Establishing reliable technological information on the safety of biofertilizers produced from a bioreactor composting technique is a must prior to its commercialization. A phytotoxicity study of biofertilizer made fro...Establishing reliable technological information on the safety of biofertilizers produced from a bioreactor composting technique is a must prior to its commercialization. A phytotoxicity study of biofertilizer made from the bioreactor composting technology at Aklan State University, Banga, Aklan, Philippines was conducted for fourteen (14) days using commercially available lettuce seeds (Lactuca sativa L.). Standard phytotoxicity attributes such as hypocotyl length, radicle length, relative germination percentage, and relative radicle growth observed during the germination stage were evaluated. Results revealed no significant difference in the radicle lengths of the germinated lettuce seeds as affected by the varying levels of biofertilizer dilution at H(3) = 10.567, p = 0.061 > 0.05. On the other hand, the hypocotyl length of the lettuce showed significant differences in response to varying levels of biofertilizer dilution with Welch’s F(5, 5.163) = 8.175, p = 0.017 < 0.05. Also, the different levels of biofertilizer affected significantly the germination percentage of lettuce seeds F(5, 12) = 5.822, p = 0.006 < 0.05. All levels of biofertilizer treatments indicated a decrease in relative germination percentage. However, those seeds applied with 10% biofertilizer have the highest reduction of germination percentage, equivalent to 86.9% (RGP = 13.10%). All levels of biofertilizer showed an increase in radicle growth in contrast to the negative control plant except for the one given a 10% level of biofertilizer. Seeds that received 10% biofertilizer showed an extremely high reduction in radicle growth, equivalent to 72.22% (RRG = 27.78%). The study shows that applying low levels of the bioreactor-produced biofertilizer will observably reduce the measure of the germination characteristics of lettuce seeds, but not necessarily low enough to be considered phytotoxic. However, the application of at least 10% bioreactor-produced biofertilizer can presumptively lead to phytotoxicity.展开更多
Population development of key groups of anaerobic and aerobic bacteria involved in municipal refuse decomposition under laboratory landfill bioreactors with and without leachate recycle and inoculation was measured si...Population development of key groups of anaerobic and aerobic bacteria involved in municipal refuse decomposition under laboratory landfill bioreactors with and without leachate recycle and inoculation was measured since modeling municipal refuse was landfilled in bioreactors for about 210 days. Hydrolytic fermentative bacteria (HFB), hydrogen producing acetogenic bacteria (HPAB), methane producing bacteria (MPB), sulfate reducing bacteria (SRB), anaerobic and aerobic cellulolytic bacteria and denitrabacteria were enumerated by the most probable number technique. The results showed that the dominant microorganism groups were the methanogenic bacteria including hydrolytic fermentative, hydrogen producing acetogenic and methane producing bacteria. They were present in fresh refuse but at low values and positively affected by leachate recycle and refuse inoculation. The amounts of HFB or HPAB in digesters D4 and D5 operated with inoculation and leachate recycle reached their maximum values of 10 10 -10 12 cells/g dry refuse for HFB or 10 5-10 6 cells/g dry refuse for HPAB on day 60, in digester D3 operated with leachate recycle on day 120 for HFB (10\+9 cells/g dry refuse) or on day 90 for HPAB (10\+5 cells/g dry refuse), and in digesters D1 and D2 on day 210 for HFB (10 9 cells/g dry refuse) or on day 90 for HPAB (10 4-10 6 cells/g dry refuse). The population of methane producing bacteria in digesters D4 and D5 sharply increased on days 60 and 90 respectively, however in digesters D1, D2 and D3 on day 120. Leachate recycle and inoculation changed the cellulolytic microorganisms composition of refuse ecosystem, the higher amounts of anaerobic cellulolytic bacteria were measured in digesters D4 and D5 (10 7 cells/g dry refuse), followed by digesters D3 (10 6 cells/g dry refuse), D2 or D1(10 4 cells/g dry refuse). However, the amounts of aerobic cellulolytic bacteria were much lower than that of anaerobic cellulolytic bacteria. And it was higher in digester D3 than those in digesters D1, D2, D4 and D5 The amounts of SRB and denitrabacteria were also higher in digester D5 than those in digesters D1, D2, D3 and D4 Refuse decomposition could be accelerated by leachate recycle and inoculation in the view of microorganism development.展开更多
AIM:To construct and evaluate the functionality of a choanoid-fluidized bed bioreactor(CFBB)based on microencapsulated immortalized human hepatocytes.METHODS:Encapsulated hepatocytes were placed in the constructed CFB...AIM:To construct and evaluate the functionality of a choanoid-fluidized bed bioreactor(CFBB)based on microencapsulated immortalized human hepatocytes.METHODS:Encapsulated hepatocytes were placed in the constructed CFBB and circulated through Dulbecco’s Modified Eagle’s Medium(DMEM)for 12 h,and then through exchanged plasma for 6 h,and compared with encapsulated cells cultivated under static conditions in a spinner flask.Levels of alanine aminotransferase(ALT)and albumin were used to evaluate the CFBB during media circulation,whereas levels of ALT,total bilirubin(TBil),and albumin were used to evaluate it during plasma circulation.Mass transfer and hepatocyte injury were evaluated by comparing the results from the two experimental conditions.In addition,the viability and microstructure of encapsulated cells were observed in the different environments.RESULTS:The bioartificial liver model based on a CFBB was verified by in vitro experiments.The viability of encapsulated cells accounting for 84.6%±3.7%in CFBB plasma perfusion was higher than the 74.8%±3.1%in the static culture group(P<0.05)after 6 h.ALT release from cells was 29±3.5 U/L vs 40.6±3.2U/L at 12 h(P<0.01)in the CFBB medium circulation and static medium culture groups,respectively.Albumin secretion from cells was 234.2±27.8μg/1×107cells vs 167.8±29.3μg/1×107 cells at 6 h(P<0.01),274.4±34.6μg/1×107 cells vs 208.4±49.3μg/1×107 cells(P<0.05)at 12 h,in the two medium circulation/culture groups,respectively.Furthermore,ALT and TBil levels were 172.3±24.1 U/L vs 236.3±21.5 U/L(P<0.05),240.1±23.9μmol/L vs 241.9±31.4μmol/L(P>0.05)at 6 h in the CFBB plasma perfusion and static plasma culture groups,respectively.There was no significant difference in albumin concentration between the two experimental plasma groups at any time point.The microstructure of the encapsulated hepatocytes remained healthier in the CFBB group compared with the static culture group after 6 h of plasma perfusion.CONCLUSION:The CFBB can function as a bioartificial liver based on a bioreactor.The efficacy of this novel bioreactor is promising for the study of liver failure.展开更多
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...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 "niches",to impact stem cell fate decision. The niche factors include the regulatory factors such as oxygen, extracellular matrix(synthetic and decellularized), paracrine/autocrine signaling and physical forces(i.e., mechanical force, electrical force and flow shear). The use of novel bioreactors with precise control and recapitulation of niche factors through modulating reactor operation parameters can enable efficient stem cell expansion and differentiation. Recently, the development of microfluidic devices and microbioreactors also provides powerful tools to manipulate the stem cell microenvironment by adjusting flow rate and cytokine gradients. In general,bioreactor engineering can be used to better modulate stem cell niches critical for stem cell expansion, differentiation and applications as novel cell-based biomedicines. This paper reviews important factors that can be more precisely controlled in bioreactors and their effects on stem cell engineering.展开更多
BACKGROUND:Bioartificial liver support systems are becoming an effective therapy for hepatic failure.Bioreactors,as key devices in these systems,can provide a favorable growth and metabolic environment,mass exchange,a...BACKGROUND:Bioartificial liver support systems are becoming an effective therapy for hepatic failure.Bioreactors,as key devices in these systems,can provide a favorable growth and metabolic environment,mass exchange,and immunological isolation as a platform.Currently,stagnancy in bioreactor research is the main factor restricting the development of bioartificial liver support systems.DATA SOURCES:A PubMed database search of English-language literature was performed to identify relevant articles using the Keywords "bioreactor","bioartificial liver","hepatocyte",and"liver failure".More than 40 articles related to the bioreactors of bioartificial livers were reviewed.RESULTS:Some progress has been made in the improvement of structures,functions,and modified macromolecular materials related to bioreactors in recent years.The current data on the improvement of bioreactor configurations for bioartificial livers or on the potential of the use of certain scaffold materials in bioreactors,combined with the clinical efficacy and safety evaluation of cultured hepatocytes in vitro,indicate that the AMC(Academic Medical Center)BAL bioreactor and MELS(modular extracorporeal liver support) BAL bioreactor system can partly replace the synthetic and metabolic functions of the liver in phaseⅠclinical studies.In addition,it has been indicated that the microfluidic PDMS(polydimethylsiloxane)bioreactor,or SlideBioreactor,and the microfabricated grooved bioreactor are appropriate for hepatocyte culture,which is also promising for bioartificial livers.Similarly,modified scaffolds can promote the adhesion,growth,and function of hepatocytes,and provide reliable materials for bioreactors.CONCLUSIONS:Bioreactors,as key devices in bioartificial livers,play an important role in the therapy for liver failure both now and in the future.Bioreactor configurations are indispensable for the development of bioartificial livers used for liver failure,just as the modified scaffold materials available for bioreactors are favorable to the construction of effective bioartificial livers.展开更多
The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphi...The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphism (RFLP). Of the screened clones, almost full-length 16S rDNA sequences of 64 clones were sequenced. Phylogenetic tree was constructed with a database containing clone sequences from this study and bacterial rDNA sequences from NCBI for identification purposes. The 90.6% of the clones were a?liated with the two phyla Bacteroidetes (50%) and Proteobacteria (40%), and β-, γ-, and δ-Proteobacteria accounted for 7.8%, 28.1%, and 4.7%, respectively. Minor portions were a?liated with the Actinobacteria and Firmicutes (both 3.1%). Only 6 out of 64 16S rDNA sequences exhibited similarities of more than 97% to classified bacterial species, which indicated that a substantial fraction of the clone sequences were derived from unknown taxa. Rarefaction analysis of operational taxonomic units (OTUs) clusters demonstrated that 150 clones screened were still insu?cient to describe the whole bacterial diversity. Measurement of water quality parameter demonstrated that performance of the SMBR maintained high level, and the SMBR system remained stable during this study.展开更多
Objective:To investigate the effects of some culture conditions on production of asialicoside from centella(Centella asiatica L.Urban)cells cultured in 5-L bioreactor.Methods:The centell cell suspension culture was co...Objective:To investigate the effects of some culture conditions on production of asialicoside from centella(Centella asiatica L.Urban)cells cultured in 5-L bioreactor.Methods:The centell cell suspension culture was conducted in 5-L bioreactor to investigate the growth and asiaticoside accumulation under various conditions.Asiaticoside content was determined by HPLC analysis.Results:The results showed that the cell growth and asiaticoside accumulation peaked after 24d of culture at an agitation speed of 150 r/min and aeration rate of 2.5 L/min.The cell biomass reached a maximum value of 302.45 g fresh weight(31.43 g dry weight)and growth index of 3.03with inoculum size of 100 g.However,asiaticoside content was the highest(60.08 mg/g dry weight)when culture was initiated with an inoculum size of 50 g.Conclusions:The present study found the suitable conditions for growth of centella cells and their asiaticoside production in bioreactor.展开更多
In order to obtain the reasonable operating conditions and minimize the power consumption in the stirred bioreactor, the hydrodynamic experiments in the stirred bioreactor have been taken to obtain the basic data. Sub...In order to obtain the reasonable operating conditions and minimize the power consumption in the stirred bioreactor, the hydrodynamic experiments in the stirred bioreactor have been taken to obtain the basic data. Subsequently, an Eulerian model for the gas–liquid–solid three phase flow in the stirred bioreactor has been proposed and the CFD simulation has been conducted. By comparing the results of experiment and simulation, it can be concluded that the simulation results were consistent with the experimental data. The inner relationship between operating variables and indicators could be obtained by comparing the results of just suspension speed, gas holdup, power consumption and operational maps, further the reasonable operating conditions could be also determined under the minimum power consumption. The operational maps could provide the theoretical foundation for industrial application of the gas–liquid–solid stirred bioreactors under the low solid concentration(no more than 20 wt%).展开更多
This study demonstrated the feasibility of implementing of MBR in pharmaceutical wastewater independently, and concluded different applications of MBR in industries. Membrane bioreactor (MBR) technology was a new wast...This study demonstrated the feasibility of implementing of MBR in pharmaceutical wastewater independently, and concluded different applications of MBR in industries. Membrane bioreactor (MBR) technology was a new wastewater treatment technology with a combination of membrane separation technology and biological treatment technology, which had unique advantages on pharmaceutical wastewater treatment. The modified membrane rector design provided a significantly lower concentration of NH3-N, Phosphorous, Total Nitrogen and COD around the membranes, and subsequently a more sustainable membrane performance due to much lower overall fouling rates. In this paper, the classification and structure of biological waste water treatment by using MBR technology were summed up along with some examples of MBR in industrial wastewater treatment, which was emphatically analyzed and discussed. Finally, the prospect of MBR in industrial wastewater treatment was described. The industrial wastewater was a high-strength wastewater which had characteristics of complicated constituents, high organics concentration, highly toxic.展开更多
The wastewater treatment from brassylic acid manufacturing plant using membrane bioreactor (MBR) was studied. The membrane bioreactor consisted of batch operation biological aeration tank and ultrafiltration evaluatio...The wastewater treatment from brassylic acid manufacturing plant using membrane bioreactor (MBR) was studied. The membrane bioreactor consisted of batch operation biological aeration tank and ultrafiltration evaluation tank. The content of test included the affection of variation operation conditions on ultrafiltration separation, the general characteristics of MBR process, and the difference comparing with the conventional biological treatment. The results are as follows: (1) among the test membrane material, polyether sulphone (PES) membrane is more suitable for the wastewater treatment; (2) when the cutoff molecular weight is among 10000 50000, the higher the cutoff molecular weight, the bigger the water flux is in the test; (3) under the operation pressure, water flux increases accompanying with the increasing of operation pressure; (4) the paper filtered COD concentration has more affection on the water flux than the suspended solid concentration; (5) as the volume loading of MBR increases, the accumulation of high molecule organic substance and colloid increases, the membrane permeate COD concentration and paper filtered COD concentration increase too, meanwhile the water flux reduces; (6) when the sludge retention time of activated sludge of MBR increases, the accumulation of high molecule organic substance and colloid reduces, the membrane permeate COD concentration and paper filtered COD concentration reduce too, and the water flux increases; (7) comparing with the conventional biological process, the microbial activity is higher, but the microbial species is less.展开更多
A lab scale membrane bioreactor system was built to investigate the removal of Di-2-Ethyl Hexyl Phthalates (DEHP) in wastewater under variation of three runs: two hydraulic retention time (HRT) 24 and 36 hours in addi...A lab scale membrane bioreactor system was built to investigate the removal of Di-2-Ethyl Hexyl Phthalates (DEHP) in wastewater under variation of three runs: two hydraulic retention time (HRT) 24 and 36 hours in addition to two biomass: concentrated and light sludge. Solid phase extraction (SPE) followed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was applied to quantitatively identify DEHP in wastewater samples. Membrane bioreactor was built and operated to investigate DEHP removal. Higher HRT removed DEHP more efficiently than lower HRT. The concentrated MLSS could achieve higher removal efficiency than the lighter MLSS at the same HRT value. The performance of MBR in removing DEHP, TOC and COD from wastewater with a maximum removal efficiency were 29%, 85%, and 98%, respectively. Mass balance of DEHP in the system indicated that a majority was removed by adsorption process rather than filtration or microbiological process.展开更多
This paper describes three-dimensional computational fluid dynamics(CFD) simulations of gas–liquid flow in a novel laboratory-scale bioreactor contained dual ventilation-pipe and double sieve-plate bioreactor(DVDSB)u...This paper describes three-dimensional computational fluid dynamics(CFD) simulations of gas–liquid flow in a novel laboratory-scale bioreactor contained dual ventilation-pipe and double sieve-plate bioreactor(DVDSB)used for sophorolipid(SL) production. To evaluate the role of hydrodynamics in reactor design, the comparisons between conventional fed-batch fermenter and DVDSB on the hydrodynamic behavior are predicted by the CFD methods. Important hydrodynamic parameters of the gas–liquid two-phase system such as the liquid phase velocity field, turbulent kinetic energy and volume-averaged overall and time-averaged local gas holdups were simulated and analyzed in detail. The numerical results were also validated by experimental measurements of overall gas holdups. The yield of sophorolipids was significantly improved to 484 g·L^(-1)with a 320 h fermentation period in the new reactor.展开更多
Embryonic stem(ES)cells have the ability to differ-entiate into all germ layers,holding great promise not only for a model of early embryonic development but also for a robust cell source for cell-replacement therapie...Embryonic stem(ES)cells have the ability to differ-entiate into all germ layers,holding great promise not only for a model of early embryonic development but also for a robust cell source for cell-replacement therapies and for drug screening.Embryoid body (EB)formation from ES cells is a common method for producing different cell lineages for further applications. However,conventional techniques such as hanging drop or static suspension culture are either inherently incapable of large scale production or exhibit limited control over cell aggregation during EB formation and subsequent EB aggregation.For standardized mass EB production,a well defined scale-up platform is necessary.Recently,novel scenario methods of EB formation in hydrodynamic conditions created by bioreactor culture systems using stirred suspension systems(spinner flasks),rotating cell culture system and rotary orbital culture have allowed large-scale EB formation.Their use allows for continuous monitoring and control of the physical and chemical environment which is difficult to achieve by traditional methods.This review summarizes the current state of production of EBs derived from pluripotent cells in various culture systems.Furthermore,an overview of high quality EB formation strategies coupled with systems for in vitro differentiation into various cell types to be applied in cell replacement therapy is provided in this review. Recently,new insights in induced pluripotent stem(iPS) cell technology showed that differentiation and lineage commitment are not irreversible processes and this has opened new avenues in stem cell research.These cells are equivalent to ES cells in terms of both self-renewal and differentiation capacity.Hence,culture systems for expansion and differentiation of iPS cells can also apply methodologies developed with ES cells,although direct evidence of their use for iPS cells is still limited.展开更多
In order to understand the effect of low temperature on the formation process of aerobic granules and contaminants removal characteristics,the aerobic granules-membrane bioreactor (AGS-MBR) has been started up and ope...In order to understand the effect of low temperature on the formation process of aerobic granules and contaminants removal characteristics,the aerobic granules-membrane bioreactor (AGS-MBR) has been started up and operated at low temperature using the carbon resource of sodium acetate. Aerobic granules cultivated in AGS-MBR possess smooth surface and compact structure in morphology as well as better settling property and higher biomass after 38 days. The average parameters of aerobic granules are: diameter 3. 1 mm,wet density 1. 041 g/mL,sludge volume index 42. 35 mL/g and settling velocity 20. 6 - 45. 2 cm/min. During the start-up of AGS-MBR,the respectively average contaminants removal efficiencies at low temperature are 91. 9% for chemical oxygen demand (COD) ,89. 2% for NH4 + -N and 86. 3% for PO43- -P,and the overgrowth of filamentous bacteria has been well controlled. In addition,the hollow fiber microfiltration (MF) membrane fouling is light and the regime membrane layer is capable of enhancing membrane filtration as well as the average growth of trans-membrane pressure (TMP) is 1. 07 kPa/d. Compared with the conventional cultivation of aerobic granules,the sludge granulation time significantly decreases from 73 days to 38 days by the application of microfiltration membrane at low temperature.展开更多
The production capability of a fermentation process is predominately determined by individual strains,which ultimately affected ultimately by interactions between the scale-dependent flow field developed within biorea...The production capability of a fermentation process is predominately determined by individual strains,which ultimately affected ultimately by interactions between the scale-dependent flow field developed within bioreactors and the physiological response of these strains.Interpreting these complicated interactions is key for better understanding the scale-up of the fermentation process.We review these two aspects and address progress in strategies for scaling up fermentation processes.A perspective on how to incorporate the multiomics big data into the scale-up strategy is presented to improve the design and operation of industrial fermentation processes.展开更多
A new procedure for blueberry (Vaccinium corymbosum L.) micropropagation in programmed Temporary Immersion Bioreactors (TIBs based on two separate bottles) was developed for the commercial genotypes Biloxi, Sharp Blue...A new procedure for blueberry (Vaccinium corymbosum L.) micropropagation in programmed Temporary Immersion Bioreactors (TIBs based on two separate bottles) was developed for the commercial genotypes Biloxi, Sharp Blue and Brillita. Plant cultures were developed in a controlled environment with 0.4 MPa CO2 enrichment, sucrose-reduced medium, and light intensity of 60 mM m-2·s-1. Principal component analysis showed that component 1 (C1) grouped 64.08% of the total variability, while the first two components accounted for 86.97%. Representation of the principal components demonstrated three clusters corresponding with the blueberry genotypes, and within each cluster plants micropropagated in agar-base medium grouped separately from those plants multiplied in TIBs. Both plant number and total internodes traits (related to the productive efficiency) were demonstrated superior in blueberries propagated in TIBs. Additionally, when transferred to greenhouse conditions, blueberries propagated in TIBs showed higher adaptability and growing rates than those cultured by the conventional approach, altogether evidencing the occurrence of a photomixotrophic stage in the vitroplantlets cultured in TIBs.展开更多
Compared with conventional cylinder airlift bioreactors(CCABs)that produce coarse bubbles,a novel rectangular dynamic membrane airlift bioreactor(RDMAB)developed in our lab produces fine bubbles to enhance the volumet...Compared with conventional cylinder airlift bioreactors(CCABs)that produce coarse bubbles,a novel rectangular dynamic membrane airlift bioreactor(RDMAB)developed in our lab produces fine bubbles to enhance the volumetric oxygen mass transfer coefficient(k_(L)a)and gas holdup,as well as improve the bioprocess in a bioreactor.In this study,we compared mass transfer,gas holdup,and batch and con-tinuous fermentation for RNA production in CCAB and RDMAB.In addition,unstructured kinetic models for microbial growth,substrate utilization,and RNA formation were established.In batch fermentation,biomass,RNA yield,and substrate utilization in the RDMAB were higher than those in the CCAB,which indicates that dynamic membrane aeration produced a high k_(L)a by fine bubbles;a higher k_(L)a is more bene-ficial to aerobic fermentation.The starting time of continuous fermentation in the RDMAB was 20 h ear-lier than that in the CCAB,which greatly improved the biological process.During continuous fermentation,maintaining the same dissolved oxygen level and a constant dilution rate,the biomass accumulation and RNA concentration in the RDMAB were 9.71% and 11.15% higher than those in the CCAB,respectively.Finally,the dilution rate of RDMAB was 16.7% higher than that of CCAB during con-tinuous fermentation while maintaining the same air aeration.In summary,RDMAB is more suitable for continuous fermentation processes.Developing new aeration and structural geometry in airlift bioreac-tors to enhance k_(L)a and gas holdup is becoming increasingly important to improve bioprocesses in a bioreactor.展开更多
In this study,the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic-aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewat...In this study,the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic-aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewater containing three commercial reactive azo dyes was considered.Two stage processes performed better than one stage ones,both in terms of overall organic and color removal,as well as the higher contribution of anaerobic stage to the overall removal performance,thereby making them a more energy efficient option.The employment of a moving bed sequencing batch biofilm reactor,which uses both suspended and attached biomass,for the implementation of the anaerobic stage of the process,was compared with a sequencing batch reactor that only employs suspended biomass.The results showed that,although there was no meaningful difference in biomass concentration between the two bioreactors,the latter reactor had better performance in terms of chemical oxygen demand(COD)removal efficiency and rate and color removal rate.Further exploratory tests revealed a difference between the roles of suspended and attached bacterial populations,with the former yielding better color removal whilst the latter had better COD removal performance.The sequential anaerobic–aerobic process,employing an aerobic membrane bioreactor in the aerobic stage resulted in COD and color removal of 77.1±7.9%and 79.9±1.5%,respectively.The incomplete COD and color removal was attributed to the presence of soluble microbial products in the effluent and the autoxidation of dye reduction metabolites,respectively.Also,aerobic partial mineralization of the dye reduction metabolites,was experimentally observed.展开更多
The present work initially identified the design parameters of a temporary immersion bioreactor to later scale it to a complete system for the </span><i><span style="font-family:Verdana;">i...The present work initially identified the design parameters of a temporary immersion bioreactor to later scale it to a complete system for the </span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> multiplication of </span><i><span style="font-family:Verdana;">Ananas comosus</span></i><span style="font-family:Verdana;"> var. </span><span style="font-family:Verdana;">Trujillana</span><span style="font-family:Verdana;"> Red. Thus, a low-cost pneumatic temporary immersion bioreactor system was designed and built with 24 tanks of 2 L each. The automation of the system was designed and implemented by means of a timer circuit whose design parameters were: duration of the propagation process, which depends on the multiplication period of the crop and is an open variable, which means that the operator decides when to turn off the system;the duration of each dive, which for reasons of </span><span style="font-family:Verdana;">complexity</span><span style="font-family:Verdana;"> of the algorithm was standardized as one minute;immersion frequency, which was programmed for intervals of 1, 2, 3, 4, 5, 6, 7, 8 hours respectively and duration of aeration, which from a test run times of 0.20 were chosen, 30, 40, 50, 60, 70, and 80 seconds that correspond to the time of delivery of compressed air;additionally, the multiplication rate of </span><i><span style="font-family:Verdana;">Ananas comosus</span></i><span style="font-family:Verdana;"> var. </span><span style="font-family:Verdana;">Trujillana</span><span style="font-family:Verdana;"> Red in the immersion system which was 6.5 times per propagative unit inoculated in thirty days.展开更多
The efficiency of a novel microalgal culture system (an airlift loop bioreactor [ALB] engaged with a fluidic oscillator to produce microbubbles) is compared with both a conventional ALB (producing fine bubbles without...The efficiency of a novel microalgal culture system (an airlift loop bioreactor [ALB] engaged with a fluidic oscillator to produce microbubbles) is compared with both a conventional ALB (producing fine bubbles without the fluidic oscillator) and non-aerated flask culture. The impact of CO2 mass transfer on Dunaliella salina growth is assessed, through varying the gas (5% CO2, 95% N2) dosing flow rate. The results showed that approximately 6 - 8 times higher chlorophyll content was achieved in the aerated ALB cultures than in the non-aerated flasks, and there was a 20% - 40% increase in specific growth rate of D. salina in the novel ALB with microbubbles when compared with the conventional ALB cultures. The increase in chlorophyll content was found to be proportional to the total amount of CO2 mass transfer. For the same dosing time and flow rate, higher CO2 mass transfer rate (microbubble dosing) resulted in a greater growth rate.展开更多
文摘Establishing reliable technological information on the safety of biofertilizers produced from a bioreactor composting technique is a must prior to its commercialization. A phytotoxicity study of biofertilizer made from the bioreactor composting technology at Aklan State University, Banga, Aklan, Philippines was conducted for fourteen (14) days using commercially available lettuce seeds (Lactuca sativa L.). Standard phytotoxicity attributes such as hypocotyl length, radicle length, relative germination percentage, and relative radicle growth observed during the germination stage were evaluated. Results revealed no significant difference in the radicle lengths of the germinated lettuce seeds as affected by the varying levels of biofertilizer dilution at H(3) = 10.567, p = 0.061 > 0.05. On the other hand, the hypocotyl length of the lettuce showed significant differences in response to varying levels of biofertilizer dilution with Welch’s F(5, 5.163) = 8.175, p = 0.017 < 0.05. Also, the different levels of biofertilizer affected significantly the germination percentage of lettuce seeds F(5, 12) = 5.822, p = 0.006 < 0.05. All levels of biofertilizer treatments indicated a decrease in relative germination percentage. However, those seeds applied with 10% biofertilizer have the highest reduction of germination percentage, equivalent to 86.9% (RGP = 13.10%). All levels of biofertilizer showed an increase in radicle growth in contrast to the negative control plant except for the one given a 10% level of biofertilizer. Seeds that received 10% biofertilizer showed an extremely high reduction in radicle growth, equivalent to 72.22% (RRG = 27.78%). The study shows that applying low levels of the bioreactor-produced biofertilizer will observably reduce the measure of the germination characteristics of lettuce seeds, but not necessarily low enough to be considered phytotoxic. However, the application of at least 10% bioreactor-produced biofertilizer can presumptively lead to phytotoxicity.
基金TheNationalNaturalScienceFoundationofChina (No .5 980 80 12 )andZhejiangProvince (No .5 9912 7)
文摘Population development of key groups of anaerobic and aerobic bacteria involved in municipal refuse decomposition under laboratory landfill bioreactors with and without leachate recycle and inoculation was measured since modeling municipal refuse was landfilled in bioreactors for about 210 days. Hydrolytic fermentative bacteria (HFB), hydrogen producing acetogenic bacteria (HPAB), methane producing bacteria (MPB), sulfate reducing bacteria (SRB), anaerobic and aerobic cellulolytic bacteria and denitrabacteria were enumerated by the most probable number technique. The results showed that the dominant microorganism groups were the methanogenic bacteria including hydrolytic fermentative, hydrogen producing acetogenic and methane producing bacteria. They were present in fresh refuse but at low values and positively affected by leachate recycle and refuse inoculation. The amounts of HFB or HPAB in digesters D4 and D5 operated with inoculation and leachate recycle reached their maximum values of 10 10 -10 12 cells/g dry refuse for HFB or 10 5-10 6 cells/g dry refuse for HPAB on day 60, in digester D3 operated with leachate recycle on day 120 for HFB (10\+9 cells/g dry refuse) or on day 90 for HPAB (10\+5 cells/g dry refuse), and in digesters D1 and D2 on day 210 for HFB (10 9 cells/g dry refuse) or on day 90 for HPAB (10 4-10 6 cells/g dry refuse). The population of methane producing bacteria in digesters D4 and D5 sharply increased on days 60 and 90 respectively, however in digesters D1, D2 and D3 on day 120. Leachate recycle and inoculation changed the cellulolytic microorganisms composition of refuse ecosystem, the higher amounts of anaerobic cellulolytic bacteria were measured in digesters D4 and D5 (10 7 cells/g dry refuse), followed by digesters D3 (10 6 cells/g dry refuse), D2 or D1(10 4 cells/g dry refuse). However, the amounts of aerobic cellulolytic bacteria were much lower than that of anaerobic cellulolytic bacteria. And it was higher in digester D3 than those in digesters D1, D2, D4 and D5 The amounts of SRB and denitrabacteria were also higher in digester D5 than those in digesters D1, D2, D3 and D4 Refuse decomposition could be accelerated by leachate recycle and inoculation in the view of microorganism development.
基金Supported by The Grants from the National Scientific and Technological Major Project of China,No.2011ZX10004-901,No.2013ZX10004904the National Science and Technology Major Project,No.2012ZX10002006
文摘AIM:To construct and evaluate the functionality of a choanoid-fluidized bed bioreactor(CFBB)based on microencapsulated immortalized human hepatocytes.METHODS:Encapsulated hepatocytes were placed in the constructed CFBB and circulated through Dulbecco’s Modified Eagle’s Medium(DMEM)for 12 h,and then through exchanged plasma for 6 h,and compared with encapsulated cells cultivated under static conditions in a spinner flask.Levels of alanine aminotransferase(ALT)and albumin were used to evaluate the CFBB during media circulation,whereas levels of ALT,total bilirubin(TBil),and albumin were used to evaluate it during plasma circulation.Mass transfer and hepatocyte injury were evaluated by comparing the results from the two experimental conditions.In addition,the viability and microstructure of encapsulated cells were observed in the different environments.RESULTS:The bioartificial liver model based on a CFBB was verified by in vitro experiments.The viability of encapsulated cells accounting for 84.6%±3.7%in CFBB plasma perfusion was higher than the 74.8%±3.1%in the static culture group(P<0.05)after 6 h.ALT release from cells was 29±3.5 U/L vs 40.6±3.2U/L at 12 h(P<0.01)in the CFBB medium circulation and static medium culture groups,respectively.Albumin secretion from cells was 234.2±27.8μg/1×107cells vs 167.8±29.3μg/1×107 cells at 6 h(P<0.01),274.4±34.6μg/1×107 cells vs 208.4±49.3μg/1×107 cells(P<0.05)at 12 h,in the two medium circulation/culture groups,respectively.Furthermore,ALT and TBil levels were 172.3±24.1 U/L vs 236.3±21.5 U/L(P<0.05),240.1±23.9μmol/L vs 241.9±31.4μmol/L(P>0.05)at 6 h in the CFBB plasma perfusion and static plasma culture groups,respectively.There was no significant difference in albumin concentration between the two experimental plasma groups at any time point.The microstructure of the encapsulated hepatocytes remained healthier in the CFBB group compared with the static culture group after 6 h of plasma perfusion.CONCLUSION:The CFBB can function as a bioartificial liver based on a bioreactor.The efficacy of this novel bioreactor is promising for the study of liver failure.
文摘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 "niches",to impact stem cell fate decision. The niche factors include the regulatory factors such as oxygen, extracellular matrix(synthetic and decellularized), paracrine/autocrine signaling and physical forces(i.e., mechanical force, electrical force and flow shear). The use of novel bioreactors with precise control and recapitulation of niche factors through modulating reactor operation parameters can enable efficient stem cell expansion and differentiation. Recently, the development of microfluidic devices and microbioreactors also provides powerful tools to manipulate the stem cell microenvironment by adjusting flow rate and cytokine gradients. In general,bioreactor engineering can be used to better modulate stem cell niches critical for stem cell expansion, differentiation and applications as novel cell-based biomedicines. This paper reviews important factors that can be more precisely controlled in bioreactors and their effects on stem cell engineering.
基金supported by grants from the National High Technolgoy Research and Development(863)Program of China(2006AA02A140)the National Natural Science Foundation of China(30630023)Zhejiang Health Science Foundation(2007A081)
文摘BACKGROUND:Bioartificial liver support systems are becoming an effective therapy for hepatic failure.Bioreactors,as key devices in these systems,can provide a favorable growth and metabolic environment,mass exchange,and immunological isolation as a platform.Currently,stagnancy in bioreactor research is the main factor restricting the development of bioartificial liver support systems.DATA SOURCES:A PubMed database search of English-language literature was performed to identify relevant articles using the Keywords "bioreactor","bioartificial liver","hepatocyte",and"liver failure".More than 40 articles related to the bioreactors of bioartificial livers were reviewed.RESULTS:Some progress has been made in the improvement of structures,functions,and modified macromolecular materials related to bioreactors in recent years.The current data on the improvement of bioreactor configurations for bioartificial livers or on the potential of the use of certain scaffold materials in bioreactors,combined with the clinical efficacy and safety evaluation of cultured hepatocytes in vitro,indicate that the AMC(Academic Medical Center)BAL bioreactor and MELS(modular extracorporeal liver support) BAL bioreactor system can partly replace the synthetic and metabolic functions of the liver in phaseⅠclinical studies.In addition,it has been indicated that the microfluidic PDMS(polydimethylsiloxane)bioreactor,or SlideBioreactor,and the microfabricated grooved bioreactor are appropriate for hepatocyte culture,which is also promising for bioartificial livers.Similarly,modified scaffolds can promote the adhesion,growth,and function of hepatocytes,and provide reliable materials for bioreactors.CONCLUSIONS:Bioreactors,as key devices in bioartificial livers,play an important role in the therapy for liver failure both now and in the future.Bioreactor configurations are indispensable for the development of bioartificial livers used for liver failure,just as the modified scaffold materials available for bioreactors are favorable to the construction of effective bioartificial livers.
基金the National NaturalScience Foundation of China (No. 39925007)the HiTech Research and Development Program (863) of China(No. 2002AA60l021)the Pilot Project of KnowledgeInnovation Program of Chinese Academy of Sciences (No.KSCX2-SW-102)
文摘The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphism (RFLP). Of the screened clones, almost full-length 16S rDNA sequences of 64 clones were sequenced. Phylogenetic tree was constructed with a database containing clone sequences from this study and bacterial rDNA sequences from NCBI for identification purposes. The 90.6% of the clones were a?liated with the two phyla Bacteroidetes (50%) and Proteobacteria (40%), and β-, γ-, and δ-Proteobacteria accounted for 7.8%, 28.1%, and 4.7%, respectively. Minor portions were a?liated with the Actinobacteria and Firmicutes (both 3.1%). Only 6 out of 64 16S rDNA sequences exhibited similarities of more than 97% to classified bacterial species, which indicated that a substantial fraction of the clone sequences were derived from unknown taxa. Rarefaction analysis of operational taxonomic units (OTUs) clusters demonstrated that 150 clones screened were still insu?cient to describe the whole bacterial diversity. Measurement of water quality parameter demonstrated that performance of the SMBR maintained high level, and the SMBR system remained stable during this study.
基金supported by the National Foundation for Science and Technology Development(NAFOSTED)of Vietnam(Grant No.106.16-2012.80)
文摘Objective:To investigate the effects of some culture conditions on production of asialicoside from centella(Centella asiatica L.Urban)cells cultured in 5-L bioreactor.Methods:The centell cell suspension culture was conducted in 5-L bioreactor to investigate the growth and asiaticoside accumulation under various conditions.Asiaticoside content was determined by HPLC analysis.Results:The results showed that the cell growth and asiaticoside accumulation peaked after 24d of culture at an agitation speed of 150 r/min and aeration rate of 2.5 L/min.The cell biomass reached a maximum value of 302.45 g fresh weight(31.43 g dry weight)and growth index of 3.03with inoculum size of 100 g.However,asiaticoside content was the highest(60.08 mg/g dry weight)when culture was initiated with an inoculum size of 50 g.Conclusions:The present study found the suitable conditions for growth of centella cells and their asiaticoside production in bioreactor.
基金Supported by the National Natural Science Foundation of China(21476049,21506033)Department of Science and Technology of Fujian Province,China(2014R1004-3,2015J01052,2016H4023 and FG-2016005)
文摘In order to obtain the reasonable operating conditions and minimize the power consumption in the stirred bioreactor, the hydrodynamic experiments in the stirred bioreactor have been taken to obtain the basic data. Subsequently, an Eulerian model for the gas–liquid–solid three phase flow in the stirred bioreactor has been proposed and the CFD simulation has been conducted. By comparing the results of experiment and simulation, it can be concluded that the simulation results were consistent with the experimental data. The inner relationship between operating variables and indicators could be obtained by comparing the results of just suspension speed, gas holdup, power consumption and operational maps, further the reasonable operating conditions could be also determined under the minimum power consumption. The operational maps could provide the theoretical foundation for industrial application of the gas–liquid–solid stirred bioreactors under the low solid concentration(no more than 20 wt%).
文摘This study demonstrated the feasibility of implementing of MBR in pharmaceutical wastewater independently, and concluded different applications of MBR in industries. Membrane bioreactor (MBR) technology was a new wastewater treatment technology with a combination of membrane separation technology and biological treatment technology, which had unique advantages on pharmaceutical wastewater treatment. The modified membrane rector design provided a significantly lower concentration of NH3-N, Phosphorous, Total Nitrogen and COD around the membranes, and subsequently a more sustainable membrane performance due to much lower overall fouling rates. In this paper, the classification and structure of biological waste water treatment by using MBR technology were summed up along with some examples of MBR in industrial wastewater treatment, which was emphatically analyzed and discussed. Finally, the prospect of MBR in industrial wastewater treatment was described. The industrial wastewater was a high-strength wastewater which had characteristics of complicated constituents, high organics concentration, highly toxic.
文摘The wastewater treatment from brassylic acid manufacturing plant using membrane bioreactor (MBR) was studied. The membrane bioreactor consisted of batch operation biological aeration tank and ultrafiltration evaluation tank. The content of test included the affection of variation operation conditions on ultrafiltration separation, the general characteristics of MBR process, and the difference comparing with the conventional biological treatment. The results are as follows: (1) among the test membrane material, polyether sulphone (PES) membrane is more suitable for the wastewater treatment; (2) when the cutoff molecular weight is among 10000 50000, the higher the cutoff molecular weight, the bigger the water flux is in the test; (3) under the operation pressure, water flux increases accompanying with the increasing of operation pressure; (4) the paper filtered COD concentration has more affection on the water flux than the suspended solid concentration; (5) as the volume loading of MBR increases, the accumulation of high molecule organic substance and colloid increases, the membrane permeate COD concentration and paper filtered COD concentration increase too, meanwhile the water flux reduces; (6) when the sludge retention time of activated sludge of MBR increases, the accumulation of high molecule organic substance and colloid reduces, the membrane permeate COD concentration and paper filtered COD concentration reduce too, and the water flux increases; (7) comparing with the conventional biological process, the microbial activity is higher, but the microbial species is less.
文摘A lab scale membrane bioreactor system was built to investigate the removal of Di-2-Ethyl Hexyl Phthalates (DEHP) in wastewater under variation of three runs: two hydraulic retention time (HRT) 24 and 36 hours in addition to two biomass: concentrated and light sludge. Solid phase extraction (SPE) followed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was applied to quantitatively identify DEHP in wastewater samples. Membrane bioreactor was built and operated to investigate DEHP removal. Higher HRT removed DEHP more efficiently than lower HRT. The concentrated MLSS could achieve higher removal efficiency than the lighter MLSS at the same HRT value. The performance of MBR in removing DEHP, TOC and COD from wastewater with a maximum removal efficiency were 29%, 85%, and 98%, respectively. Mass balance of DEHP in the system indicated that a majority was removed by adsorption process rather than filtration or microbiological process.
基金Supported by the National Key Basic Research Program of China(No.2014CB745100)National Natural Science Foundation of China(No.21576197)+1 种基金Tianjin Research Program of Application Foundation and Advanced Technology(No.14JCQNJC06700)Technological Research and Development Programs of the China Offshore Environmental Services Ltd.(CY-HB-10-ZC-055)
文摘This paper describes three-dimensional computational fluid dynamics(CFD) simulations of gas–liquid flow in a novel laboratory-scale bioreactor contained dual ventilation-pipe and double sieve-plate bioreactor(DVDSB)used for sophorolipid(SL) production. To evaluate the role of hydrodynamics in reactor design, the comparisons between conventional fed-batch fermenter and DVDSB on the hydrodynamic behavior are predicted by the CFD methods. Important hydrodynamic parameters of the gas–liquid two-phase system such as the liquid phase velocity field, turbulent kinetic energy and volume-averaged overall and time-averaged local gas holdups were simulated and analyzed in detail. The numerical results were also validated by experimental measurements of overall gas holdups. The yield of sophorolipids was significantly improved to 484 g·L^(-1)with a 320 h fermentation period in the new reactor.
基金Supported by Grants from EU FP6("MEDRAT"-LSHG-CT-2005-518240"CLONET",MRTN-CT-2006-035468),EU FP7("Partn ErS",PIAP-GA-2008-218205+6 种基金"InduHeart",EU FP7-PEOPLE-IRG-2008-234390"InduStem",PIAP-GA-2008-230675"Plurisys",HEALTH-F4-2009-223485)NKFP_07_1-ES2HEART-HU,No.OM-00202-2007 CHE-TRF senior scholarship,No.RTA 5080010supported by grant under the program Strategic Scholarships for Frontier Research Network for the Joint Ph.D.Program Thai Doctoral degree from the Office of the Higher Education Commission,Thailand,No.CHE-PhD-SW-2005-100
文摘Embryonic stem(ES)cells have the ability to differ-entiate into all germ layers,holding great promise not only for a model of early embryonic development but also for a robust cell source for cell-replacement therapies and for drug screening.Embryoid body (EB)formation from ES cells is a common method for producing different cell lineages for further applications. However,conventional techniques such as hanging drop or static suspension culture are either inherently incapable of large scale production or exhibit limited control over cell aggregation during EB formation and subsequent EB aggregation.For standardized mass EB production,a well defined scale-up platform is necessary.Recently,novel scenario methods of EB formation in hydrodynamic conditions created by bioreactor culture systems using stirred suspension systems(spinner flasks),rotating cell culture system and rotary orbital culture have allowed large-scale EB formation.Their use allows for continuous monitoring and control of the physical and chemical environment which is difficult to achieve by traditional methods.This review summarizes the current state of production of EBs derived from pluripotent cells in various culture systems.Furthermore,an overview of high quality EB formation strategies coupled with systems for in vitro differentiation into various cell types to be applied in cell replacement therapy is provided in this review. Recently,new insights in induced pluripotent stem(iPS) cell technology showed that differentiation and lineage commitment are not irreversible processes and this has opened new avenues in stem cell research.These cells are equivalent to ES cells in terms of both self-renewal and differentiation capacity.Hence,culture systems for expansion and differentiation of iPS cells can also apply methodologies developed with ES cells,although direct evidence of their use for iPS cells is still limited.
基金Sponsored by the National High Technology Research and Development Program of China (863 Program,Grant No.2008AA06Z304)State Water Pollution Control and Harnessing of the Major Projects (Grant No.2009ZX07424-005)International Cooperation Program (Grant No.2010DFA92460)
文摘In order to understand the effect of low temperature on the formation process of aerobic granules and contaminants removal characteristics,the aerobic granules-membrane bioreactor (AGS-MBR) has been started up and operated at low temperature using the carbon resource of sodium acetate. Aerobic granules cultivated in AGS-MBR possess smooth surface and compact structure in morphology as well as better settling property and higher biomass after 38 days. The average parameters of aerobic granules are: diameter 3. 1 mm,wet density 1. 041 g/mL,sludge volume index 42. 35 mL/g and settling velocity 20. 6 - 45. 2 cm/min. During the start-up of AGS-MBR,the respectively average contaminants removal efficiencies at low temperature are 91. 9% for chemical oxygen demand (COD) ,89. 2% for NH4 + -N and 86. 3% for PO43- -P,and the overgrowth of filamentous bacteria has been well controlled. In addition,the hollow fiber microfiltration (MF) membrane fouling is light and the regime membrane layer is capable of enhancing membrane filtration as well as the average growth of trans-membrane pressure (TMP) is 1. 07 kPa/d. Compared with the conventional cultivation of aerobic granules,the sludge granulation time significantly decreases from 73 days to 38 days by the application of microfiltration membrane at low temperature.
基金The authors would like to acknowledge the Projects 21776082 and 21978085 supported by National Natural Science Foundation of ChinaProject 22221818014 supported by the Fundamental Research Funds for the Central Universities.
文摘The production capability of a fermentation process is predominately determined by individual strains,which ultimately affected ultimately by interactions between the scale-dependent flow field developed within bioreactors and the physiological response of these strains.Interpreting these complicated interactions is key for better understanding the scale-up of the fermentation process.We review these two aspects and address progress in strategies for scaling up fermentation processes.A perspective on how to incorporate the multiomics big data into the scale-up strategy is presented to improve the design and operation of industrial fermentation processes.
文摘A new procedure for blueberry (Vaccinium corymbosum L.) micropropagation in programmed Temporary Immersion Bioreactors (TIBs based on two separate bottles) was developed for the commercial genotypes Biloxi, Sharp Blue and Brillita. Plant cultures were developed in a controlled environment with 0.4 MPa CO2 enrichment, sucrose-reduced medium, and light intensity of 60 mM m-2·s-1. Principal component analysis showed that component 1 (C1) grouped 64.08% of the total variability, while the first two components accounted for 86.97%. Representation of the principal components demonstrated three clusters corresponding with the blueberry genotypes, and within each cluster plants micropropagated in agar-base medium grouped separately from those plants multiplied in TIBs. Both plant number and total internodes traits (related to the productive efficiency) were demonstrated superior in blueberries propagated in TIBs. Additionally, when transferred to greenhouse conditions, blueberries propagated in TIBs showed higher adaptability and growing rates than those cultured by the conventional approach, altogether evidencing the occurrence of a photomixotrophic stage in the vitroplantlets cultured in TIBs.
基金supported by National Key Research and Development Program of China (2020YFE0100100, 2021YFC21041002018YFA0901500)+1 种基金Basic Science (Natural Science) Research Project of Jiangsu Province Colleges and Universities(21KJB530014)Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture
文摘Compared with conventional cylinder airlift bioreactors(CCABs)that produce coarse bubbles,a novel rectangular dynamic membrane airlift bioreactor(RDMAB)developed in our lab produces fine bubbles to enhance the volumetric oxygen mass transfer coefficient(k_(L)a)and gas holdup,as well as improve the bioprocess in a bioreactor.In this study,we compared mass transfer,gas holdup,and batch and con-tinuous fermentation for RNA production in CCAB and RDMAB.In addition,unstructured kinetic models for microbial growth,substrate utilization,and RNA formation were established.In batch fermentation,biomass,RNA yield,and substrate utilization in the RDMAB were higher than those in the CCAB,which indicates that dynamic membrane aeration produced a high k_(L)a by fine bubbles;a higher k_(L)a is more bene-ficial to aerobic fermentation.The starting time of continuous fermentation in the RDMAB was 20 h ear-lier than that in the CCAB,which greatly improved the biological process.During continuous fermentation,maintaining the same dissolved oxygen level and a constant dilution rate,the biomass accumulation and RNA concentration in the RDMAB were 9.71% and 11.15% higher than those in the CCAB,respectively.Finally,the dilution rate of RDMAB was 16.7% higher than that of CCAB during con-tinuous fermentation while maintaining the same air aeration.In summary,RDMAB is more suitable for continuous fermentation processes.Developing new aeration and structural geometry in airlift bioreac-tors to enhance k_(L)a and gas holdup is becoming increasingly important to improve bioprocesses in a bioreactor.
基金supported by Takmiliran textile dyeing factory(272219601)Materials and Energy Research Center(MERC)(99392003).
文摘In this study,the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic-aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewater containing three commercial reactive azo dyes was considered.Two stage processes performed better than one stage ones,both in terms of overall organic and color removal,as well as the higher contribution of anaerobic stage to the overall removal performance,thereby making them a more energy efficient option.The employment of a moving bed sequencing batch biofilm reactor,which uses both suspended and attached biomass,for the implementation of the anaerobic stage of the process,was compared with a sequencing batch reactor that only employs suspended biomass.The results showed that,although there was no meaningful difference in biomass concentration between the two bioreactors,the latter reactor had better performance in terms of chemical oxygen demand(COD)removal efficiency and rate and color removal rate.Further exploratory tests revealed a difference between the roles of suspended and attached bacterial populations,with the former yielding better color removal whilst the latter had better COD removal performance.The sequential anaerobic–aerobic process,employing an aerobic membrane bioreactor in the aerobic stage resulted in COD and color removal of 77.1±7.9%and 79.9±1.5%,respectively.The incomplete COD and color removal was attributed to the presence of soluble microbial products in the effluent and the autoxidation of dye reduction metabolites,respectively.Also,aerobic partial mineralization of the dye reduction metabolites,was experimentally observed.
文摘The present work initially identified the design parameters of a temporary immersion bioreactor to later scale it to a complete system for the </span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> multiplication of </span><i><span style="font-family:Verdana;">Ananas comosus</span></i><span style="font-family:Verdana;"> var. </span><span style="font-family:Verdana;">Trujillana</span><span style="font-family:Verdana;"> Red. Thus, a low-cost pneumatic temporary immersion bioreactor system was designed and built with 24 tanks of 2 L each. The automation of the system was designed and implemented by means of a timer circuit whose design parameters were: duration of the propagation process, which depends on the multiplication period of the crop and is an open variable, which means that the operator decides when to turn off the system;the duration of each dive, which for reasons of </span><span style="font-family:Verdana;">complexity</span><span style="font-family:Verdana;"> of the algorithm was standardized as one minute;immersion frequency, which was programmed for intervals of 1, 2, 3, 4, 5, 6, 7, 8 hours respectively and duration of aeration, which from a test run times of 0.20 were chosen, 30, 40, 50, 60, 70, and 80 seconds that correspond to the time of delivery of compressed air;additionally, the multiplication rate of </span><i><span style="font-family:Verdana;">Ananas comosus</span></i><span style="font-family:Verdana;"> var. </span><span style="font-family:Verdana;">Trujillana</span><span style="font-family:Verdana;"> Red in the immersion system which was 6.5 times per propagative unit inoculated in thirty days.
文摘The efficiency of a novel microalgal culture system (an airlift loop bioreactor [ALB] engaged with a fluidic oscillator to produce microbubbles) is compared with both a conventional ALB (producing fine bubbles without the fluidic oscillator) and non-aerated flask culture. The impact of CO2 mass transfer on Dunaliella salina growth is assessed, through varying the gas (5% CO2, 95% N2) dosing flow rate. The results showed that approximately 6 - 8 times higher chlorophyll content was achieved in the aerated ALB cultures than in the non-aerated flasks, and there was a 20% - 40% increase in specific growth rate of D. salina in the novel ALB with microbubbles when compared with the conventional ALB cultures. The increase in chlorophyll content was found to be proportional to the total amount of CO2 mass transfer. For the same dosing time and flow rate, higher CO2 mass transfer rate (microbubble dosing) resulted in a greater growth rate.
