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关键词： Euglena gracilis   Extracellular polymeric substances   Fed-batch fermentation   Harvesting   Paramylon  

摘要： Bacterial extracellular polymeric substances (EPS) are promising materials that have a role in enhancing growth, metabolite production, and harvesting efficiency. However, the validity of the EPS effectiveness in scale-up cultivation of microalgae is still unknown. Therefore, in order to verify whether the bacterial metabolites work in the scale-up fermentation of microalgae, we conducted a bioreactor fermentation following the addition of bacterial EPS derived from the marine bacterium, Pseudoalteromonas sp., to Euglena gracilis. Various culture strategies (i.e., batch, glucose fed-batch, and glucose and EPS fed-batch) were conducted to maximize metabolite production of E. gracilis in scale-up cultivation. Consequently, biomass and paramylon concentrations in the continuous glucose and EPS-treated culture were enhanced by 3.0-fold and 4.2-fold (36.1 +/- 1.4 g L-1 and 25.6 +/- 0.1 g L-1), respectively, compared to the non-treated control (12.0 +/- 0.3 g L-1 and 6.1 +/- 0.1 g L-1). Also, the supplementation led to the enhanced concentrations of alpha-tocopherols and total fatty acids by 3.7-fold and 2.8-fold, respectively. The harvesting efficiency was enhanced in EPS-supplemented cultivation due to the flocculation of E. gracilis. To the best of our knowledge, this is the first study that verifies the effect of bacterial EPS in scale-up cultivation of microalgae. Also, our results showed the highest paramylon productivity than any other previous reports. The results obtained in this study showed that the scale-up cultivation of E. gracilis using bacterial EPS has the potential to be used as a platform to guide further increases in scale and in the industrial environment.

关键词： Immobilized bioreactor   Denitrification   Fungal pellet   Low C   N   High throughput sequencing  

摘要： In this study, fungal pellets immobilized denitrifying Pseudomonas stutteri sp. GF3 was cultivated to establish a bioreactor. The denitrification effect of fixed bacteria with fungal pellets was tested by response surface methodology (RSM). Analysis of the bioreactor showed that the denitrification efficiency reached 100% under the optimal conditions and the denitrification efficiency of the actual wastewater treatment in the stable phase reached 95.91%. Moreover, the organic matter and functional groups in the bioreactor under different C/N conditions were analyzed by fluorescence excitation-emission matrix (EEM) spectra and Fourier transform infrared spectroscopy (FTIR), which revealed that metabolic activities of denitrifying bacteria were enhanced with the increase of C/N. The morphology and structure of bacteria immobilized by fungal pellets explored by scanning electron microscope (SEM) showed the filamentous porous fungal pellets loaded with bacteria. Community structure analysis by high-throughput sequencing demonstrated that strain GF3 might was the dominant strain in bioreactor.

关键词： bioreactor production   COVID-19   rVSV-ZEBOV   Vero suspension culture   viral vaccine bioprocess  

摘要： The Vero cell line is the most used continuous cell line in viral vaccine manufacturing. This adherent cell culture platform requires the use of surfaces to support cell growth, typically roller bottles, or microcarriers. We have recently compared the production of rVSV-ZEBOV on Vero cells between microcarrier and fixed-bed bioreactors. However, suspension cultures are considered superior with regard to process scalability. Therefore, we further explore the Vero suspension system for recombinant vesicular stomatitis virus (rVSV)-vectored vaccine production. Previously, this suspension cell line was only able to be cultivated in a proprietary medium. Here, we expand the adaptation and bioreactor cultivation to a serum-free commercial medium. Following small-scale optimization and screening studies, we demonstrate bioreactor productions of highly relevant vaccines and vaccine candidates against Ebola virus disease, HIV, and coronavirus disease 2019 in the Vero suspension system. rVSV-ZEBOV, rVSV-HIV, and rVSV(Ind)-msp-S-F-Gtc can replicate to high titers in the bioreactor, reaching 3.87 x 10(7) TCID50/ml, 2.12 x 10(7) TCID50/ml, and 3.59 x 10(9) TCID50/ml, respectively. Furthermore, we compare cell-specific productivities, and the quality of the produced viruses by determining the ratio of total viral particles to infectious viral particles.

关键词： effective filtration size   membrane bioreactor   particle size distribution   COD fractionation   retained COD   modelling  

摘要： This study reviews particle size distribution (PSD) analysis for industrial effluents. Evaluation of available experimental data indicated that the approach started with arbitrary selection of size distribution. Following a pioneering study on pulp and paper effluent, sequential filtration and ultrafiltration has established itself as a prescribed methodology complementing respirometric assessment of chemical oxygen demand (COD) fractionation based on biodegradation characteristics. Results indicated that most industrial effluents exhibited a COD distribution where soluble fractions accounted for the majority of the total COD, with significant implications for the understanding of membrane bioreactor (MBR) systems. Observations on the accumulation of soluble COD in the reactor to levels much higher than the permeate COD paved the way to define an experimental PSD methodology for assessing the effective filtration size for the membrane module. This novel parameter considered in the light of reported PSD analyses showed that a portion of what was conventionally considered soluble COD would be retained by the size barrier of the membrane and recycled back to the reactor. Thus, MBR systems require a new mathematical model structure that would include a modified COD fractionation, account for the retained COD fractions as additional model components and utilize related mass balance relationships in order to yield an accurate mechanistic description of microbial reactions taking place in the system. (c) 2021 Society of Chemical Industry (SCI).

摘要： Pharmaceuticals are often not fully removed in wastewater treatment plants (WWTPs) and are thus being detected at trace levels in water bodies all over the world posing a risk to numerous organisms. These organic micropollutants (OMPs) reach WWTPs at concentrations sometimes too low to serve as growth substrate for microorganisms;thus, co-metabolism is thought to be the main conversion mechanism. In this study, the microbial removal of six pharmaceuticals was investigated in a membrane bioreactor at increasing concentrations (4-800 nM) of the compounds and using three different hydraulic retention times (HRT;1, 3.5 and 5 days). The bioreactor was inoculated with activated sludge from a municipal WWTP and fed with ammonium, acetate and methanol as main growth substrates to mimic co-metabolism. Each pharmaceutical had a different average removal efficiency: acetaminophen (100%) > fluoxetine (50%) > metoprolol (25%) > diclofenac (20%) > metformin (15%) > carbamazepine (10%). Higher pharmaceutical influent concentrations proportionally increased the removal rate of each compound, but surprisingly not the removal percentage. Furthermore, only metformin removal improved to 80-100% when HRT or biomass concentration was increased. Microbial community changes were followed with 16S rRNA gene amplicon sequencing in response to the increment of pharmaceutical concentration: Nitrospirae and Planctomycetes 16S rRNA relative gene abundance decreased, whereas Acidobacteria and Bacteroidetes increased. Remarkably, the Dokdonella genus, previously implicated in acetaminophen metabolism, showed a 30-fold increase in abundance at the highest concentration of pharmaceuticals applied. Taken together, these results suggest that the incomplete removal of most pharmaceutical compounds in WWTPs is dependent on neither concentration nor reaction time. Accordingly, we propose a chemical equilibrium or a growth substrate limitation as the responsible mechanisms of the incomplete removal. Final

关键词： Salinity build up   OMBR   Wastewater treatment   Draw solution   Hybrid UF-OMBR   Recalcitrant compounds  

摘要： Two strategies were investigated for salinity build up prevention in osmotic membrane bioreactors (OMBR) treating a real refinery wastewater. Firstly, a solute with lower diffusivity (MgCl2, for 102 days) was used. The impact on the microbiological activity was lower, which favored the recalcitrant compounds degradation. However, without salinity relief, the mixed liquor (ML) salinity increased, impacting the forward osmosis (FO) flux (0.18 L/m2h). Secondly, an ultrafiltration (UF) membrane was submerged within the ML and the draw solution (DS) replaced to NaCl. The ML conductivity was stable along 330 days without a severe flux decay (1.07 L/m2h). Nonetheless, the reverse NaCl flux had a higher impact on the microbiological activity and the concentration of dissolved organic carbon and ammoniacal nitrogen started to increase in the UF permeate. Due to the lower permeate flux, the OMBR had a higher membrane area requirement which represented the main contributor for the total operating costs. (c) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： CHO history   cytogenetics   evolution   identity   name assignment  

摘要： Chinese Hamster Ovary [CHO] cells are the workhorse for production of modern biopharmaceuticals. They are however immortalized cells with a high propensity for genetic change. Judging from published culture records, CHO cell populations have undergone hundreds of population doublings since their origin in the late 1950s. Different cell populations were established and named from 1 to 3 decades after their generation, such as CHO-Pro-, CHO-K1, CHO-DG44, CHO-S, CHO-DUK, CHO-DXB-11 to indicate origin and certain phenotypic features. These names are commonly used in scientific publications still today. This article discusses the relevance of such names. We argue that they provide a false sense of identity. To substantiate this, we provide the long (and poorly recorded) history of CHO cells as well as their highly complex genetics. Finally, we suggest an alternative naming system for CHO cells which provides more relevant information. While the implementation of a new naming convention will require substantial discussions among members of the relevant community, it should improve interpretation and comparability between laboratories. This, in turn will help scientific communities and industrial users to attain and further the full potential of CHO cells.

关键词： Slurry wastewater   Polyacrylate containing wastewater   Anaerobic treatment   Biodegradability   Spiral symmetry stream anaerobic bioreactor  

摘要： Polyacrylate containing wastewater (PCW) is the typical sewage discharged by the textile industry. It has extremely poor biodegradability, and chemical methods were used conventionally as the only way for treating PCW. This study is demonstrating a novel biological method. In batch experiment monod kinetics was applied to the experimental data, which indicated that anaerobic treatment used for PCW is feasible. The pilot-scale experiment combined a Spiral Symmetry Stream Anaerobic Bioreactor (SSSAB) and an air-lift external circulation vortex enhancement nitrogen removal fluidized bed bioreactor (AFB). The COD and NH4+-N removal reached up to 95.2% and 96.6%, respectively, which were higher than the value obtained by other chemical methods. High-throughput sequencing analysis indicated that the relative abundance of Proteobacteria, Firmicutes and Bacteroidetes increased, which contribute to the degradation of PCW. Therefore, PCW can be degraded efficiently by using a SSSAB-AFB technique and thus provides an alternative to the chemical methods.

关键词： cellulose degradation   co‐   denitrification   denitrification   fungi   soil   woodchip bioreactor  

摘要： Aims The aim of this study was to obtain cold-adapted denitrifying fungi that could be used for bioaugmentation in woodchip bioreactors to remove nitrate from agricultural subsurface drainage water. Methods and results We isolated a total of 91 nitrate-reducing fungal strains belonging to Ascomycota and Mucoromycota from agricultural soil and a woodchip bioreactor under relatively cold conditions (5 and 15 degrees C). When these strains were incubated with N-15-labelled nitrate, N-29(2) was frequently produced, suggesting the occurrence of co-denitrification (microbially mediated nitrosation). Two strains also produced N-30(2), indicating their ability to reduce N2O. Of the 91 nitrate-reducing fungal strains, fungal nitrite reductase gene (nirK) and cytochrome P450 nitric oxide reductase gene (p450nor) were detected by PCR in 34 (37%) and 11 (12%) strains, respectively. Eight strains possessed both nirK and p450nor, further verifying their denitrification capability. In addition, most strains degraded cellulose under denitrification condition. Conclusions Diverse nitrate-reducing fungi were isolated from soil and a woodchip bioreactor. These fungi reduced nitrate to gaseous N forms at relatively low temperatures. These cold-adapted, cellulose-degrading and nitrate-reducing fungi could support themselves and other denitrifiers in woodchip bioreactors. Significance and Impact of the Study The cold-adapted, cellulose-degrading and nitrate-reducing fungi isolated in this study could be useful to enhance nitrate removal in woodchip bioreactors under low-temperature conditions.

关键词： laboratory automation   maximum likelihood estimation   process control system   robotic integration   stirred tank bioreactor  

摘要： Given its geometric similarity to large-scale production plants and the excellent possibilities for precise process control and monitoring, the classic stirred tank bioreactor (STR) still represents the gold standard for bioprocess development at a laboratory scale. However, compared to microbioreactor technologies, bioreactors often suffer from a low degree of process automation and deriving key performance indicators (KPIs) such as specific rates or yields often requires manual sampling and sample processing. A widely used parallelized STR setup was automated by connecting it to a liquid handling system and controlling it with a custom-made process control system. This allowed for the setup of a flexible modular platform enabling autonomous operation of the bioreactors without any operator present. Multiple unit operations like automated inoculation, sampling, sample processing and analysis, and decision making, for example for automated induction of protein production were implemented to achieve such functionality. The data gained during application studies was used for fitting of bioprocess models to derive relevant KPIs being in good agreement with literature. By combining the capabilities of STRs with the flexibility of liquid handling systems, this platform technology can be applied to a multitude of different bioprocess development pipelines at laboratory scale.