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关键词： Biogas   Biochemical methane potential   Biofuels   Anaerobic digestion  

摘要： PurposeA small scale bioreactor was designed and built to investigate the amount of biogas, and, specifically, methane, produced from different *** studies between the system designed and a standard type apparatus were performed using two substrates, fish offal and grass *** specific methane potentials of the substrates, for the small scale batch reactor and the standard system, respectively, were 78.823.5mL/gFM (89.4 +/- 26.7NmL/goDM) and 76.6 +/- 13.7NmL/gFM (86.9 +/- 15.5NmL/goDM) for the grass, and 20.8 +/- 1.7NmL/gFM (88.2 +/- 1.5NmL/goDM) and 15.2 +/- 6.4NmL/gFM (64.9 +/- 27.3NmL/goDM) for the fish offal. The values determined using the two different apparatus types were not significantly different (p>0.05).ConclusionsWhereas lab equipment for substrate analysis, such as determination of the total solids and volatile solids content, is available in most chemistry and biochemistry labs, the biomethane potential test is very specific for biogas technology. The major significance of this work is that the new bioreactor system, which provides similar levels of accuracy as more conventional laboratory type systems, is produced from inexpensive, easily accessible components.

关键词： Gluconobacter oxydans NL71   Sorbose   Sorbitol   Biomass   COS-SSB  

摘要： High-efficiency cell proliferation of Gluconobacter oxydans was carried out in a compressed oxygen supply and sealed bioreactor to co-produce biomass and corresponding metabolite (sorbose). Higher cell density of Gluconobacter oxydans was achieved by implementing high-oxygen tension supply strategy resulting into high sorbose production from bio-oxidation of sorbitol. The highest biomass of 8.8 g/L and highest sorbose production of 432.8 g/L were simultaneously obtained after 72 h of fed-batch operation. Moreover, continuous co-production of biomass and sorbose was successfully conducted with retaining 10% sorbitol fermentation broth as the seed of next stage culture. The key features of this bioprocess application would enable cost-competitive Gluconobacter oxydans industrial applications.

关键词： 3D systems   cytotoxicity   biomimetic bioreactor   alginate types   silver nanoparticles  

摘要： In this work, functional characterization of biomaterials concerning potential application as articular cartilage implants was performed by using a biomimetic bioreactor with dynamic compression in the physiological regime (10% strain, 0.84 Hz frequency, 1 h on/1 h off). Specifically, two alginate types with low (LG) and high (HG) guluronic/mannuronic residue ratios with electrochemically synthesized silver nanoparticles (AgNPs) were evaluated. HG Ag/alginate hydrogels were clearly indicated as potential candidates due to better initial mechanical properties as compared to LG hydrogels (dynamic compression modulus of similar to 60 vs. similar to 40 kPa) as well as the mechanical stability displayed during 7 days of dynamic compression. Cytotoxicity studies in 3D bovine cartilage explant cultures under dynamic compression have shown negligible effects as compared to standard 2D monolayers of bovine chondrocytes where moderate cytotoxicity was observed. Finally, experimental and mathematical modeling studies revealed different mechanisms of AgNP release under physiological-like bioreactor conditions as compared to static conditions. Overall, the results clearly demonstrate bioreactor advantages in characterization and selection of candidate biomaterials as well as potentials to bridge the in vitro-in vivo gap. (c) 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 755-768, 2019.

关键词： bioreactor   Bradford assay   media exchange   space experiment   International Space Station (ISS)  

摘要： Life science research has been actively carried out in space for a long time using bioreactor equipment, in anticipation of manned space exploration and space tourism. Such studies have reported that the microgravity environment has a negative effect on the human body, including the musculoskeletal system, nervous system, and endocrine system. Bone loss and muscular atrophy are issues that need to be resolved before long-term exposure of the human body to a space environment. To address this problem, Y. K. Kim et al. designed a system in 2015 and performed an evaluation of an automated bioreactor development model (DM) for space experiments. In this study, we developed an automated bioreactor engineering model (EM) based on the previous literature, and conducted media exchange performance testing using the Bradford assay. We used a novel method that allowed quantitative assessment of the media exchange rate versus the conventional assessment method using visual observation with a camera. By measuring the media exchange rate of the automated bioreactor EM, we attempted to verify applicability for the system for space experiments. We expect that the experimental method proposed in this study is useful for logical determination of liquid exchange or circulation in different closed systems.

关键词： Microbial fuel cell   Dissolved organic carbon   Macrophyte residues bioreactor   Aeration rate   Energy-saving  

摘要： The increasing application of plant residues bioreactor for aquatic environment remediation may release numerous dissolved organic carbon (DOC) into aquatic ecosystems. In this study, a microbial fuel cell (MFC) sensor was integrated with a macrophyte residues bioreactor (MRBR) to provide an energy-saving way for reduction of DOC concentrations in the effluent. Through re-utilization of macrophyte residues as solid carbon source, DOC concentrations in the effluent of MRBR increased to the maximum on day 5 and then dropped down rapidly to a low value, while the ratio of bioavailable DOC decreased gradually. Interestingly, it was found that there existed a linear relationship between DOC concentrations in initial residue leachate and the voltage from MFC biosensor (R-2 = 0.9852). Accordingly, aerobic biofilm through aeration were applied in the upper part of MRBR to enhance the degradation of DOC prior to discharge to aquatic systems, and aeration rate was adjusted based on MFC sensor signal. Further experiments demonstrated that when voltage decreased from 0.18 V to 0.09 V, a half of aeration rate (7.5 L min(-1)) could still lead to a high DOC degradation efficiency (above 50%) and a low DOC concentration (similar to 10 mg L-1) in the reactor effluent. Thus, the integrated MFC signal could be used to regulate the aeration rate in order to obtain a low DOC concentration in effluents under an energy-saving way. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Sulfur-oxidizing autotrophic denitrification   Fe-0-oxidizing autotrophic denitrification   Anoxic fluidized bed membrane bioreactor   Microbial community  

摘要： The integrated sulfur- and Fe-0-based autotrophic denitrification process in an anoxic fluidized-bed membrane bioreactor (AnFB-MBR) was developed for the nitrate-contaminated water treatment in order to control sulfate generation and avoid alkalinity supplement. The nitrate removal rate of the AnFB-MBR reached 1.22 g NO3--N L-1 d(-1) with NO3--N ranging 40-200 mg L-1 at hydraulic retention times of 1.0-5.0 h. The denitrification in the integrated system was simultaneously carried out by sulfur- and Fe-0-oxidizing autotrophic denitrifiers. The effluent sulfate generation was decreased by 29.3-70.3% and 31.2-50.9% due to the functional role of Fe-0-based denitrification in the integrated system. Alkalinity produced by Fe-0-oxidizing autotrophic denitrification could compensate for the alkalinity consumption by sulfur-based autotrophic denitrification. The sulfur- and Fe-0-oxidizing autotrophic denitrifying bacterial consortium was composed mainly of bacteria from Thiobacillus, Sulfurimonas, and Geothrix genera. The integrated modes leads to a harmonious co-existence of sulfur- and Fe-0-oxidizing denitrifying microbes, which may make a difference to the functional performance of the bioreactor. Overall, the integrated sulfur- and Fe-0-based autotrophic denitrification could overcome the shortcomings of excess sulfate generation and external alkalinity supplementation compared to the sole sulfur-based autotrophic denitrification, indicating further potential for the technology in practice. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： wastewater treatment   nitrogen removal   nitrate   ammonium   viruses   bacteria   F-specific RNA bacteriophage   Escherichia coli   woodchip   coconut husk   gravel   treatment wetland  

摘要： Denitrifying bioreactors, simple treatment systems consisting of a container filled with a particulate organic carbon source, are an effective and low-cost technology for the effective removal of nitrogen (N) from water by enhancing denitrification (i. e. the bacterial conversion of nitrate [NO 3 - ] to N gas). To date, studies on denitrifying bioreactors have mainly focused on the ability of, and factors influencing, the removal of NO 3 - within these systems. In the research presented in this thesis, a more holistic view of denitrifying bioreactors was taken in which N removal was assessed in conjunction with the removal of faecal microbial contaminants. The objectives of this research were: (1) to assess how well denitrifying bioreactors can remove microbial contaminant loads from wastewater and (2) to assess the potential role of alternative N removal pathways, namely anaerobic ammonium oxidation (anammox) and codenitrification for N removal in denitrifying bioreactors. The first part of this thesis focused on the removal of microbial contaminants in denitrifying bioreactors. Removal of microbial contaminants from wastewater is a key factor in wastewater treatment, since the contamination of receiving waters with inadequately treated wastewater can contribute to the transmission of infectious disease caused by waterborne pathogenic microorganisms. First, the removal of bacterial and viral indicators (Escherichia coli [E. coli] and F-specific RNA bacteriophage [FRNA bacteriophage]) was assessed along the longitudinal transect of a full-scale operating woodchip bioreactor (~114 m 3 in size with 9 sampling wells along the length of the bioreactors) loaded with nitrified septic tank effluent. In addition to significant reduction in NO 3 - loads, the bioreactor demonstrated consistent and substantial reduction of E. coli (2.9 log 10 reduction) and FRNA bacteriophage (3.9 log 10 reduction) despite receiving highly fluctuating inflow concentrations (up to 3.5 × 10 5 MP

关键词： Industrial wastewater treatment   Continuous two-phase partitioning   bioreactor (C-TPPB)   Toxic organic compounds   Process optimization   Biological treatment  

摘要： In this study, we propose the application of a Continuous Two-Phase Partitioning Bioreactor (C-TPPB) operated with the tubing effluent recycle to enhance the biodegradation of toxic substrates in industrial wastewaters under severe loading conditions. Stepwise increasing influent concentrations (from 200 to 900 mg L-1) of 2,4-dichlorophenol (2,4-DCP) were fed to a C-TPPB operated with Hytrel G3548 tubing to simulate phenolic wastewater. Practically complete 2,4-DCP removal has been achieved during the entire experimental period, but the increased load reduced biodegradation efficiency. At influent concentration of 700 mg L-1, the first effluent recycle (recycle /influent flow rate ratio = 0.3) was applied: biodegradation efficiency doubled from 40 to 80% and was maintained until influent concentrations of 800 mg L-1. Higher influent concentrations caused a decrease in 2,4-DCP biodegradation, so the effluent recycle ratio was increased to 0.5 at 900 mg L-1 and, also in this case, the bioreactor showed a fast recovery (similar to 24 h) of the biodegradation efficiency at 80%. Mass transfer data analysis showed that the effluent recycle resulted in an increase of the mass transfer coefficient. This positive effect, joined with the reduction of the influent concentrations, demonstrated the feasibility of recycle application in enhancing the C-TPPB performance. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Packed-bed bioreactor   Two-stage culture strategy   Human induced hepatocyte   Operating parameters optimization   Cell growth   Function evaluation  

摘要： A packed-bed (PB) bioreactor for bioartificial liver (BAL) was fabricated based on an optimum two-stage culture strategy and evaluated in vitro in this research. Human induced hepatocytes (hiHeps) were first expanded using Cytodex 3 microcarriers and the choice of microcarrier concentration and fetal bovine serum (FBS) content was optimized. Then, the cells expanded under the optimum expansion condition were perfused into a perfusion system containing Fibra-Cel (FC) disks to fabricate a PB bioreactor. Operating parameters including flow rate and seeding density for perfusion culture were optimized, respectively. Results indicated that during suspension culture, rapid cell proliferation and favorable amino acid metabolism were achieved at 3 mg/mL microcarriers combined with 1% FBS. While for the perfusion culture, the most effective flow rate and seeding density were 2 mL/min and 1 x 10(6) cells/mL, respectively. Under this optimum perfusion condition, hiHeps showed good proliferation ability, high viability, homogeneous distribution, high metabolism activities and efficient albumin secretion as well as high liver-specific genes expression. Therefore, the two-stage culture strategy based on operating parameters optimization provides a new method for the development of PB bioreactors. (C) 2018, The Society for Biotechnology, Japan. All rights reserved.

关键词： High-speed counter-current chromatography bioreactor   Biotransformation   Enzyme   Polydatin   Resveratrol  

摘要： Resveratrol, widely spread in many spermatophytes, is now receiving much attention for its significant pharmacological properties. However, compared with the precursor substance of polydatin, lower content in natural plants limits the use in food and pharmaceutical fields. The aim of the present research was to establish a novel bioreactor with high-speed counter-current chromatography (HSCCC) for the highly efficient biotransformation of resveratrol from polydatin. The suitable enzyme was optimized by the enzyme kinetics parameters. Further, the solvent system and parameters of HSCCC bioreactor was selected according to the partition coefficient, solubility, enzyme activity and retention of the stationary phase. After test different flow-rate, 2 mL/min was chosen as the optimum flow-rate with retention of the stationary phase 71.18% and the purity of resveratrol over 90% within 25 h. The novel HSCCC bioreactor was easy to immobilize and recycle the enzyme, and may be highly application in the preparation of resveratrol.