemistry of the compost bioreactor components of a composite acid mine drainage passive remediation system.

    Science.gov (United States)

    Johnson, D Barrie; Hallberg, Kevin B

    2005-02-01

    The compost bioreactor ("anaerobic cell") components of three composite passive remediation systems constructed to treat acid mine drainage (AMD) at the former Wheal Jane tin mine, Cornwall, UK were studied over a period of 16 months. While there was some amelioration of the preprocessed AMD in each of the three compost bioreactors, as evidenced by pH increase and decrease in metal concentrations, only one of the cells showed effective removal of the two dominant heavy metals (iron and zinc) present. With two of the compost bioreactors, concentrations of soluble (ferrous) iron draining the cells were significantly greater than those entering the reactors, indicating that there was net mobilisation (by reductive dissolution) of colloidal and/or solid-phase ferric iron compounds within the cells. Soluble sulfide was also detected in waters draining all three compost bioreactors which was rapidly oxidised, in contrast to ferrous iron. Oxidation and hydrolysis of iron, together with sulfide oxidation, resulted in reacidification of processed AMD downstream of the compost bioreactors in two of the passive treatment systems. The dominant cultivatable microorganism in waters draining the compost bioreactors was identified, via analysis of its 16S rRNA gene, as a Thiomonas sp. and was capable of accelerating the dissimilatory oxidation of both ferrous iron and reduced sulfur compounds. Sulfate-reducing bacteria (SRB) were also detected, although only in the bioreactor that was performing well were these present in significant numbers. This particular compost bioreactor had been shut down for 10 months prior to the monitoring period due to operational problems. This unforeseen event appears to have allowed more successful development of AMD-tolerant and other microbial populations with critical roles in AMD bioremediation, including neutrophilic SRB (nSRB), in this compost bioreactor than in the other two, where the throughput of AMD was not interrupted. This study has

  9. Status of FED/INTOR electromagnetics

    International Nuclear Information System (INIS)

    Murray, J.G.

    1983-02-01

    This report provides a summary of the electromagnetic studies, calculations, and conclusions in the evolution of the base design of FED/INTOR (Fusion Engineering Device/International Tokamak Reactor). The electromagnetic feastures include the startup, control, disruptions, and design of structures. This report provides information concerning the evolution of the electromagnetic studies on FED and the justification for the eddy current design feature. The report shows that a major design feature required is the provision of a low induction and resistive path for toroidal currents to flow in the structures in order to provide self-stabilization and to manage the disruption energy dissipation

  10. Biofabrication of customized bone grafts by combination of additive manufacturing and bioreactor knowhow

    International Nuclear Information System (INIS)

    Costa, Pedro F; Gomes, Manuela E; Reis, Rui L; Vaquette, Cédryck; Baldwin, Jeremy; Chhaya, Mohit; Theodoropoulos, Christina; Hutmacher, Dietmar W

    2014-01-01

    This study reports on an original concept of additive manufacturing for the fabrication of tissue engineered constructs (TEC), offering the possibility of concomitantly manufacturing a customized scaffold and a bioreactor chamber to any size and shape. As a proof of concept towards the development of anatomically relevant TECs, this concept was utilized for the design and fabrication of a highly porous sheep tibia scaffold around which a bioreactor chamber of similar shape was simultaneously built. The morphology of the bioreactor/scaffold device was investigated by micro-computed tomography and scanning electron microscopy confirming the porous architecture of the sheep tibiae as opposed to the non-porous nature of the bioreactor chamber. Additionally, this study demonstrates that both the shape, as well as the inner architecture of the device can significantly impact the perfusion of fluid within the scaffold architecture. Indeed, fluid flow modelling revealed that this was of significant importance for controlling the nutrition flow pattern within the scaffold and the bioreactor chamber, avoiding the formation of stagnant flow regions detrimental for in vitro tissue development. The bioreactor/scaffold device was dynamically seeded with human primary osteoblasts and cultured under bi-directional perfusion for two and six weeks. Primary human osteoblasts were observed homogenously distributed throughout the scaffold, and were viable for the six week culture period. This work demonstrates a novel application for additive manufacturing in the development of scaffolds and bioreactors. Given the intrinsic flexibility of the additive manufacturing technology platform developed, more complex culture systems can be fabricated which would contribute to the advances in customized and patient-specific tissue engineering strategies for a wide range of applications. (paper)

  11. Biofabrication of customized bone grafts by combination of additive manufacturing and bioreactor knowhow.

    Science.gov (United States)

    Costa, Pedro F; Vaquette, Cédryck; Baldwin, Jeremy; Chhaya, Mohit; Gomes, Manuela E; Reis, Rui L; Theodoropoulos, Christina; Hutmacher, Dietmar W

    2014-09-01

    This study reports on an original concept of additive manufacturing for the fabrication of tissue engineered constructs (TEC), offering the possibility of concomitantly manufacturing a customized scaffold and a bioreactor chamber to any size and shape. As a proof of concept towards the development of anatomically relevant TECs, this concept was utilized for the design and fabrication of a highly porous sheep tibia scaffold around which a bioreactor chamber of similar shape was simultaneously built. The morphology of the bioreactor/scaffold device was investigated by micro-computed tomography and scanning electron microscopy confirming the porous architecture of the sheep tibiae as opposed to the non-porous nature of the bioreactor chamber. Additionally, this study demonstrates that both the shape, as well as the inner architecture of the device can significantly impact the perfusion of fluid within the scaffold architecture. Indeed, fluid flow modelling revealed that this was of significant importance for controlling the nutrition flow pattern within the scaffold and the bioreactor chamber, avoiding the formation of stagnant flow regions detrimental for in vitro tissue development. The bioreactor/scaffold device was dynamically seeded with human primary osteoblasts and cultured under bi-directional perfusion for two and six weeks. Primary human osteoblasts were observed homogenously distributed throughout the scaffold, and were viable for the six week culture period. This work demonstrates a novel application for additive manufacturing in the development of scaffolds and bioreactors. Given the intrinsic flexibility of the additive manufacturing technology platform developed, more complex culture systems can be fabricated which would contribute to the advances in customized and patient-specific tissue engineering strategies for a wide range of applications.

  12. On-line removal of volatile fatty acids from CELSS anaerobic bioreactor via nanofiltration.

    Science.gov (United States)

    Colon, G; Sager, J C

    2001-01-01

    The CELSS resource recovery system, which is a waste-processing system, uses aerobic and anaerobic bioreactors to recover plants nutrients and secondary foods from the inedible biomass. The anaerobic degradation of the inedible biomass, by means of culture of rumen bacteria, generates organic compounds such as volatile fatty acids (VFA) (acetic, propionic, butyric) and ammonia. The presence of VFA in the bioreactor medium at fairly low concentrations decreases the microbial population's metabolic reactions due to end-product inhibition. Technologies to remove VFA continuously from the bioreactor are of high interest. Several candidate technologies were analyzed, such as organic solvent liquid-liquid extraction, adsorption and/or ion exchange, dialysis, electrodialysis, and pressure-driven membrane separation processes. The proposed technique for the on-line removal of VFA from the anaerobic bioreactor was a nanofiltration membrane recycle bioreactor. In order to establish the nanofiltration process performance variables before coupling it to the bioreactor, a series of experiments was carried out using a 10,000 molecular weight cutoff (MWCO) tubular ceramic membrane module. The variables studied were the bioreactor slurry permeation characteristics, such as: the permeate flux, VFA and nutrient removal rates as a function of applied transmembrane pressure, fluid recirculation velocity, suspended matter concentration, and process operating time. Results indicated that the permeate flux, VFA, and nutrients removal rates are directly proportional to the fluid recirculation velocity in the range between 0.6 and 1.0 m/s, applied pressure when these are lower than 1.5 bar, and inversely proportional to the total suspended solids concentration in the range between 23,466 and 34,880 mg/L. At applied pressure higher than 1.5 bar the flux is not more linearly dependent due to concentration polarization and fouling effects over the membrane surface. It was also found that the

  13. On-line removal of volatile fatty acids from CELSS anaerobic bioreactor via nanofiltration

    Science.gov (United States)

    Colon, Guillermo

    1995-01-01

    The CELSS (controlled ecological life support system) resource recovery system, which is a waste processing system, uses aerobic and anaerobic bioreactors to recover plants nutrients and secondary foods from the inedible biomass. The anaerobic degradation of the inedible biomass by means of culture of rumen bacteria,generates organic compounds such as volatile fatty acids (acetic, propionic, butyric, VFA) and ammonia. The presence of VFA in the bioreactor medium at fairly low concentrations decreases the microbial population's metabolic reactions due to end-product inhibition. Technologies to remove VFA continuously from the bioreactor are of high interest. Several candidate technologies were analyzed, such as organic solvent liquid-liquid extraction, adsorption and/or ion exchange, dialysis, electrodialysis, and pressure driven membrane separation processes. The proposed technique for the on-line removal of VFA from the anaerobic bioreactor was a nanofiltration membrane recycle bioreactor. In order to establish the nanofiltration process performance variables before coupling it to the bioreactor, a series of experiments were carried out using a 10,000 MWCO tubular ceramic membrane module. The variables studied were the bioreactor slurry permeation characteristics, such as, the permeate flux, VFA and the nutrient removal rates as a function of applied transmembrane pressure, fluid recirculation velocity, suspended matter concentration, and process operating time. Results indicate that the permeate flux, VFA and nutrients removal rates are directly proportional to the fluid recirculation velocity in the range between 0.6 to 1.0 m/s, applied pressure when these are low than 1.5 bar, and inversely proportional to the total suspended solids concentration in the range between 23,466 to 34,880. At applied pressure higher than 1.5 bar the flux is not more linearly dependent due to concentration polarization and fouling effects over the membrange surface. It was also found

  14. Optimization of a bundle divertor for FED

    International Nuclear Information System (INIS)

    Hively, L.M.; Rothe, K.E.; Minkoff, M.

    1982-01-01

    Optimal double-T bundle divertor configurations have been obtained for the Fusion Engineering Device (FED). On-axis ripple is minimized, while satisfying a series of engineering constraints. The ensuing non-linear optimization problem is solved via a sequence of quadratic programming subproblems, using the VMCON algorithm. The resulting divertor designs are substantially improved over previous configurations

  15. FUZZY SLIDING MODE CONTROLLER FOR DOUBLY FED ...

    African Journals Online (AJOL)

    2010-12-31

    Dec 31, 2010 ... against internal and external perturbations, but the FSMC is superior to ... controller, doubly fed induction motor, fuzzy logic control. 1. ... capabilities in accounting for modeling imprecision and bounded disturbances. It ..... To show the effect of the parameters uncertainties, we have simulated the system with.

  16. FED, Geometry Input Generator for Program TRUMP

    International Nuclear Information System (INIS)

    Schauer, D.A.; Elrod, D.C.

    1996-01-01

    1 - Description of program or function: FED reduces the effort required to obtain the necessary geometric input for problems which are to be solved using the heat-transfer code, TRUMP (NESC 771). TRUMP calculates transient and steady-state temperature distributions in multidimensional systems. FED can properly zone any body of revolution in one, or three dimensions. 2 - Method of solution: The region of interest must first be divided into areas which may consist of a common material. The boundaries of these areas are the required FED input. Each area is subdivided into volume nodes, and the geometrical properties are calculated. Finally, FED connects the adjacent nodes to one another, using the proper surface area, interface distance, and, if specified, radiation form factor and interface conductance. 3 - Restrictions on the complexity of the problem: Rectangular bodies can only be approximated by using a very large radius of revolution compared to the total radial thickness and by considering only a small angular segment in the circumferential direction

  17. Control of aromatic-waste air streams by soil bioreactors

    International Nuclear Information System (INIS)

    Miller, D.E.; Canter, L.W.

    1991-01-01

    Contamination of groundwater resources is a serious environmental problem which is continuing to increase in occurrence in the United States. It has been reported that leaking underground gasoline storage tanks may pose the most serious threat of all sources of groundwater contamination. Gasolines are comprised of a variety of aliphatic and aromatic hydrocarbons. The aromatic portion consists primarily of benzene, toluene, ethylbenzene, and xylenes (BTEX compounds). BTEX compounds are also among the most frequency identified substances at Superfund sites. Pump and treat well systems are the most common and frequently used technique for aquifer restoration. Treatment is often in the form of air stripping to remove the volatile components from the contaminated water. Additionally, soil ventilation processes have been used to remove volatile components from the vadose zone. Both air stripping and soil ventilation produce a waste gas stream containing volatile compounds which is normally treated by carbon adsorption or incineration. Both treatment processes require a substantial capital investment and continual operation and maintenance expenditures. The objective of the study was to examine the potential of using soil bioreactors to treat a waste gas stream produced by air stripping or soil ventilation process. Previous studies have shown that various hydrocarbons can be successfully treated with soils. The study examined the removal of BTEX compounds within soil columns and the influence of soil type, inlet concentration, and inlet flow rate on the removal efficiency

  18. Membrane bio-reactor for textile wastewater treatment plant upgrading.

    Science.gov (United States)

    Lubello, C; Gori, R

    2005-01-01

    Textile industries carry out several fiber treatments using variable quantities of water, from five to forty times the fiber weight, and consequently generate large volumes of wastewater to be disposed of. Membrane Bio-reactors (MBRs) combine membrane technology with biological reactors for the treatment of wastewater: micro or ultrafiltration membranes are used for solid-liquid separation replacing the secondary settling of the traditional activated sludge system. This paper deals with the possibility of realizing a new section of one existing WWTP (activated sludge + clariflocculation + ozonation) for the treatment of treating textile wastewater to be recycled, equipped with an MBR (76 l/s as design capacity) and running in parallel with the existing one. During a 4-month experimental period, a pilot-scale MBR proved to be very effective for wastewater reclamation. On average, removal efficiency of the pilot plant (93% for COD, and over 99% for total suspended solids) was higher than the WWTP ones. Color was removed as in the WWTP. Anionic surfactants removal of pilot plant was lower than that of the WWTP (90.5 and 93.2% respectively), while the BiAS removal was higher in the pilot plant (98.2 vs. 97.1). At the end cost analysis of the proposed upgrade is reported.

  19. Multi-membrane chitosan hydrogels as chondrocytic cell bioreactors.

    Science.gov (United States)

    Ladet, S G; Tahiri, K; Montembault, A S; Domard, A J; Corvol, M-T M

    2011-08-01

    We investigated the bioactivity of new chitosan-based multi-membrane hydrogel (MMH) architectures towards chondrocyte-like cells. The microstructure of the hydrogels constituting the membranes precludes any living cell penetration, whereas their lower scale architecture allows the protein diffusion. The biological behavior of chondrocytes implanted within the MMH inter-membrane spaces was studied for 45 days in culture. Chondrocytes formed cell aggregates and proliferated without loosing their chondrogenic phenotype as illustrated by collagen II and aggrecan expressions at the mRNA and protein levels. Cells produced neo-formed alcyan blue matrix proteins filling MMH interspaces. The HiF-2α/SOX9 pattern of expression suggested that the elevated chondrocytic phenotype in MMH could be related to a better hypoxic local environment than in classical culture conditions. Pro-inflammatory markers were not expressed during the period of culture. The low level of nitric oxide accumulation within the inter-membrane spaces and in the incubation medium implied that chitosan consumed nitrites produced by entrapped chondrocytes, in relation with the decrease of its molecular weight of 50%. Our data suggest that MMH structures may be considered as complex chondrocytic cell bioreactors; "active decoys of biological media", potentially promising for various biomedical applications like the inter-vertebral disk replacement. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Oxygen-controlled Biosurfactant Production in a Bench Scale Bioreactor

    Science.gov (United States)

    de Kronemberger, Frederico Araujo; Anna, Lidia Maria Melo Santa; Fernandes, Ana Carolina Loureiro Brito; de Menezes, Reginaldo Ramos; Borges, Cristiano Piacsek; Freire, Denise Maria Guimarães

    Rhamnolipids have been pointed out as promising biosurfactants. The most studied microorganisms for the aerobic production of these molecules are the bacteria of the genus Pseudomonas. The aim of this work was to produce a rhamnolipid-type biosurfactant in a bench-scale bioreactor by one strain of Pseudomonas aeruginosa isolated from oil environments. To study the microorganism growth and production dependency on oxygen, a nondispersive oxygenation device was developed, and a programmable logic controller (PLC) was used to set the dissolved oxygen (DO) concentration. Using the data stored in a computer and the predetermined characteristics of the oxygenation device, it was possible to evaluate the oxygen uptake rate (OUR) and the specific OUR (SOUR) of this microorganism. These rates, obtained for some different DO concentrations, were then compared to the bacterial growth, to the carbon source consumption, and to the rhamnolipid and other virulence factors production. The SOUR presented an initial value of about 60.0 mg02/gdw h. Then, when the exponential growth phase begins, there is a rise in this rate. After that, the SOUR reduces to about 20.0 mg02/gdw h. The carbon source consumption is linear during the whole process.

  1. A risk analysis for production processes with disposable bioreactors.

    Science.gov (United States)

    Merseburger, Tobias; Pahl, Ina; Müller, Daniel; Tanner, Markus

    2014-01-01

    : Quality management systems are, as a rule, tightly defined systems that conserve existing processes and therefore guarantee compliance with quality standards. But maintaining quality also includes introducing new enhanced production methods and making use of the latest findings of bioscience. The advances in biotechnology and single-use manufacturing methods for producing new drugs especially impose new challenges on quality management, as quality standards have not yet been set. New methods to ensure patient safety have to be established, as it is insufficient to rely only on current rules. A concept of qualification, validation, and manufacturing procedures based on risk management needs to be established and realized in pharmaceutical production. The chapter starts with an introduction to the regulatory background of the manufacture of medicinal products. It then continues with key methods of risk management. Hazards associated with the production of medicinal products with single-use equipment are described with a focus on bioreactors, storage containers, and connecting devices. The hazards are subsequently evaluated and criteria for risk evaluation are presented. This chapter concludes with aspects of industrial application of quality risk management.

  2. Numerical simulation of fluid flow in a rotational bioreactor

    Science.gov (United States)

    Ganimedov, V. L.; Papaeva, E. O.; Maslov, N. A.; Larionov, P. M.

    2017-10-01

    Application of scaffold technology for the problem of bone tissue regeneration has great prospects in modern medicine. The influence of fluid shear stress on stem cells cultivation and its differentiation into osteoblasts is the subject of intensive research. Mathematical modeling of fluid flow in bioreactor allowed us to determine the structure of flow and estimate the level of mechanical stress on cells. The series of computations for different rotation frequencies (0.083, 0.124, 0.167, 0.2 and 0.233 Hz) was performed for the laminar flow regime approximation. It was shown that the Taylor vortices in the gap between the cylinders qualitatively change the distribution of static pressure and shear stress in the region of vortices connection. It was shown that an increase in the rotation frequency leads to an increase of the unevenness in distribution of the above mentioned functions. The obtained shear stress and static pressure dependence on the rotational frequency make it possible to choose the operating mode of the reactor depending on the provided requirements. It was shown that in the range of rotation frequencies chosen in this work (0.083 < f < 0.233 Hz), the shear stress does not exceed the known literature data (0.002 - 0.1 Pa).

  3. Alternative energy efficient membrane bioreactor using reciprocating submerged membrane.

    Science.gov (United States)

    Ho, J; Smith, S; Roh, H K

    2014-01-01

    A novel membrane bioreactor (MBR) pilot system, using membrane reciprocation instead of air scouring, was operated at constant high flux and daily fluctuating flux to demonstrate its application under peak and diurnal flow conditions. Low and stable transmembrane pressure was achieved at 40 l/m(2)/h (LMH) by use of repetitive membrane reciprocation. The results reveal that the inertial forces acting on the membrane fibers effectively propel foulants from the membrane surface. Reciprocation of the hollow fiber membrane is beneficial for the constant removal of solids that may build up on the membrane surface and inside the membrane bundle. The membrane reciprocation in the reciprocating MBR pilot consumed less energy than coarse air scouring used in conventional MBR systems. Specific energy consumption for the membrane reciprocation was 0.072 kWh/m(3) permeate produced at 40 LMH flux, which is 75% less than for a conventional air scouring system as reported in literature without consideration of energy consumption for biological aeration (0.29 kWh/m(3)). The daily fluctuating flux test confirmed that the membrane reciprocation is effective to handle fluctuating flux up to 50 LMH. The pilot-scale reciprocating MBR system successfully demonstrated that fouling can be controlled via 0.43 Hz membrane reciprocation with 44 mm or higher amplitude.

  4. Periodically operated bioreactors for the treatment of soils and leachates

    International Nuclear Information System (INIS)

    Irvine, R.L.; Cassidy, D.P.

    1995-01-01

    Limited contaminant bioavailability at concentrations above the required cleanup level reduces biodegradation rate and renders solid-phase bioremediation more cost effective than complete treatment in a bioslurry reactor. Slurrying followed by solid-phase bioremediation combines the advantages and minimizes the weaknesses of each treatment method when used alone. Periodic aeration during solid-phase bioremediation has the potential to lower treatment costs relative to continuous aeration. A biological treatment system consisting of slurrying followed by periodic aeration in solid-phase sequencing batch reactors (SP-SBRs) was developed and tested in the laboratory using a silty loam contaminated predominantly with the plasticizer bis(2-ethylhexyl)phthalate (BEHP) or (DEHP) and a silty clay loam contaminated with diesel fuel. The first experiment evaluated the effect of water content and mixing time during slurrying on subsequent treatment in continuously aerated solid-phase bioreactors. The second experiment compared treatment of slurried soil in SP-SBRs using three different periodic aeration strategies with continuous aeration

  5. Removal of trace organic chemical contaminants by a membrane bioreactor.

    Science.gov (United States)

    Trinh, T; van den Akker, B; Stuetz, R M; Coleman, H M; Le-Clech, P; Khan, S J

    2012-01-01

    Emerging wastewater treatment processes such as membrane bioreactors (MBRs) have attracted a significant amount of interest internationally due to their ability to produce high quality effluent suitable for water recycling. It is therefore important that their efficiency in removing hazardous trace organic contaminants be assessed. Accordingly, this study investigated the removal of trace organic chemical contaminants through a full-scale, package MBR in New South Wales, Australia. This study was unique in the context of MBR research because it characterised the removal of 48 trace organic chemical contaminants, which included steroidal hormones, xenoestrogens, pesticides, caffeine, pharmaceuticals and personal care products (PPCPs). Results showed that the removal of most trace organic chemical contaminants through the MBR was high (above 90%). However, amitriptyline, carbamazepine, diazepam, diclofenac, fluoxetine, gemfibrozil, omeprazole, sulphamethoxazole and trimethoprim were only partially removed through the MBR with the removal efficiencies of 24-68%. These are potential indicators for assessing MBR performance as these chemicals are usually sensitive to changes in the treatment systems. The trace organic chemical contaminants detected in the MBR permeate were 1 to 6 orders of magnitude lower than guideline values reported in the Australian Guidelines for Water Recycling. The outcomes of this study enhanced our understanding of the levels and removal of trace organic contaminants by MBRs.

  6. Use of NASA Bioreactor in Engineering Tissue for Bone Repair

    Science.gov (United States)

    Duke, Pauline

    1998-01-01

    This study was proposed in search for a new alternative for bone replacement or repair. Because the systems commonly used in repair of bony defects form bone by going through a cartilaginous phase, implantation of a piece of cartilage could enhance the healing process by having a more advanced starting point. However, cartilage has seldom been used to replace bone due, in part, to the limitations in conventional culture systems that did not allow production of enough tissue for implants. The NASA-developed bioreactors known as STLV (Slow Turning Lateral Vessel) provide homogeneous distribution of cells, nutrients, and waste products, with less damaging turbulence and shear forces than conventional systems. Cultures under these conditions have higher growth rates, viability, and longevity, allowing larger "tissue-like" aggregates to form, thus opening the possibilities of producing enough tissue for implantation, along with the inherent advantages of in vitro manipulations. To assure large numbers of cells and to eliminate the use of timed embryos, we proposed to use an immortalized mouse limb bud cell line as the source of cells.

  7. Food industrial wastewater reuse by membrane bio-reactor

    Directory of Open Access Journals (Sweden)

    Patthanant Natpinit

    2007-11-01

    Full Text Available The objective of this investigation was to study the possibility and performance of treating food industrial wastewater by Membrane BioReactor (MBR. In addition, the effluent of MBR was treated by Reverse Osmosis system (RO to reuse in boiler or cooling tower. The membranes of hollow fiber type were filled in the aerobic tank with aerobe bacteria. The total area of membrane 6 units was 630 m2 so the flux of the operation was 0.25 m/d or 150 m3/d. The spiral wound RO was operated at 100 m3/d of influent and received 72 m3/d of permeate. The sludge volume (MLSS of MBR was maintained at 8,000-10,000 mg/l. The average COD and SS of MBR influent were 600 mg/l and 300 mg/l respectively. After treating by MBR, COD and SS of effluent were maintained at less than 100 mg/l and less than 10 mg/l respectively. In the same way, COD and SS of RO permeate were less than 10 mg/l and less than 5 mg/l respectively.

  8. Hepatocyte-based flow analytical bioreactor for xenobiotics metabolism bioprediction

    Directory of Open Access Journals (Sweden)

    M Helvenstein

    2017-04-01

    Full Text Available The research for new in vitro screening tools for predictive metabolic profiling of drug candidates is of major interest in the pharmaceutical field. The main motivation is to avoid late rejection in drug development and to deliver safer drugs to the market. Thanks to the superparamagnetic properties of iron oxide nanoparticles, a flow bioreactor has been developed which is able to perform xenobiotic metabolism studies. The selected cell line (HepaRG maintained its metabolic competencies once iron oxide nanoparticles were internalized. Based on magnetically trapped cells in a homemade immobilization chamber, through which a flow of circulating phase was injected to transport nutrients and/or the studied xenobiotic, off-line and online (when coupled to a high-performance liquid chromatography chain metabolic assays were developed using diclofenac as a reference compound. The diclofenac demonstrated a similar metabolization profile chromatogram, both with the newly developed setup and with the control situation. Highly versatile, this pioneering and innovative instrumental design paves the way for a new approach in predictive metabolism studies.

  9. Low energy consumption vortex wave flow membrane bioreactor.

    Science.gov (United States)

    Wang, Zhiqiang; Dong, Weilong; Hu, Xiaohong; Sun, Tianyu; Wang, Tao; Sun, Youshan

    2017-11-01

    In order to reduce the energy consumption and membrane fouling of the conventional membrane bioreactor (MBR), a kind of low energy consumption vortex wave flow MBR was exploited based on the combination of biofilm process and membrane filtration process, as well as the vortex wave flow technique. The experimental results showed that the vortex wave flow state in the membrane module could be formed when the Reynolds number (Re) of liquid was adjusted between 450 and 1,050, and the membrane flux declined more slowly in the vortex wave flow state than those in the laminar flow state and turbulent flow state. The MBR system was used to treat domestic wastewater under the condition of vortex wave flow state for 30 days. The results showed that the removal efficiency for CODcr and NH 3 -N was 82% and 98% respectively, and the permeate quality met the requirement of 'Water quality standard for urban miscellaneous water consumption (GB/T 18920-2002)'. Analysis of the energy consumption of the MBR showed that the average energy consumption was 1.90 ± 0.55 kWh/m 3 (permeate), which was only two thirds of conventional MBR energy consumption.

  10. Clofibric acid and gemfibrozil removal in membrane bioreactors.

    Science.gov (United States)

    Gutierrez-Macias, Tania; Nacheva, Petia Mijaylova

    2015-01-01

    The removal of two blood lipid regulators, clofibric acid (CLA) and gemfibrozil (GFZ), was evaluated using two identical aerobic membrane bioreactors with 6.5 L effective volume each. Polysulfone ultrafiltration hollow fiber membranes were submerged in the reactors. Different operating conditions were tested varying the organic load (F/M), hydraulic residence time (HRT), biomass concentration measured as total suspended solids in the mixed liquor (MLTSS) and the sludge retention time (SRT). Complete GFZ removal was obtained with F/M of 0.21-0.48 kg COD kgTSS⁻¹ d⁻¹, HRT of 4-10 hours, SRT of 10-32 d and MLTSS of 6-10 g L⁻¹. The GFZ removal can be attributed to biodegradation and there was no accumulation of the compound in the biomass. The CLA removals improved with the SRT and HRT increase and F/M decrease. Average removals of 78-79% were obtained with SRT 16-32 d, F/M of 0.21-0.34 kgCOD kgTSS⁻¹ d⁻¹, HRT of 7-10 hours and MLTSS of 6-10 g L⁻¹. Biodegradation was found to be the main removal pathway.

  11. Modeling of Hybrid Growth Wastewater Bio-reactor

    International Nuclear Information System (INIS)

    EI Nashaei, S.; Garhyan, P.; Prasad, P.; Abdel Halim, H.S.; Ibrahim, G.

    2004-01-01

    The attached/suspended growth mixed reactors are considered one of the recently tried approaches to improve the performance of the biological treatment by increasing the volume of the accumulated biomass in terms of attached growth as well as suspended growth. Moreover, the domestic WW can be easily mixed with a high strength non-hazardous industrial wastewater and treated together in these bio-reactors if the need arises. Modeling of Hybrid hybrid growth wastewater reactor addresses the need of understanding the rational of such system in order to achieve better design and operation parameters. This paper aims at developing a heterogeneous mathematical model for hybrid growth system considering the effect of diffusion, external mass transfer, and power input to the system in a rational manner. The model will be based on distinguishing between liquid/solid phase (bio-film and bio-floc). This model would be a step ahead to the fine tuning the design of hybrid systems based on the experimental data of a pilot plant to be implemented in near future

  12. The efficiency of a membrane bioreactor in drinking water denitrification

    Directory of Open Access Journals (Sweden)

    Petrovič Aleksandra

    2015-01-01

    Full Text Available The membrane bioreactor (MBR system was investigated regarding its nitrate removal capacity from drinking water. The performance of a pilot-scale MBR was tested, depending on the operational parameters, using sucrose as a carbon source. Drinking water from the source was introduced into the reactor in order to study the influence of flow-rate on the nitrate removal and denitrification efficiency of drinking water. The content of the nitrate was around 70 mg/L and the C/N ratio was 3:1. Nitrate removal efficiencies above 90% were obtained by flow-rates lower than 4.8 L/h. The specific denitrification rates varied between 0.02 and 0.16 g/L NO3/ (g/L MLSS•d. The efficiencies and nitrate removal were noticeably affected by the flow-rate and hydraulic retention times. At the maximum flow-rate of 10.2 L/h still 68% of the nitrate had been removed, whilst the highest specific denitrification rate was achieved at 0.2738 g/L NO3/ (g/L MLSS•d. The maximum reactor removal capacity was calculated at 8.75 g NO3/m3•h.

  13. Online optimal experimental re-design in robotic parallel fed-batch cultivation facilities.

    Science.gov (United States)

    Cruz Bournazou, M N; Barz, T; Nickel, D B; Lopez Cárdenas, D C; Glauche, F; Knepper, A; Neubauer, P

    2017-03-01

    We present an integrated framework for the online optimal experimental re-design applied to parallel nonlinear dynamic processes that aims to precisely estimate the parameter set of macro kinetic growth models with minimal experimental effort. This provides a systematic solution for rapid validation of a specific model to new strains, mutants, or products. In biosciences, this is especially important as model identification is a long and laborious process which is continuing to limit the use of mathematical modeling in this field. The strength of this approach is demonstrated by fitting a macro-kinetic differential equation model for Escherichia coli fed-batch processes after 6 h of cultivation. The system includes two fully-automated liquid handling robots; one containing eight mini-bioreactors and another used for automated at-line analyses, which allows for the immediate use of the available data in the modeling environment. As a result, the experiment can be continually re-designed while the cultivations are running using the information generated by periodical parameter estimations. The advantages of an online re-computation of the optimal experiment are proven by a 50-fold lower average coefficient of variation on the parameter estimates compared to the sequential method (4.83% instead of 235.86%). The success obtained in such a complex system is a further step towards a more efficient computer aided bioprocess development. Biotechnol. Bioeng. 2017;114: 610-619. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. The development of an industrial-scale fed-batch fermentation simulation.

    Science.gov (United States)

    Goldrick, Stephen; Ştefan, Andrei; Lovett, David; Montague, Gary; Lennox, Barry

    2015-01-10

    This paper describes a simulation of an industrial-scale fed-batch fermentation that can be used as a benchmark in process systems analysis and control studies. The simulation was developed using a mechanistic model and validated using historical data collected from an industrial-scale penicillin fermentation process. Each batch was carried out in a 100,000 L bioreactor that used an industrial strain of Penicillium chrysogenum. The manipulated variables recorded during each batch were used as inputs to the simulator and the predicted outputs were then compared with the on-line and off-line measurements recorded in the real process. The simulator adapted a previously published structured model to describe the penicillin fermentation and extended it to include the main environmental effects of dissolved oxygen, viscosity, temperature, pH and dissolved carbon dioxide. In addition the effects of nitrogen and phenylacetic acid concentrations on the biomass and penicillin production rates were also included. The simulated model predictions of all the on-line and off-line process measurements, including the off-gas analysis, were in good agreement with the batch records. The simulator and industrial process data are available to download at www.industrialpenicillinsimulation.com and can be used to evaluate, study and improve on the current control strategy implemented on this facility. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  15. Evaluation of biomass production in unleaded gasoline and BTEX-fed batch reactors.

    Science.gov (United States)

    Acuna-Askar, K; Englande, A J; Ramirez-Medrano, A; Coronado-Guardiola, J E; Chavez-Gomez, B

    2003-01-01

    BTEX removal under aerobic conditions by unleaded gasoline acclimated biomass and BTEX acclimated biomass, and the effect of surfactant on BTEX biodegradation were evaluated. The effect of BTEX concentration as the sole source of carbon for biomass acclimation and the effect of yeast extract on cell growth in unleaded gasoline-fed reactors were also evaluated. For the unleaded gasoline acclimated biomass, benzene was shown the most recalcitrant among all BTEX, followed by o-xylene and toluene with 16-23%, 35-41% and 57-69% biodegradation, respectively. Ethylbenzene was consistently the fastest BTEX chemical removed with 99% biodegradation for the four bioreactor acclimated biomasses tested. For the 1,200 ppm BTEX acclimated biomass, benzene showed the highest removal efficiency (99%) among the four biomass environmental conditions tested, along with 99% toluene and 99% ethylbenzene biodegradation. O-xylene showed 92-94% removal. In all bioassays tested Tergitol NP-10 was fully removed, and did not have a substantial effect on BTEX biodegradation at the end of a 10-day evaluation.

  16. Air purification from TCE and PCE contamination in a hybrid bioreactors and biofilter integrated system.

    Science.gov (United States)

    Tabernacka, Agnieszka; Zborowska, Ewa; Lebkowska, Maria; Borawski, Maciej

    2014-01-15

    A two-stage waste air treatment system, consisting of hybrid bioreactors (modified bioscrubbers) and a biofilter, was used to treat waste air containing chlorinated ethenes - trichloroethylene (TCE) and tetrachloroethylene (PCE). The bioreactor was operated with loadings in the range 0.46-5.50gm(-3)h(-1) for TCE and 2.16-9.02gm(-3)h(-1) for PCE. The biofilter loadings were in the range 0.1-0.97gm(-3)h(-1) for TCE and 0.2-2.12gm(-3)h(-1) for PCE. Under low pollutant loadings, the efficiency of TCE elimination was 23-25% in the bioreactor and 54-70% in the biofilter. The efficiency of PCE elimination was 44-60% in the bioreactor and 50-75% in the biofilter. The best results for the bioreactor were observed one week after the pollutant loading was increased. However, the process did not stabilize. In the next seven days contaminant removal efficiency, enzymatic activity and biomass content were all diminished. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Modeling of hydrodynamics in hollow fiber membrane bioreactor for mammalian cells cultivation

    Directory of Open Access Journals (Sweden)

    N. V. Menshutina

    2016-01-01

    Full Text Available The mathematical modelling in CFD-packages are powerfull instrument for design and calculation of any engineering tasks. CFD-package contains the set of programs that allow to model the different objects behavior based on the mathematical lows. ANSYS Fluent are widely used for modelling of biotechnological and chemical-technological processes. This package is convenient to describe their hydrodynamics. As cell cultivation is one of the actual scientific direction in modern biotechnology ANSYS Fluent was used to create the model of hollow fiber membrane bioreactor. The fibers are hollow cylindrical membrane to be used for cell cultivation. The criterion of process effectiveness for cell growth is full filling of the membrane surface by cells in the bioreactor. While the cell growth the fiber permeability is decreased which effects to feed flow through membrane pores. The specific feature of this process is to ensure such feed flow to deliver the optimal nutrition for the cells on the external membrane surface. The velocity distribution inside the fiber and in all bioreactor as a whole has been calculated based on mass an impulse conservation equations taking into account the mathematical model assumptions. The hydrodynamics analysis in hollow fiber membrane bioreactor is described by the three-dimensional model created in ANSYS Fluent. The specific features of one membrane model are considered and for whole bioreactor too.

  18. A Novel Pulsatile Bioreactor for Mechanical Stimulation of Tissue Engineered Cardiac Constructs

    Directory of Open Access Journals (Sweden)

    Günther Eissner

    2011-07-01

    Full Text Available After myocardial infarction, the implantation of stem cell seeded scaffolds on the ischemic zone represents a promising strategy for restoration of heart function. However, mechanical integrity and functionality of tissue engineered constructs need to be determined prior to implantation. Therefore, in this study a novel pulsatile bioreactor mimicking the myocardial contraction was developed to analyze the behavior of mesenchymal stem cells derived from umbilical cord tissue (UCMSC colonized on titanium-coated polytetrafluorethylene scaffolds to friction stress. The design of the bioreactor enables a simple handling and defined mechanical forces on three seeded scaffolds at physiological conditions. The compact system made of acrylic glass, Teflon®, silicone, and stainless steel allows the comparison of different media, cells and scaffolds. The bioreactor can be gas sterilized and actuated in a standard incubator. Macroscopic observations and pressure-measurements showed a uniformly sinusoidal pulsation, indicating that the bioreactor performed well. Preliminary experiments to determine the adherence rate and morphology of UCMSC after mechanical loadings showed an almost confluent cellular coating without damage on the cell surface. In summary, the bioreactor is an adequate tool for the mechanical stress of seeded scaffolds and offers dynamic stimuli for pre-conditioning of cardiac tissue engineered constructs in vitro.

  19. Microscale 3D Liver Bioreactor for In Vitro Hepatotoxicity Testing under Perfusion Conditions

    Directory of Open Access Journals (Sweden)

    Nora Freyer

    2018-03-01

    Full Text Available The accurate prediction of hepatotoxicity demands validated human in vitro models that can close the gap between preclinical animal studies and clinical trials. In this study we investigated the response of primary human liver cells to toxic drug exposure in a perfused microscale 3D liver bioreactor. The cellularized bioreactors were treated with 5, 10, or 30 mM acetaminophen (APAP used as a reference substance. Lactate production significantly decreased upon treatment with 30 mM APAP (p < 0.05 and ammonia release significantly increased in bioreactors treated with 10 or 30 mM APAP (p < 0.0001, indicating APAP-induced dose-dependent toxicity. The release of prostaglandin E2 showed a significant increase at 30 mM APAP (p < 0.05, suggesting an inflammatory reaction towards enhanced cellular stress. The expression of genes involved in drug metabolism, antioxidant reactions, urea synthesis, and apoptosis was differentially influenced by APAP exposure. Histological examinations revealed that primary human liver cells in untreated control bioreactors were reorganized in tissue-like cell aggregates. These aggregates were partly disintegrated upon APAP treatment, lacking expression of hepatocyte-specific proteins and transporters. In conclusion, our results validate the suitability of the microscale 3D liver bioreactor to detect hepatotoxic effects of drugs in vitro under perfusion conditions.

  20. Efficacy of Bioremediation of Agricultural Runoff Using Bacterial Communities in Woodchip Bioreactors.

    Science.gov (United States)

    Mortensen, Z. H.; Leandro, M.; Silveus, J. M.

    2016-12-01

    California's agricultural sector is fundamental in the State's economic growth and is responsible for supplying a large portion of the country's produce. In order to meet the market's demand for crop production the region's agrarian landscape requires an abundance of nutrient rich irrigation. The resultant agricultural effluent is a source of increased nutrient content in California's watershed and groundwater systems, promoting eutrophication and contributing to negative impacts on local ecosystems and human health. Previous studies have examined the denitrification potential of woodchip bioreactors. However, research has been deficient regarding specific variables that may affect the remediation process. To evaluate the efficacy of woodchip bioreactors in remediating waters containing high nitrate concentrations, denitrification rates were examined and parameters such as temperature, laminar flow, and hydraulic residence times were measured to identify potential methods for increasing denitrification efficiency. By measuring the rate of denitrification in a controlled environment where potentially confounding factors can be manipulated, physical components affecting the efficiency of woodchip bioreactors were examined to assess effects. Our research suggests the implementation of woodchip bioreactors to treat agricultural runoff would significantly reduce the concentration of nitrate in agricultural effluent and contribute to the mitigation of negative impacts associated with agricultural irrigation. Future research should focus on the ability of woodchip bioreactors to successfully remediate other agricultural pollutants, such as phosphates and pesticides, to optimize the efficiency of the bioremediation process.

  1. Industrialization of a perfusion bioreactor: Prime example of a non-straightforward process.

    Science.gov (United States)

    Talò, G; Turrisi, C; Arrigoni, C; Recordati, C; Gerges, I; Tamplenizza, M; Cappelluti, A; Riboldi, S A; Moretti, M

    2018-02-01

    Bioreactors are essential enabling technologies for the translation of advanced therapies medicinal products from the research field towards a successful clinical application. In order to speed up the translation and the spread of novel tissue engineering products into the clinical routine, tissue engineering bioreactors should evolve from laboratory prototypes towards industrialized products. In this work, we thus challenged the industrialization process of a novel technological platform, based on an established research prototype of perfusion bioreactor, following a GMP-driven approach. We describe how the combination of scientific background, intellectual property, start-up factory environment, wise industrial advice in the biomedical field, design, and regulatory consultancy allowed us to turn a previously validated prototype technology into an industrial product suitable for serial production with improved replicability and user-friendliness. The solutions implemented enhanced aesthetics, ergonomics, handling, and safety of the bioreactor, and they allowed compliance with the fundamental requirements in terms of traceability, reproducibility, efficiency, and safety of the manufacturing process of advanced therapies medicinal products. The result is an automated incubator-compatible device, housing 12 disposable independent perfusion chambers for seeding and culture of any perfusable tissue. We validated the cell seeding process of the industrialized bioreactor by means of the Design of Experiment approach, whilst the effectiveness of perfusion culture was evaluated in the context of bone tissue engineering. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Treating domestic sewage by Integrated Inclined-Plate-Membrane bio-reactor

    Science.gov (United States)

    Song, Li Ming; Wang, Zi; Chen, Lei; Zhong, Min; Dong, Zhan Feng

    2017-12-01

    Membrane fouling shorten the service life of the membrane and increases aeration rate for membrane surface cleaning. Two membrane bio-reactors, one for working and another for comparing, were set up to evaluate the feasibility of alleviating membrane fouling and improving wastewater treatment efficiency by integrating inclined-plate precipitation and membrane separation. The result show that: (1) Inclined-plate in reactor had a good effect on pollutant removal of membrane bioreactor. The main role of inclined-plate is dividing reactor space and accelerating precipitation. (2) Working reactor have better performance in COD, TN and TP removal, which can attribute to that working reactor (integrated inclined-plate-Membrane bioreactor) takes both advantages of membrane separation and biological treatment. When influent COD, TP and TN concentration is 163-248 mg/L, 2.08-2.81 mg/L and 24.38-30.49 mg/L in working reactor, effluent concentration is 27-35 mg/L, 0.53-0.59 mg/L and 11.28-11.56 mg/L, respectively. (3) Membrane fouling was well alleviated in integrated inclined-plate-Membrane bioreactor, and membrane normal service time is significantly longer than that in comparing reactor, which can attribute to accelerating precipitation of inclined-plate. In summary, integrated inclined-plate-Membrane bioreactor is a promising technology to alleviating membrane fouling and improving wastewater treatment efficiency, having good performance and bright future in application.

  3. Microscale 3D Liver Bioreactor for In Vitro Hepatotoxicity Testing under Perfusion Conditions.

    Science.gov (United States)

    Freyer, Nora; Greuel, Selina; Knöspel, Fanny; Gerstmann, Florian; Storch, Lisa; Damm, Georg; Seehofer, Daniel; Foster Harris, Jennifer; Iyer, Rashi; Schubert, Frank; Zeilinger, Katrin

    2018-03-15

    The accurate prediction of hepatotoxicity demands validated human in vitro models that can close the gap between preclinical animal studies and clinical trials. In this study we investigated the response of primary human liver cells to toxic drug exposure in a perfused microscale 3D liver bioreactor. The cellularized bioreactors were treated with 5, 10, or 30 mM acetaminophen (APAP) used as a reference substance. Lactate production significantly decreased upon treatment with 30 mM APAP ( p < 0.05) and ammonia release significantly increased in bioreactors treated with 10 or 30 mM APAP ( p < 0.0001), indicating APAP-induced dose-dependent toxicity. The release of prostaglandin E2 showed a significant increase at 30 mM APAP ( p < 0.05), suggesting an inflammatory reaction towards enhanced cellular stress. The expression of genes involved in drug metabolism, antioxidant reactions, urea synthesis, and apoptosis was differentially influenced by APAP exposure. Histological examinations revealed that primary human liver cells in untreated control bioreactors were reorganized in tissue-like cell aggregates. These aggregates were partly disintegrated upon APAP treatment, lacking expression of hepatocyte-specific proteins and transporters. In conclusion, our results validate the suitability of the microscale 3D liver bioreactor to detect hepatotoxic effects of drugs in vitro under perfusion conditions.

  4. Biological reduction of nitrates in wastewaters from nuclear processing using a fluidized-bed bioreactor

    International Nuclear Information System (INIS)

    Pitt, W.W.; Hancher, C.W.; Patton, B.D.

    1981-01-01

    There are a number of nitrate-containing wastewater sources, as concentrated as 30 wt.% NO 3 - and as large as 2000 m 3 /day, in the nuclear fuel cycle. The biological reduction of nitrate in wastewater to gaseous nitrogen, accompanied by the oxidation of a nutrient carbon source to gaseous carbon dioxide, is an ecologically sound and cost-effective method of treating wastewaters containing nitrates. These nitrate-containing wastewater sources can be successfully biologically denitrified to meet discharge standards in the range of 10 to 20 gN(NO 3 - )/m 3 by the use of a fluidized-bed bioreactor. The denitrification bacteria are a mixed culture derived from garden soil; the major strain is Pseudomonas. In the fluidized-bed bioreactor the bacteria are allowed to attach to 0.25- to 0.50-mm-diam coal fluidization particles, which are then fluidized by the upward flow of influent wastewater. Maintaining the bacteria-to-coal weight ratio at approximately 1:10 results in a bioreactor bacteria loading of greater than 20,000 g/m 3 . This paper describes the results of a biodenitrification R and D program based on the use of fluidized bioreactors capable of operating at nitrate levels up to 7000 g/m 3 and achieving denitrification rates as high as 80 g N(NO 3 - ) per day per liter of empty bioreactor volume. 4 figures, 7 tables

  5. Benzoate-induced stress enhances xylitol yield in aerobic fed-batch culture of Candida mogii TISTR 5892.

    Science.gov (United States)

    Wannawilai, Siwaporn; Sirisansaneeyakul, Sarote; Chisti, Yusuf

    2015-01-20

    Production of the natural sweetener xylitol from xylose via the yeast Candida mogii TISTR 5892 was compared with and without the growth inhibitor sodium benzoate in the culture medium. Sodium benzoate proved to be an uncompetitive inhibitor in relatively poorly oxygenated shake flask aerobic cultures. In a better controlled aerobic environment of a bioreactor, the role of sodium benzoate could equally well be described as competitive, uncompetitive or noncompetitive inhibitor of growth. In intermittent fed-batch fermentations under highly aerobic conditions, the presence of sodium benzoate at 0.15gL(-1) clearly enhanced the xylitol titer relative to the control culture without the sodium benzoate. The final xylitol concentration and the average xylitol yield on xylose were nearly 50gL(-1) and 0.57gg(-1), respectively, in the presence of sodium benzoate. Both these values were substantially higher than reported for the same fermentation under microaerobic conditions. Therefore, a fed-batch aerobic fermentation in the presence of sodium benzoate is promising for xylitol production using C. mogii. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Solid substrate fermentation of lignite by the coal-solubilizing mould, Trichoderma atroviride, in a new type of bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Holker, U.; Hofer, M. [University of Bonn, Bonn (Germany)

    2002-07-01

    Trichoderma atroviride CBS 349 is able to solubilize lignite. The mould was cultured under non-sterile conditions in a new type of bioreactor for solid substrate fermentation. German lignite (lithotype A, Bergheim) was used as complex solid substrate. Over 40 days 140 g of 1.5 kg lignite held in a 25 1-bioreactor was solubilized by the fungus.

  7. Full-scale demonstration of treatment of mechanically separated organic residue in a bioreactor at VAM in Wijster

    NARCIS (Netherlands)

    Oonk, H.; Woelders, H.

    1999-01-01

    At the VAM waste treatment company in Wijster a demonstration is in progress of bioreactor technology for the treatment of mechanically separated organic residue (MSOR) of a waste separation plant. This bioreactor is an in situ fermentation cell in which physical, chemical and biological processes

  8. Evaluation of mixing and mass transfer in a stirred pilot scale bioreactor utilizing CFD

    DEFF Research Database (Denmark)

    Bach, Christian; Yang, Jifeng; Larsson, Hilde Kristina

    2017-01-01

    Knowledge and prediction of mixing and mass transfer in agitated bioreactors is fundamental for process development and scale up. In particular key process parameters such as mixing time and volumetric mass transfer coefficient are essential for bioprocess development. In this work the mixing...... and mass transfer performance of a high power agitated pilot scale bioreactor has been characterized using a novel combination of computational fluid dynamics (CFD) and experimental investigations. The effect of turbulence inside the vessel was predicted using a standard RANS k-ε model. Mixing time...... transfer coefficients were in accordance with the experimental data. This work illustrates the possibility of predicting the two phase fluid dynamic performance of an agitated pilot scale bioreactor using validated CFD models. These models can be applied to illustrate the effect of changing the physical...

  9. Novel bacterial sulfur oxygenase reductases from bioreactors treating gold-bearing concentrates

    DEFF Research Database (Denmark)

    Chen, Z-W; Liu, Y-Y; Wu, J-F

    2007-01-01

    The microbial community and sulfur oxygenase reductases of metagenomic DNA from bioreactors treating gold-bearing concentrates were studied by 16S rRNA library, real-time polymerase chain reaction (RT-PCR), conventional cultivation, and molecular cloning. Results indicated that major bacterial......) of bacteria and archaea were 4.59 x 10(9) and 6.68 x 10(5), respectively. Bacterial strains representing Acidithiobacillus, Leptospirillum, and Sulfobacillus were isolated from the bioreactors. To study sulfur oxidation in the reactors, pairs of new PCR primers were designed for the detection of sulfur...... oxygenase reductase (SOR) genes. Three sor-like genes, namely, sor (Fx), sor (SA), and sor (SB) were identified from metagenomic DNAs of the bioreactors. The sor (Fx) is an inactivated SOR gene and is identical to the pseudo-SOR gene of Ferroplasma acidarmanus. The sor (SA) and sor (SB) showed...

  10. Nitrate removal from aquaculture effluents using woodchip bioreactors improved by adding sulfur granules and crushed seashells

    DEFF Research Database (Denmark)

    von Ahnen, Mathis; Pedersen, Per Bovbjerg; Dalsgaard, Johanne

    2018-01-01

    This study examined the effects on nitrate removal when adding sulfur granules and crushed seashells to a woodchip bioreactor treating aquaculture effluents. Using a central composite design, the two components were added at three levels (0.000, 0.125 and 0.250 m3/m3 bioreactor volume) to 13......, the inclusion of crushed seashells together with sulfur granules helped to maintain the pH above 7.4 and prevent a production (i.e., release) of nitrite. According to the modeled response surfaces, a sulfur granule:crushed seashell:woodchip mixture ratio containing about 0.2 m3 sulfur granules and 0.1 m3...... crushed seashells per m3 reactor volume would give the best results with respect to high N removal and minimal nitrite release. In conclusion, the study showed that N removal in woodchip bioreactors may be improved by adding sulfur granules and seashells, contributing to the optimization of woodchip...

  11. Preparation of kombucha from winter savory (Satureja Montana L. in the laboratory bioreactor

    Directory of Open Access Journals (Sweden)

    Cvetković Dragoljub D.

    2005-01-01

    Full Text Available The possibility of obtaining kombucha from winter savory tea has been tested in the laboratory bioreactor by applying starter cultures and traditional way of inoculation. On the basis of the obtained results, it can be concluded that applying the inoculating method with the beverage from the previous process of biotransformation yielded kombucha beverage (capacity 15 I from winter savory tea in the laboratory bioreactor. The application of defined starter culture from the isolate of yeast and acetic acid bacteria of local tea in the glass jar (capacity 5 I gave 3 litres of kombucha beverage, which is acceptable according to the basic parameters and sensory characteristics. However, the application of the same starter culture in the laboratory bioreactor did not result in synchronized activity of yeast and bacteria.

  12. Applicability of anaerobic membrane bioreactors for landfill leachate treatment: Review and opportunity

    Science.gov (United States)

    Abuabdou, Salahaldin M. A.; Bashir, Mohammed J. K.; Aun, Ng Choon; Sethupathi, Sumathi

    2018-04-01

    Sanitary landfilling is nowadays the most common way to eliminate municipal solid wastes (MSW). The resulted landfill leachate is a highly contaminated liquid. Even small quantities of this high-strength leachate can cause serious damage to surface and ground water receptors. Thus, these leachates must be appropriately treated before being discharged into the environment. In the last years, anaerobic membrane bioreactor (AnMBR) technology is being considered as a very attractive alternative for leachate treatment due to the significant advantages. In the last decade, many studies have been conducted in which various types of anaerobic reactors were used in combination with membranes. This paper is a review of the potential of anaerobic membrane bioreactor technology for municipal landfill leachate treatment. A critical review in AnMBR performance interesting landfill leachate in lab scale is also done. In addition, the review discusses the impact of the various factors on both biological and filtration performances of anaerobic membrane bioreactors.

  13. Energy-efficient adjustable speed double inverter-fed woundrotor ...

    African Journals Online (AJOL)

    Energy-efficient adjustable speed double inverter-fed woundrotor induction motor ... at speeds up to double rated without the magnetic flux reducing is presented. ... Keywords: power, double-fed wound-rotor induction motor drive, steel and ...

  14. Engineering testing requirements in FED/INTOR

    International Nuclear Information System (INIS)

    Abdou, M.A.; Nygren, R.E.; Morgan, G.D.; Trachsel, C.A.; Wire, G.; Oppermann, E.; Puigh, R.; Gold, R.E.

    1982-10-01

    The FED/INTOR critical issues activity has addressed three key testing requirements that have the largest impact on the design, operation and cost of FED/INTOR. These are: (1) the total testing time (fluence) during the device lifetime, (2) the minimum number of back-to-back cycles, and (3) the neutron wall load (power density in the first wall/blanket). The testing program activities were structured into three tasks in order to define the benefits, and in some cases, costs and risks of these testing requirements. The three tasks were carried out with wide participation of experts from a number of organizations in the United States. Similar effort was performed by Japan, the European Community and the Soviet Union

  15. Bacterial community dynamics during start-up of a trickle-bed bioreactor degrading aromatic compounds.

    Science.gov (United States)

    Stoffels, M; Amann, R; Ludwig, W; Hekmat, D; Schleifer, K H

    1998-03-01

    This study was performed with a laboratory-scale fixed-bed bioreactor degrading a mixture of aromatic compounds (Solvesso100). The starter culture for the bioreactor was prepared in a fermentor with a wastewater sample of a care painting facility as the inoculum and Solvesso100 as the sole carbon source. The bacterial community dynamics in the fermentor and the bioreactor were examined by a conventional isolation procedure and in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotides. Two significant shifts in the bacterial community structure could be demonstrated. The original inoculum from the wastewater of the car factory was rich in proteobacteria of the alpha and beta subclasses, while the final fermentor enrichment was dominated by bacteria closely related to Pseudomonas putida or Pseudomonas mendocina, which both belong to the gamma subclass of the class Proteobacteria. A second significant shift was observed when the fermentor culture was transferred as inoculum to the trickle-bed bioreactor. The community structure in the bioreactor gradually returned to a higher complexity, with the dominance of beta and alpha subclass proteobacteria, whereas the gamma subclass proteobacteria sharply declined. Obviously, the preceded pollutant adaptant did not lead to a significant enrichment of bacteria that finally dominated in the trickle-bed bioreactor. In the course of experiments, three new 16S as well as 23S rRNA-targeted probes for beta subclass proteobacteria were designed, probe SUBU1237 for the genera Burkholderia and Sutterella, probe ALBO34a for the genera Alcaligenes and Bordetella, and probe Bcv13b for Burkholderia cepacia and Burkholderia vietnamiensis. Bacteria hybridizing with the probe Bcv13b represented the main Solvesso100-degrading population in the reactor.

  16. An evaluation of different bioreactor configurations for continuous bio-ethanol production

    International Nuclear Information System (INIS)

    Ntihuga, Jean Nepomuscene; Senn, Thomas; Gschwind, Peter; Kohlus, Reinhard

    2013-01-01

    Highlights: • Two bioreactor configurations were constructed and compared. • Continuous bioethanol production was performed in both bioreactors. • Plate heat exchanger bioreactor was the best for solid mash fermentation. • Operational power costs of both bioreactors were different in small scale levels. • Further study needed for both bioreactors with optimized parameters. - Abstract: In this preliminary investigation, a so-called Blenke cascade and plate heat exchanger bioreactor configuration were compared in terms of mixing characteristics, contamination free process, operational power costs and overall performance. At room temperature, fermentation was initially started as batch run and switched to continuous operation, when the residual sugars within the reactor were detected to be C ⩽ 1% (g/L). Samples from both configurations were taken and analyzed for ethanol and residual sugar content, as well as for any infection of the fermentation and lactic acid content, respectively. Mixing characteristics were studied by the residence time distribution method. Both geometries behaved as a finite number n of continuous stirred tanks in series, behaving as a plug flow with superimposed axial dispersion. The number of tanks in series n obtained in the plate heat exchanger configuration was 1.5–3 times larger than those in the Blenke cascade. The average ethanol productivity was Q p = 3.07 (g/L h) and Q p = 2.31 (g/L h) for cascade and plate exchanger configuration, respectively. The analysis of operational power costs indicates relevant differences between the two reactors at laboratory scale; however, systems with different types of pumps and viscosities are compared. From an industrial scale point of view, specific operational costs decrease with scale-up, as no mechanical mixing is needed in the fermenters

  17. Biological manganese removal from acid mine drainage in constructed wetlands and prototype bioreactors.

    Science.gov (United States)

    Hallberg, Kevin B; Johnson, D Barrie

    2005-02-01

    Mine drainage waters vary considerably in the range and concentration of heavy metals they contain. Besides iron, manganese is frequently present at elevated concentrations in waters draining both coal and metal mines. Passive treatment systems (aerobic wetlands and compost bioreactors) are designed to remove iron by biologically induced oxidation/precipitation. Manganese, however, is problematic as it does not readily form sulfidic minerals and requires elevated pH (>8) for abiotic oxidation of Mn (II) to insoluble Mn (IV). As a result, manganese removal in passive remediation systems is often less effective than removal of iron. This was found to be the case at the pilot passive treatment plant (PPTP) constructed to treat water draining the former Wheal Jane tin mine in Cornwall, UK, where effective removal of manganese occurred only in one of the three rock filter components of the composite systems over a 1-year period of monitoring. Water in the two rock filter systems where manganese removal was relatively poor was generally system. These differences in water chemistry and manganese removal were due to variable performances in the compost bioreactors that feed the rock filter units in the composite passive systems at Wheal Jane. An alternative approach for removing soluble manganese from mine waters, using fixed bed bioreactors, was developed. Ferromanganese nodules (about 2 cm diameter), collected from an abandoned mine adit in north Wales, were used to inoculate the bioreactors (working volume ca. 700 ml). Following colonization by manganese-oxidizing microbes, the aerated bioreactor catalysed the removal of soluble manganese, via oxidation of Mn (II) and precipitation of the resultant Mn (IV) in the bioreactor, in synthetic media and mine water from the Wheal Jane PPTP. Such an approach has potential application for removing soluble Mn from mine streams and other Mn-contaminated water courses.

  18. Temporal Changes in Extracellular Polymeric Substances on Hydrophobic and Hydrophilic Membrane Surfaces in a Submerged Membrane Bioreactor

    KAUST Repository

    Matar, Gerald Kamil

    2016-03-02

    Membrane surface hydrophilic modification has always been considered to mitigating biofouling in membrane bioreactors (MBRs). Four hollow-fiber ultrafiltration membranes (pore sizes ∼0.1 μm) differing only in hydrophobic or hydrophilic surface characteristics were operated at a permeate flux of 10 L/m2.h in the same lab-scale MBR fed with synthetic wastewater. In addition, identical membrane modules without permeate production (0 L/m2.h) were operated in the same lab-scale MBR. Membrane modules were autopsied after 1, 10, 20 and 30 days of MBR operation, and total extracellular polymeric substances (EPS) accumulated on the membranes were extracted and characterized in detail using several analytical tools, including conventional colorimetric tests (Lowry and Dubois), liquid chromatography with organic carbon detection (LC-OCD), fluorescence excitation - emission matrices (FEEM), fourier transform infrared (FTIR) and confocal laser scanning microscope (CLSM). The transmembrane pressure (TMP) quickly stabilized with higher values for the hydrophobic membranes than hydrophilic ones. The sulfonated polysulfone (SPSU) membrane had the highest negatively charged membrane surface, accumulated the least amount of foulants and displayed the lowest TMP. The same type of organic foulants developed with time on the four membranes and the composition of biopolymers shifted from protein dominance at early stages of filtration (day 1) towards polysaccharides dominance during later stages of MBR filtration. Nonmetric multidimensional scaling of LC-OCD data showed that biofilm samples clustered according to the sampling event (time) regardless of the membrane surface chemistry (hydrophobic or hydrophilic) or operating mode (with or without permeate flux). These results suggest that EPS composition may not be the dominant parameter for evaluating membrane performance and possibly other parameters such as biofilm thickness, porosity, compactness and structure should be considered

  19. Microbial dynamics in upflow anaerobic sludge blanket (UASB) bioreactor granules in response to short-term changes in substrate feed

    Energy Technology Data Exchange (ETDEWEB)

    Kovacik, William P.; Scholten, Johannes C.; Culley, David E.; Hickey, Robert; Zhang, Weiwen; Brockman, Fred J.

    2010-08-01

    The complexity and diversity of the microbial communities in biogranules from an upflow anaerobic sludge blanket (UASB) bioreactor were determined in response to short-term changes in substrate feeds. The reactor was fed simulated brewery wastewater (SBWW) (70% ethanol, 15% acetate, 15% propionate) for 1.5 months (phase 1), acetate / sulfate for 2 months (phase 2), acetate-alone for 3 months (phase 3), and then a return to SBWW for 2 months (phase 4). Performance of the reactor remained relatively stable throughout the experiment as shown by COD removal and gas production. 16S rDNA, methanogen-associated mcrA and sulfate reducer-associated dsrAB genes were PCR amplified, then cloned and sequenced. Sequence analysis of 16S clone libraries showed a relatively simple community composed mainly of the methanogenic Archaea (Methanobacterium and Methanosaeta), members of the Green Non-Sulfur (Chloroflexi) group of Bacteria, followed by fewer numbers of Syntrophobacter, Spirochaeta, Acidobacteria and Cytophaga-related Bacterial sequences. Methanogen-related mcrA clone libraries were dominated throughout by Methanobacter and Methanospirillum related sequences. Although not numerous enough to be detected in our 16S rDNA libraries, sulfate reducers were detected in dsrAB clone libraries, with sequences related to Desulfovibrio and Desulfomonile. Community diversity levels (Shannon-Weiner index) generally decreased for all libraries in response to a change from SBWW to acetate-alone feed. But there was a large transitory increase noted in 16S diversity at the two-month sampling on acetate-alone, entirely related to an increase in Bacterial diversity. Upon return to SBWW conditions in phase 4, all diversity measures returned to near phase 1 levels.

  20. Saccharification of Agricultural Lignocellulose Feedstocks and Protein-Level Responses by a Termite Gut-Microbe Bioreactor

    International Nuclear Information System (INIS)

    Rajarapu, Swapna Priya; Scharf, Michael E.

    2017-01-01

    This study investigated saccharification and protein-level responses to the candidate biofuel feedstocks corn stover (CS) and soybean residue (SR) by the gut of a lower termite. The focus termite was Reticulitermes flavipes, which is a highly efficient digester of wood lignocellulose that houses a mixture of prokaryotic and eukaryotic microbes in its gut. Our specific objectives were to (i) measure saccharification potential of the CS and SR feedstocks by termite gut protein extracts, (ii) identify specific proteins in the termite gut responding to feeding on CS and SR diets, and (iii) evaluate gut lignocellulase and accessory enzyme activity responses to CS and SR feeding. Cellulose paper was the control diet. Although CS was saccharified at higher levels, termite gut protein extracts saccharified both CS and SR irrespective of feedstock loading. Consumption of the CS and SR feedstocks by termites resulted in surprisingly few differences in gut protein profiles, with the main exception being elevated myosin abundance with SR feeding. Activity of potential lignocellulases and accessory enzymes was generally similar between CS and SR fed guts as well; however, cellobiohydrolase/exoglucanase activity was higher with CS feeding and glutathione peroxidase activity with SR feeding. These findings have significance from two perspectives. First, SR feeding/digestion appears to cause physiological stress in the termite gut that likely would extend to other types of microbial environments including those within industrial bioreactors. Second, because termites can survive on exclusive CS and SR diets and their guts exhibit clear CS and SR saccharification activity, this validates the R. flavipes system as a potential source for CS and SR degrading enzymes; in particular, cellobiohydrolases/exoglucanases and glutathione peroxidases from this system may play roles in CS and SR breakdown.

  1. Saccharification of Agricultural Lignocellulose Feedstocks and Protein-Level Responses by a Termite Gut-Microbe Bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Rajarapu, Swapna Priya; Scharf, Michael E., E-mail: mscharf@purdue.edu [Department of Entomology, Purdue University, West Lafayette, IN (United States)

    2017-04-07

    This study investigated saccharification and protein-level responses to the candidate biofuel feedstocks corn stover (CS) and soybean residue (SR) by the gut of a lower termite. The focus termite was Reticulitermes flavipes, which is a highly efficient digester of wood lignocellulose that houses a mixture of prokaryotic and eukaryotic microbes in its gut. Our specific objectives were to (i) measure saccharification potential of the CS and SR feedstocks by termite gut protein extracts, (ii) identify specific proteins in the termite gut responding to feeding on CS and SR diets, and (iii) evaluate gut lignocellulase and accessory enzyme activity responses to CS and SR feeding. Cellulose paper was the control diet. Although CS was saccharified at higher levels, termite gut protein extracts saccharified both CS and SR irrespective of feedstock loading. Consumption of the CS and SR feedstocks by termites resulted in surprisingly few differences in gut protein profiles, with the main exception being elevated myosin abundance with SR feeding. Activity of potential lignocellulases and accessory enzymes was generally similar between CS and SR fed guts as well; however, cellobiohydrolase/exoglucanase activity was higher with CS feeding and glutathione peroxidase activity with SR feeding. These findings have significance from two perspectives. First, SR feeding/digestion appears to cause physiological stress in the termite gut that likely would extend to other types of microbial environments including those within industrial bioreactors. Second, because termites can survive on exclusive CS and SR diets and their guts exhibit clear CS and SR saccharification activity, this validates the R. flavipes system as a potential source for CS and SR degrading enzymes; in particular, cellobiohydrolases/exoglucanases and glutathione peroxidases from this system may play roles in CS and SR breakdown.

  2. Sky Subtraction with Fiber-Fed Spectrograph

    Science.gov (United States)

    Rodrigues, Myriam

    2017-09-01

    "Historically, fiber-fed spectrographs had been deemed inadequate for the observation of faint targets, mainly because of the difficulty to achieve high accuracy on the sky subtraction. The impossibility to sample the sky in the immediate vicinity of the target in fiber instruments has led to a commonly held view that a multi-object fibre spectrograph cannot achieve an accurate sky subtraction under 1% contrary to their slit counterpart. The next generation of multi-objects spectrograph at the VLT (MOONS) and the planed MOS for the E-ELT (MOSAIC) are fiber-fed instruments, and are aimed to observed targets fainter than the sky continuum level. In this talk, I will present the state-of-art on sky subtraction strategies and data reduction algorithm specifically developed for fiber-fed spectrographs. I will also present the main results of an observational campaign to better characterise the sky spatial and temporal variations ( in particular the continuum and faint sky lines)."

  3. Microbial competition among anammox bacteria in nitrite-limited bioreactors

    KAUST Repository

    Zhang, Lei; Narita, Yuko; Gao, Lin; Ali, Muhammad; Oshiki, Mamoru; Ishii, Satoshi; Okabe, Satoshi

    2017-01-01

    Phylogenetically diverse anammox bacteria have been detected in most of anoxic natural and engineered ecosystems and thus regarded as key players in the global nitrogen cycle. However, ecological niche differentiation of anammox bacteria remains unresolved despite its ecological and practical importance. In this study, the microbial competitions for a common substrate (nitrite) among three anammox species (i.e. “Candidatus Brocadia sinica”, “Candidatus Jettenia caeni” and “Candidatus Kuenenia stuttgartiensis”) were systematically investigated in nitrite-limited gel-immobilized column reactors (GICR) and membrane bioreactors (MBRs) under different nitrogen loading rates (NLRs). 16 S rRNA gene-based population dynamics revealed that “Ca. J. caeni” could proliferate only at low NLRs, whereas “Ca. B. sinica” outcompeted other two species at higher NLRs in both types of reactors. Furthermore, FISH analysis revealed that “Ca. J. caeni” was mainly present as spherical microclusters at the inner part (low NO2− environment), whereas “Ca. B. sinica” was present throughout the gel beads and granules. This spatial distribution supports the outcomes of the competition experiments. However, the successful competition of “Ca. J. caeni” at low NLR could not be explained with the Monod model probably due to inaccuracy of kinetic parameters such as half saturation constant (Ks) for nitrite and a difference in the maintenance rate (m). In addition, the growth of “Ca. K. stuttgartiensis” could not be observed in any experimental conditions, suggesting possible unknown factor(s) is missing. Taken together, NLR was one of factors determining ecological niche differentiation of “Ca. B. sinica” and “Ca. J. caeni”.

  4. Microbial competition among anammox bacteria in nitrite-limited bioreactors

    KAUST Repository

    Zhang, Lei

    2017-08-26

    Phylogenetically diverse anammox bacteria have been detected in most of anoxic natural and engineered ecosystems and thus regarded as key players in the global nitrogen cycle. However, ecological niche differentiation of anammox bacteria remains unresolved despite its ecological and practical importance. In this study, the microbial competitions for a common substrate (nitrite) among three anammox species (i.e. “Candidatus Brocadia sinica”, “Candidatus Jettenia caeni” and “Candidatus Kuenenia stuttgartiensis”) were systematically investigated in nitrite-limited gel-immobilized column reactors (GICR) and membrane bioreactors (MBRs) under different nitrogen loading rates (NLRs). 16 S rRNA gene-based population dynamics revealed that “Ca. J. caeni” could proliferate only at low NLRs, whereas “Ca. B. sinica” outcompeted other two species at higher NLRs in both types of reactors. Furthermore, FISH analysis revealed that “Ca. J. caeni” was mainly present as spherical microclusters at the inner part (low NO2− environment), whereas “Ca. B. sinica” was present throughout the gel beads and granules. This spatial distribution supports the outcomes of the competition experiments. However, the successful competition of “Ca. J. caeni” at low NLR could not be explained with the Monod model probably due to inaccuracy of kinetic parameters such as half saturation constant (Ks) for nitrite and a difference in the maintenance rate (m). In addition, the growth of “Ca. K. stuttgartiensis” could not be observed in any experimental conditions, suggesting possible unknown factor(s) is missing. Taken together, NLR was one of factors determining ecological niche differentiation of “Ca. B. sinica” and “Ca. J. caeni”.

  5. Membrane Bioreactors design and operation improvements: The Spanish Experience

    International Nuclear Information System (INIS)

    Iglesias Esteban, R.; Ortega de Miguel, E.; Martinez Tarifa, M. A.; Simon Andreu, P.; Moragas Bouyart, L.; Garcia Fernandez, E.; Robuste Cartro, J.; Rodriguez-Roda layret, I.

    2012-01-01

    A Membrane Bioreactor (MBR) is a modification of a conventional activated sludge (CAS) plant where the secondary settling ins replaced by a low pressure ultrafiltration (UF) or micro filtration (MF) membranes separation process in order to obtain an effluent almost free of suspended solids and microorganisms. since the first MBR installation in 2002, the number and capacity of these systems have exponentially increased in spain, driven by the high quality of the effluent which allows direct reuse and discharge into environmentally sensitive areas, the compactness and automation of these plants and the possibility of upgrading existing wastewater treatment plants (WWTP) which no longer reach the required effluent quality levels. There were 45 operating MBR systems in 2011 and the total municipal wastewater treatment capacity by this type of plants will be about 90 hm 3 in 204 when the current projects have been implemented. Today, Spain public and private wastewater management agencies consider MBR plants as an alternative of treatment but first they had to face a complex learning period to operate and design this kind of system. A significant progress has been made over the last years, but especially energy efficiency responds to the challenge of continuous improvement. Membrane fouling control consumes most of the energy involved in the process therefore, anti fouling materials and better membrane air-scour systems that allow the frequency and intensity of air flow to be controlled in realtime, are being investigated. This brings MBR closer to the CAS process in terms of energy efficiency. Breakthroughs in the design and operation of MBR plants are being collected in a guide for the implementation of MBR led by CEDEX, in which the main managers and operators are involved. This paper presents some of these improvements. (Author) 9 refs.

  6. Pilot-scale experiment on anaerobic bioreactor landfills in China

    International Nuclear Information System (INIS)

    Jiang, Jianguo; Yang, Guodong; Deng, Zhou; Huang, Yunfeng; Huang, Zhonglin; Feng, Xiangming; Zhou, Shengyong; Zhang, Chaoping

    2007-01-01

    Developing countries have begun to investigate bioreactor landfills for municipal solid waste management. This paper describes the impacts of leachate recirculation and recirculation loadings on waste stabilization, landfill gas (LFG) generation and leachate characteristics. Four simulated anaerobic columns, R1-R4, were each filled with about 30 tons of waste and recirculated weekly with 1.6, 0.8 and 0.2 m 3 leachate and 0.1 m 3 tap water. The results indicated that the chemical oxygen demand (COD) half-time of leachate from R1 was about 180 days, which was 8-14 weeks shorter than that of R2-R4. A large amount of LFG was first produced in R1, and its generation rate was positively correlated to the COD or volatile fatty acid concentrations of influent leachates after the 30th week. By the 50th week of recirculation, the waste in R1 was more stabilized, with 931.2 kg COD or 175.6 kg total organic carbon released and with the highest landfill gas production. However, this contributed mainly to washout by leachate, which also resulted in the reduction of LFG generation potential and accumulation of ammonia and/or phosphorus in the early stage. Therefore, the regimes of leachate recirculation should be adjusted to the phases of waste stabilization to enhance efficiency of energy recovery. Integrated with the strategy of in situ leachate management, extra pre-treatment or post-treatment methods to remove the nutrients are recommended

  7. Gut-Bioreactor and Human Health in Future.

    Science.gov (United States)

    Purohit, Hemant J

    2018-03-01

    Gut-microbiome provides the complementary metabolic potential to the human system. To understand the active participation and the performance of the microbial community in human health, the concept of gut as a plug-flow reactor with the fed-batch mode of operation can provide better insight. The concept suggests the virtual compartmentalized gut with sequential stratification of the microbial community in response to a typical host genotype. It also provides the analysis plan for gut microbiome; and its relevance in developing health management options under the identified clinical conditions.

  8. Production of diosgenin from Dioscorea zingiberensis with mixed culture in a new tray bioreactor

    Directory of Open Access Journals (Sweden)

    Yutong Cheng

    2016-01-01

    Full Text Available A new tray bioreactor was developed for the production of diosgenin from Dioscorea zingiberensis with Trichoderma reesei and Aspergillus fumigatus. The influence of initial moisture content, temperature, tray bed depth and mixing times was investigated. The best fermentation condition is initial moisture content of 75%, bioreactor temperature of 35°C, solid bed depth of 1.5 cm and three mixings carrying out on the first, third and fifth day. Under the optimized fermentation conditions, after 144 h incubation, maximum diogenin concentration of 68.2 μmol/g was detected.

  9. Validation of computational non-Newtonian fluid model for membrane bioreactor

    DEFF Research Database (Denmark)

    Sørensen, Lasse; Bentzen, Thomas Ruby; Skov, Kristian

    2015-01-01

    Membrane bioreactor (MBR) systems are often considered as the wastewater treatment method of the future due to its high effluent quality. One of the main problems with such systems is a relative large energy consumption, which has led to research in this specific area. A powerful tool for optimiz......Membrane bioreactor (MBR) systems are often considered as the wastewater treatment method of the future due to its high effluent quality. One of the main problems with such systems is a relative large energy consumption, which has led to research in this specific area. A powerful tool...

  10. Differentiation of cartilaginous anlage in entire embryonic mouse limbs cultured in a rotating bioreactor.

    Science.gov (United States)

    Duke, P.; Oakley, C.; Montufar-Solis, D.

    The embryonic mammalian limb is sensitive both in vivo and in vitro to changes in gravitational force. Hypergravity of centrifugation and microgravity of space decreased size of elements due to precocious or delayed chondrogenesis respectively. In recapitulating spaceflight experiments, premetatarsals were cultured in suspension in a low stress, low sheer rotating bioreactor, and found to be shorter than those cultured in standard culture dishes, and cartilage development was delayed. This study only measured length of the metatarsals, and did not account for possible changes in width and/or in form of the skeletal elements. Shorter cartilage elements in limbbuds cultured in the bioreactor may be due to the ability of the system to reproduce a more in vivo 3D shape than traditional organ cultures. Tissues subjected to traditional organ cultures become flattened by their own weight, attachment to the filter, and restrictions imposed by nutrient diffusion. The purpose of the current experiment was to determine if entire limb buds could be successfully cultured in the bioreactor, and to compare the effects on 3D shape with that of culturing in a culture dish system. Fore and hind limbs from E11-E13 ICR mouse embryos were placed either in the bioreactor, in Trowell culture, or fixed as controls. Limbbuds were cultured for six days, fixed, and processed either as whole mounts or embedded for histology. Qualitative analysis revealed that the Trowell culture specimens were flattened, while bioreactor culture specimens had a more in vivo-like 3D limb shape. Sections of limbbuds from both types of cultures had excellent cartilage differentiation, with apparently more cell maturation, and hypertrophy in the specimens cultured in the bioreactor. Morphometric quantitation of the cartilaginous elements for comparisons of the two culture systems was complicated due to some limb buds fusing together during culture. This problem was especially noticeable in the younger limbs, and

  11. Differentiation of cartilaginous anlagen in entire embryonic mouse limbs cultured in a rotating bioreactor

    Science.gov (United States)

    Montufar-Solis, D.; Oakley, C. R.; Jefferson, Y.; Duke, P. J.

    2003-10-01

    Mechanisms involved in development of the embryonic limb have remained the same throughout eons of genetic and environmental evolution under Earth gravity (lg). During the spaceflight era it has been of interest to explore the ancient theory that form of the skeleton develops in response to gravity, and that changes in gravitational forces can change the developmental pattern of the limb. This has been shown in vivo and in vitro, allowing the hypergravity of centrifugation and microgravity of space to be used as tools to increase our knowledge of limb development. In recapitulations of spaceflight experiments, premetatarsals were cultured in suspension in a bioreactor, and found to be shorter and less differentiated than those cultured in standard culture dishes. This study only measured length of the metatarsals, and did not account for possible changes due to the skeletal elements having a more in vivo 3D shape while in suspension vs. flattened tissues compressed by their own weight. A culture system with an outcome closer to in vivo and that supports growth of younger limb buds than traditional systems will allow studies of early Hox gene expression, and contribute to the understanding of very early stages of development. The purpose of the current experiment was to determine if entire limb buds could be cultured in the bioreactor, and to compare the growth and differentiation with that of culturing in a culture dish system. Fore and hind limbs from E11-E13 ICR mouse embryos were cultured for six days, either in the bioreactor or in center-well organ culture dishes, fixed, and embedded for histology. E13 specimens grown in culture dishes were flat, while bioreactor culture specimens had a more in vivo-like 3D limb shape. Sections showed excellent cartilage differentiation in both culture systems, with more cell maturation, and hypertrophy in the specimens cultured in the bioreactor. Younger limb buds fused together during culture, so an additional set of El 1

  12. EXPERIMENTAL STUDY ON THE GAS-LIQUID FLOW IN THE MEMBRANE MICROPORE AERATION BIOREACTOR

    Directory of Open Access Journals (Sweden)

    DONG LIU

    2008-12-01

    Full Text Available Particle Image Velocimetry (PIV has been developed to measure the typical two-phase flow of various work conditions in Membrane Micropore Aeration Bioreactor (MMAB. The fluid phase is separated out using image processing techniques, which provides accurate measurements for the Bioreactor’s flow field, and makes it possible for quantitative analysis of the momentum exchange, heat exchange and the process of micro-admixture. The experimental method PIV used in this paper can preferably measure the complex flow in the reactor and initiates a new approach for the bioreactor design which mainly depends on experience at present.

  13. JSC technician checks STS-44 DSO 316 bioreactor and rotating wall vessel hdwr

    Science.gov (United States)

    1991-01-01

    JSC technician Tacey Prewitt checks the progress on a bioreactor experiment in JSC's Life Sciences Laboratory Bldg 37 biotechnology laboratory. Similar hardware is scheduled for testing aboard Atlantis, Orbiter Vehicle (OV) 104, during STS-44. Detailed Supplementary Objective (DSO) 316 Bioreactor/Flow and Particle Trajectory in Microgravity will checkout the rotating wall vessel hardware and hopefully will confirm researchers' theories and calculations about how flow fields work in space. Plastic beads of various sizes rather than cell cultures are being flown in the vessel for the STS-44 test.

  14. Bio-Gas production from municipal sludge waste using anaerobic membrane bioreactor

    International Nuclear Information System (INIS)

    Lee, Y. H.; Lee, S.

    2009-01-01

    A laboratory scale anaerobic membrane bioreactor (AnMBR) system for the bio-methane gas production was operated for 60 days with municipal sludge wastes as a sole carbon source. The AnMRR system utilized the external cross-flow membrane module and was equipped with on-line data acquisition which enables continuous monitoring of the performance of both bioreactor and membrane through the analyses of pH, temperature, gas production; permeate flow rate, and transmembrane pressure (TMP). Such a configuration also provides an efficient tool to study rapid variations of monitoring membrane pressure (TMP). (Author)

  15. Development and application of a milliliter-scale bioreactor for continuous microbial cultivations

    DEFF Research Database (Denmark)

    Bolic, Andrijana

    measurementwhere light was sent through the MSBR bottom and sample to a mirror-like surface in the MSBR and returned back to a fiber bundle. Aerobic and anaerobic batch cultivations were performed with Saccharomyces cerevisiae and Lactobacillus paracasei, respectively. A high evaporation rate was experienced...... bioreactor functionality usually comes in regular lab size, which then transforms a smallscale bioreactor platform to a regular size experimental set up. To address this issue, effort was placed in developing 2 push/pull pumps that were able to deliver gas and medium ina controlled manner as a part...

  16. Parallel steady state studies on a milliliter scale accelerate fed-batch bioprocess design for recombinant protein production with Escherichia coli.

    Science.gov (United States)

    Schmideder, Andreas; Cremer, Johannes H; Weuster-Botz, Dirk

    2016-11-01

    In general, fed-batch processes are applied for recombinant protein production with Escherichia coli (E. coli). However, state of the art methods for identifying suitable reaction conditions suffer from severe drawbacks, i.e. direct transfer of process information from parallel batch studies is often defective and sequential fed-batch studies are time-consuming and cost-intensive. In this study, continuously operated stirred-tank reactors on a milliliter scale were applied to identify suitable reaction conditions for fed-batch processes. Isopropyl β-d-1-thiogalactopyranoside (IPTG) induction strategies were varied in parallel-operated stirred-tank bioreactors to study the effects on the continuous production of the recombinant protein photoactivatable mCherry (PAmCherry) with E. coli. Best-performing induction strategies were transferred from the continuous processes on a milliliter scale to liter scale fed-batch processes. Inducing recombinant protein expression by dynamically increasing the IPTG concentration to 100 µM led to an increase in the product concentration of 21% (8.4 g L -1 ) compared to an implemented high-performance production process with the most frequently applied induction strategy by a single addition of 1000 µM IPGT. Thus, identifying feasible reaction conditions for fed-batch processes in parallel continuous studies on a milliliter scale was shown to be a powerful, novel method to accelerate bioprocess design in a cost-reducing manner. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1426-1435, 2016. © 2016 American Institute of Chemical Engineers.

  17. FED-A, an advanced performance FED based on low safety factor and current drive

    International Nuclear Information System (INIS)

    Peng, Y.K.M.; Rutherford, P.H.

    1983-08-01

    The FED-A study aims to quantify the potential improvement in cost-effectiveness of the Fusion Engineering Device (FED) by assuming low safety factor q (less than 2 as opposed to about 3) at the plasma edge and noninductive current drive (as opposed to only inductive current drive). The FED-A performance objectives are set to be : (1) ignition assuming International Tokamak Reactor (INTOR) plamsa confinement scaling, but still achieving a fusion power amplification Q greater than or equal to 5 when the confinement is degraded by a factor of 2; (2) neutron wall loading of about 1 MW/m 2 , with 0.5 MW/m 2 as a conservative lower bound; and (3) more clearly power-reactor-like operations, such as steady state

  18. An integral term adaptive neural control of fed-batch fermentation biotechnological process; Control neuronal adaptable con termino integral para un proceso biotecnologico de fermentacion por lote alimentado

    Energy Technology Data Exchange (ETDEWEB)

    Baruch, Ieroham; Hernandez, Luis Alberto; Barrera Cortes, Josefina [Centro de Investigacion y de Estudios Avanzados, Instituto Politecnico Nacional, Mexico D.F. (Mexico)

    2005-07-15

    A nonlinear mathematical model of aerobic biotechnological process of a fed-batch fermentation system is derived using ordinary differential equations. A neurocontrol is applied using Recurrent Trainable Neural Network (RTNN) plus integral term; the first network performs an approximation of the plant's output; the second network generates the control signal so that the biomass concentration could be regulated by the nutrient influent flow rate into the bioreactor. [Spanish] Un modelo matematico no lineal de un proceso biotecnologico aerobio de un sistema de fermentacion por lote alimentado es presentado mediante ecuaciones diferenciales ordinarias. Es propuesto un control utilizando dos redes neuronales recurrentes entrenables (RNRE) con la adicion de un termino integral; la primera red representa un aproximador de la salida de la planta y la segunda genera la senal de control tal que la concentracion de la biomasa pueda ser regulada mediante la alimentacion de un flujo con nutrientes al biorreactor.

  19. Comparison of the Modeling Approach between Membrane Bioreactor and Conventional Activated Sludge Processes

    DEFF Research Database (Denmark)

    Jiang, Tao; Sin, Gürkan; Spanjers, Henri

    2009-01-01

    Activated sludge models (ASM) have been developed and largely applied in conventional activated sludge (CAS) systems. The applicability of ASM to model membrane bioreactors (MBR) and the differences in modeling approaches have not been studied in detail. A laboratory-scale MBR was modeled using ASM...

  20. Pilot-scale testing membrane bioreactor for wastewater reclamation in industrial laundry

    DEFF Research Database (Denmark)

    Andersen, Martin; Kristensen, Gert Holm; Brynjolf, M.

    2002-01-01

    A pilot-scale study of membrane bioreactor treatment for reclamation of wastewater from Berendsen Textile Service industrial laundry in Søborg, Denmark was carried out over a 4 month period. A satisfactory COD degradation was performed resulting in a low COD in the permeate (

  1. Microbial population heterogeneity versus bioreactor heterogeneity: evaluation of Redox Sensor Green as an exogenous metabolic biosensor

    DEFF Research Database (Denmark)

    Baert, Jonathan; Delepierre, Anissa; Telek, Samuel

    2016-01-01

    Microbial heterogeneity in metabolic performances has attracted a lot of attention, considering its potential impact on industrial bioprocesses. However, little is known about the impact of extracellular perturbations (i.e. bioreactor heterogeneity) on cell-to-cell variability in metabolic...

  2. Large-scale bioreactor production of the herbicide-degrading Aminobacter sp. strain MSH1

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Knudsen, Berith Elkær; Frkova, Zuzana

    2014-01-01

    The Aminobacter sp. strain MSH1 has potential for pesticide bioremediation because it degrades the herbicide metabolite 2,6-dichlorobenzamide (BAM). Production of the BAM-degrading bacterium using aerobic bioreactor fermentation was investigated. A mineral salt medium limited for carbon and with ......The Aminobacter sp. strain MSH1 has potential for pesticide bioremediation because it degrades the herbicide metabolite 2,6-dichlorobenzamide (BAM). Production of the BAM-degrading bacterium using aerobic bioreactor fermentation was investigated. A mineral salt medium limited for carbon...... and with an element composition similar to the strain was generated. The optimal pH and temperature for strain growth were determined using shaker flasks and verified in bioreactors. Glucose, fructose, and glycerol were suitable carbon sources for MSH1 (μ =0.1 h−1); slower growth was observed on succinate and acetic...... acid (μ =0.01 h−1). Standard conditions for growth of theMSH1 strain were defined at pH 7 and 25 °C, with glucose as the carbon source. In bioreactors (1 and 5 L), the specific growth rate of MSH1 increased from μ =0.1 h−1 on traditional mineral salt medium to μ =0.18 h−1 on the optimized mineral salt...

  3. Control of an air pressure actuated disposable bioreactor for cultivating heart valves

    NARCIS (Netherlands)

    Beelen, M.J.; Neerincx, P.E.; Molengraft, van de M.J.G.

    2011-01-01

    A disposable injection molded bioreactor for growing tissue-engineered heart valves is controlled to mimic the physiological heart cycle. Tissue-engineered heart valves, cultured from human stem cells, are a possible alternative for replacing failing aortic heart valves, where nowadays biological

  4. Investigation of microbial adaptation to salinity variation for treatment of reverse osmosis concentrate by membrane bioreactor

    DEFF Research Database (Denmark)

    Jang, Duksoo; Moon, Chungman; Ahn, Kyuhong

    2014-01-01

    quantitative study on a microbial adaptation strategy for variations on salt concentration (0–20 g/L), lab-scale membrane bioreactors (7L working volume) with polypropylene hollow fiber membrane module (pore size 0.4 μm) were used with different adaptation strategies: instant and stepwise mode. The performance...

  5. Effects of chemical sludge disintegration on the performances of wastewater treatment by membrane bioreactor.

    Science.gov (United States)

    Oh, Young-Khee; Lee, Ki-Ryong; Ko, Kwang-Baik; Yeom, Ick-Tae

    2007-06-01

    A new wastewater treatment process combining a membrane bioreactor (MBR) with chemical sludge disintegration was tested in bench scale experiments. In particular, the effects of the disintegration treatment on the excess sludge production in MBR were investigated. Two MBRs were operated. In one reactor, a part of the mixed liquor was treated with NaOH and ozone gas consecutively and was returned to the bioreactor. The flow rate of the sludge disintegration stream was 1.5% of the influent flow rate. During the 200 days of operation, the MLSS level in the bioreactor with the disintegration treatment was maintained relatively constant at the range of 10,000-11,000 mg/L while it increased steadily up to 25,000 mg/L in the absence of the treatment. In the MBR with the sludge disintegration, relatively constant transmembrane pressures (TMPs) could be maintained for more than 6 months while the MBR without disintegration showed an abrupt increase of TMP in the later phase of the operation. In conclusion, a complete control of excess sludge production in the membrane-coupled bioreactor was possible without significant deterioration of the treated water quality and membrane performances.

  6. Molecular assessment of complex microbial communities degrading long chain fatty acids (LCFA) in methanogenic bioreactors

    NARCIS (Netherlands)

    Sousa, D.Z.; Pereira, M.A.; Smidt, H.; Stams, A.J.M.; Alves, M.M.

    2007-01-01

    Microbial diversity of anaerobic sludge after extended contact with long chain fatty acids (LCFA) was studied using molecular approaches. Samples containing high amounts of accumulated LCFA were obtained after continuous loading of two bioreactors with oleate or with palmitate. These sludge samples

  7. Treatment of industrial wastewaters by anaerobic membrane bioreactors : Implications of substrate characteristics

    NARCIS (Netherlands)

    Dereli, R.K.

    2015-01-01

    The success of anaerobic digestion relies on the presence of highly active methanogenic biomass, requiring effective retention of slow growing anaerobic microorganisms inside bioreactor by decoupling the hydraulic retention time (HRT) from solids residence time (SRT) or the employment of long SRTs

  8. MTBE BIODEGRADATION IN A GRAVITY FLOW, HIGH-BIOMASS RETAINING BIOREACTOR

    Science.gov (United States)

    The aerobic biodegradation of methyl tert-butyl ether (MtBE), a widely used fuel oxygenate, was investigated using a pilot-scale biomass-retaining bioreactor called a Biomass Concentrator Reactor (BCR). The reactor was operated for a year at a flow rate of 2500 L/d on Ci...

  9. Removal of Cr, Mn, and Co from textile wastewater by horizontal rotating tubular bioreactor.

    Science.gov (United States)

    Zeiner, Michaela; Rezić, Tonci; Santek, Bozidar; Rezić, Iva; Hann, Stephan; Stingeder, Gerhard

    2012-10-02

    Environmental pollution by industrial wastewaters polluted with toxic heavy metals is of great concern. Various guidelines regulate the quality of water released from industrial plants and of surface waters. In wastewater treatment, bioreactors with microbial biofilms are widely used. A horizontal rotating tubular bioreactor (HRTB) is a combination of a thin layer and a biodisc reactor with an interior divided by O-ring shaped partition walls as carriers for microbial biomass. Using a biofilm of heavy metal resistant bacteria in combination with this special design provides various advantages for wastewater treatment proven in a pilot study. In the presented study, the applicability of HRTB for removing metals commonly present in textile wastewaters (chromium, manganese, cobalt) was investigated. Artificial wastewaters with a load of 125 mg/L of each metal underwent the bioreactor treatment. Different process parameters (inflow rate, rotation speed) were applied for optimizing the removal efficiency. Samples were drawn along the bioreactor length for monitoring the metal contents on site by UV-vis spectrometry. The metal uptake of the biomass was determined by ICP-MS after acidic microwave assisted digestion. The maximum removal rates obtained for chromium, manganese, and cobalt were: 100%, 94%, and 69%, respectively.

  10. Characterization of the size-fractionated biomacromolecules: Tracking their role and fate in a membrane bioreactor

    DEFF Research Database (Denmark)

    Meng, Fangang; Zhou, Zhongbo; Ni, Bing-Jie

    2011-01-01

    and nuclear magnetic resonance (NMR) measurements were used to characterize BMM in a membrane bioreactor (MBR) from a chemical perspective. Overall, the BMM in sludge supernatant were mainly present in three fractions: colloidal BMM (BMMc, >0.45 μm), biopolymeric BMM (BMMb, 0.45 μm–100 kDa) and low molecular...

  11. Lipase-supported metal-organic framework bioreactor catalyzes warfarin synthesis.

    Science.gov (United States)

    Liu, Wan-Ling; Yang, Ni-Shin; Chen, Ya-Ting; Lirio, Stephen; Wu, Cheng-You; Lin, Chia-Her; Huang, Hsi-Ya

    2015-01-02

    A green and sustainable strategy synthesizes clinical medicine warfarin anticoagulant by using lipase-supported metal-organic framework (MOF) bioreactors (see scheme). These findings may be beneficial for future studies in the industrial production of chemical, pharmaceutical, and agrochemical precursors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Characterization and Application of a Disposable Rotating Bed Bioreactor for Mesenchymal Stem Cell Expansion

    Directory of Open Access Journals (Sweden)

    Anne Neumann

    2014-11-01

    Full Text Available Recruitment of mesenchymal stromal cells (MSC into the field of tissue engineering is a promising development since these cells can be expanded vivo to clinically relevant numbers and, after expansion, retain their ability to differentiate into various cell lineages. Safety requirements and the necessity to obtain high cell numbers without frequent subcultivation of cells raised the question of the possibility of expanding MSC in one-way (single-use disposable bioreactors. In this study, umbilical cord-derived MSC (UC-MSC were expanded in a disposable Z 2000 H bioreactor under dynamic conditions. Z was characterized regarding residence time and mixing in order to evaluate the optimal bioreactor settings, enabling optimal mass transfer in the absence of shear stress, allowing an reproducible expansion of MSC, while maintaining their stemness properties. Culture of the UC-MSC in disposable Z 2000 H bioreactor resulted in a reproducible 8-fold increase of cell numbers after 5 days. Cells were shown to maintain specific MSC surface marker expression as well as trilineage differentiation potential and lack stress-induced premature senescence.

  13. Characterization and Application of a Disposable Rotating Bed Bioreactor for Mesenchymal Stem Cell Expansion.

    Science.gov (United States)

    Neumann, Anne; Lavrentieva, Antonina; Heilkenbrinker, Alexandra; Loenne, Maren; Kasper, Cornelia

    2014-11-27

    Recruitment of mesenchymal stromal cells (MSC) into the field of tissue engineering is a promising development since these cells can be expanded vivo to clinically relevant numbers and, after expansion, retain their ability to differentiate into various cell lineages. Safety requirements and the necessity to obtain high cell numbers without frequent subcultivation of cells raised the question of the possibility of expanding MSC in one-way (single-use) disposable bioreactors. In this study, umbilical cord-derived MSC (UC-MSC) were expanded in a disposable Z 2000 H bioreactor under dynamic conditions. Z was characterized regarding residence time and mixing in order to evaluate the optimal bioreactor settings, enabling optimal mass transfer in the absence of shear stress, allowing an reproducible expansion of MSC, while maintaining their stemness properties. Culture of the UC-MSC in disposable Z 2000 H bioreactor resulted in a reproducible 8-fold increase of cell numbers after 5 days. Cells were shown to maintain specific MSC surface marker expression as well as trilineage differentiation potential and lack stress-induced premature senescence.

  14. Application of a stir-tank bioreactor for perfusion culture and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-18

    Jan 18, 2010 ... The bioreactor we used could be an efficient cell culture system and demonstrates industrial potential. ... overcoming the harmful effects of browning have no conclusive .... solvent under reduced pressure, the ethanol extract liquids was re- ... was detected in the exhaust medium with a perfusion rate of more ...

  15. Bioreactor cultivation enhances NTEB formation and differentiation of NTES cells into cardiomyocytes.

    Science.gov (United States)

    Lü, Shuanghong; Liu, Sheng; He, Wenjun; Duan, Cuimi; Li, Yanmin; Liu, Zhiqiang; Zhang, Ye; Hao, Tong; Wang, Yanmeng; Li, Dexue; Wang, Changyong; Gao, Shaorong

    2008-09-01

    Autogenic embryonic stem cells established from somatic cell nuclear transfer (SCNT) embryos have been proposed as unlimited cell sources for cell transplantation-based treatment of many genetic and degenerative diseases, which can eliminate the immune rejection that occurs after transplantation. In the present study, pluripotent nuclear transfer ES (NTES) cell lines were successfully established from different strains of mice. One NTES cell line, NT1, with capacity of germline transmission, was used to investigate in vitro differentiation into cardiomyocytes. To optimize differentiation conditions for mass production of embryoid bodies (NTEBs) from NTES cells, a slow-turning lateral vessel (STLV) rotating bioreactor was used for culturing the NTES cells to produce NTEBs compared with a conventional static cultivation method. Our results demonstrated that the NTEBs formed in STLV bioreactor were more uniform in size, and no large necrotic centers with most of the cells in NTEBs were viable. Differentiation of the NTEBs formed in both the STLV bioreactor and static culture into cardiomyocytes was induced by ascorbic acid, and the results demonstrated that STLV-produced NTEBs differentiated into cardiomyocytes more efficiently. Taken together, our results suggested that STLV bioreactor provided a more ideal culture condition, which can facilitate the formation of better quality NTEBs and differentiation into cardiomyocytes more efficiently in vitro.

  16. Mechanisms and Effectivity of Sulfate Reducing Bioreactors Using a Chitinous Substrate in Treating Mining Influenced Water

    Science.gov (United States)

    Mining-influenced water (MIW) is the main environmental challenge associated with the mining industry. Passive MIW remediation can be achieved through microbial activity in sulfate-reducing bioreactors (SRBRs), but their actual removal rates depend on different factors, one of wh...

  17. CONSTRUCTION OF MODULAR FIELD-BIOREACTOR FOR ACID MINE DRAINAGE TREATMENT

    Science.gov (United States)

    The paper focuses on the improvements to engineered features of a passive technology that has been used for remediation of acid rock drainage (ARD). This passive remedial technology, a sulfate-reducing bacteria (SRB) bioreactor, takes advantage of the ability of SRB that, if sup...

  18. Bio-layer management in anaerobic membrane bioreactors for wastewater treatment

    NARCIS (Netherlands)

    Jeison, D.; Lier, van J.B.

    2006-01-01

    Membrane separation technology represents an alternative way to achieve biomass retention in anaerobic bioreactors for wastewater treatment. Due to high biomass concentrations of anaerobic reactors, cake formation is likely to represent a major cause of flux decline. In the presented research,

  19. Antioxidant compounds in Salvia officinalis L. shoot and hairy root cultures in the nutrient sprinkle bioreactor

    Directory of Open Access Journals (Sweden)

    Izabela Grzegorczyk

    2011-01-01

    Full Text Available The study focused on the production of compounds with antioxidant activity in hairy root and shoot cultures of Salvia officinalis grown in laboratory-scale sprinkle nutrient bioreactors. HPLC analysis showed that production of rosmarinic acid in transformed roots (34.65 ±1.07 mg l-1 was higher that in shoot culture (26.24 ±0.48 mg l-1. In the latter diterpenoids: carnosic acid (1.74 ±0.02 mg l-1 and carnosol (1.34 ±0.01 mg l-1 were also found. Biomass accumulation after a growth period in the bioreactor was also studied. An 18-fold increase in hairy root biomass was recorded after 40 days of culture. In sage shoot culture, biomass increased 43 times after 21 days of bioreactor run. The current operating conditions of the bioreactor were not suitable for the propagation of Salvia officinalis mainly due to the hyperhydricity problem of leaves and stems.

  20. Role of Bioreactor Technology in Tissue Engineering for Clinical Use and Therapeutic Target Design

    Directory of Open Access Journals (Sweden)

    Clare Selden

    2018-04-01

    Full Text Available Micro and small bioreactors are well described for use in bioprocess development in pre-production manufacture, using ultra-scale down and microfluidic methodology. However, the use of bioreactors to understand normal and pathophysiology by definition must be very different, and the constraints of the physiological environment influence such bioreactor design. This review considers the key elements necessary to enable bioreactors to address three main areas associated with biological systems. All entail recreation of the in vivo cell niche as faithfully as possible, so that they may be used to study molecular and cellular changes in normal physiology, with a view to creating tissue-engineered grafts for clinical use; understanding the pathophysiology of disease at the molecular level; defining possible therapeutic targets; and enabling appropriate pharmaceutical testing on a truly representative organoid, thus enabling better drug design, and simultaneously creating the potential to reduce the numbers of animals in research. The premise explored is that not only cellular signalling cues, but also mechano-transduction from mechanical cues, play an important role.

  1. COMPOST-FREE BIOREACTOR TREATMENT OF ACID ROCK DRAINAGE LEVIATHAN MINE, CALIFORNIA INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    As part of the Superfund Innovative Technology Evaluation (SITE) program, an evaluation of the compost-free bioreactor treatment of acid rock drainage (ARD) from the Aspen Seep was conducted at the Leviathan Mine Superfund site located in a remote, high altitude area of Alpine Co...

  2. COMPOST-FREE BIOREACTOR TREATMENT OF ACID ROCK DRAINAGE - TECHNOLOGY CAPSULE

    Science.gov (United States)

    As part of the Superfund Innovative Technology Evaluation (SITE) program, an evaluation of the compost-free bioreactor treatment of acid rock drainage (ARD) from the Aspen Seep was conducted at the Leviathan Mine Superfund site located in a remote, high altitude area of Alpine Co...

  3. Operational experience with a seasonally operated full-scale membrane bioreactor plant

    Czech Academy of Sciences Publication Activity Database

    Gómez, M.; Dvořák, L.; Růžičková, I.; Holba, Marek; Wanner, J.

    2012-01-01

    Roč. 121, OCT 2012 (2012), s. 241-247 ISSN 0960-8524 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : full-scale membrane bioreactor * soluble microbibal products * nutrient removal * fouling * microbiological effluent quality Subject RIV: EF - Botanics Impact factor: 4.750, year: 2012

  4. Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater

    International Nuclear Information System (INIS)

    Khondee, Nichakorn; Tathong, Sitti; Pinyakong, Onruthai; Powtongsook, Sorawit; Chatchupong, Thawach; Ruangchainikom, Chalermchai; Luepromchai, Ekawan

    2012-01-01

    Highlights: ► Sphingobium sp. P2 effectively degraded various lubricant samples. ► Efficiency of Sphingobium sp. P2 increased after immobilization on chitosan. ► High removal efficiency was due to both sorption and degradation processes. ► The immobilized bacteria (4 g L −1 ) were applied in internal loop airlift bioreactor. ► The bioreactor continuously removed lubricant from emulsified wastewater. - Abstract: An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80–90% of the 200 mg L −1 total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4 g L −1 immobilized bacteria, was later designed and operated at 2.0 h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85 ± 5% TPH and 73 ± 11% chemical oxygen demand (COD) from the carwash wastewater with 25–200 mg L −1 amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries.

  5. Degradation of triclosan and triclocarban and formation of transformation products in activated sludge using benchtop bioreactors

    Science.gov (United States)

    Benchtop bioreactors were run aerobically with activated sludge samples collected from a large municipal wastewater treatment plant (WWTP) to understand how increased hydraulic retention time (HRT) and varying treatment temperatures (21°C and 30°C) impact concentrations of the endocrine disrupting a...

  6. Modeling and design of optimal flow perfusion bioreactors for tissue engineering applications.

    Science.gov (United States)

    Hidalgo-Bastida, L Araida; Thirunavukkarasu, Sundaramoorthy; Griffiths, Sarah; Cartmell, Sarah H; Naire, Shailesh

    2012-04-01

    Perfusion bioreactors have been used in different tissue engineering applications because of their consistent distribution of nutrients and flow-induced shear stress within the tissue-engineering scaffold. A widely used configuration uses a scaffold with a circular cross-section enclosed within a cylindrical chamber and inlet and outlet pipes which are connected to the chamber on either side through which media is continuously circulated. However, fluid-flow experiments and simulations have shown that the majority of the flow perfuses through the center. This pattern creates stagnant zones in the peripheral regions as well as in those of high flow rate near the inlet and outlet. This non-uniformity of flow and shear stress, owing to a circular design, results in limited cell proliferation and differentiation in these areas. The focus of this communication is to design an optimized perfusion system using computational fluid dynamics as a mathematical tool to overcome the time-consuming trial and error experimental method. We compared the flow within a circular and a rectangular bioreactor system. Flow simulations within the rectangular bioreactor are shown to overcome the limitations in the circular design. This communication challenges the circular cross-section bioreactor configuration paradigm and provides proof of the advantages of the new design over the existing one. Copyright © 2011 Wiley Periodicals, Inc.

  7. Plastic carrier polishing chamber reduces pollution swapping from denitrifying woodchip bioreactors

    Science.gov (United States)

    Denitrifying bioreactors with solid organic carbon sources (i.e., “woodchip bioreactors”) have proven to be relatively simple and cost effective treatment systems for nitrate-laden agricultural and aquacultural waters and wastewaters. However, because this technology is still relatively new, design ...

  8. Plastic biofilm carrier after corn cobs reduces nitrate loading in laboratory denitrifying bioreactors

    Science.gov (United States)

    Nitrate-nitrogen removal rates can be increased substantially in denitrifying bioreactors with a corn cob bed medium compared to woodchips; however, additional organic carbon (C) is released into the effluent. This laboratory column experiment was conducted to test the performance of a post-bed cha...

  9. Bioreactors based on immobilized fungi: bioremediation under non-sterile conditions

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Kateřina; Novotný, Čeněk

    2018-01-01

    Roč. 102, č. 1 (2018), s. 39-46 ISSN 0175-7598 Institutional support: RVO:61388971 Keywords : Waste effluents * Bioremediation * White-rot fungal bioreactors Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.420, year: 2016

  10. Kinetic model for an up-flow anaerobic packed bed bioreactor: Dairy ...

    African Journals Online (AJOL)

    Kinetic studies of anaerobic digestion process of cheese whey were conducted in a pilot-scale up-flow anaerobic packed bed bioreactor (UAPB). An influent COD concentration of 59419 mg/l was utilized at steady state condition. Logistic and Monod kinetic models were employed to describe microbial activities of cheese ...

  11. Manufacturing recombinant proteins in kg-ton quantities using animal cells in bioreactors.

    Science.gov (United States)

    De Jesus, Maria; Wurm, Florian M

    2011-06-01

    Mammalian cells in bioreactors as production host are the focus of this review. We wish to briefly describe today's technical status and to highlight emerging trends in the manufacture of recombinant therapeutic proteins, focusing on Chinese hamster ovary (CHO) cells. CHO cells are the manufacturing host system of choice for more than 70% of protein pharmaceuticals on the market [21]. The current global capacity to grow mammalian cells in bioreactors stands at about 0.5 million liters, whereby the largest vessels can have a working volume of about 20,000l. We are focusing in this article on the upstream part of protein manufacturing. Over the past 25 years, volumetric yields for recombinant cell lines have increased about 20-fold mainly as the result of improvements in media and bioprocess design. Future yield increases are expected to come from improved gene delivery methods, from improved, possibly genetically modified host systems, and from further improved bioprocesses in bioreactors. Other emerging trends in protein manufacturing that are discussed include the use of disposal bioreactors and transient gene expression. We specifically highlight here current research in our own laboratories. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Comparison of spectroscopy technologies for improved monitoring of cell culture processes in miniature bioreactors

    DEFF Research Database (Denmark)

    Rowland-Jones, Ruth C.; van der Berg, Franciscus Winfried J; Racher, Andrew J.

    2017-01-01

    Cell culture process development requires the screening of large numbers of cell lines and process conditions. The development of miniature bioreactor systems has increased the throughput of such studies; however, there are limitations with their use. One important constraint is the limited numbe...

  13. An integrated membrane bioreactor - nanofiltration concept with concentrate recirculation for wastewater treatment and nutrient recovery

    NARCIS (Netherlands)

    Kappel, C.

    2014-01-01

    Increasing water shortages drive the need for water reuse. Membranes are a very suitable technology for purification of wastewater. Membrane bioreactor (MBR) permeate can be polished by nanofiltration (NF), allowing the production of high quality reusable water. The NF concentrate potentially is an

  14. Membrane filtration device for studying compression of fouling layers in membrane bioreactors.

    Directory of Open Access Journals (Sweden)

    Mads Koustrup Jørgensen

    Full Text Available A filtration devise was developed to assess compressibility of fouling layers in membrane bioreactors. The system consists of a flat sheet membrane with air scouring operated at constant transmembrane pressure to assess the influence of pressure on resistance of fouling layers. By fitting a mathematical model, three model parameters were obtained; a back transport parameter describing the kinetics of fouling layer formation, a specific fouling layer resistance, and a compressibility parameter. This stands out from other on-site filterability tests as model parameters to simulate filtration performance are obtained together with a characterization of compressibility. Tests on membrane bioreactor sludge showed high reproducibility. The methodology's ability to assess compressibility was tested by filtrations of sludges from membrane bioreactors and conventional activated sludge wastewater treatment plants from three different sites. These proved that membrane bioreactor sludge showed higher compressibility than conventional activated sludge. In addition, detailed information on the underlying mechanisms of the difference in fouling propensity were obtained, as conventional activated sludge showed slower fouling formation, lower specific resistance and lower compressibility of fouling layers, which is explained by a higher degree of flocculation.

  15. Anaerobic and aerobic slurry bioreactors for remediation of a heavy soil contaminated with lindane

    International Nuclear Information System (INIS)

    Robles-Gonzalez, I. V.; Rios-Leal, E.; Galindez-Mayer, J.; Sastre-conde, I.; Poggi-Varaldo, H. M.

    2009-01-01

    Slurry bioreactors (SB) can be used for bioremediation of polluted heavy soils such as those characterized by high contents of clay and organic matter, when the contaminants are recalcitrant, toxic, and display hysteretic behaviour, and/or when bioremediation should be accomplished in short times under the pressure and monitoring of environmental agencies and regulators. (Author)

  16. Microbial population analysis of nutrient removal-related organisms in membrane bioreactors

    NARCIS (Netherlands)

    Silva, A.F.; Carvalho, G.; Oehmen, A.; Lousada-Ferreira, M.; Van Nieuwenhuijzen, A.; Reis, M.A.M.; Crespo, M.T.B.

    2012-01-01

    Membrane bioreactors (MBR) are an important and increasingly implemented wastewater treatment technology, which are operated at low food to microorganism ratios (F/M) and retain slow-growing organisms. Enhanced biological phosphorus removal (EBPR)-related organisms grow slower than ordinary

  17. Permitting of Landfill Bioreactor Operations: Ten Years after the RD&D Rule

    Science.gov (United States)

    Prior to promulgation of the Rule, there were approximately 20 full-scale bioreactor projects in North America, including one in Canada. Of these, six were permitted by EPA (four Project XL sites and two projects listed separately under a cooperative research agreement at the Ou...

  18. Membrane modification to avoid wettability changes due to protein adsorption in an emulsion/membrane bioreactor.

    NARCIS (Netherlands)

    Schroen, C.G.P.H.; Wijers, M.C.; Cohen Stuart, M.A.; Padt, van der A.; Riet, van 't K.

    1993-01-01

    This study addresses problems encountered with an emulsion/membrane bioreactor. In this reactor, enzyme- (lipase) catalyzed hydrolysis in an emulsion was combined with two in-line separation steps. One is carried out with a hydrophilic membrane, to separate the water phase, the other with a

  19. Draft Genome Sequence of a Novel Desulfobacteraceae Member from a Sulfate-Reducing Bioreactor Metagenome

    OpenAIRE

    Almstrand, Robert; Pinto, Ameet J.; Figueroa, Linda A.; Sharp, Jonathan O.

    2016-01-01

    Sulfate-reducing bacteria are important players in the global sulfur cycle and of considerable commercial interest. The draft genome sequence of a sulfate-reducing bacterium of the family Desulfobacteraceae, assembled from a sulfate-reducing bioreactor metagenome, indicates that heavy-metal? and acid-resistance traits of this organism may be of importance for its application in acid mine drainage mitigation.

  20. Monitoring of Leachate Recirculation in a Bioreactor Using Electrical Resistivity

    Science.gov (United States)

    Grellier, S.; Bureau, N.; Robain, H.; Tabbagh, A.; Camerlynck, C.; Guerin, R.

    2004-05-01

    The bioreactor is a concept of waste landfill management consisting in speeding up the biodegradation by optimizing the moisture content through leachate recirculation. Electrical resistivity tomography (ERT) is carried out with fast resistivity-meter (Syscal Pro, IRIS Instruments, developed in the framework of the research project CERBERE 01V0665-69, funded by the French Research Ministry) to monitor leachate recirculation. During a recirculation period waste moisture increases, so that electrical resistivity may decrease, but at the same time temperature and mineralization of both waste and leachate become intermixed. If waste temperature is much higher than leachate temperature electrical resistivity will not decrease as much as if the temperature difference was smaller. If leachate mineralization (i.e. leachate conductivity) is higher than that of wet waste in the landfill, electrical resistivity will tend to decrease. Otherwise for example after an addition of rain water into the leachate storage or in case of very wet waste, the resistivities of each medium (leachate and wet waste) can be almost the same, so that leachate mineralization will not have a great influence on waste resistivity. Resistivity measurements were performed during 85 minutes injection trials (with a discharge of 20 m3 h-1) where leachate was injected through a vertical borehole perforated between 1.85 and 4.15 m. Three first measurements are made during the injection (3, 30 and 60 minutes from the beginning of the injection) and the two other after the injection period (8 and 72 minutes after the end of the injection). Apparent and interpreted resistivity variations that occurred during injection trials, expressed as the relative differences (in %) between apparent, respectively interpreted, resistivity during injection and apparent, respectively interpreted, resistivity before injection (reference measurement) show the formation of a plume (a negative anomaly: resistivity decreases with

  1. Optimal operating conditions for maximum biogas production in anaerobic bioreactors

    International Nuclear Information System (INIS)

    Balmant, W.; Oliveira, B.H.; Mitchell, D.A.; Vargas, J.V.C.; Ordonez, J.C.

    2014-01-01

    The objective of this paper is to demonstrate the existence of optimal residence time and substrate inlet mass flow rate for maximum methane production through numerical simulations performed with a general transient mathematical model of an anaerobic biodigester introduced in this study. It is herein suggested a simplified model with only the most important reaction steps which are carried out by a single type of microorganisms following Monod kinetics. The mathematical model was developed for a well mixed reactor (CSTR – Continuous Stirred-Tank Reactor), considering three main reaction steps: acidogenesis, with a μ max of 8.64 day −1 and a K S of 250 mg/L, acetogenesis, with a μ max of 2.64 day −1 and a K S of 32 mg/L, and methanogenesis, with a μ max of 1.392 day −1 and a K S of 100 mg/L. The yield coefficients were 0.1-g-dry-cells/g-pollymeric compound for acidogenesis, 0.1-g-dry-cells/g-propionic acid and 0.1-g-dry-cells/g-butyric acid for acetogenesis and 0.1 g-dry-cells/g-acetic acid for methanogenesis. The model describes both the transient and the steady-state regime for several different biodigester design and operating conditions. After model experimental validation, a parametric analysis was performed. It was found that biogas production is strongly dependent on the input polymeric substrate and fermentable monomer concentrations, but fairly independent of the input propionic, acetic and butyric acid concentrations. An optimisation study was then conducted and optimal residence time and substrate inlet mass flow rate were found for maximum methane production. The optima found were very sharp, showing a sudden drop of methane mass flow rate variation from the observed maximum to zero, within a 20% range around the optimal operating parameters, which stresses the importance of their identification, no matter how complex the actual bioreactor design may be. The model is therefore expected to be a useful tool for simulation, design, control and

  2. Optimal neutral beam heating scenario for FED

    International Nuclear Information System (INIS)

    Hively, L.M.; Houlberg, W.A.; Attenberger, S.E.

    1981-01-01

    Optimal neutral beam heating scenarios are determined for FED based on a 1/one-half/-D transport analysis. Tradeoffs are examined between neutral beam energy, power, and species mix for positive ion systems. A ramped density startup is found to provide the most economical heating. The resulting plasma power requirements are reduced by 10-30% from a constant density startup. For beam energies between 100 and 200 keV, the power needed to heat the plasma does not decrease significantly as beam energy is increased. This is due to reduced ion heating, more power in the fractional energy components, and rising power supply requirements as beam energy increases

  3. Supervision of Fed-Batch Fermentations

    DEFF Research Database (Denmark)

    Gregersen, Lars; Jørgensen, Sten Bay

    1999-01-01

    Process faults may be detected on-line using existing measurements based upon modelling that is entirely data driven. A multivariate statistical model is developed and used for fault diagnosis of an industrial fed-batch fermentation process. Data from several (25) batches are used to develop...... a model for cultivation behaviour. This model is validated against 13 data sets and demonstrated to explain a significant amount of variation in the data. The multivariate model may directly be used for process monitoring. With this method faults are detected in real time and the responsible measurements...

  4. Exocrine pancreatic secretion is stimulated in piglets fed Fish oil compared with those fed Coconut Oil or Lard

    DEFF Research Database (Denmark)

    Hedemann, Mette Skou; Pedersen, Asger Roer; Engberg, Ricarda M.

    2001-01-01

    An experiment was conducted to study the effect of feeding diets containing fat sources with different fatty acid composition (fish oil, coconut oil or lard, 10 g/100 g diet) on exocrine pancreatic secretion in piglets after weaning. A total of 16 barrows were weaned at 4 wk of age; 3 d later...... the coconut oil or lard diets. The output [U/(h. kg(0.75))] of lipase was higher in piglets fed fish oil than in piglets fed lard or coconut oil. The output of colipase was greater in piglets fed fish oil and coconut oil than in those fed lard. The dietary treatments did not affect the output of carboxylester...... hydrolase. The output of trypsin was significantly lower in piglets fed lard than in piglets fed fish oil or coconut oil diets and the output of carboxypeptidase B was greater in those fed the fish oil diet. Protein, chymotrypsin, carboxypeptidase A, elastase and amylase outputs did not differ among...

  5. PENGURANGAN KADAR CO2 MENGGUNAKAN SPIRULINA PLATENSIS DALAM TUBULAR BIOREACTOR

    Directory of Open Access Journals (Sweden)

    Zainal Syam Arifin

    2015-06-01

    Full Text Available Increasing the population impact on increasing energy demand. On the other hand, the energy generation industry has been blamed as one of the contributors of carbon dioxide about 25% of total CO2 emissions worldwide. Meanwhile, the production of biogas, which aims to address the increasing need of energy, produces carbon dioxide in the range of 25–50% by volume. To overcome this, a cheap method, optimum and efficient as well as environmentally friendly in reducing CO2 levels by using Spirulina platensis is needed. This research aims to created a mathematical models and found the optimum flow rate to reduced levels of CO2 by using Spirulina platensis. This study used a glass tubular bioreactor (D = 2.6 cm at a temperature of 30°C and irradiated with a fluorescent lamp Philips TL 36 Watt, color temperature: 6,200K cool daylight, light output: 2,600 lm, 72 lm/W. Tubular reactor was placed in a box lined with silver foil walls on three sides. With mathematical models of tubular reactor, the reaction rate constants could be predicted. Based on calculations of data and graphs, optimum volumetric velocity could also be predicted. Variation of flowrate to observed the reduction rate of CO2 was 0.25 mL/sec, 0.35 mL/sec, 0.5 mL/sec, 0.75 mL/sec, 1 mL/sec. Carbon source was 99.99% CO2.Observations of Spirulina growth was made on the flow rate of 0.25 mL/sec at the initial levels of dry weight 2.1208 g/L. The results of this study indicated that the low flowratewas a more effective way to reduced carbon dioxide levels using Spirulina platensis (= 2.82×10-4 sec-1. The highest conversion was obtained at a volumetric flow rate of 0.25 mL/sec and optimum speeds in the range of 0.3 to 0.4 mL/sec. The rate of incoming CO2 flux should be less than 0.047 mL/cm2.detik. Specific Growth Rate (µ of Spirulina platensis in this study was 2.56×10-2 minute-1.   Keywords: Spirulina platensis, a vertical tubular bioreactor, CO2 reduction     ABSTRAK

  6. Applicability of a novel osmotic membrane bioreactor using a specific draw solution in wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Nguyen Cong [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC (China); Chen, Shiao-Shing, E-mail: f10919@ntut.edu.tw [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC (China); Nguyen, Hau Thi [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC (China); Ngo, Huu Hao, E-mail: h.ngo@uts.edu.au [School of Civil and Environmental Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Broadway, NSW 2007 (Australia); Guo, Wenshan [School of Civil and Environmental Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Broadway, NSW 2007 (Australia); Hao, Chan Wen [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC (China); Lin, Po-Hsun [New Materials Research and Development Dept., China Steel Corporation, Taiwan, ROC (China)

    2015-06-15

    This study aims to develop a new osmotic membrane bioreactor by combining a moving bed biofilm reactor (MBBR) with forward osmosis membrane bioreactor (FOMBR) to treat wastewater. Ethylenediaminetetraacetic acid disodium salt coupled with polyethylene glycol tert-octylphenyl ether was used as an innovative draw solution in this membrane hybrid system (MBBR–OsMBR) for minimizing the reverse salt flux and maintaining a healthy environment for the microorganism community. The results showed that the hybrid system achieved a stable water flux of 6.94 L/m{sup 2} h and low salt accumulation in the bioreactor for 68 days of operation. At a filling rate of 40% (by volume of the bioreactor) of the polyethylene balls used as carriers, NH{sub 4}{sup +}-N and PO{sub 4}{sup 3−}-P were almost removed (> 99%) while producing relatively low NO{sub 3}{sup −}-N and NO{sub 2}{sup −}-N in the effluent (e.g. < 0.56 and 0.96 mg/L, respectively). Furthermore, from analysis based on scanning electron microscopy, Fourier transform infrared spectroscopy, and fluorescence emission–excitation matrix spectrophotometry, there was a thin gel-like fouling layer on the FO membrane, which composed of bacteria as well as biopolymers and protein-like substances. Nonetheless, the formation of these fouling layers of the FO membrane in MBBR–OsMBR was reversible and removed by a physical cleaning technique. - Highlights: • A novel osmotic membrane bioreactor (MBBR–OsMBR) using a novel draw solution (DS) was developed. • The MBBR–OsMBR system successfully reduced membrane fouling. • EDTA sodium coupled with Triton X-100 as novel DS resulted in low salt accumulation. • Nitrification and denitrification were well performed in a biocarrier. • The MBBR–OsMBR could remarkably remove phosphorus.

  7. Applicability of a novel osmotic membrane bioreactor using a specific draw solution in wastewater treatment

    International Nuclear Information System (INIS)

    Nguyen, Nguyen Cong; Chen, Shiao-Shing; Nguyen, Hau Thi; Ngo, Huu Hao; Guo, Wenshan; Hao, Chan Wen; Lin, Po-Hsun

    2015-01-01

    This study aims to develop a new osmotic membrane bioreactor by combining a moving bed biofilm reactor (MBBR) with forward osmosis membrane bioreactor (FOMBR) to treat wastewater. Ethylenediaminetetraacetic acid disodium salt coupled with polyethylene glycol tert-octylphenyl ether was used as an innovative draw solution in this membrane hybrid system (MBBR–OsMBR) for minimizing the reverse salt flux and maintaining a healthy environment for the microorganism community. The results showed that the hybrid system achieved a stable water flux of 6.94 L/m 2 h and low salt accumulation in the bioreactor for 68 days of operation. At a filling rate of 40% (by volume of the bioreactor) of the polyethylene balls used as carriers, NH 4 + -N and PO 4 3− -P were almost removed (> 99%) while producing relatively low NO 3 − -N and NO 2 − -N in the effluent (e.g. < 0.56 and 0.96 mg/L, respectively). Furthermore, from analysis based on scanning electron microscopy, Fourier transform infrared spectroscopy, and fluorescence emission–excitation matrix spectrophotometry, there was a thin gel-like fouling layer on the FO membrane, which composed of bacteria as well as biopolymers and protein-like substances. Nonetheless, the formation of these fouling layers of the FO membrane in MBBR–OsMBR was reversible and removed by a physical cleaning technique. - Highlights: • A novel osmotic membrane bioreactor (MBBR–OsMBR) using a novel draw solution (DS) was developed. • The MBBR–OsMBR system successfully reduced membrane fouling. • EDTA sodium coupled with Triton X-100 as novel DS resulted in low salt accumulation. • Nitrification and denitrification were well performed in a biocarrier. • The MBBR–OsMBR could remarkably remove phosphorus

  8. Design considerations and challenges for mechanical stretch bioreactors in tissue engineering.

    Science.gov (United States)

    Lei, Ying; Ferdous, Zannatul

    2016-05-01

    With the increase in average life expectancy and growing aging population, lack of functional grafts for replacement surgeries has become a severe problem. Engineered tissues are a promising alternative to this problem because they can mimic the physiological function of the native tissues and be cultured on demand. Cyclic stretch is important for developing many engineered tissues such as hearts, heart valves, muscles, and bones. Thus a variety of stretch bioreactors and corresponding scaffolds have been designed and tested to study the underlying mechanism of tissue formation and to optimize the mechanical conditions applied to the engineered tissues. In this review, we look at various designs of stretch bioreactors and common scaffolds and offer insights for future improvements in tissue engineering applications. First, we summarize the requirements and common configuration of stretch bioreactors. Next, we present the features of different actuating and motion transforming systems and their applications. Since most bioreactors must measure detailed distributions of loads and deformations on engineered tissues, techniques with high accuracy, precision, and frequency have been developed. We also cover the key points in designing culture chambers, nutrition exchanging systems, and regimens used for specific tissues. Since scaffolds are essential for providing biophysical microenvironments for residing cells, we discuss materials and technologies used in fabricating scaffolds to mimic anisotropic native tissues, including decellularized tissues, hydrogels, biocompatible polymers, electrospinning, and 3D bioprinting techniques. Finally, we present the potential future directions for improving stretch bioreactors and scaffolds. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:543-553, 2016. © 2016 American Institute of Chemical Engineers.

  9. In Vivo-Like Culture Conditions in a Bioreactor Facilitate Improved Tissue Quality in Corneal Storage.

    Science.gov (United States)

    Schmid, Richard; Tarau, Ioana-Sandra; Rossi, Angela; Leonhardt, Stefan; Schwarz, Thomas; Schuerlein, Sebastian; Lotz, Christian; Hansmann, Jan

    2018-01-01

    The cornea is the most-transplanted tissue worldwide. However, the availability and quality of grafts are limited due to the current methods of corneal storage. In this study, a dynamic bioreactor system is employed to enable the control of intraocular pressure and the culture at the air-liquid interface. Thereby, in vivo-like storage conditions are achieved. Different media combinations for endothelium and epithelium are tested in standard and dynamic conditions to enhance the viability of the tissue. In contrast to culture conditions used in eye banks, the combination of the bioreactor and biochrom medium 1 allows to preserve the corneal endothelium and the epithelium. Assessment of transparency, swelling, and the trans-epithelial-electrical-resistance (TEER) strengthens the impact of the in vivo-like tissue culture. For example, compared to corneas stored under static conditions, significantly lower optical densities and significantly higher TEER values were measured (p-value <0.05). Furthermore, healing of epithelial defects is enabled in the bioreactor, characterized by re-epithelialization and initiated stromal regeneration. Based on the obtained results, an easy-to-use 3D-printed bioreactor composed of only two parts was derived to translate the technology from the laboratory to the eye banks. This optimized bioreactor facilitates noninvasive microscopic monitoring. The improved storage conditions ameliorate the quality of corneal grafts and the storage time in the eye banks to increase availability and reduce re-grafting. © 2017 The Authors. Biotechnology Journal Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  10. Increasing tetracycline concentrations on the performance and communities of mixed microalgae-bacteria photo-bioreactors

    KAUST Repository

    Xiong, Yanghui

    2017-12-11

    This study investigated the impact of varying concentrations of tetracycline on the performance of mixed microalgae-bacteria photo-bioreactors. Photo-bioreactors were assessed for their ability to remove carbon dioxide (CO2) from the biogas of anaerobic membrane bioreactor (anMBR), and nutrients from the anaerobic effluent. The varying concentrations of tetracycline had no impact on the removal of CO2 from biogas. 29% v/v of CO2 was completely removed to generate >20% v/v of oxygen (O2) in all reactors. Removal of nutrients and biomass was not affected at low concentrations of tetracycline (≤150μg/L), but 20mg/L of tetracycline lowered the biomass generation and removal efficiencies of phosphate. Conversely, high chlorophyll a and b content was observed at 20mg/L of tetracycline. High tetracycline level had no impact on the diversity of 18S rRNA gene-based microalgal communities but adversely affected the 16S rRNA gene-based microbial communities. Specifically, both Proteobacteria and Bacteroidetes phyla decreased in relative abundance but not phylum Chloroplast. Additionally, both nitrogen-fixing (e.g. Flavobacterium, unclassified Burkholderiales and unclassified Rhizobiaceae) and denitrifying groups (e.g. Hydrogenophaga spp.) were significantly reduced in relative abundance at high tetracycline concentration. Phosphate-accumulating microorganisms, Acinetobacter spp. and Pseudomonas spp. were similarly reduced upon exposure to high tetracycline concentration. Unclassified Comamonadaceae, however, increased in relative abundance, which correlated with an increase in the abundance of tetracycline resistance genes associated with efflux pump mechanism. Overall, the findings demonstrate that antibiotic concentrations in municipal wastewaters will not significantly affect the removal of nutrients by the mixed microalgae-bacteria photo-bioreactors. However, utilizing such photo-bioreactors as a polishing step for anMBRs that treat wastewaters with high tetracycline

  11. Converter fed sub sea motor drives

    Energy Technology Data Exchange (ETDEWEB)

    Raad, R O

    1995-09-01

    Minor offshore gas and oil resources located 20-50 km from existing installations may often be commercially exploited only by use of complete sub sea solutions. This thesis deals with analyses of a sub sea adjustable speed electric motor which is fed by a frequency converter via a long cable (up to 50 km) between the converter and the motor. The author develops a general model for analysing such motor drive systems with the objective of verifying the feasibility of specific applications and of specifying the requirements on the system components. The simulation model is used to identify the critical frequency ranges in which the converter must not generate significant harmonics, to verify the start-up strategy chosen, and to verify the stability with potential disturbances applied to the system. Simulation models are developed for both transient and steady state analyses. They are accurate up to 5 kHz and can incorporate the frequency dependency of the motor and cable parameters. Ideal thyristors and diodes are used. The models are implemented in existing simulation tools. Most of the results relate to a base case with a 670 kW squirrel cage motor fed from a 30 km long cable, but cases with 3 MW rating or with 50 km cable have also been analyzed and found to be feasible. Each specific application must be separately studied. Results of simulation calculations are presented and conclusions given. 53 refs., 124 figs., 23 tabs.

  12. Green and sustainable succinic acid production from crude glycerol by engineered Yarrowia lipolytica via agricultural residue based in situ fibrous bed bioreactor.

    Science.gov (United States)

    Li, Chong; Gao, Shi; Yang, Xiaofeng; Lin, Carol Sze Ki

    2018-02-01

    In situ fibrous bed bioreactor (isFBB) for efficient succinic acid (SA) production by Yarrowia lipolytica was firstly developed in our former study. In this study, agricultural residues including wheat straw, corn stalk and sugarcane bagasse were investigated for the improvement of isFBB, and sugarcane bagasse was demonstrated to be the best immobilization material. With crude glycerol as the sole carbon source, optimization for isFBB batch fermentation was carried out. Under the optimal conditions of 20g sugarcane bagasse as immobilization material, 120gL -1 crude glycerol as carbon source and 4Lmin -1 of aeration rate, the resultant SA concentration was 53.6gL -1 with an average productivity of 1.45gL -1 h -1 and a SA yield of 0.45gg -1 . By feeding crude glycerol, SA titer up to 209.7gL -1 was obtained from fed batch fermentation, which was the highest value that ever reported. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Evaluation of process performance, energy consumption and microbiota characterization in a ceramic membrane bioreactor for ex-situ biomethanation of H2 and CO2.

    Science.gov (United States)

    Alfaro, Natalia; Fdz-Polanco, María; Fdz-Polanco, Fernando; Díaz, Israel

    2018-06-01

    The performance of a pilot ceramic membrane bioreactor for the bioconversion of H 2 and CO 2 to bioCH 4 was evaluated in thermophilic conditions. The loading rate was between 10 and 30 m 3  H 2 /m 3 reactor  d and the system transformed 95% of H 2 fed. The highest methane yield found was 0.22 m 3  CH 4 /m 3  H 2 , close to the maximum stoichiometric value (0.25 m 3  CH 4 /m 3  H 2 ) thus indicating that archaeas employed almost all H 2 transferred to produce CH 4 . k L a value of 268 h -1 was reached at 30 m 3  H 2 /m 3 reactor  d. DGGE and FISH revealed a remarkable archaeas increase related to the selection-effect of H 2 on community composition over time. Methanothermobacter thermautotrophicus was the archaea found with high level of similarity. This study verified the successful application of membrane technology to efficiently transfer H 2 from gas to the liquid phase, the development of a hydrogenotrophic community from a conventional thermophilic sludge and the technical feasibility of the bioconversion. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor.

    Science.gov (United States)

    Sahar, E; Ernst, M; Godehardt, M; Hein, A; Herr, J; Kazner, C; Melin, T; Cikurel, H; Aharoni, A; Messalem, R; Brenner, A; Jekel, M

    2011-01-01

    The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8-10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin - at an MLSS of 6-9 g/L - showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected.

  15. Evaluation of energy-distribution of a hybrid microbial fuel cell-membrane bioreactor (MFC-MBR) for cost-effective wastewater treatment.

    Science.gov (United States)

    Wang, Jie; Bi, Fanghua; Ngo, Huu-Hao; Guo, Wenshan; Jia, Hui; Zhang, Hongwei; Zhang, Xinbo

    2016-01-01

    A low-cost hybrid system integrating a membrane-less microbial fuel cell (MFC) with an anoxic/oxic membrane bioreactor (MBR) was studied for fouling mitigation. The appended electric field in the MBR was supplied by the MFC with continuous flow. Supernatant from an anaerobic reactor with low dissolved oxygen was used as feed to the MFC in order to enhance its performance compared with that fed with synthetic wastewater. The voltage output of MFC maintained at 0.52±0.02V with 1000Ω resister. The electric field intensity could reach to 0.114Vcm(-1). Compared with the conventional MBR (CMBR), the contents rather than the components of foulants on the cake layer of fouled MFC-MBR system was significantly reduced. Although only 0.5% of the feed COD was translated into electricity and applied to MBR, the hybrid system showed great feasibility without additional consumption but extracting energy from waste water and significantly enhancing the membrane filterability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Grey water treatment by a continuous process of an electrocoagulation unit and a submerged membrane bioreactor system

    KAUST Repository

    Bani-Melhem, Khalid; Smith, Edward

    2012-01-01

    This paper presents the performance of an integrated process consisting of an electro-coagulation (EC) unit and a submerged membrane bioreactor (SMBR) technology for grey water treatment. For comparison purposes, another SMBR process without

  17. Treatment of cattle-slaughterhouse wastewater and the reuse of sludge for biodiesel production by microalgal heterotrophic bioreactors

    Directory of Open Access Journals (Sweden)

    Mariana Manzoni Maroneze

    2014-12-01

    Full Text Available Microalgal heterotrophic bioreactors are a potential technological development that can convert organic matter, nitrogen and phosphorus of wastewaters into a biomass suitable for energy production. The aim of this work was to evaluate the performance of microalgal heterotrophic bioreactors in the secondary treatment of cattle-slaughterhouse wastewater and the reuse of microalgal sludge for biodiesel production. The experiments were performed in a bubble column bioreactor using the microalgae Phormidium sp. Heterotrophic microalgal bioreactors removed 90 % of the chemical oxygen demand, 57 % of total nitrogen and 52 % of total phosphorus. Substantial microalgal sludge is produced in the process (substrate yield coefficient of 0.43 mg sludge mg chemical oxygen demand−¹, resulting in a biomass with high potential for producing biodiesel (ester content of more than 99 %, cetane number of 55, iodine value of 73.5 g iodine 100 g−¹, unsaturation degree of ~75 % and a cold filter plugging point of 5 ºC.

  18. Selection of suitable fertilizer draw solute for a novel fertilizer-drawn forward osmosis-anaerobic membrane bioreactor hybrid system

    KAUST Repository

    Kim, Youngjin; Chekli, Laura; Shim, Wang-Geun; Phuntsho, Sherub; Li, Sheng; Ghaffour, NorEddine; Leiknes, TorOve; Shon, Ho Kyong

    2016-01-01

    In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further

  19. Assessing the removal of organic micro-pollutants from anaerobic membrane bioreactor effluent by fertilizer-drawn forward osmosis

    KAUST Repository

    Kim, Youngjin; Li, Sheng; Chekli, Laura; Woo, Yun Chul; Wei, Chunhai; Phuntsho, Sherub; Ghaffour, NorEddine; Leiknes, TorOve; Shon, Ho Kyong

    2017-01-01

    In this study, the behavior of organic micro-pollutants (OMPs) transport including membrane fouling was assessed in fertilizer-drawn forward osmosis (FDFO) during treatment of the anaerobic membrane bioreactor (AnMBR) effluent. The flux decline

  20. Evaluation of hollow fiber and mini perm bioreactors as an alternative to murine ascites for small scale monoclonal antibody production

    International Nuclear Information System (INIS)

    Abdalla, O. M.

    2006-12-01

    The objective of this study was to compare monoclonal antibody production in hollow fiber, mini perm bioreactor systems and murine ascites to determine the feasibility of the bioreactor system as a potential alternative to the use of mice. One hybridoma cell line was grown in hollow fiber, mini perm bioreactor systems and in groups of 5 mice. Mice were primed with 0.5 ml pristane intraperitoneally 14 days prior to inoculation of 1x10 7 hybridoma cells. Each mouse was tapped a maximum of three times for collection of ascites. Bioreactors were harvested three times weekly for 30 days and were monitored by cell counts, cell viability and media consumption. Time and materials logs were maintained. The total quantity of monoclonal antibody produced in 5 mice versus the total production for the two different bioreactors (hollow fiber and mini perm) in 30 days was as follows: cell line 2AC10E6C7 produce 158 mg vs.97.5 mg, vs 21.54 mg respectively. Mean monoclonal antibody concentration ranged from 4.07 to 8.37 mg/ml in murine ascites, from 0.71 to 3.8 mg/ml in hollow fiber bioreactor system, and from 0.035 to 1.06 in mini perm. Although time and material costs were generally greater for the bioreactors, these results suggest that hollow fiber and mini perm bioreactor systems merit further investigations as potentially viable in vitro alternatives to the use of mice for small scale (<1mg) monoclonal antibody production.(Author)

  1. Evaluation of Hollow Fiber And Miniperm Bioreactors as An Alternative to Murine Ascites for Small Scale Monoclonal Antibody Production

    International Nuclear Information System (INIS)

    Abedalla, O. M.

    2007-01-01

    The objective of this study was to compare monoclonal antibody production in hollow fiber, miniPERM bioreactor systems and murine ascites to determine the feasibility of the bioreactor system as a potential alternative to the use of mice. One hybridoma cell line was grown in hollow fiber, miniPERM bioreactor systems and in groups of 5 mice. Mice were primed with 0.5 ml pristane intraperitoneally 14 days prior to inoculation of 1X10 7 hybridoma cells. Each mouse was tapped a maximum of three times for collection of ascites. Bioreactors were harvested three times weekly for 30 days and were monitored by cell counts, cell viability and media consumption. Time and materials logs were maintained. The total quantity of monoclonal antibody produced in 5 mice versus the total production for the two different bioreactors (hollow fiber and miniPERM) in 30 days was as follows: cell line 2AC10E6C7 produce 158 mg vs.97.5 mg; vs 21.54 mg respectively. Mean monoclonal antibody concentration ranged from 4.07 to 8.37 mg/ml in murine ascites, from 0.71 to 3.8 mg/ml in hollow fiber bioreactor system, and from 0.035 to 1.06 in miniPERM. Although time and material costs were generally greater for the bioreactors, these results suggest that hollow fiber and miniPERM bioreactor systems merit further investigations as potentially viable in vitro alternatives to the use of mice for small scale (< 1 g) monoclonal antibody production.

  2. L-strip proximity fed ga

    Directory of Open Access Journals (Sweden)

    Ashish Singh

    2014-03-01

    Full Text Available In this article, the analysis of dualband L-strip fed compact semi-circular disk microstrip patch antenna has been presented using circuit theory concept. The antenna parameters such as return loss, VSWR and radiation pattern are calculated. The effect of geometric dimensions of the proposed antenna such as length of vertical and horizontal portion of L-strip is investigated. It is found that antenna resonate at two distinct modes i.e. 1.3 GHz and 6.13 GHz for lower and upper resonance frequencies respectively. The bandwidth of the proposed antenna at lower resonance frequency is 6.61% (simulated and 10.64% (theoretical whereas at upper resonance frequency, it is 6.02% (simulated and 9.06 % (theoretical. The theoretical results are compared with IE3D simulation results as well as experimental results and they are in close agreement.

  3. Nano-ceramic composite scaffolds for bioreactor-based bone engineering.

    Science.gov (United States)

    Lv, Qing; Deng, Meng; Ulery, Bret D; Nair, Lakshmi S; Laurencin, Cato T

    2013-08-01

    Composites of biodegradable polymers and bioactive ceramics are candidates for tissue-engineered scaffolds that closely match the properties of bone. We previously developed a porous, three-dimensional poly (D,L-lactide-co-glycolide) (PLAGA)/nanohydroxyapatite (n-HA) scaffold as a potential bone tissue engineering matrix suitable for high-aspect ratio vessel (HARV) bioreactor applications. However, the physical and cellular properties of this scaffold are unknown. The present study aims to evaluate the effect of n-HA in modulating PLAGA scaffold properties and human mesenchymal stem cell (HMSC) responses in a HARV bioreactor. By comparing PLAGA/n-HA and PLAGA scaffolds, we asked whether incorporation of n-HA (1) accelerates scaffold degradation and compromises mechanical integrity; (2) promotes HMSC proliferation and differentiation; and (3) enhances HMSC mineralization when cultured in HARV bioreactors. PLAGA/n-HA scaffolds (total number = 48) were loaded into HARV bioreactors for 6 weeks and monitored for mass, molecular weight, mechanical, and morphological changes. HMSCs were seeded on PLAGA/n-HA scaffolds (total number = 38) and cultured in HARV bioreactors for 28 days. Cell migration, proliferation, osteogenic differentiation, and mineralization were characterized at four selected time points. The same amount of PLAGA scaffolds were used as controls. The incorporation of n-HA did not alter the scaffold degradation pattern. PLAGA/n-HA scaffolds maintained their mechanical integrity throughout the 6 weeks in the dynamic culture environment. HMSCs seeded on PLAGA/n-HA scaffolds showed elevated proliferation, expression of osteogenic phenotypic markers, and mineral deposition as compared with cells seeded on PLAGA scaffolds. HMSCs migrated into the scaffold center with nearly uniform cell and extracellular matrix distribution in the scaffold interior. The combination of PLAGA/n-HA scaffolds with HMSCs in HARV bioreactors may allow for the generation of engineered

  4. Hepatic Differentiation of Human Induced Pluripotent Stem Cells in a Perfused Three-Dimensional Multicompartment Bioreactor

    Directory of Open Access Journals (Sweden)

    Nora Freyer

    2016-08-01

    Full Text Available The hepatic differentiation of human induced pluripotent stem cells (hiPSC holds great potential for application in regenerative medicine, pharmacological drug screening, and toxicity testing. However, full maturation of hiPSC into functional hepatocytes has not yet been achieved. In this study, we investigated the potential of a dynamic three-dimensional (3D hollow fiber membrane bioreactor technology to improve the hepatic differentiation of hiPSC in comparison to static two-dimensional (2D cultures. A total of 100 × 106 hiPSC were seeded into each 3D bioreactor (n = 3. Differentiation into definitive endoderm (DE was induced by adding activin A, Wnt3a, and sodium butyrate to the culture medium. For further maturation, hepatocyte growth factor and oncostatin M were added. The same differentiation protocol was applied to hiPSC maintained in 2D cultures. Secretion of alpha-fetoprotein (AFP, a marker for DE, was significantly (p < 0.05 higher in 2D cultures, while secretion of albumin, a typical characteristic for mature hepatocytes, was higher after hepatic differentiation of hiPSC in 3D bioreactors. Functional analysis of multiple cytochrome P450 (CYP isoenzymes showed activity of CYP1A2, CYP2B6, and CYP3A4 in both groups, although at a lower level compared to primary human hepatocytes (PHH. CYP2B6 activities were significantly (p < 0.05 higher in 3D bioreactors compared with 2D cultures, which is in line with results from gene expression. Immunofluorescence staining showed that the majority of cells was positive for albumin, cytokeratin 18 (CK18, and hepatocyte nuclear factor 4-alpha (HNF4A at the end of the differentiation process. In addition, cytokeratin 19 (CK19 staining revealed the formation of bile duct-like structures in 3D bioreactors similar to native liver tissue. The results indicate a better maturation of hiPSC in the 3D bioreactor system compared to 2D cultures and emphasize the potential of dynamic 3D culture

  5. Bioreactor-induced mesenchymal progenitor cell differentiation and elastic fiber assembly in engineered vascular tissues.

    Science.gov (United States)

    Lin, Shigang; Mequanint, Kibret

    2017-09-01

    In vitro maturation of engineered vascular tissues (EVT) requires the appropriate incorporation of smooth muscle cells (SMC) and extracellular matrix (ECM) components similar to native arteries. To this end, the aim of the current study was to fabricate 4mm inner diameter vascular tissues using mesenchymal progenitor cells seeded into tubular scaffolds. A dual-pump bioreactor operating either in perfusion or pulsatile perfusion mode was used to generate physiological-like stimuli to promote progenitor cell differentiation, extracellular elastin production, and tissue maturation. Our data demonstrated that pulsatile forces and perfusion of 3D tubular constructs from both the lumenal and ablumenal sides with culture media significantly improved tissue assembly, effectively inducing mesenchymal progenitor cell differentiation to SMCs with contemporaneous elastin production. With bioreactor cultivation, progenitor cells differentiated toward smooth muscle lineage characterized by the expression of smooth muscle (SM)-specific markers smooth muscle alpha actin (SM-α-actin) and smooth muscle myosin heavy chain (SM-MHC). More importantly, pulsatile perfusion bioreactor cultivation enhanced the synthesis of tropoelastin and its extracellular cross-linking into elastic fiber compared with static culture controls. Taken together, the current study demonstrated progenitor cell differentiation and vascular tissue assembly, and provides insights into elastin synthesis and assembly to fibers. Incorporation of elastin into engineered vascular tissues represents a critical design goal for both mechanical and biological functions. In the present study, we seeded porous tubular scaffolds with multipotent mesenchymal progenitor cells and cultured in dual-pump pulsatile perfusion bioreactor. Physiological-like stimuli generated by bioreactor not only induced mesenchymal progenitor cell differentiation to vascular smooth muscle lineage but also actively promoted elastin synthesis and

  6. Comparative analysis of top-lit bubble column and gas-lift bioreactors for microalgae-sourced biodiesel production

    International Nuclear Information System (INIS)

    Seyed Hosseini, Nekoo; Shang, Helen; Ross, Gregory M.; Scott, John Ashley

    2016-01-01

    Highlights: • Top-lit gas-lift and bubble columns were studied as deep algal cultivation tank. • A theoretical energy requirement analysis and a hydrodynamic model were developed. • Areal productivities of both bioreactors were notably higher than traditional raceways. • A gas-lift reactor sparged with 6% carbon dioxide achieved the highest lipid production. • Hydrodynamic and light stresses increased the lipid content suitable for biodiesel. - Abstract: The development of top-lit one-meter deep bioreactors operated as either a gas-lift or bubble column system using air and carbon dioxide enriched air was studied. The goal was high productivity cultivation of algae with elevated lipid levels suitable for conversion into biodiesel. A theoretical energy requirement analysis and a hydrodynamic model were developed to predict liquid circulation velocities in the gas-lift bioreactor, which agreed well with experimental measurements. The influence of operational parameters such as design of bioreactor, gas flow rates and carbon dioxide concentration on the growth and lipid volumetric production of Scenedesmus dimorphus was evaluated using factorial design. While biomass productivity was 12% higher in the bubble column bioreactor (68.2 g_d_w m"−"2 day"−"1), maximum lipid volumetric production (0.19 g_L_i_p_i_d L"−"1) was found in a gas-lift bioreactor sparged with 6% carbon dioxide due to hydrodynamic and light stresses.

  7. Analysis of the efficiency of recombinant Escherichia coli strain cultivation in a gas-vortex bioreactor.

    Science.gov (United States)

    Savelyeva, Anna V; Nemudraya, Anna A; Podgornyi, Vladimir F; Laburkina, Nadezhda V; Ramazanov, Yuriy A; Repkov, Andrey P; Kuligina, Elena V; Richter, Vladimir A

    2017-09-01

    The levels of aeration and mass transfer are critical parameters required for an efficient aerobic bioprocess, and directly depend on the design features of exploited bioreactors. A novel apparatus, using gas vortex for aeration and mass transfer processes, was constructed in the Center of Vortex Technologies (Novosibirsk, Russia). In this paper, we compared the efficiency of recombinant Escherichia coli strain cultivation using novel gas-vortex technology with conventional bioprocess technologies such as shake flasks and bioreactors with mechanical stirrers. We demonstrated that the system of aeration and agitation used in gas-vortex bioreactors provides 3.6 times higher volumetric oxygen transfer coefficient in comparison with mechanical bioreactor. The use of gas-vortex bioreactor for recombinant E. coli strain cultivation allows to increase the efficiency of target protein expression at 2.2 times for BL21(DE3)/pFK2 strain and at 3.5 times for auxotrophic C600/pRT strain (in comparison with stirred bioreactor). © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  8. Effects of granular activated carbon on methane removal performance and methanotrophic community of a lab-scale bioreactor.

    Science.gov (United States)

    Lee, Eun-Hee; Choi, Sun-Ah; Yi, Taewoo; Kim, Tae Gwan; Lee, Sang-Don; Cho, Kyung-Suk

    2015-01-01

    Two identical lab-scale bioreactor systems were operated to examine the effects of granular activated carbon (GAC) on methane removal performance and methanotrophic community. Both bioreactor systems removed methane completely at a CH4 loading rate of 71.2 g-CH4·d(-1) for 17 days. However, the methane removal efficiency declined to 88% in the bioreactor without GAC, while the bioreactor amended with GAC showed greater methane removal efficiency of 97% at a CH4 loading rate of 107.5 g-CH4·d(-1). Although quantitative real-time PCR showed that methanotrophic populations were similar levels of 5-10 × 10(8) pmoA gene copy number·VSS(-1) in both systems, GAC addition changed the methanotrophic community composition of the bioreactor systems. Microarray assay revealed that GAC enhanced the type I methanotrophic genera including Methylobacter, Methylomicrobium, and Methylomonas of the system, which suggests that GAC probably provided a favorable environment for type I methanotrophs. These results indicated that GAC is a promising support material in bioreactor systems for CH4 mitigation.

  9. Lipid production in batch and fed-batch cultures of Rhodosporidium toruloides from 5 and 6 carbon carbohydrates

    Directory of Open Access Journals (Sweden)

    Wiebe Marilyn G

    2012-05-01

    Full Text Available Abstract Background Microbial lipids are a potential source of bio- or renewable diesel and the red yeast Rhodosporidium toruloides is interesting not only because it can accumulate over 50% of its dry biomass as lipid, but also because it utilises both five and six carbon carbohydrates, which are present in plant biomass hydrolysates. Methods R. toruloides was grown in batch and fed-batch cultures in 0.5 L bioreactors at pH 4 in chemically defined, nitrogen restricted (C/N 40 to 100 media containing glucose, xylose, arabinose, or all three carbohydrates as carbon source. Lipid was extracted from the biomass using chloroform-methanol, measured gravimetrically and analysed by GC. Results Lipid production was most efficient with glucose (up to 25 g lipid L−1, 48 to 75% lipid in the biomass, at up to 0.21 g lipid L−1 h−1 as the sole carbon source, but high lipid concentrations were also produced from xylose (36 to 45% lipid in biomass. Lipid production was low (15–19% lipid in biomass with arabinose as sole carbon source and was lower than expected (30% lipid in biomass when glucose, xylose and arabinose were provided simultaneously. The presence of arabinose and/or xylose in the medium increased the proportion of palmitic and linoleic acid and reduced the proportion of oleic acid in the fatty acids, compared to glucose-grown cells. High cell densities were obtained in both batch (37 g L−1, with 49% lipid in the biomass and fed-batch (35 to 47 g L−1, with 50 to 75% lipid in the biomass cultures. The highest proportion of lipid in the biomass was observed in cultures given nitrogen during the batch phase but none with the feed. However, carbohydrate consumption was incomplete when the feed did not contain nitrogen and the highest total lipid and best substrate consumption were observed in cultures which received a constant low nitrogen supply. Conclusions Lipid production in R. toruloides was lower from arabinose and mixed

  10. Evaluation of microorganisms with sulfidogenic metabolic potential under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Isabel Kimiko Sakamoto

    2012-10-01

    Full Text Available The aim of this work was to identify groups of microorganisms that are capable of degrading organic matter utilizing sulfate as an electron acceptor. The assay applied for this purpose consisted of running batch reactors and monitoring lactate consumption, sulfate reduction and sulfide production. A portion of the lactate added to the batch reactors was consumed, and the remainder was converted into acetic, propionic and butyric acid after 111 hours of operation These results indicate the presence of sulfate-reducing bacteria (SRB catalyzing both complete and incomplete oxidation of organic substrates. The sulfate removal efficiency was 49.5% after 1335 hours of operation under an initial sulfate concentration of 1123 mg/L. The SRB concentrations determined by the most probable number (MPN method were 9.0x10(7 cells/mL at the beginning of the assay and 8.0x10(5 cells/mL after 738 hours of operation.

  11. Air purification from a mixture VOCs in the pilot-scale trickle-bed bioreactor (TBB

    Directory of Open Access Journals (Sweden)

    Sarzyński Rafał

    2017-01-01

    Full Text Available The efficiency of the air bio-purification from the mixture of two volatile organic compounds (styrene and p-xylene was studied. The process was carried out in a pilot-scale trickle-bed bioreactor installation designed to purify ∼200 m3h-1 of the polluted air. The bioreactor operated at concurrent flow of gas and liquid (mineral salt solution through packing (polypropylene Ralu rings covered with a thin layer of microorganisms (bacterial consortium of Pseudomonas sp. E-022150 and Pseudomonas putida mt-2. The experiments, carried out for various values of a reactor load with pollutant, confirmed the great efficiency of the investigated process. At the tested bed load with pollution (inlet specific pollutant load was changed within the range of 41 – 84 gm-3 h -1, styrene conversion degree changed within the range of 80-87% and p-xylene conversion degree within the range of 42-48%.

  12. Asymptotic stability of a coupled advection-diffusion-reaction system arising in bioreactor processes

    Directory of Open Access Journals (Sweden)

    Maria Crespo

    2017-08-01

    Full Text Available In this work, we present an asymptotic analysis of a coupled system of two advection-diffusion-reaction equations with Danckwerts boundary conditions, which models the interaction between a microbial population (e.g., bacteria, called biomass, and a diluted organic contaminant (e.g., nitrates, called substrate, in a continuous flow bioreactor. This system exhibits, under suitable conditions, two stable equilibrium states: one steady state in which the biomass becomes extinct and no reaction is produced, called washout, and another steady state, which corresponds to the partial elimination of the substrate. We use the linearization method to give sufficient conditions for the linear asymptotic stability of the two stable equilibrium configurations. Finally, we compare our asymptotic analysis with the usual asymptotic analysis associated to the continuous bioreactor when it is modeled with ordinary differential equations.

  13. Mathematical modelling and optimization of hydrogen continuous production in a fixed bed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Palazzi, E.; Perego, P.; Fabiano, B. [University of Genoa, Genova (Italy). Chemical and Process Engineering Department ' G.B. Bonino'

    2002-09-01

    The purpose of this paper is to investigate, both theoretically and experimentally, hydrogen production from agro-industrial by-products using a continuous bioreactor packed with a mixture of spongy and glass beads and inoculated with Enterobacter aerogenes. Replicated series of experimental runs were performed to study the effects of residence time on hydrogen evolution rate and to characterize the critical conditions for the wash out, as a function of the inlet glucose concentration and of the fluid superficial velocity. A further series of experimental runs was focused on the effects of both residence time and inlet glucose concentration over hydrogen productivity. A kinetic model of the process was developed and showed good agreement with experimental data, thus representing a potential tool to design a large-scale fermenter. In fact, the model was applied to the optimal design of a bioreactor suitable of feeding a phosphoric acid fuel cell of a target power. (author)

  14. Anaerobic digestion of citrus waste using two-stage membrane bioreactor

    Science.gov (United States)

    Millati, Ria; Lukitawesa; Dwi Permanasari, Ervina; Wulan Sari, Kartika; Nur Cahyanto, Muhammad; Niklasson, Claes; Taherzadeh, Mohammad J.

    2018-03-01

    Anaerobic digestion is a promising method to treat citrus waste. However, the presence of limonene in citrus waste inhibits anaerobic digestion process. Limonene is an antimicrobial compound and could inhibit methane forming bacteria that takes a longer time to recover than the injured acid forming bacteria. Hence, volatile fatty acids will be accumulated and methane production will be decreased. One way to solve this problem is by conducting anaerobic digestion process into two stages. The first step is aimed for hydrolysis, acidogenesis, and acetogenesis reactions and the second stage is aimed for methanogenesis reaction. The separation of the system would further allow each stage in their optimum conditions making the process more stable. In this research, anaerobic digestion was carried out in batch operations using 120 ml-glass bottle bioreactors in 2 stages. The first stage was performed in free-cells bioreactor, whereas the second stage was performed in both bioreactor of free cells and membrane bioreactor. In the first stage, the reactor was set into ‘anaerobic’ and ‘semi-aerobic’ conditions to examine the effect of oxygen on facultative anaerobic bacteria in acid production. In the second stage, the protection of membrane towards the cells against limonene was tested. For the first stage, the basal medium was prepared with 1.5 g VS of inoculum and 4.5 g VS of citrus waste. The digestion process was carried out at 55°C for four days. For the second stage, the membrane bioreactor was prepared with 3 g of cells that were encased and sealed in a 3×6 cm2 polyvinylidene fluoride membrane. The medium contained 40 ml basal medium and 10 ml liquid from the first stage. The bioreactors were incubated at 55°C for 2 days under anaerobic condition. The results from the first stage showed that the maximum total sugar under ‘anaerobic’ and ‘semi-aerobic’ conditions was 294.3 g/l and 244.7 g/l, respectively. The corresponding values for total volatile

  15. Micro propagation of Stevia rebaudiana Bertoni through temporary immersion bioreactor system

    International Nuclear Information System (INIS)

    Norazlina Noordin; Rusli Ibrahim; Nur Hidayah Sajahan; Siti Maryam Mohd Nahar; Siti Hajar Mohd Nahar

    2012-01-01

    Stevia rebaudiana Bertoni is a perennial herb that belongs to the family of Asteraceae. It is a natural sweetener plant known as sweet leaf, which is estimated to be 300 times sweeter than cane sugar. In this study, micro propagation of this natural herb via temporary immersion bioreactor system was successfully conducted. Shoot tips and nodal segment were used as explants to induce multiply shoots. It was found that shoot tips on MS medium supplemented with 1 mg/l Kinetin showed the highest shoot multiplication after 3 weeks of culture. Shoot elongation and rooting was successfully optimized in MS basal medium 2 weeks later. Mass propagation of stevia shoots were carried out in temporary immersion bioreactor and this system showed promising potential as an alternative approach for rapid and continuous production of in vitro stevia plantlets. (author)

  16. Determination of Ammonia Oxidizing Bacteria and Nitrate Oxidizing Bacteria in Wastewater and Bioreactors

    Science.gov (United States)

    Francis, Somilez Asya

    2014-01-01

    The process of water purification has many different physical, chemical, and biological processes. One part of the biological process is the task of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Both play critical roles in the treatment of wastewater by oxidizing toxic compounds. The broad term is nitrification, a naturally occurring process that is carried out by AOB and NOB by using oxidation to convert ammonia to nitrite and nitrite to nitrate. To monitor this biological activity, bacterial staining was performed on wastewater contained in inoculum tanks and biofilm samples from bioreactors. Using microscopy and qPCR, the purpose of this experiment was to determine if the population of AOB and NOB in wastewater and membrane bioreactors changed depending on temperature and hibernation conditions to determine the optimal parameters for AOB/NOB culture to effectively clean wastewater.

  17. Recycle bioreactor for bioethanol production from wheat starch. 1. Cold enzyme hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Lang, X.; Hill, G.A.; MacDonald, D.G. [Department of Chemical Engineering, Saskatchewan (Canada)

    2001-06-01

    A 5 L membrane bioreactor system has been designed and operated at low temperature to hydrolyze starch granules directly to sugars using barley {alpha}-amylase. The system includes a temperature and pH controlled, well-mixed bioreactor; microfilters to separate and recycle granules; and ultrafilters to separate and recycle enzyme molecules. Operation in batch mode demonstrated similar kinetics and low productivity observed earlier in shake flasks, whereas continuous flow operation was not successful due to enzyme inhibition and degradation. Sequential batch mode operation, involving filtration after each batch hydrolysis, produced optimum productivity measured at 0.16 grams of starch granules hydrolyzed per gram of enzyme per hour for more than 100 hours of operation. (author)

  18. Air purification from a mixture VOCs in the pilot-scale trickle-bed bioreactor (TBB)

    Science.gov (United States)

    Sarzyński, Rafał; Gąszczak, Agnieszka; Janecki, Daniel; Bartelmus, Grażyna

    2017-10-01

    The efficiency of the air bio-purification from the mixture of two volatile organic compounds (styrene and p-xylene) was studied. The process was carried out in a pilot-scale trickle-bed bioreactor installation designed to purify ˜200 m3h-1 of the polluted air. The bioreactor operated at concurrent flow of gas and liquid (mineral salt solution) through packing (polypropylene Ralu rings) covered with a thin layer of microorganisms (bacterial consortium of Pseudomonas sp. E-022150 and Pseudomonas putida mt-2). The experiments, carried out for various values of a reactor load with pollutant, confirmed the great efficiency of the investigated process. At the tested bed load with pollution (inlet specific pollutant load was changed within the range of 41 - 84 gm-3 h -1), styrene conversion degree changed within the range of 80-87% and p-xylene conversion degree within the range of 42-48%.

  19. New bioreactor vessel for tissue engineering of human nasal septal chondrocytes

    Directory of Open Access Journals (Sweden)

    Princz Sascha

    2016-09-01

    Full Text Available Cultivation of human nasal septal chondrocytes in a self-established automated bioreactor system with a new designed reactor glass vessel and the results of a computational fluid dynamics model are presented. The first results show the effect of a homogeneous fluidic condition of the continuous medium flow and the resulting stresses on the scaffolds’ surface and their influence on the migration of the cells into the scaffold matrix under these conditions. For this purpose computational models, generated with the computational fluid dynamics software STAR-CCM+, and the results of alcian blue staining for newly synthesized sulphated glycosaminoglycans have been compared during cultivation in the new and a first version of the glass reactor vessel with inhomogeneous fluidic conditions, with the same automated bioreactor system and under similar cultivation conditions.

  20. Efficient high-throughput biological process characterization: Definitive screening design with the ambr250 bioreactor system.

    Science.gov (United States)

    Tai, Mitchell; Ly, Amanda; Leung, Inne; Nayar, Gautam

    2015-01-01

    The burgeoning pipeline for new biologic drugs has increased the need for high-throughput process characterization to efficiently use process development resources. Breakthroughs in highly automated and parallelized upstream process development have led to technologies such as the 250-mL automated mini bioreactor (ambr250™) system. Furthermore, developments in modern design of experiments (DoE) have promoted the use of definitive screening design (DSD) as an efficient method to combine factor screening and characterization. Here we utilize the 24-bioreactor ambr250™ system with 10-factor DSD to demonstrate a systematic experimental workflow to efficiently characterize an Escherichia coli (E. coli) fermentation process for recombinant protein production. The generated process model is further validated by laboratory-scale experiments and shows how the strategy is useful for quality by design (QbD) approaches to control strategies for late-stage characterization. © 2015 American Institute of Chemical Engineers.

  1. Bioreactors for plant cells: hardware configuration and internal environment optimization as tools for wider commercialization.

    Science.gov (United States)

    Georgiev, Milen I; Weber, Jost

    2014-07-01

    Mass production of value-added molecules (including native and heterologous therapeutic proteins and enzymes) by plant cell culture has been demonstrated as an efficient alternative to classical technologies [i.e. natural harvest and chemical (semi)synthesis]. Numerous proof-of-concept studies have demonstrated the feasibility of scaling up plant cell culture-based processes (most notably to produce paclitaxel) and several commercial processes have been established so far. The choice of a suitable bioreactor design (or modification of an existing commercially available reactor) and the optimization of its internal environment have been proven as powerful tools toward successful mass production of desired molecules. This review highlights recent progress (mostly in the last 5 years) in hardware configuration and optimization of bioreactor culture conditions for suspended plant cells.

  2. Structural analysis of a fibrocement anaerobic bioreactor for finite elements method

    International Nuclear Information System (INIS)

    Guardia-Puebla, Yans; Pacheco-GamboaI, Raúl; Ramos-Botello, Yoan; Palma-Ramírez, Leonardo; Rodríguez-Pérez, Suyén

    2015-01-01

    The paper consist on asses the mechanical resistant of the fibrocement tanks as a proposal of an anaerobic system of low cost for biogas production. For the design was used the finite elements method (FEM), which it is fundamental tool to carried out the structural analysis of the resistant to the traction of the anaerobic bioreactor. With this new system, a suitable option to spread, of sustainable and economic means, the biogas production on rural zones. For the design was used fibrocement tanks of 1900 L, and pipes and accessories plastics, achieving a maximum volume of cumulative biogas of 1,12 m"3.The fibrocement tank was not accomplished with the necessary specifications to achieve the design aim; for that reason, a new dimensional design was developed to guarantee the traction resistant as anaerobic bioreactors. (author)

  3. Performance evaluation of startup for a yeast membrane bioreactor (MBRy) treating landfill leachate.

    Science.gov (United States)

    Amaral, Míriam C S; Gomes, Rosimeire F; Brasil, Yara L; Oliveira, Sílvia M A; Moravia, Wagner G

    2017-12-06

    The startup process of a membrane bioreactor inoculated with yeast biomass (Saccharomyces cerevisiae) and used in the treatment of landfill leachate was evaluated. The yeast membrane bioreactor (MBRy) was inoculated with an exogenous inoculum, a granulated active dry commercial bakers' yeast. The MBRy was successfully started up with a progressive increase in the landfill leachate percentage in the MBRy feed and the use of Sabouraud Dextrose Broth. The membrane plays an important role in the startup phase because of its full biomass retention and removal of organic matter. MBRy is a suitable and promising process to treat recalcitrant landfill leachate. After the acclimation period, the COD and NH 3 removal efficiency reached values of 72 ± 3% and 39 ± 2% respectively. MBRy shows a low membrane-fouling potential. The membrane fouling was influenced by soluble microbial products, extracellular polymeric substances, sludge particle size, and colloidal dissolved organic carbon.

  4. Cu removal and response mechanisms of periphytic biofilms in a tubular bioreactor.

    Science.gov (United States)

    Ma, Lan; Wang, Fengwu; Yu, Yuanchun; Liu, Junzhuo; Wu, Yonghong

    2018-01-01

    This work studied Cu removal and response mechanisms of periphytic biofilms in a tubular bioreactor. Periphytic biofilms immobilized in a tubular bioreactor were used to remove Cu from wastewater with different Cu concentrations. Results showed that periphytic biofilms had a high removal efficiency (max. 99%) at a hydraulic retention time (HRT) of 12h under initial Cu concentrations of 2.0 and 10.0mgL -1 . Periphyton quickly adapted to Cu stress by regulating the community composition. Species richness, evenness and carbon metabolic diversity of the periphytic community increased when exposed to Cu. Diatoms, green algae, and bacteria (Gammaproteobacteria and Bacteroidia) were the dominant microorganisms and responsible for Cu removal. This study indicates that periphytic biofilms are promising in Cu removal from wastewater due to their strong adaptation capacity to Cu toxicity and also provides valuable information for understanding the relationships between microbial communities and heavy metal stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The problem of fouling in submerged membrane bioreactors - Model validation and experimental evidence

    Science.gov (United States)

    Tsibranska, Irene; Vlaev, Serafim; Tylkowski, Bartosz

    2018-01-01

    Integrating biological treatment with membrane separation has found a broad area of applications and industrial attention. Submerged membrane bioreactors (SMBRs), based on membrane modules immersed in the bioreactor, or side stream ones connected in recycle have been employed in different biotechnological processes for separation of thermally unstable products. Fouling is one of the most important challenges in the integrated SMBRs. A number of works are devoted to fouling analysis and its treatment, especially exploring the opportunity for enhanced fouling control in SMBRs. The main goal of the review is to provide a comprehensive yet concise overview of modeling the fouling in SMBRs in view of the problematics of model validation, either by real system measurements at different scales or by analysis of the obtained theoretical results. The review is focused on the current state of research applying computational fluid dynamics (CFD) modeling techniques.

  6. Performance of the ACWA Pilot Immobilized Cell Bioreactor in Degradation of HD and Tetrytol Payloads of the M60 Chemical Round

    National Research Council Canada - National Science Library

    Guelta, Mark A; Chester, Nancy A; Kurnas, Carl W; Haley, Mark V; Lupton, F. S; Koch, Mark

    2002-01-01

    .... Neutralization followed by biodegradation was one technology identified as having potential. Guelta and DeFrank conducted preliminary laboratory studies using 1-liter Immobilized Cell Bioreactors (ICB...

  7. Towards a continuous two-phase partitioning bioreactor for xenobiotic removal

    Energy Technology Data Exchange (ETDEWEB)

    Tomei, M.Concetta, E-mail: tomei@irsa.cnr.it [Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015 Monterotondo Stazione, Rome (Italy); Mosca Angelucci, Domenica [Water Research Institute, C.N.R., Via Salaria km 29.300, CP 10, 00015 Monterotondo Stazione, Rome (Italy); Daugulis, Andrew J. [Department of Chemical Engineering, Queen’s University, Kingston, Ontario K7 L 3N6 (Canada)

    2016-11-05

    Highlights: • A prototype of a continuous two-phase partitioning bioreactor was investigated. • The bioreactor contained coiled tubing of a selected extruded polymer, Hytrel 8206. • Mass transfer and removal of a xenobiotic, 4-cholorophenol, were investigated. • Removal efficiencies in the tubing wastewater stream were always ≥ 96%. • Presence of polymer tubing buffered increasing in organic load to the hybrid system. - Abstract: The removal of a xenobiotic (4-chlorophenol) from contaminated water was investigated in a simulated continuous two-phase partitioning bioreactor (C-TPPB), fitted with coiled tubing comprised of a specifically-selected extruded polymer, Hytrel 8206. Wastewater flowed inside the tubing, the pollutant diffused through the tubing wall, and was removed in the aqueous bioreactor phase at typical biological removal rates in the C-TTPB simulated by varying aqueous phase throughput to the reactor. Operating over a range of influent substrate concentrations (500–1500 mg L{sup −1}) and hydraulic retention times in the tubing (4–8 h), overall mass transfer coefficients were 1.7–3.5 × 10{sup −7} m s{sup −1}, with the highest value corresponding to the highest tubing flow rate. Corresponding mass transfer rates are of the same order as biological removal rates, and thus do not limit the removal process. The C-TPPB showed good performance over all organic and hydraulic loading ranges, with removal efficiencies of 4CP in the tubing wastewater stream always ≥96%. Additionally, the presence of the Hytrel tubing was able to buffer increases in organic loading to the hybrid system, enhancing overall process stability. Biological testing of the C-TPPB confirmed the abiotic test results demonstrating even higher 4-chlorophenol removal efficiency (∼99%) in the tubing stream.

  8. Hexavalent chromium reduction in a sulfur reducing packed-bed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Sahinkaya, Erkan, E-mail: erkansahinkaya@yahoo.com [Department of Bioengineering, Istanbul Medeniyet University, Goeztepe, Istanbul (Turkey); Kilic, Adem [Department of Environmental Engineering, Harran University, Osmanbey Campus, 63000 Sanliurfa (Turkey); Altun, Muslum [Department of Chemistry, Hacettepe University, Beytepe, Ankara (Turkey); Komnitsas, Kostas [Department of Mineral Resources Engineering, Technical University of Crete, 73100 Chania (Greece); Lens, Piet N.L. [Unesco-IHE Institute for Water Education, Westvest 7, Delft 2611 AX (Netherlands)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Elemental sulfur can be used as electron acceptor for sulfide production. Black-Right-Pointing-Pointer Biogenically produced sulfide reduces Cr(VI) to the much less toxic and immobile form of Cr(III). Black-Right-Pointing-Pointer Sulfur packed bioreactor is efficient for Cr(VI) containing wastewater treatment. Black-Right-Pointing-Pointer Reduced form of chromium precipitates in the bioreactor. - Abstract: The most commonly used approach for the detoxification of hazardous industrial effluents and wastewaters containing Cr(VI) is its reduction to the much less toxic and immobile form of Cr(III). This study investigates the cleanup of Cr(VI) containing wastewaters using elemental sulfur as electron acceptor, for the production of hydrogen sulfide that induces Cr(VI) reduction. An elemental sulfur reducing packed-bed bioreactor was operated at 28-30 Degree-Sign C for more than 250 days under varying influent Cr(VI) concentrations (5.0-50.0 mg/L) and hydraulic retention times (HRTs, 0.36-1.0 day). Ethanol or acetate (1000 mg/L COD) was used as carbon source and electron donor. The degree of COD oxidation varied between 30% and 85%, depending on the operating conditions and the type of organic carbon source. The oxidation of organic matter was coupled with the production of hydrogen sulfide, which reached a maximum concentration of 750 mg/L. The biologically produced hydrogen sulfide reduced Cr(VI) chemically to Cr(III) that precipitated in the reactor. Reduction of Cr(VI) and removal efficiency of total chromium always exceeded 97% and 85%, respectively, implying that the reduced chromium was retained in the bioreactor. This study showed that sulfur can be used as an electron acceptor to produce hydrogen sulfide that induces efficient reduction and immobilization of Cr(VI), thus enabling decontamination of Cr(VI) polluted wastewaters.

  9. The Influence of Bioreactor Geometry and the Mechanical Environment on Engineered Tissues

    KAUST Repository

    Osborne, J. M.; O’ Dea, R. D.; Whiteley, J. P.; Byrne, H. M.; Waters, S. L.

    2010-01-01

    A three phase model for the growth of a tissue construct within a perfusion bioreactor is examined. The cell population (and attendant extracellular matrix), culture medium, and porous scaffold are treated as distinct phases. The bioreactor system is represented by a two-dimensional channel containing a cell-seeded rigid porous scaffold (tissue construct), which is perfused with a culture medium. Through the prescription of appropriate functional forms for cell proliferation and extracellular matrix deposition rates, the model is used to compare the influence of cell density-, pressure-, and culture medium shear stress-regulated growth on the composition of the engineered tissue. The governing equations are derived in O'Dea et al. "A Three Phase Model for Tissue Construct Growth in a Perfusion Bioreactor," Math. Med. Biol., in which the long-wavelength limit was exploited to aid analysis; here, finite element methods are used to construct two-dimensional solutions to the governing equations and to investigate thoroughly their behavior. Comparison of the total tissue yield and averaged pressures, velocities, and shear stress demonstrates that quantitative agreement between the two-dimensional and long-wavelength approximation solutions is obtained for channel aspect ratios of order 10 -2 and that much of the qualitative behavior of the model is captured in the long-wavelength limit, even for relatively large channel aspect ratios. However, we demonstrate that in order to capture accurately the effect of mechanotransduction mechanisms on tissue construct growth, spatial effects in at least two dimensions must be included due to the inherent spatial variation of mechanical stimuli relevant to perfusion bioreactors, most notably, fluid shear stress, a feature not captured in the long-wavelength limit. Copyright © 2010 by ASME.

  10. Mass propagation of shoots of Stevia rebaudiana using a large scale bioreactor.

    Science.gov (United States)

    Akita, M; Shigeoka, T; Koizumi, Y; Kawamura, M

    1994-01-01

    A procedure for the mass propagation of multiple shoots of Stevia rebaudiana is described. Isolated shoot primordia were used as the inoculum to obtain clusters of shoot primordia. Such clusters were grown in a 500 liter bioreactor to obtain shoots. A total of 64.6 Kg of shoots were propagated from 460 g of the inoculated shoot primordia. These shoots were easily acclimatized in soil.

  11. Characterization and Application of a Disposable Rotating BedBioreactor for Mesenchymal Stem Cell Expansion

    OpenAIRE

    Neumann, Anne; Lavrentieva, Antonina; Heilkenbrinker, Alexandra; Loenne, Maren; Kasper, Cornelia

    2014-01-01

    Recruitment of mesenchymal stromal cells (MSC) into the field of tissue engineering is a promising development since these cells can be expanded vivo to clinically relevant numbers and, after expansion, retain their ability to differentiate into various cell lineages. Safety requirements and the necessity to obtain high cell numbers without frequent subcultivation of cells raised the question of the possibility of expanding MSC in one-way (single-use) disposable bioreactors. In this study, u...

  12. Low-cost sensor system for non-invasive monitoring of cell growth in disposable bioreactors

    OpenAIRE

    Reinecke, Tobias; Biechele, Philipp; Schulte, V.; Scheper, Thomas; Zimmermann, Stefan

    2015-01-01

    To ensure productivity and product quality, the parameters of biotechnological processes need to be monitored. Along temperature or pH, one important parameter is the cell density in the culture medium. In this work, we present a low-cost sensor system for online cell growth monitoring in bioreactors via permittivity measurements based on coplanar transmission lines. To evaluate the sensor, E. coli cultivations are performed. We found a good correlation between optical density of the culture ...

  13. Stoichiometric and kinetic analysis of extreme halophilic Archaea on various substrates in a corrosion resistant bioreactor.

    Science.gov (United States)

    Lorantfy, Bettina; Seyer, Bernhard; Herwig, Christoph

    2014-01-25

    Extreme halophilic Archaea are extremophile species which can thrive in hypersaline environments of up to 3-5 M sodium chloride concentration. Although their ecology and physiology are widely identified on the microbiological level, little emphasis has been laid on quantitative bioprocess development with extreme halophiles. The goal of this study was to establish, on the one hand, a methodological basis for quantitative bioprocess analysis of extreme halophilic Archaea with an extreme halophilic strain as an example. Firstly, as a novel usage, a corrosion resistant bioreactor setup for extreme halophiles has been implemented. Then, paying special attention to total bioprocess quantification approaches, an indirect method for biomass quantification using on-line process signals was introduced. Subsequently, robust quantitative data evaluation methods for halophiles could be developed, providing defined and controlled cultivation conditions in the bioreactor and therefore obtaining suitable quality of on-line as well as off-line datasets. On the other hand, new physiological results of extreme halophiles in bioreactor have also been obtained based on the quantitative methodological tools. For the first time, quantitative data on stoichiometry and kinetics were collected and evaluated on different carbon sources. The results on various substrates were interpreted, with proposed metabolic mechanisms, by linking to the reported primary carbon metabolism of extreme halophilic Archaea. Moreover, results of chemostat cultures demonstrated that extreme halophilic organisms show Monod-kinetics on different sole carbon sources. A diauxic growth pattern was described on a mixture of substrates in batch cultivations. In addition, the methodologies presented here enable one to characterize the utilized strain Haloferax mediterranei (HFX) as a potential new host organism. Thus, this study offers a strong methodological basis as well as a fundamental physiological assessment for

  14. Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Khondee, Nichakorn; Tathong, Sitti [International Postgraduate Programs in Environmental Management, Graduate School, Chulalongkorn University, Bangkok (Thailand); Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Pinyakong, Onruthai [Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management (NCE-EHWM), Chulalongkorn University, Bangkok (Thailand); Powtongsook, Sorawit [Center of Excellence for Marine Biotechnology (c/o Department of Marine Science, Chulalongkorn University), National Center for Genetic Engineering and Biotechnology, Pathum Thani (Thailand); Chatchupong, Thawach; Ruangchainikom, Chalermchai [Environmental Research and Management Department, PTT Research and Technology Institute, Ayutthaya (Thailand); Luepromchai, Ekawan, E-mail: ekawan.l@chula.ac.th [Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management (NCE-EHWM), Chulalongkorn University, Bangkok (Thailand)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Sphingobium sp. P2 effectively degraded various lubricant samples. Black-Right-Pointing-Pointer Efficiency of Sphingobium sp. P2 increased after immobilization on chitosan. Black-Right-Pointing-Pointer High removal efficiency was due to both sorption and degradation processes. Black-Right-Pointing-Pointer The immobilized bacteria (4 g L{sup -1}) were applied in internal loop airlift bioreactor. Black-Right-Pointing-Pointer The bioreactor continuously removed lubricant from emulsified wastewater. - Abstract: An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80-90% of the 200 mg L{sup -1} total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4 g L{sup -1} immobilized bacteria, was later designed and operated at 2.0 h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85 {+-} 5% TPH and 73 {+-} 11% chemical oxygen demand (COD) from the carwash wastewater with 25-200 mg L{sup -1} amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries.

  15. Nitrate-Mediated Microbially Enhanced Oil Recovery (N-MEOR) from model upflow bioreactors.

    Science.gov (United States)

    Gassara, Fatma; Suri, Navreet; Voordouw, Gerrit

    2017-02-15

    Microbially Enhanced Oil Recovery (MEOR) can enhance oil production with less energy input and less costs than other technologies. The present study used different aqueous electron donors (acetate, glucose, molasses) and an aqueous electron acceptor (nitrate) to stimulate growth of heterotrophic nitrate reducing bacteria (hNRB) to improve production of oil. Initial flooding of columns containing heavy oil (viscosity of 3400cP at 20°C) with CSBK (Coleville synthetic brine medium) produced 0.5 pore volume (PV) of oil. Bioreactors were then inoculated with hNRB with 5.8g/L of molasses and 0, 10, 20, 40, 60 or 80mM nitrate, as well as with 17mM glucose or 57mM acetate and 80mM nitrate. During incubations no oil was produced in the bioreactors that received 5.8g/L of molasses and 0, 10, 20, 40 or 60mM nitrate. However, the bioreactors injected with 5.8g/L of molasses, 17mM glucose or 57mM acetate and 80mM nitrate produced 13.9, 11.3±3.1 and 17.8±6.6% of residual oil, respectively. The significant production of oil from these bioreactors may be caused by N 2 -CO 2 gas production. Following continued injection with CSBK without nitrate, subsequent elution of significant residual oil (5-30%) was observed. These results also indicate possible involvement of fermentation products (organic acids, alcohols) to enhance heavy oil recovery. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Enhancement of oxygen transfer and nitrogen removal in a membrane separation bioreactor for domestic wastewater treatment.

    Science.gov (United States)

    Chiemchaisri, C; Yamamoto, K

    2005-01-01

    Biological nitrogen removal in a membrane separation bioreactor developed for on-site domestic wastewater treatment was investigated. The bioreactor employed hollow fiber membrane modules for solid-liquid separation so that the biomass could be completely retained within the system. Intermittent aeration was supplied with 90 minutes on and off cycle to achieve nitrification and denitrification reaction for nitrogen removal. High COD and nitrogen removal of more than 90% were achieved under a moderate temperature of 25 degrees C. As the temperature was stepwise decreased from 25 to 5 degrees C, COD removal in the system could be constantly maintained while nitrogen removal was deteriorated. Nevertheless, increasing aeration supply could enhance nitrification at low temperature with benefit from complete retention of nitrifying bacteria within the system by membrane separation. At low operating temperature range of 5 degrees C, nitrogen removal could be recovered to more than 85%. A mathematical model considering diffusion resistance of limiting substrate into the bio-particle is applied to describe nitrogen removal in a membrane separation bioreactor. The simulation suggested that limitation of the oxygen supply was the major cause of inhibition of nitrification during temperature decrease. Nevertheless, increasing aeration could promote oxygen diffusion into the bio-particle. Sufficient oxygen was supplied to the nitrifying bacteria and the nitrification could proceed. In the membrane separation bioreactor, biomass concentration under low temperature operation was allowed to increase by 2-3 times of that of moderate temperature to compensate for the loss of bacterial activities so that the temperature effect was masked.

  17. Desarrollo de un Modelo Reológico de Lodos Activados Para Bioreactores Con Membrana (MBR)

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Bentzen, Thomas Ruby; Moreau, A.A.

    2012-01-01

    Los bioreactores con membranas (MBR) han ganado cada vez más importancia en la última década para el tratamiento de aguas residuales [1] en comparación con los tratamientos convencionales. Entre sus causas cuentan su alta retención de sólidos, ocupación de menos espacio y la generación de una mej...

  18. The Influence of Bioreactor Geometry and the Mechanical Environment on Engineered Tissues

    KAUST Repository

    Osborne, J. M.

    2010-01-01

    A three phase model for the growth of a tissue construct within a perfusion bioreactor is examined. The cell population (and attendant extracellular matrix), culture medium, and porous scaffold are treated as distinct phases. The bioreactor system is represented by a two-dimensional channel containing a cell-seeded rigid porous scaffold (tissue construct), which is perfused with a culture medium. Through the prescription of appropriate functional forms for cell proliferation and extracellular matrix deposition rates, the model is used to compare the influence of cell density-, pressure-, and culture medium shear stress-regulated growth on the composition of the engineered tissue. The governing equations are derived in O\\'Dea et al. "A Three Phase Model for Tissue Construct Growth in a Perfusion Bioreactor," Math. Med. Biol., in which the long-wavelength limit was exploited to aid analysis; here, finite element methods are used to construct two-dimensional solutions to the governing equations and to investigate thoroughly their behavior. Comparison of the total tissue yield and averaged pressures, velocities, and shear stress demonstrates that quantitative agreement between the two-dimensional and long-wavelength approximation solutions is obtained for channel aspect ratios of order 10 -2 and that much of the qualitative behavior of the model is captured in the long-wavelength limit, even for relatively large channel aspect ratios. However, we demonstrate that in order to capture accurately the effect of mechanotransduction mechanisms on tissue construct growth, spatial effects in at least two dimensions must be included due to the inherent spatial variation of mechanical stimuli relevant to perfusion bioreactors, most notably, fluid shear stress, a feature not captured in the long-wavelength limit. Copyright © 2010 by ASME.

  19. Novel Dual Stage Membrane Bioreactor for the Continuous Remediation of Electroplating Wastewater

    OpenAIRE

    B. A. Q. Santos; S. K. O. Ntwampe; G. Muchatibaya

    2013-01-01

    In this study, the designed dual stage membrane bioreactor (MBR) system was conceptualized for the treatment of cyanide and heavy metals in electroplating wastewater. The design consisted of a primary treatment stage to reduce the impact of fluctuations and the secondary treatment stage to remove the residual cyanide and heavy metal contaminants in the wastewater under alkaline pH conditions. The primary treatment stage contained hydrolyzed Citrus sinensis (C. sinensis) p...

  20. High-rate, High Temperature Acetotrophic Methanogenesis Governed by a Three Population Consortium in Anaerobic Bioreactors

    OpenAIRE

    Ho, Dang; Jensen, Paul; Gutierrez-Zamora, Maria-Luisa; Beckmann, Sabrina; Manefield, Mike; Batstone, Damien

    2016-01-01

    A combination of acetate oxidation and acetoclastic methanogenesis has been previously identified to enable high-rate methanogenesis at high temperatures (55 to 65°C), but this capability had not been linked to any key organisms. This study combined RNA-stable isotope probing on 13C-labelled acetate and 16S amplicon sequencing to identify the active micro-organisms involved in high-rate methanogenesis. Active biomass was harvested from three bench-scale thermophilic bioreactors treating waste...

  1. Small-scale, hydrogen-oxidizing-denitrifying bioreactor for treatment of nitrate-contaminated drinking water.

    Science.gov (United States)

    Smith, Richard L; Buckwalter, Seanne P; Repert, Deborah A; Miller, Daniel N

    2005-05-01

    Nitrate removal by hydrogen-coupled denitrification was examined using flow-through, packed-bed bioreactors to develop a small-scale, cost effective system for treating nitrate-contaminated drinking-water supplies. Nitrate removal was accomplished using a Rhodocyclus sp., strain HOD 5, isolated from a sole-source drinking-water aquifer. The autotrophic capacity of the purple non-sulfur photosynthetic bacterium made it particularly adept for this purpose. Initial tests used a commercial bioreactor filled with glass beads and countercurrent, non-sterile flow of an autotrophic, air-saturated, growth medium and hydrogen gas. Complete removal of 2 mM nitrate was achieved for more than 300 days of operation at a 2-h retention time. A low-cost hydrogen generator/bioreactor system was then constructed from readily available materials as a water treatment approach using the Rhodocyclus strain. After initial tests with the growth medium, the constructed system was tested using nitrate-amended drinking water obtained from fractured granite and sandstone aquifers, with moderate and low TDS loads, respectively. Incomplete nitrate removal was evident in both water types, with high-nitrite concentrations in the bioreactor output, due to a pH increase, which inhibited nitrite reduction. This was rectified by including carbon dioxide in the hydrogen stream. Additionally, complete nitrate removal was accomplished with wastewater-impacted surface water, with a concurrent decrease in dissolved organic carbon. The results of this study using three chemically distinct water supplies demonstrate that hydrogen-coupled denitrification can serve as the basis for small-scale remediation and that pilot-scale testing might be the next logical step.

  2. Physicochemical properties influencing denitrification rate and microbial activity in denitrification bioreactors

    Science.gov (United States)

    Schmidt, C. A.

    2012-12-01

    The use of N-based fertilizer will need to increase to meet future demands, yet existing applications have been implicated as the main source of coastal eutrophication and hypoxic zones. Producing sufficient crops to feed a growing planet will require efficient production in combination with sustainable treatment solutions. The long-term success of denitrification bioreactors to effectively remove nitrate (NO¬3), indicates this technology is a feasible treatment option. Assessing and quantifying the media properties that affect NO¬3 removal rate and microbial activity can improve predictions on bioreactor performance. It was hypothesized that denitrification rates and microbial biomass would be correlated with total C, NO¬3 concentration, metrics of organic matter quality, media surface area and laboratory measures of potential denitrification rate. NO¬3 removal rates and microbial biomass were evaluated in mesocosms filled with different wood treatments and the unique influence of these predictor variables was determined using a multiple linear regression analysis. NO3 reduction rates were independent of NO¬3 concentration indicating zero order reaction kinetics. Temperature was strongly correlated with denitrification rate (r2=0.87; Q10=4.7), indicating the variability of bioreactor performance in differing climates. Fiber quality, and media surface area were strong (R>0.50), unique predictors of rates and microbial biomass, although C:N ratio and potential denitrification rate did not predict actual denitrification rate or microbial biomass. Utilizing a stepwise multiple linear regression, indicates that the denitrification rate can be effectively (r2=0.56;pdetergent fiber and surface area alone are quantified. These results will assist with the widespread implementation of denitrification bioreactors to achieve significant N load reductions in large watersheds. The nitrate reduction rate as a function of groundwater temperature for all treatments

  3. Growth Performance and Hematological Traits of Weaner Pigs Fed ...

    African Journals Online (AJOL)

    Sixty Weaner pigs with an average initial live weight of 6.81 ± 1.0kg were studied for their growth and haematological parameters when fed graded levels of raw bambara waste (BW) using a completely randomized design (CRD). They were fed five diets containing 0, 25, 50, 75 and 100 percentage composition for 5 months ...

  4. A preliminary study on growth response of broiler finishers fed ...

    African Journals Online (AJOL)

    A preliminary study on growth response of broiler finishers fed processed mottle Mucuna beans ( Mucuna pruriens var. utilis ) ... They were fed diets (20% CP, 13 MJME/kg) incorporating 0%, 5% and 10% processed mottle “Mucuna” beans. A completely randomized design was used. Feed and water were supplied and ...

  5. PHA Productivity and Yield of Ralstonia eutropha When Intermittently or Continuously Fed a Mixture of Short Chain Fatty Acids

    Directory of Open Access Journals (Sweden)

    Panchali Chakraborty

    2012-01-01

    Full Text Available The research described in this present study was part of a larger effort focused on developing a dual substrate, dual fermentation process to produce Polyhydroxyalkanoate (PHA. The focus of this study was developing and optimizing a strategy for feeding a mixture of SCFAs (simulated ARF and maximizing PHA production in a cost-effective way. Three different feeding strategies were examined in this study. The substrate evaluated in this study for the growth phase of R. eutropha was condensed corn solubles, a low-value byproduct of the dry-mill, corn ethanol industry. The culture was grown to high cell densities in nitrogen-supplemented condensed corn solubles media in 5 L bioreactors. The overall growth rate of R. eutropha was 0.2 h−1. The 20 mL ARF feeding every 3 h from 48 to 109 h strategy gave the best results in terms of PHA production. PHA productivity (0.0697 g L−1 h−1, PHA concentration (8.37 g L−1, and PHA content (39.52% were the highest when ARF was fed every 3 h for 61 h. This study proved that condensed corn solubles can be potentially used as a growth medium to boost PHA production by R. eutropha thus reducing the overall cost of biopolymer production.

  6. PHA Productivity and Yield of Ralstonia eutropha When Intermittently or Continuously Fed a Mixture of Short Chain Fatty Acids

    Science.gov (United States)

    Chakraborty, Panchali; Muthukumarappan, Kasiviswanathan; Gibbons, William R.

    2012-01-01

    The research described in this present study was part of a larger effort focused on developing a dual substrate, dual fermentation process to produce Polyhydroxyalkanoate (PHA). The focus of this study was developing and optimizing a strategy for feeding a mixture of SCFAs (simulated ARF) and maximizing PHA production in a cost-effective way. Three different feeding strategies were examined in this study. The substrate evaluated in this study for the growth phase of R. eutropha was condensed corn solubles, a low-value byproduct of the dry-mill, corn ethanol industry. The culture was grown to high cell densities in nitrogen-supplemented condensed corn solubles media in 5 L bioreactors. The overall growth rate of R. eutropha was 0.2 h−1. The 20 mL ARF feeding every 3 h from 48 to 109 h strategy gave the best results in terms of PHA production. PHA productivity (0.0697 g L−1 h−1), PHA concentration (8.37 g L−1), and PHA content (39.52%) were the highest when ARF was fed every 3 h for 61 h. This study proved that condensed corn solubles can be potentially used as a growth medium to boost PHA production by R. eutropha thus reducing the overall cost of biopolymer production. PMID:23118512

  7. Production of carotenoids and lipids by Rhodococcus opacus PD630 in batch and fed-batch culture.

    Science.gov (United States)

    Thanapimmetha, Anusith; Suwaleerat, Tharatron; Saisriyoot, Maythee; Chisti, Yusuf; Srinophakun, Penjit

    2017-01-01

    Production of carotenoids by Rhodococcus opacus PD630 is reported. A modified mineral salt medium formulated with glycerol as an inexpensive carbon source was used for the fermentation. Ammonium acetate was the nitrogen source. A dry cell mass concentration of nearly 5.4 g/L could be produced in shake flasks with a carotenoid concentration of 0.54 mg/L. In batch culture in a 5 L bioreactor, without pH control, the maximum dry biomass concentration was ~30 % lower than in shake flasks and the carotenoids concentration was 0.09 mg/L. Both the biomass concentration and the carotenoids concentration could be raised using a fed-batch operation with a feed mixture of ammonium acetate and acetic acid. With this strategy, the final biomass concentration was 8.2 g/L and the carotenoids concentration was 0.20 mg/L in a 10-day fermentation. A control of pH proved to be unnecessary for maximizing the production of carotenoids in this fermentation.

  8. Impact of Furfural on Rapid Ethanol Production Using a Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    Mohammad J. Taherzadeh

    2013-03-01

    Full Text Available A membrane bioreactor was developed to counteract the inhibition effect of furfural in ethanol production. Furfural, a major inhibitor in lignocellulosic hydrolyzates, is a highly toxic substance which is formed from pentose sugars released during the acidic degradation of lignocellulosic materials. Continuous cultivations with complete cell retention were performed at a high dilution rate of 0.5 h−1. Furfural was added directly into the bioreactor by pulse injection or by addition into the feed medium to obtain furfural concentrations ranging from 0.1 to 21.8 g L−1. At all pulse injections of furfural, the yeast was able to convert the furfural very rapidly by in situ detoxification. When injecting 21.8 g L−1 furfural to the cultivation, the yeast converted it by a specific conversion rate of 0.35 g g−1 h−1. At high cell density, Saccharomyces cerevisiae could tolerate very high furfural levels without major changes in the ethanol production. During the continuous cultures when up to 17.0 g L−1 furfural was added to the inlet medium, the yeast successfully produced ethanol, whereas an increase of furfural to 18.6 and 20.6 g L−1 resulted in a rapidly decreasing ethanol production and accumulation of sugars in the permeate. This study show that continuous ethanol fermentations by total cell retention in a membrane bioreactor has a high furfural tolerance and can conduct rapid in situ detoxification of medium containing high furfural concentrations.

  9. Bioprocess development for kefiran production by Lactobacillus kefiranofaciens in semi industrial scale bioreactor

    Directory of Open Access Journals (Sweden)

    Daniel Joe Dailin

    2016-07-01

    Full Text Available Lactobacillus kefiranofaciens is non-pathogenic gram positive bacteria isolated from kefir grains and able to produce extracellular exopolysaccharides named kefiran. This polysaccharide contains approximately equal amounts of glucose and galactose. Kefiran has wide applications in pharmaceutical industries. Therefore, an approach has been extensively studied to increase kefiran production for pharmaceutical application in industrial scale. The present work aims to maximize kefiran production through the optimization of medium composition and production in semi industrial scale bioreactor. The composition of the optimal medium for kefiran production contained sucrose, yeast extract and K2HPO4 at 20.0, 6.0, 0.25 g L−1, respectively. The optimized medium significantly increased both cell growth and kefiran production by about 170.56% and 58.02%, respectively, in comparison with the unoptimized medium. Furthermore, the kinetics of cell growth and kefiran production in batch culture of L. kefiranofaciens was investigated under un-controlled pH conditions in 16-L scale bioreactor. The maximal cell mass in bioreactor culture reached 2.76 g L−1 concomitant with kefiran production of 1.91 g L−1.

  10. Bioprocess development for kefiran production by Lactobacillus kefiranofaciens in semi industrial scale bioreactor.

    Science.gov (United States)

    Dailin, Daniel Joe; Elsayed, Elsayed Ahmed; Othman, Nor Zalina; Malek, Roslinda; Phin, Hiew Siaw; Aziz, Ramlan; Wadaan, Mohamad; El Enshasy, Hesham Ali

    2016-07-01

    Lactobacillus kefiranofaciens is non-pathogenic gram positive bacteria isolated from kefir grains and able to produce extracellular exopolysaccharides named kefiran. This polysaccharide contains approximately equal amounts of glucose and galactose. Kefiran has wide applications in pharmaceutical industries. Therefore, an approach has been extensively studied to increase kefiran production for pharmaceutical application in industrial scale. The present work aims to maximize kefiran production through the optimization of medium composition and production in semi industrial scale bioreactor. The composition of the optimal medium for kefiran production contained sucrose, yeast extract and K2HPO4 at 20.0, 6.0, 0.25 g L(-1), respectively. The optimized medium significantly increased both cell growth and kefiran production by about 170.56% and 58.02%, respectively, in comparison with the unoptimized medium. Furthermore, the kinetics of cell growth and kefiran production in batch culture of L. kefiranofaciens was investigated under un-controlled pH conditions in 16-L scale bioreactor. The maximal cell mass in bioreactor culture reached 2.76 g L(-1) concomitant with kefiran production of 1.91 g L(-1).

  11. Phosphorus and water recovery by a novel osmotic membrane bioreactor-reverse osmosis system.

    Science.gov (United States)

    Luo, Wenhai; Hai, Faisal I; Price, William E; Guo, Wenshan; Ngo, Hao H; Yamamoto, Kazuo; Nghiem, Long D

    2016-01-01

    An osmotic membrane bioreactor-reverse osmosis (OMBR-RO) hybrid system integrated with periodic microfiltration (MF) extraction was evaluated for simultaneous phosphorus and clean water recovery from raw sewage. In this hybrid system, the forward osmosis membrane effectively retained inorganic salts and phosphate in the bioreactor, while the MF membrane periodically bled them out for phosphorus recovery with pH adjustment. The RO process was used for draw solute recovery and clean water production. Results show that phosphorus recuperation from the MF permeate was most effective when the solution pH was adjusted to 10, whereby the recovered precipitate contained 15-20% (wt/wt) of phosphorus. Periodic MF extraction also limited salinity build-up in the bioreactor, resulting in a stable biological performance and an increase in water flux during OMBR operation. Despite the build-up of organic matter and ammonia in the draw solution, OMBR-RO allowed for the recovery of high quality reused water. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  12. Performance of an anaerobic, static bed, fixed film bioreactor for chlorinated solvent treatment

    Science.gov (United States)

    Lorah, Michelle M.; Walker, Charles; Graves, Duane

    2015-01-01

    Anaerobic, fixed film, bioreactors bioaugmented with a dechlorinating microbial consortium were evaluated as a potential technology for cost effective, sustainable, and reliable treatment of mixed chlorinated ethanes and ethenes in groundwater from a large groundwater recovery system. Bench- and pilot-scale testing at about 3 and 13,500 L, respectively, demonstrated that total chlorinated solvent removal to less than the permitted discharge limit of 100 μg/L. Various planned and unexpected upsets, interruptions, and changes demonstrated the robustness and reliability of the bioreactor system, which handled the operational variations with no observable change in performance. Key operating parameters included an adequately long hydraulic retention time for the surface area, a constant supply of electron donor, pH control with a buffer to minimize pH variance, an oxidation reduction potential of approximately −200 millivolts or lower, and a well-adapted biomass capable of degrading the full suite of chlorinated solvents in the groundwater. Results indicated that the current discharge criteria can be met using a bioreactor technology that is less complex and has less downtime than the sorption based technology currently being used to treat the groundwater.

  13. Microbial biosafety of pilot-scale bioreactor treating MTBE and TBA-contaminated drinking water supply.

    Science.gov (United States)

    Schmidt, Radomir; Klemme, David A; Scow, Kate; Hristova, Krassimira

    2012-03-30

    A pilot-scale sand-based fluidized bed bioreactor (FBBR) was utilized to treat both methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) from a contaminated aquifer. To evaluate the potential for re-use of the treated water, we tested for a panel of water quality indicator microorganisms and potential waterborne pathogens including total coliforms, Escherichia coli, Salmonella and Shigella spp., Campylobacter jejuni, Aeromonas hydrophila, Legionella pneumophila, Vibrio cholerae, Yersinia enterocolytica and Mycobacterium avium in both influent and treated waters from the bioreactor. Total bacteria decreased during FBBR treatment. E. coli, Salmonella and Shigella spp., C. jejuni, V. cholerae, Y. enterocolytica and M. avium were not detected in aquifer water or bioreactor treated water samples. For those pathogens detected, including total coliforms, L. pneumophila and A. hydrophila, numbers were usually lower in treated water than influent samples, suggesting removal during treatment. The detection of particular bacterial species reflected their presence or absence in the influent waters. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Oxygen mass transfer in a stirred tank bioreactor using different impeller configurations for environmental purposes

    Science.gov (United States)

    2013-01-01

    In this study, a miniature stirred tank bioreactor was designed for treatment of waste gas containing benzene, toluene and xylene. Oxygen mass transfer characteristics for various twin and single-impeller systems were investigated for 6 configurations in a vessel with 10 cm of inner diameter and working volume of 1.77L. Three types of impellers, namely, Rushton turbine, Pitched 4blades and Pitched 2blades impellers with downward pumping have been used. Deionized water was used as a liquid phase. With respect to other independent variables such as agitation speed, aeration rate, type of sparger, number of impellers, the relative performance of these impellers was assessed by comparing the values of (KLa) as a key parameter. Based on the experimental data, empirical correlations as a function of the operational conditions have been proposed, to study the oxygen transfer rates from air bubbles generated in the bioreactor. It was shown that twin Rushton turbine configuration demonstrates superior performance (23% to 77% enhancement in KLa) compared with other impeller compositions and that sparger type has negligible effect on oxygen mass transfer rate. Agitation speeds of 400 to 800 rpm were the most efficient speeds for oxygen mass transfer in the stirred bioreactor. PMID:23369581

  15. Engineering Parameters in Bioreactor's Design: A Critical Aspect in Tissue Engineering

    Science.gov (United States)

    Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors. PMID:24000327

  16. Engineering parameters in bioreactor's design: a critical aspect in tissue engineering.

    Science.gov (United States)

    Salehi-Nik, Nasim; Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Anisi, Fatemeh; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.

  17. Membrane bioreactor technology: A novel approach to the treatment of compost leachate

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kayleigh; Ghoshdastidar, Avik J.; Hanmore, Jillian [Department of Chemistry, Acadia University, Wolfville, NS, Canada B4P 2R6 (Canada); Frazee, James [E and Q Consulting and Associates Limited, Wolfville, NS, Canada B4P 2R1 (Canada); Tong, Anthony Z., E-mail: anthony.tong@acadiau.ca [Department of Chemistry, Acadia University, Wolfville, NS, Canada B4P 2R6 (Canada)

    2013-11-15

    Highlights: • First membrane bioreactor treatment method for compost leachate. • No chemical additive or UV radiation source in this new biological method. • Removal rates of more than 99% for organics and ammonium were achieved. • Heavy metals were reduced by at least 82.7% except copper. - Abstract: Compost leachate forms during the composting process of organic material. It is rich in oxidizable organics, ammonia and metals, which pose a risk to the environment if released without proper treatment. An innovative method based on the membrane bioreactor (MBR) technology was developed to treat compost leachate over 39 days. Water quality parameters, such as pH, dissolved oxygen, ammonia, nitrate, nitrite and chemical oxygen demand (COD) were measured daily. Concentrations of caffeine and metals were measured over the course of the experiment using gas chromatography – mass spectrometry (GC/MS) and inductively coupled plasma – mass spectrometry (ICP–MS) respectively. A decrease of more than 99% was achieved for a COD of 116 g/L in the initial leachate. Ammonia was decreased from 2720 mg/L to 0.046 mg/L, while the nitrate concentration in the effluent rose to 710 mg/L. The bacteria in the MBR system adjusted to the presence of the leachate, and increased 4 orders of magnitude. Heavy metals were removed by at least 82.7% except copper. These successful results demonstrated the membrane bioreactor technology is feasible, efficient method for the treatment of compost leachate.

  18. Application of enhanced membrane bioreactor (eMBR) to treat dye wastewater.

    Science.gov (United States)

    Rondon, Hector; El-Cheikh, William; Boluarte, Ida Alicia Rodriguez; Chang, Chia-Yuan; Bagshaw, Steve; Farago, Leanne; Jegatheesan, Veeriah; Shu, Li

    2015-05-01

    An enhanced membrane bioreactor (eMBR) consisting of two anoxic bioreactors (ARs) followed by an aerated membrane bioreactor (AMBR), UV-unit and a granular activated carbon (GAC) filter was employed to treat 50-100 mg/L of remazol blue BR dye. The COD of the feed was 2334 mg/L and COD:TN:TP in the feed was 119:1.87:1. A feed flow rate of 5 L/d was maintained when the dye concentration was 50 mg/L; 10 L/d of return activated sludge was recirculated to each AR from the AMBR. Once the biological system is acclimatised, 95% of dye, 99% of COD, 97% of nitrogen and 73% of phosphorus were removed at a retention time of 74.4 h. When the effluent from the AMBR was drawn at a flux rate of 6.5 L/m(2)h, the trans-membrane pressure reached 40 kPa in every 10 days. AMBR effluent was passed through the UV-unit and GAC filter to remove the dye completely. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Modeling of mixing in stirred bioreactors 4. mixing time for aerated bacteria, yeasts and fungus broths

    Directory of Open Access Journals (Sweden)

    Cascaval Dan

    2004-01-01

    Full Text Available The mixing time for bioreactors depends mainly on the rheoiogicai properties of the broths, the biomass concentration and morphology, mixing system characteristics and fermentation conditions. For quantifying the influence of these factors on the mixing efficiency for stirred bioreactors, aerated broths of bacteria (P. shermanii, yeasts (S. cerevisiae and fungi (P. chrysogenum, free mycelia and mycelial aggregates of different concentrations have been investigated using a laboratory bioreactor with a double turbine impeller. The experimental data indicated that the influence of the rotation speed, aeration rate and stirrer positions on the mixing intensity strongly differ from one system to another and must be correlated with the microorganism characteristics, namely: the biomass concentration and morphology. Moreover, compared with non-aerated broths, variations of the mixing time with the considered parameters are very different, due to the complex flow mechanism of gas-liquid dispersions. By means of the experimental data and using a multiregression analysis method some mathematical correlations for the mixing time of the general form: tm = a1*Cx2+a2*Cx+a3*IgVa+a4-N2+a5-N+a6/a7*L2+a8*L+a9 were established. The proposed equations offer good agreement with the experiments, the average deviation being ±6.7% - ±9.4 and are adequate for the flow regime Re < 25,000.

  20. Cost effective dry anaerobic digestion in textile bioreactors: Experimental and economic evaluation.

    Science.gov (United States)

    Patinvoh, Regina J; Osadolor, Osagie A; Sárvári Horváth, Ilona; Taherzadeh, Mohammad J

    2017-12-01

    The aim of this work was to study dry anaerobic digestion (dry-AD) of manure bedded with straw using textile-based bioreactor in repeated batches. The 90-L reactor filled with the feedstocks (22-30% total solid) and inoculum without any further treatment, while the biogas produced were collected and analyzed. The digestate residue was also analyzed to check its suitability as bio-fertilizer. Methane yield after acclimatization increased from 183 to 290NmlCH 4 /gVS, degradation time decreased from 136 to 92days and the digestate composition point to suitable bio-fertilizer. The results then used to carry out economical evaluation, which shows dry-AD in textile bioreactors is a profitable method of handling the waste with maximum payback period of 5years, net present value from $7,000 to $9,800,000 (small to large bioreactors) with internal rate of return from 56.6 to 19.3%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Effect of different leachate/acetate ratios in a submerged anaerobic membrane bioreactor (SAnMBR)

    Energy Technology Data Exchange (ETDEWEB)

    Taskan, Ergin [Department of Environmental Engineering, Faculty of Engineering, Firat University, Elazig (Turkey); Hasar, Halil [Department of Environmental Engineering, Faculty of Engineering, Firat University, Elazig (Turkey); National Research Center on Membrane Technologies, Maslak, Istanbul (Turkey)

    2012-05-15

    Leachate treatment using a membrane bioreactor is an effective method. This study presents a configuration including an anaerobic bioreactor and a membrane module, called submerged anaerobic membrane bioreactor (SAnMBR), for treating influent with leachate/acetate rations (L/A), that were kept to be 10, 25, 50, 75, and 100% at a constant SRT (100 days). COD removal decreased from 85 to 75% when the L/A ratio increased from 10 to 100. To prevent membrane fouling, a SAnMBR was operated in the case of circulation of mixed liquor under continuous and intermittent suction. The average fluxes were 2.60 and 0.40 L/m{sup 2} h at the periods of intermittent and continuous suction, respectively. The methane production varied between 0.25 and 0.32 L CH{sub 4}/g COD{sub removed}. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. PERFORMANCE OF NEWLY CONFIGURED SUBMERGED MEMBRANE BIOREACTOR FOR AEROBIC INDUSTRIAL WASTEWATER TREATMENT

    Directory of Open Access Journals (Sweden)

    I Gede Wenten

    2012-02-01

    Full Text Available The application of membrane to replace secondary clarifier of conventional activated sludge, known as membrane bioreactor, has led to a small footprint size of treatment with excellent effluent quality. The use of MBR eliminates almost all disadvantages encountered in conventional wastewater treatment plant such as low biomass concentration and washout of fine suspended solids. However, fouling remains as a main drawback. To minimize membrane fouling, a new configuration of submerged membrane bioreactor for aerobic industrial wastewater treatment has been developed. For the new configuration, a bed of porous particle is applied to cover the submerged ends-free mounted ultrafiltration membrane. Membrane performance was assessed based on flux productivity and selectivity. By using tapioca wastewater containing high organic matter as feed solution, reasonably high and stable fluxes around 11 l/m2.h were achieved with COD removal efficiency of more than 99%. The fouling analysis also shows that the newly configured ends-free membrane bioreactor exhibits lower irreversible resistance compared with the submerged one. In addition, the performance of pilot scale system, using a membrane module  with 10 m2 effective area and reactor tank with 120 L volume, was also assessed. The flux achieved from the pilot scale system around 8 l/m2.h with COD removal of more than 99%. Hence, this study has demonstrated the feasibility of the newly configured submerged ends-free MBR at larger scale.

  3. Combination of electrochemical processes with membrane bioreactors for wastewater treatment and fouling control: A review

    Directory of Open Access Journals (Sweden)

    Benny Marie B. Ensano

    2016-08-01

    Full Text Available This paper provides a critical review about the integration of electrochemical processes into membrane bioreactors (MBR in order to understand the influence of these processes on wastewater treatment performance and membrane fouling control. The integration can be realized either in an internal or an external configuration. Electrically enhanced membrane bioreactors or electro membrane bioreactors (eMBRs combine biodegradation, electrochemical and membrane filtration processes into one system providing higher effluent quality as compared to conventional MBRs and activated sludge plants. Furthermore, electrochemical processes, such as electrocoagulation, electrophoresis and electroosmosis, help to mitigate deposition of foulants into the membrane and enhance sludge dewaterability by controlling the morphological properties and mobility of the colloidal particles and bulk liquid. Intermittent application of minute electric field has proven to reduce energy consumption and operational cost as well as minimize the negative effect of direct current field on microbial activity which are some of the main concerns in eMBR technology. The present review discusses important design considerations of eMBR, its advantages as well as its applications to different types of wastewater. It also presents several challenges that need to be addressed for future development of this hybrid technology which include treatment of high strength industrial wastewater and removal of emerging contaminants, optimization study, cost benefit analysis and the possible combination with microbial electrolysis cell for biohydrogen production.

  4. Numerical Simulation of Mixing in a Micro-well Scale Bioreactor by Computational Fluid Dynamics

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The introduction of the multi-well plate miniaturisation technology with its associated automated dispensers, readers and integrated systems coupled with advances in life sciences has a propelling effect on the rate at which new potential drug molecules are discovered. The translation of these discoveries to real outcome now demands parallel approaches which allow large numbers of process options to be rapidly assessed. The engineering challenges in achieving this provide the motivation for the proposed work. In this work we used computational fluid dynamics(CFD) analysis to study flow conditions in a gas-liquid contactor which has the potential to be used as a fermenter on a multi-well format. The bioreactor had a working volume of 6.5 mL with the major dimensions equal to those of a single well of a 24-well plate. The 6.5 mL bioreactor was mechanically agitated and aerated by a single sparger placed beneath the bottom impeller. Detailed numerical procedure for solving the governing flow equations is given. The CFD results are combined with population balance equations to establish the size of the bubbles and their distribution in the bioreactor, Power curves with and without aeration are provided based on the simulated results.

  5. Predictive control of hollow-fiber bioreactors for the production of monoclonal antibodies.

    Science.gov (United States)

    Dowd, J E; Weber, I; Rodriguez, B; Piret, J M; Kwok, K E

    1999-05-20

    The selection of medium feed rates for perfusion bioreactors represents a challenge for process optimization, particularly in bioreactors that are sampled infrequently. When the present and immediate future of a bioprocess can be adequately described, predictive control can minimize deviations from set points in a manner that can maximize process consistency. Predictive control of perfusion hollow-fiber bioreactors was investigated in a series of hybridoma cell cultures that compared operator control to computer estimation of feed rates. Adaptive software routines were developed to estimate the current and predict the future glucose uptake and lactate production of the bioprocess at each sampling interval. The current and future glucose uptake rates were used to select the perfusion feed rate in a designed response to deviations from the set point values. The routines presented a graphical user interface through which the operator was able to view the up-to-date culture performance and assess the model description of the immediate future culture performance. In addition, fewer samples were taken in the computer-estimated cultures, reducing labor and analytical expense. The use of these predictive controller routines and the graphical user interface decreased the glucose and lactate concentration variances up to sevenfold, and antibody yields increased by 10% to 43%. Copyright 1999 John Wiley & Sons, Inc.

  6. Optimization of Wastewater of Batik Buaran Pekalongan by Using Photocatalytic Membrane Bioreactor

    Science.gov (United States)

    Arifan, Fahmi; Nugraheni, FS; Lianandaya, Niken Elsa

    2018-02-01

    The purpose of this study is to determine the final COD concentration reduction by changing COD and MLSS concentration on the performance of submerged membrane bioreactor (MBRs) as a waste treatment of Batik in Buaran Pekalongan. The method is covers the process of seeding, the acclimatization process and the main process. Description of the process that we take an active mud from IPLT Buaran Pekalongan, then we analyze the sludge MLSS, MLVSS, COD, BOD, and TSS. After that we enter the active sludge in the bath nursery that has been given aerator (a tool for aeration) and made provision in the form of NPK nutrients and glucose at a ratio of 1:10. Activated sludge from the acclimatization process is inserted into the MBRs (membrane bioreactor submerged) that is equipped with an aerator. Then prepare influent(waste to be lowered concentration of COD). How, liquid waste of Batik Pekalongan Buaran COD diluted concentration of 10,000 mg / l and 15,000 mg / l, and then inserted in influent tub. After that liquid waste of Batik Buaran Pekalongan influent flowed into Photocatalytic Membrane Bioreactor, of MPB effluent flowed into the tub (result).

  7. Heat and Mass Transfer Remote Control in Bioreactors of Technological Lines

    Directory of Open Access Journals (Sweden)

    Viktorija M. Mel’nick

    2017-10-01

    Full Text Available Background. The main problems that arise when using equipment for cultivation are to ensure the heat and mass transfer processes in devices, presence of turbulent and stagnant zones, high-energy consumption, low heat transfer coefficients when working with viscous fluids. Objective. The aim of the paper is the experimental determination of the remote control heat transfer advantages in production line bioreactors using ultrasonic beam compared to contact methods. Methods. An experimental study of the heat and mass transfer process in a bioreactor on the stand with UZP-6-1 immersion unit of the ultrasonic radiator with radiation frequency 42 kHz is carried out. Results. Sound waves emitted into a liquid form a concentration zone of passable sound energy in the confocal vessel form of a cylindrical surface and force the liquid to move along the inner surface of the glass along the ascending cylindrical spiral, forming a motive flow throughout the volume, causing peripheral layers of liquid and bottom layers to move in a horizontal and vertical planes, without leaving stagnant zones. The closer to the coincidence angle is the directed ultrasonic beam the greater is the effectiveness of the driving flow. Conclusions. The use of sound waves allows obtaining a high-quality product in technological lines based on bioreactors with minimal risk for the technological process. Radiation parameters and working volume physic-mechanical properties change allow fully using the properties of resonant manifestations of the sound wave influence on the working liquid with minimal costs.

  8. Membrane bioreactor technology: A novel approach to the treatment of compost leachate

    International Nuclear Information System (INIS)

    Brown, Kayleigh; Ghoshdastidar, Avik J.; Hanmore, Jillian; Frazee, James; Tong, Anthony Z.

    2013-01-01

    Highlights: • First membrane bioreactor treatment method for compost leachate. • No chemical additive or UV radiation source in this new biological method. • Removal rates of more than 99% for organics and ammonium were achieved. • Heavy metals were reduced by at least 82.7% except copper. - Abstract: Compost leachate forms during the composting process of organic material. It is rich in oxidizable organics, ammonia and metals, which pose a risk to the environment if released without proper treatment. An innovative method based on the membrane bioreactor (MBR) technology was developed to treat compost leachate over 39 days. Water quality parameters, such as pH, dissolved oxygen, ammonia, nitrate, nitrite and chemical oxygen demand (COD) were measured daily. Concentrations of caffeine and metals were measured over the course of the experiment using gas chromatography – mass spectrometry (GC/MS) and inductively coupled plasma – mass spectrometry (ICP–MS) respectively. A decrease of more than 99% was achieved for a COD of 116 g/L in the initial leachate. Ammonia was decreased from 2720 mg/L to 0.046 mg/L, while the nitrate concentration in the effluent rose to 710 mg/L. The bacteria in the MBR system adjusted to the presence of the leachate, and increased 4 orders of magnitude. Heavy metals were removed by at least 82.7% except copper. These successful results demonstrated the membrane bioreactor technology is feasible, efficient method for the treatment of compost leachate

  9. Comparison of aerobic granulation and anaerobic membrane bioreactor technologies for winery wastewater treatment.

    Science.gov (United States)

    Basset, N; López-Palau, S; Dosta, J; Mata-Álvarez, J

    2014-01-01

    An anaerobic membrane bioreactor and aerobic granulation technologies were tested at laboratory scale to treat winery wastewater, which is characterised by a high and variable biodegradable organic load. Both technologies have already been tested for alcohol fermentation wastewaters, but there is a lack of data relating to their application to winery wastewater treatment. The anaerobic membrane bioreactor, with an external microfiltration module, was started up for 230 days, achieving a biogas production of up to 0.35 L CH4L(-1)d(-1) when 1.5 kg COD m(-3)d(-1) was applied. Average flux was 10.5 L m(-2) h(-1) (LMH), obtaining a treated effluent free of suspended solids and a chemical oxygen demand (COD) concentration lower than 100 mg COD L(-1). In contrast, the aerobic granular sequencing batch reactor coped with 15 kg COD m(-3)d(-1), but effluent quality was slightly worse. Aerobic granulation was identified as a suitable technique to treat this kind of wastewater due to excellent settleability, high biomass retention and a good ability to handle high organic loads and seasonal fluctuations. However, energy generation from anaerobic digestion plays an important role, favouring anaerobic membrane bioreactor application, although it was observed to be sensitive to sudden load fluctuations, which led to a thorough pH control and alkali addition.

  10. Anaerobic treatment of agro-industrial wastewaters for COD removal in expanded granular sludge bed bioreactor

    Directory of Open Access Journals (Sweden)

    Abumalé Cruz-Salomón

    2017-12-01

    Full Text Available Untreated agro-industrial wastewaters are undesirable in the aquatic environment due to the presence of high organic matter contents. However, they may constitute a large potential for biogas production. The present investigation is focused on three laboratory-scale anaerobic expanded granular sludge bed (EGSB bioreactors, continuously operated for 60 d under mesophilic condition with the aim of exploring the feasibility of treating three most significant agro-industrial wastewaters in Chiapas, Mexico (i.e., cheese whey, vinasse, and coffee-processing wastewater. The EGSB bioreactors were operated with a hydraulic retention time (HRT of 6 d under stable conditions (i.e., buffer index (BI of 0.31, 0.34, and 0.03, generating a maximum chemical oxygen demand (COD removal efficiency of 91, 74, and 96% with an average methane production of 340, 245, and 300 mL/g COD∙d for cheese whey, vinasse, and coffee-processing wastewater, respectively. According to the obtained results, the EGSB bioreactors could be a sustainable alternative to simultaneously solve the environmental problems and to produce bioenergy.

  11. The effect of leachate recirculation with enzyme cellulase addition on waste stability in landfill bioreactor

    Science.gov (United States)

    Saffira, N.; Kristanto, G. A.

    2018-01-01

    Landfill bioreactor with leachate recirculation is known to enhance waste stabilization. However, the composition of waste in Indonesia is comprised by organic waste which is lignocellulosic materials that considered take a long time to degrade under anaerobic condition. To accelerate the degradation process, enzyme addition is ought to do. Cellulase is an enzyme that can catalyse cellulose and other polysaccharide decomposition processes. Therefore, operation of waste degradation using leachate recirculation with a cellulase addition to enhance waste stabilization was investigated using anaerobic bioreactor landfill. The experiment was performed on 2 conditions; leachate recirculation with cellulase addition and recirculation only as a control. The addition of cellulase is reported to be significant in decreasing organic content, represented by volatile solid parameter. The volatile solid reduction in the cellulase augmented reactor and control reactor was 17.86% and 7.90%, respectively. Cellulase addition also resulted in the highest cellulose reduction. Settlement of the landfill in a bioreactor with enzyme addition (32.67%) was reported to be higher than the control (19.33%). Stabilization of landfill review by the decreasing rate constant of the cellulose and lignin ratio parameter was more rapidly achieved by the enzyme addition (0.014 day-1) compared to control (0.002 day-1).

  12. Nitrogen removal in the bioreactor landfill system with intermittent aeration at the top of landfilled waste

    International Nuclear Information System (INIS)

    He Ruo; Shen Dongsheng

    2006-01-01

    High ammonia concentration of recycled landfill leachate makes it very difficult to treat. In this work, a vertical aerobic/anoxic/anaerobic lab-scale bioreactor landfill system, which was constructed by intermittent aeration at the top of landfilled waste, as a bioreactor for in situ nitrogen removal was investigated during waste stabilization. Intermittent aeration at the top of landfilled waste might stimulate the growth of nitrifying bacteria and denitrifying bacteria in the top and middle layers of waste. The nitrifying bacteria population for the landfill bioreactor with intermittent aeration system reached between10 6 and 10 8 cells/dry g waste, although it decreased 2 orders of magnitude on day 30, due to the inhibitory effect of the acid environment and high organic matter in the landfilled waste. The denitrifying bacteria population increased by between 4 and 13 orders of magnitude compared with conventional anaerobic landfilled waste layers. Leachate NO 3 - -N concentration was very low in both two experimental landfill reactors. After 105 days operation, leachate NH 4 + -N and TN concentrations for the landfill reactor with intermittent aeration system dropped to 186 and 289 mg/l, respectively, while they were still kept above 1000 mg/l for the landfill reactor without intermittent aerobic system. In addition, there is an increase in the rate of waste stabilization as well as an increase of 12% in the total waste settlement for the landfill reactor with intermittent aeration system

  13. An Update to Space Biomedical Research: Tissue Engineering in Microgravity Bioreactors

    Directory of Open Access Journals (Sweden)

    Abolfazl Barzegari

    2012-03-01

    Full Text Available Introduction: The severe need for constructing replacement tissues in organ transplantation has necessitated the development of tissue engineering approaches and bioreactors that can bring these approaches to reality. The inherent limitations of conventional bioreactors in generating realistic tissue constructs led to the devise of the microgravity tissue engineering that uses Rotating Wall Vessel (RWV bioreactors initially developed by NASA. Methods: In this review article, we intend to highlight some major advances and accomplishments in the rapidly-growing field of tissue engineering that could not be achieved without using microgravity. Results: Research is now focused on assembly of 3 dimensional (3D tissue fragments from various cell types in human body such as chondrocytes, osteoblasts, embryonic and mesenchymal stem cells, hepatocytes and pancreas islet cells. Hepatocytes cultured under microgravity are now being used in extracorporeal bioartificial liver devices. Tissue constructs can be used not only in organ replacement therapy, but also in pharmaco-toxicology and food safety assessment. 3D models of various cancers may be used in studying cancer development and biology or in high-throughput screening of anticancer drug candidates. Finally, 3D heterogeneous assemblies from cancer/immune cells provide models for immunotherapy of cancer. Conclusion: Tissue engineering in (simulated microgravity has been one of the stunning impacts of space research on biomedical sciences and their applications on earth.

  14. FET commutated current-FED inverter

    Science.gov (United States)

    Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)

    1983-01-01

    A shunt switch comprised of a field-effect transistor (Q.sub.1) is employed to commutate a current-fed inverter (10) using thyristors (SCR1, SCR2) or bijunction transistors (Q.sub.2, Q.sub.3) in a full bridge (1, 2, 3, 4) or half bridge (5, 6) and transformer (T.sub.1) configuration. In the case of thyristors, a tapped inverter (12) is employed to couple the inverter to a dc source to back bias the thyristors during commutation. Alternatively, a commutation power supply (20) may be employed for that purpse. Diodes (D.sub.1, D.sub.2) in series with some voltage dropping element (resistor R.sub.12 or resistors R.sub.1, R.sub.2 or Zener diodes D.sub.4, D.sub.5) are connected in parallel with the thyristors in the half bridge and transformer configuration to assure sharing the back bias voltage. A clamp circuit comprised of a winding (18) negatively coupled to the inductor and a diode (D.sub.3) return stored energy from the inductor to the power supply for efficient operation with buck or boost mode.

  15. Biomimetic fetal rotation bioreactor for engineering bone tissues-Effect of cyclic strains on upregulation of osteogenic gene expression.

    Science.gov (United States)

    Ravichandran, Akhilandeshwari; Wen, Feng; Lim, Jing; Chong, Mark Seow Khoon; Chan, Jerry K Y; Teoh, Swee-Hin

    2018-04-01

    Cells respond to physiological mechanical stresses especially during early fetal development. Adopting a biomimetic approach, it is necessary to develop bioreactor systems to explore the effects of physiologically relevant mechanical strains and shear stresses for functional tissue growth and development. This study introduces a multimodal bioreactor system that allows application of cyclic compressive strains on premature bone grafts that are cultured under biaxial rotation (chamber rotation about 2 axes) conditions for bone tissue engineering. The bioreactor is integrated with sensors for dissolved oxygen levels and pH that allow real-time, non-invasive monitoring of the culture parameters. Mesenchymal stem cells-seeded polycaprolactone-β-tricalcium phosphate scaffolds were cultured in this bioreactor over 2 weeks in 4 different modes-static, cyclic compression, biaxial rotation, and multimodal (combination of cyclic compression and biaxial rotation). The multimodal culture resulted in 1.8-fold higher cellular proliferation in comparison with the static controls within the first week. Two weeks of culture in the multimodal bioreactor utilizing the combined effects of optimal fluid flow conditions and cyclic compression led to the upregulation of osteogenic genes alkaline phosphatase (3.2-fold), osteonectin (2.4-fold), osteocalcin (10-fold), and collagen type 1 α1 (2-fold) in comparison with static cultures. We report for the first time, the independent and combined effects of mechanical stimulation and biaxial rotation for bone tissue engineering using a bioreactor platform with non-invasive sensing modalities. The demonstrated results show leaning towards the futuristic vision of using a physiologically relevant bioreactor system for generation of autologous bone grafts for clinical implantation. Copyright © 2018 John Wiley & Sons, Ltd.

  16. Effects of Bubble-Mediated Processes on Nitrous Oxide Dynamics in Denitrifying Bioreactors

    Science.gov (United States)

    McGuire, P. M.; Falk, L. M.; Reid, M. C.

    2017-12-01

    To mitigate groundwater and surface water impacts of reactive nitrogen (N), agricultural and stormwater management practices can employ denitrifying bioreactors (DNBs) as low-cost solutions for enhancing N removal. Due to the variable nature of hydrologic events, DNBs experience dynamic flows which can impact physical and biological processes within the reactors and affect performance. A particular concern is incomplete denitrification, which can release the potent greenhouse gas nitrous oxide (N2O) to the atmosphere. This study aims to provide insight into the effects of varying hydrologic conditions upon the operation of DNBs by disentangling abiotic and biotic controls on denitrification and N2O dynamics within a laboratory-scale bioreactor. We hypothesize that under transient hydrologic flows, rising water levels lead to air entrapment and bubble formation within the DNB porous media. Mass transfer of oxygen (O2) between trapped gas and liquid phases creates aerobic microenvironments that can inhibit N2O reductase (NosZ) enzymes and lead to N2O accumulation. These bubbles also retard N2O transport and make N2O unavailable for biological reduction, further enhancing atmospheric fluxes when water levels fall. The laboratory-scale DNB permits measurements of longitudinal and vertical profiles of dissolved constituents as well as trace gas concentrations in the reactor headspace. We describe a set of experiments quantifying denitrification pathway biokinetics under steady-state and transient hydrologic conditions and evaluate the role of bubble-mediated processes in enhancing N2O accumulation and fluxes. We use sulfur hexafluoride and helium as dissolved gas tracers to examine the impact of bubble entrapment upon retarded gas transport and enhanced trace gas fluxes. A planar optode sensor within the bioreactor provides near-continuous 2-D profiles of dissolved O2 within the bioreactor and allows for identification of aerobic microenvironments. We use qPCR to

  17. Progress towards a controlled culture of the marine sponge Pseudosuberites andrewsi in a bioreactor

    NARCIS (Netherlands)

    Osinga, R.; Belarbi, El H.; Molina Grima, E.; Tramper, J.; Wijffels, R.H.

    2003-01-01

    Explants of the tropical sponge Pseudosuberites andrewsi were fed with the marine diatom Phaeodactylum tricornotum. The food was supplied either as intact algae or as a filtered crude extract. Growth (measured as an increase in underwater weight) was found in both experiments. The explants fed with

  18. Efficacy and immunogenicity of live-attenuated human rotavirus vaccine in breast-fed and formula-fed European infants.

    Science.gov (United States)

    Vesikari, Timo; Prymula, Roman; Schuster, Volker; Tejedor, Juan-C; Cohen, Robert; Bouckenooghe, Alain; Damaso, Silvia; Han, Htay Htay

    2012-05-01

    Rotavirus is the main cause of severe gastroenteritis and diarrhea in infants and young children less than 5 years of age. Potential impact of breast-feeding on the efficacy and immunogenicity of human rotavirus G1P[8] vaccine was examined in this exploratory analysis. Healthy infants (N = 3994) aged 6-14 weeks who received 2 doses of human rotavirus vaccine/placebo according to a 0-1 or 0-2 month schedule were followed for rotavirus gastroenteritis during 2 epidemic seasons. Rotavirus IgA seroconversion rate (anti-IgA antibody concentration ≥ 20 mIU/mL) and geometric mean concentrations were measured prevaccination and 1-2 months post-dose 2. Vaccine efficacy against any and severe rotavirus gastroenteritis was analyzed according to the infants being breast-fed or exclusively formula-fed at the time of vaccination. Antirotavirus IgA seroconversion rate was 85.5% (95% confidence interval [CI]: 82.4-88.3) in breast-fed and 89.2% (95% CI: 84.2-93) in exclusively formula-fed infants; geometric mean concentrations in the respective groups were 185.8 U/mL (95% CI: 161.4-213.9) and 231.5 U/mL (95% CI: 185.9-288.2). Vaccine efficacy was equally high in breast-fed and exclusively formula-fed children in the first season but fell in breast-fed infants in the second rotavirus season. During the combined 2-year efficacy follow-up period, vaccine efficacy against any rotavirus gastroenteritis was 76.2% (95% CI: 68.7-82.1) and 89.8% (95% CI: 77.6-95.9) and against severe rotavirus gastroenteritis 88.4% (95% CI: 81.6-93) and 98.1% (95% CI: 88.2-100) in the breast-fed and exclusively formula-fed infants, respectively. The difference in immunogenicity of human rotavirus vaccine in breast-fed and exclusively formula-fed infants was small. Vaccine efficacy was equally high in breast-fed and exclusively formula-fed children in the first season. Breast-feeding seemed to reduce slightly the efficacy in the second season.

  19. Hydrostatic pressure and shear stress affect endothelin-1 and nitric oxide release by endothelial cells in bioreactors.

    Science.gov (United States)

    Vozzi, Federico; Bianchi, Francesca; Ahluwalia, Arti; Domenici, Claudio

    2014-01-01

    Abundant experimental evidence demonstrates that endothelial cells are sensitive to flow; however, the effect of fluid pressure or pressure gradients that are used to drive viscous flow is not well understood. There are two principal physical forces exerted on the blood vessel wall by the passage of intra-luminal blood: pressure and shear. To analyze the effects of pressure and shear independently, these two stresses were applied to cultured cells in two different types of bioreactors: a pressure-controlled bioreactor and a laminar flow bioreactor, in which controlled levels of pressure or shear stress, respectively, can be generated. Using these bioreactor systems, endothelin-1 (ET-1) and nitric oxide (NO) release from human umbilical vein endothelial cells were measured under various shear stress and pressure conditions. Compared to the controls, a decrease of ET-1 production by the cells cultured in both bioreactors was observed, whereas NO synthesis was up-regulated in cells under shear stress, but was not modulated by hydrostatic pressure. These results show that the two hemodynamic forces acting on blood vessels affect endothelial cell function in different ways, and that both should be considered when planning in vitro experiments in the presence of flow. Understanding the individual and synergic effects of the two forces could provide important insights into physiological and pathological processes involved in vascular remodeling and adaptation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. In Vitro Model for Hepatotoxicity Studies Based on Primary Human Hepatocyte Cultivation in a Perfused 3D Bioreactor System.

    Science.gov (United States)

    Knöspel, Fanny; Jacobs, Frank; Freyer, Nora; Damm, Georg; De Bondt, An; van den Wyngaert, Ilse; Snoeys, Jan; Monshouwer, Mario; Richter, Marco; Strahl, Nadja; Seehofer, Daniel; Zeilinger, Katrin

    2016-04-16

    Accurate prediction of the potential hepatotoxic nature of new pharmaceuticals remains highly challenging. Therefore, novel in vitro models with improved external validity are needed to investigate hepatic metabolism and timely identify any toxicity of drugs in humans. In this study, we examined the effects of diclofenac, as a model substance with a known risk of hepatotoxicity in vivo, in a dynamic multi-compartment bioreactor using primary human liver cells. Biotransformation pathways of the drug and possible effects on metabolic activities, morphology and cell transcriptome were evaluated. Formation rates of diclofenac metabolites were relatively stable over the application period of seven days in bioreactors exposed to 300 µM diclofenac (300 µM bioreactors (300 µM BR)), while in bioreactors exposed to 1000 µM diclofenac (1000 µM BR) metabolite concentrations declined drastically. The biochemical data showed a significant decrease in lactate production and for the higher dose a significant increase in ammonia secretion, indicating a dose-dependent effect of diclofenac application. The microarray analyses performed revealed a stable hepatic phenotype of the cells over time and the observed transcriptional changes were in line with functional readouts of the system. In conclusion, the data highlight the suitability of the bioreactor technology for studying the hepatotoxicity of drugs in vitro.