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关键词： anaerobic biodegradation   azo dye   carbon-based membrane   decolorization  

摘要： This study used a novel integrated technology of ceramic supported carbon membrane (CSCM) to degrade azo dyes through an anaerobic mixed culture. The CSCM worked simultaneously as biofilm support, redox mediator, and nano-filter to enhance the dye decolorization efficiency. The decolorization of Acid Orange 7 (AO7) was initially investigated with and without microorganisms in both ceramic support (CS) and CSCM reactors. The CSCM bioreactor (B-CSCM), operated with microorganisms, gave a maximum decolorization of 98% using a CSCM evolved from 10% weight (wt.) of Matrimid 5218 solution. To know the influence of permeate flow, feed concentration, and dye structure on the decolorization process, different B-CSCMs for dye removal experiments were studied over monoazo AO7, diazo Reactive Black 5 (RB5), and triazo Direct Blue 71 (DB71). The highest color removal, operated with 50 mg center dot L-1 feed solution and 0.05 L center dot m(-2)center dot h(-1) of permeate flux, was 98%, 82%, and 72%, respectively, for AO7, RB5, and DB71. By increasing these parameters to 100 mg center dot L-1 and 0.1 L center dot m(-2)center dot h(-1), the decolorization rate of dye solution still achieved 37% for AO7, 30% for RB5, and 26% for DB71. In addition, the system was run for weeks without apparent loss of activity. These findings make evident that the combined phenomena taking place in CSCM bioreactor result in an efficient, cost-effective, and ecofriendly azo dye decolorization method.

关键词： Chinese hamster ovary (CHO) cells   gene expression   glycans   metabolic network modelling   metabolomics   transcriptomics  

摘要： In this work, the kinetic model based on the previously developed metabolic and glycan reaction networks of the ovarian cells of the Chinese hamster ovary (CHO) cell line was improved by the inclusion of transcriptomic data that took into account the values of the RPKM gene (Reads per Kilobase of Exon per Million Reads Mapped). The transcriptomic (RNASeq) data were obtained together with metabolic and glycan data from the literature, and the concentrations with RPKM values were collected at several points in time from two fed-batch processes. First, the fluxes were determined by regression analysis of the metabolic data, then these fluxes were corrected by using the fold change in gene expression as a measure of enzyme concentrations. Next, the corrected fluxes in the kinetic model were used to calculate the concentration profiles of the metabolites, and literature data were used to evaluate the predicted results of the model. Compared to other studies where the concentration profiles of CHO cell metabolites were described using a kinetic model without consideration of RNA-Seq data to correct the fluxes, this model is unique. The additional integration of transcriptomic data led to better predictions of metabolic concentrations in the fed-batch process, which is a significant improvement of the modelling technique used.

关键词： particle size distribution   COD fractionation   sewage   entrapped COD fractions   membrane bioreactors   effective filtration size  

摘要： This study reviews the evolution of the concept and the methodology of particle size distribution (PSD) analysis for sewage. Evaluation of experimental data indicated that the analytical approach started with an empirical identification of soluble, colloidal and supra-colloidal organic matter. Then, it evolved into a sequential filtration and ultrafiltration methodology, yielding results useful enough to be an integral complement of respirometric chemical oxygen demand (COD) fractionation based on biodegradation characteristics. Default values could be defined for the distribution of COD fractions in terms of both size and biodegradation characteristics, which practically showed similar profiles, suggesting that PSD of COD could be directly used for model evaluation and design of activated sludge configurations. Size distribution of COD in sewage should be regarded as a prerequisite for activated sludge systems with a membrane module, mainly to assess the fate of COD fractions that would be entrapped and recycled back to the reactor by membrane filtration. (c) 2020 Society of Chemical Industry

关键词： AnMBR   Anaerobic co-digestion   Sewage sludge   COD mass balance   EROI   Smart city  

摘要： To support smart city in terms of municipal waste management and bioenergy recovery, a high-solid anaerobic membrane bioreactor (AnMBR) was developed for sewage sludge (SeS) and food waste (FW) treatment in this study. COD mass balance showed that 54.1%, 66.9%, 73.5%, 91.4% and 93.5% of the COD input was converted into methane at the FW ratio of 0, 25%, 50%, 75% and 100%, respectively. The corresponding net energy balance was 13.6, 14.1, 17.1, 22.9 and 27.4 kJ/g-VS, respectively. An important finding of this investigation was that, for the first time, the relationship between net energy balance and carbon to nitrogen (C/N) ratio was revealed and the established sigmoid-type function was shown to be capable of predicting energy balance at different C/N ratios regardless of the region. The outcomes of this study show the potential of high-solid AnMBRs in SeS and FW treatment for supporting smart cities in the future.

关键词： tissue engineering   3D bioprinting   bioink   bioreactor  

摘要： The field of tissue engineering has progressed tremendously over the past few decades in its ability to fabricate functional tissue substitutes for regenerative medicine and pharmaceutical research. Conventional scaffold-based approaches are limited in their capacity to produce constructs with the functionality and complexity of native tissue. Three-dimensional (3D) bioprinting offers exciting prospects for scaffolds fabrication, as it allows precise placement of cells, biochemical factors, and biomaterials in a layer-by-layer process. Compared with traditional scaffold fabrication approaches, 3D bioprinting is better to mimic the complex microstructures of biological tissues and accurately control the distribution of cells. Here, we describe recent technological advances in bio-fabrication focusing on 3D bioprinting processes for tissue engineering from data processing to bioprinting, mainly inkjet, laser, and extrusion-based technique. We then review the associated bioink formulation for 3D bioprinting of human tissues, including biomaterials, cells, and growth factors selection. The key bioink properties for successful bioprinting of human tissue were summarized. After bioprinting, the cells are generally devoid of any exposure to fluid mechanical cues, such as fluid shear stress, tension, and compression, which are crucial for tissue development and function in health and disease. The bioreactor can serve as a simulator to aid in the development of engineering human tissues from in vitro maturation of 3D cell-laden scaffolds. We then describe some of the most common bioreactors found in the engineering of several functional tissues, such as bone, cartilage, and cardiovascular applications. In the end, we conclude with a brief insight into present limitations and future developments on the application of 3D bioprinting and bioreactor systems for engineering human tissue.

关键词： Human mesenchymal stem cells   Shear stress   Microcarrier   Suspension bioreactor   Metabolism  

摘要： Human mesenchymal stem cells (hMSCs) are well known in cell therapy due to their secretion of trophic factors, multipotent differentiation potential, and ability for self-renewal. As a result, the number of clinical trials has been steadily increasing over the last decade highlighting the need for in vitro systems capable of producing large quantities of cells to meet growing demands. However, hMSCs are highly sensitive to microenvironment conditions, including shear stress caused by dynamic bioreactor systems, and can lead to alteration of cellular homeostasis. In this study, hMSCs were expanded on microcarriers within a 125 mL spinner flask bioreactor system. Our results demonstrate a three-fold expansion over seven days. Furthermore, our results show that culturing hMSCs in the microcarrier-based suspension bioreactor (compared to static planar culture) results in smaller cell size and higher levels of reactive oxidative species (ROS) and ROS regulator Sirtuin-3, which have implications on the nicotinamide adenine dinucleotide metabolic pathway and metabolic homeostasis. In addition, hMSCs in the bioreactor showed the increased Prostaglandin E-2 secretion as well as reduced the Indoleamine-pyrrole 2,3-dioxygenase secretion upon stimulus with interferon gamma. The results of this study provide understanding of potential hMSC physiology alterations impacted by bioreactor microenvironment during scalable production of hMSCs for biomanufacturing and clinical trials.

关键词： saline wastewater   industrial wastewater treatment   membrane bioreactor (MBR)   moving bed biofilm reactor (MBBR)   olive polyphenols   biofilm carriers   ultrafiltration membrane  

摘要： BACKGROUND Two laboratory-scale experimental systems - a membrane bioreactor (MBR) and a moving bed biofilm reactor-membrane bioreactor (MBBR-MBR), both treating real high-strength, saline wastewater from a table olive processing plant - were operated under identical conditions to comparatively evaluate their performance for three different hydraulic retention times (HRTs) of 88, 96 and 104 h. RESULTS The biological process of both systems, after appropriate biomass acclimatization, was stable and the removal efficiencies were rather high;i.e., regarding total organic carbon (TOC) >= 86.4% and >= 85.6% for the MBR and MBBR-MBR, respectively, and >= 89.1% regarding total polyphenols (TPh) for both systems. Concerning TOC and TPh removal, no statistically significant difference (p < 0.05) was observed between the two systems. Reduction of HRT resulted in a slight decrease in mean TOC removal efficiency, but the mean TPh removal was practically unchanged. No membrane chemical cleaning was applied to either system during the 85-day long continuous operation. CONCLUSION The comparative assessment showed that both systems (i.e., MBR and MBBR-MBR) are effective for the advanced biological treatment of table olive processing wastewater and can achieve quite high removal efficiencies of organic matter and TPh. However, direct effluent reuse for irrigation purposes seems to be hindered by its high salinity. No significant differences were observed in the performance of these systems, apart from the increased aeration (and related energy costs), which is necessary to keep the biofilm carriers floating in the case of the MBBR-MBR. (c) 2020 Society of Chemical Industry

关键词： Flowback water   Anaerobic granular sludge   Metagenome   Mesophilic/thermophilic anaerobic treatment  

摘要： Cost-effective treatment of flowback water remains a challenge for the sustainability of shale gas development. This study evaluated the efficiency of anaerobic granular sludge (AnGS) technology for flowback water treatment under mesophilic and thermophilic conditions. The granule characteristics and metagenomic characterization were also investigated. Thermophilic AnGS achieved 70.9% of COD removal and 362 NmL/d of methane production, higher than those for mesophilic AnGS (60.0% and 241 NmL/d). Thermophilic AnGS had higher extracellular polymeric substances content but low granular size and settleability. Metagenomic analysis revealed the genes related to hydrolysis acidification and carbohydrate metabolism were upregulated during thermophilic condition. Thermophilic condition most likely improved the hydrolysis of complex organics in the flowback water such as guar gum and hydrolyzed polyacrylamide, and led to higher COD removal and methane production. These results suggest that AnGS technology is a promising alternative for the treatment of flowback water, particularly when operated at thermophilic condition.

关键词： Hybrid sweetgum   Somatic embryogenesis   RITA(®)   Temporary immersion bioreactor  

摘要： Key message Temporary immersion bioreactors can improve hybrid sweetgum somatic embryo conversion and somatic seedling growth rates compared to semisolid medium, significantly improving somatic seedling production efficiency for hybrid sweetgum, an emerging woody biomass crop. Fast-growing hybrid southern hardwood trees should make excellent material for woody biomass production in the Southeastern US, if elite clones can be identified and efficiently propagated. We have enhanced the potential of sweetgum (Liquidambar styraciflua) as a biomass species by generating hybrids between the tree and its Chinese relative, Liquidambar formosana, and propagating the most promising clones via somatic embryogenesis. Some of the hybrid clones have already demonstrated superior biomass productivity compared to elite L. styraciflua trees. However, production of somatic seedlings from these clones remains labor-intensive. Bioreactors, specifically temporary immersion designs, such as the RITA (R), have been applied to improve the efficiency of in vitro propagation of a number of woody species. We tested RITA (R) bioreactors for their potential to improve the production efficiency of high-quality hybrid sweetgum somatic seedlings. In one tested genotype, a RITA (R) with 50 somatic embryos had about 66% higher conversion frequency (p < 0.05) and produced about 40% more "high-quality" somatic seedlings (p < 0.05) than when somatic embryos were germinated on semisolid medium in GA-7 vessels. In all the genotypes we tested, somatic seedlings produced in RITA (R) bioreactors had higher survival percentages by the end of acclimatization than somatic seedlings produced on semisolid medium in GA-7 vessels.

关键词： Mesenchymal stromal cells   Hypoxia   Stirred-tank bioreactor   Angiogenic potential   SphereCol microcarrier   Xenogeneic-free culture  

摘要： Mesenchymal stromal cells (MSC) have been investigated for their remarkable regenerative and immunomodulatory therapeutic potential. However, clinical trials have revealed limited results, which have led to the search for priming/preconditioning strategies to improve efficacy of these cells. MSC cultured under hypoxia exhibit increased migration, angiogenesis and release of trophic factors, decreased senescence and apoptosis, as well as high therapeutic potential in several preclinical models. Clinical applications of MSC require the implementation of scalable expansion process compliant with Good Manufacturing Practice (GMP) standards. Bioreactor systems present advantages such as reduced costs and greater process control, reproducibility and cell product standardization. Here, we describe the establishment of a scalable xenogeneic-free process for hypoxia-primed umbilical cord-MSC expansion. Efficient UC-MSC expansion was achieved after 5 days of culture in stirred-tank bioreactor under hypoxia conditions using human collagen-coated microcarriers and human serum (HS) as culture medium supplement. Cells retained their immunophenotype, multilineage differentiation and immunosuppressive potential. The association of hypoxia and 3D xenogeneic-free culture priming enhanced in vitro angiogenic properties of UC-MSC, when compared to non-primed cells. These results indicate that the fine-tuning of culture conditions, combined with expansion in a controllable, robust and closed system, could enhance functional properties and ultimately improve clinical efficacy.