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关键词： bDtBPP   Chinese hamster ovary cells   endocrine disruptor   leachables   mitochondria   Seahorse XF96   single-use bioreactors  

摘要： Single-use technologies, in particular disposable bioreactor bags, have become integral within the biopharmaceutical community. However, safety concerns arose upon the identification of toxic leachable compounds derived from the plastic materials. Although the leachable bis(2,4-di-tert-butylphenyl)-phosphate (bDtBPP) has been previously shown to inhibit CHO cell growth, it is critical to determine if other compounds like this are still present in subsequent generations of films for industrial application. This study compares the performance of CHO cells, CHO-K1, and CHO-DP12, cultured in media conditioned in an older single-use bioreactor (SUB) film (F-1) and a newer generation film (F-2) from the same vendor. CHO cells cultured in media conditioned for 7 days in the F-1 film demonstrated significantly reduced growth and antibody productivity profiles when compared to controls and media conditioned for the same time period in the newer F-2 film. Proteomic profiling of CHO cells cultured in the F-1 conditioned media identified differentially expressed proteins involved in oxidative stress response as well as compromised ATP synthesis. These potentially metabolically compromised cells exhibited reduced oxidative phosphorylation activity as well as lower glycolytic metabolism, characteristic of slower growing cells. Nonvolatile and metal leachables analysis of film extracts by LC-MS revealed a reduction in the abundance of the analyzed leachates from F-2 films when compared to F-1 films including bDtBPP, potentially explaining improved CHO cell growth in F-2 conditioned media. Furthermore, in vitro endocrine disruptor testing of the known leachable revealed this molecule to possess the potential to act as an androgen antagonist. This study demonstrates an improvement in the materials composition used in modern generations of SUBs for safe application in the bioprocess.

关键词： orbitally shaken bioreactors   CFD   mixing   oxygen transfer  

摘要： BACKGROUND Nowadays, orbitally shaken bioreactors (OSRs) show promising application in mammalian cell cultivation. Designing a suitable vessel geometry for cell culture is an important issue in the research on bioreactors. RESULTS A three-dimensional computational fluid dynamic (CFD) model was established to evaluate the performance of a hollow OSR we proposed. The CFD model was validated by comparing the simulated and experimental liquid wave heights. The fluid velocity distribution verified that the hollow cylinder wall could improve the mixing efficiency due to the vanishing of central-low velocity region. Furthermore, the volumetric oxygen transfer coefficient (k(L)a) and shear stress were investigated in the hollow OSR at different values of the inner diameter compared to the outer diameter (d(i)/d). CONCLUSION To achieve a high level of mixing, a higher value of d(i)/d is more preferable but too high a value of d(i)/d has a risk of low mixing. To achieve high oxygen transfer rate and low shear stress, the value of d(i)/d should be kept lower. For all the cases studied, the hydrodynamic stress in the hollow OSRs was moderate for mammalian cell cultivation. (c) 2019 Society of Chemical Industry

关键词： Column reactor   Lead adsorption   Lentil husk   XRD   Kinetic study  

摘要： This study depicts successful employment of fixed bed column bioreactor for adsorption of lead in continuous mode using lentil husk as sorbent. Design parameters considerably controlled the reactor performance, amongst which height of the fixed bed and flow rate were crucial in generating cleaner effluent. Adsorption capacity was found to shoot up to the level of 205.87 mg g(-1) at 10 cm bed height, 100 mg L-1 feed concentration and 20 mL min(-1) flow rate. Kinetic study done at regular intervals of time revealed high percentage removal of lead (99-96%) throughout entire span of reactor operation. Experimental data were well interpreted by Thomas model and Yoon-Nelson model. The reactor bed was regenerated after each adsorption and loaded metal was recovered up to the extent of similar to 96%. The column reactor was efficient enough to treat lead containing actual industrial effluents.

关键词： biomedical research   bioreactors   cell culture   induced pluripotent stem cells   oxygen  

摘要： For clinical and/or pharmaceutical use of human-induced pluripotent stem cells (hiPSCs), large cell quantities of high quality are demanded. Therefore, we combined the expansion of hiPSCs in closed, perfusion-based 3D bioreactors with noninvasive online monitoring of oxygen as culture control mechanism. Bioreactors with a cell compartment volume of 3 or 17 ml were inoculated with either 10 x 10(6) or 50 x 10(6) cells, and cells were expanded over 15 days with online oxygen and offline glucose and lactate measurements being performed. The CellTiter-Blue (R) Assay was performed at the end of the bioreactor experiments for indirect cell quantification. Model simulations enabled an estimation of cell numbers based on kinetic equations and experimental data during the 15-day bioreactor cultures. Calculated oxygen uptake rates (OUR), glucose consumption rates (GCR), and lactate production rates (LPR) revealed a highly significant correlation (p < 0.0001). Oxygen consumption, which was measured at the beginning and the end of the experiment, showed a strong culture growth in line with the OUR and GCR data. Furthermore, the yield coefficient of lactate from glucose and the OUR to GCR ratio revealed a shift from nonoxidative to oxidative metabolism. The presented results indicate that oxygen is equally as applicable as parameter for hiPSC expansion as glucose while providing an accurate real-time impression of hiPSC culture development. Additionally, oxygen measurements inform about the metabolic state of the cells. Thus, the use of oxygen online monitoring for culture control facilitates the translation of hiPSC use to the clinical setting.

关键词： Benzothiazole   Benzotriazole   Biotransformation   Degradation kinetics   Membrane fouling   MBR  

摘要： Lab-scale membrane bioreactors (MBRs), with aerated activated sludge and internal microfiltration module, were used for the treatment of municipal wastewater containing high, yet environmentally relevant, concentrations of benzothiazole (BT) and benzotriazole (BTA). These high production volume compounds are commonly used in the industry and households, and therefore occur ubiquitously in municipal wastewater and the aquatic environment. The aim of this study was to assess the removal of BT and BTA from synthetic municipal wastewater in MBRs and to estimate the contribution of elimination processes and to identify potential biotransformation products. The overall removal of BT and BTA was high, and after the adaptation period, it reached 99.8% and 97.2%, respectively, but recurring periods of unstable BTA removal occurred. The removal due to biotransformation was 88% for BT and 84% for BTA and the disposal with waste sludge accounted for only <1% of the removed load. The remaining fraction of the removed load of BT and BTA was attributed to be retained by phenomena associated with membrane fouling. The adaptation process was reflected in multifold increase in biodegradation kinetic coefficient (k(biol)) for BT (reported for the first time) and BTA. Biodegradation was attributed to catabolic mechanism rather than to cometabolism. Hydroxylation was observed to be the main transformation reaction for BT, whereas for BTA hydroxylation, methylation and cleavage of benzene ring were noted. This study has shown the feasibility of treating municipal wastewater with high concentrations of BT and BTA in MBRs and identified potential challenges for the removal of BTA. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： oxygen transfer   step method   pneumatic bioreactors   estimation of k(L)a   Saccharomyces cerevisiae   Bacillus subtilis  

摘要： Background Determination of the volumetric oxygen transfer coefficient (k(L)a) plays an important role in the design and characterization of bioreactors. Among all methods available, few techniques are suitable for the determination of k(L)a in pneumatic bioreactors during the course of cultivations. The present work proposes a new aeration step method for k(L)a evaluation in pneumatic bioreactors during biological consumption of oxygen. Results The aeration step method consisted in promoting step changes in the specific air flow rate (phi(air)) to change the dissolved oxygen concentration during cultivations, allowing the measurement of both overall oxygen transfer coefficient (k(L)a) and specific oxygen uptake rate (Q(O2)). These parameters were determined experimentally by employing two microorganisms, one a strict aerobe (Bacillus subtilis) and the other a facultative aerobe (Saccharomyces cerevisiae), for phi(air) values ranging from 2.0 to 5.0 vvm. For the purpose of comparison, k(L)a was also determined in experiments using water as the liquid phase, employing a dynamic gassing-out method. The k(L)a values during the cultivations ranged from 0.0137 to 0.0545 s(-1), while Q(O2) varied from 0.44 to 10.06 mol kg(-1) h(-1). The results obtained are shown to be reliable, exhibited excellent reproducibility and are in agreement with other values reported in the literature by different methodologies. Conclusion The new aeration step method proved to be reliable as an alternative technique for the determination of k(L)a and Q(O2) during microbial cultivation in pneumatic bioreactors. (c) 2019 Society of Chemical Industry

关键词： composite industrial wastewater   AAO-MBR   refractory organic compounds   membrane fouling   microbial community  

摘要： BACKGROUND A laboratory-scale anaerobic-anoxic-oxic membrane bioreactor (AAO-MBR) system was used to remove organic compounds and nitrogen in the composite industrial wastewater collected from an industrial park. RESULTS The recommended conditions for both chemical oxygen demand (COD) and nitrogen removal were as follows: hydraulic retention time of 73.6 h, sludge retention time of 35 days and mixed liquor return ratio of 300%. Under this condition, COD and total nitrogen removal efficiencies were 89.4% and 77.7%, respectively. After treatment, most organic compounds were removed, but there were still a few refractory organic compounds in the final effluent, such as 2-hydroxydesmethylimipramine, 1-dichloromethyl-3-methyl-benzene and N-phenyl-2,3-dichloromaleimide. Compared to carbohydrates, proteins in the extracellular polymetric substances accumulated more easily on the membrane surface, resulting in the membrane fouling. Ternary analysis at the family level indicated that the bacteria Desulfuromonadaceae, Rikenellaceae, and Spirochaetaceae were dominant in the anaerobic sludge, and played an important role in hydrolysis and fermentation. The abundance distributions of Nitromonadaceae, Caldilineaceae and Xanthomonadales were above 50% in the anoxic sludge, and these bacteria played an important role in denitrification. CONCLUSION The results can provide valuable information for optimizing the operation of the AAO-MBR system for the treatment of composite industrial wastewater. (c) 2019 Society of Chemical Industry

关键词： Anaerobic bioreactor   Solar radiant heating   Photo biochemical transformation   Temperature fluctuation  

摘要： Upgrading bioreactor under solar radiant heating can maintain the anaerobic fermentation process by utilizi absorption and scattering of solar energy in media to improve slurry temperature. Finding the suitable correcti factor of temperature fluctuation for calculating kinetic rate of microbial fermentation process can impro simulation accuracy of microbial fermentation process. In present work, a coupled model for simulating t processes of phototherrnal transmission and anaerobic fermentation was built. Experimental and numeric researches about the anaerobic fermentation process of upgrading bioreactor were made to investigate the effi of temperature fluctuation on the kinetic rate of biochemical reactions. The results show that the temperatt fluctuation has big effects on the biochemical reaction rate of each substance in the fermentation process. The values for calculating heat exchange number BT are discrepant for both different reactants and temperatt differences. For instance, when the temperature difference is bigger than 4 K, n = 2 is suitable to the one of cc dung in reactor A, and n = 3 is suitable to the one of pig dung and straw pitch in reactor B. The effect of n valt on daily biogas production of straw is bigger than the one of cow dung, since hydrolytic bacteria are me sensitive to temperature fluctuation.

关键词： Dyeing   Membrane bioreactor (MBR)   Nanofiltration (NF)   Reuse   Reverse osmosis (RO)   Textile wastewater  

摘要： The reuse opportunities of separate wastewater streams and end-of-pipe composite wastewater were investigated in an integrated woolen textile mill. The main purpose was to reuse either the treated composite wastewater and/or treated/untreated separate streams depending on the water quality demand of different water use points in the production processes. In this context, three separate wastewater streams (tops-fiber, bobbins thread and fabric dyeing-finishing wastewaters) and composite wastewater were analyzed in terms of quality and quantity. Moreover, raw groundwater, softened process water, cationic ion exchangers' regeneration wastewater, and reverse osmosis (RO) concentrates were also characterized. Wastewater treatability studies were conducted in pilot-scale employing membrane bioreactor (MBR), nanofiltration (NF) and brackish water reverse osmosis (BWRO) processes at different test conditions. In the wastewater characterization studies, peaks and oscillations were found in the separate wastewater streams depending on the production schedules and applied dyeing recipes. Therefore, due to mixing effects of separate streams, it was decided to employ pilot-scale treatability tests on the composite wastewater. In the MBR process, the average chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), and color removals were 70, 74, 86, 28, 43, and 62%, respectively. In MBR + NF and MBR + RO tests, the removals of all analyzed parameters were 40-99 and 52-99%, respectively. The pH, conductivity, turbidity, color, and TN concentrations in MBR + RO effluent were 7.6-7.8, 57-65 mu S/cm, 0.6-1.2 NTU, 25-44 Pt-Co, and 14-16 mg/L, respectively. In addition, the COD, BOD5 and total hardness values were found under 1 mg/L. The treated water was finally disinfected with ultraviolet (UV) light to ensure microbial safety before reuse in dyeing process. Treated water samples were tested in different