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关键词： Integrated microbial fuel cells (MFCs)   Anaerobic treatment process (AnTP)   Membrane bioreactor (MBR)   Energy recovery   Biosensor  

摘要： The promising and challenging approach of microbial fuel cell (MFC) is a novel concept in wastewater treatment facilities which utilizes microbial metabolism to produce direct electricity while treating wastewater/sludge. Despite potential advantages of MFCs and encouraging results obtained at laboratory-scale, low power density and high costs of initial investment and operation have limited their commercial application. Therefore, in order to promote MFCs utilization in a sustainable manner, the synergistic effect of MFCs integrated to other wastewater treatment processes seems efficacious. Among the proposed MFC hybrid systems, the integration of anaerobic treatment processes (AnTPs) and membrane bioreactors (MBRs) with MFCs have been adopted due to the practical implementation potential and the highly positive synergetic effect on energy recovery, power output and treatment efficiency. In AnTP-MFC coupled system, efficient handling of high COD-loaded influents and significant organic load reduction along with improved energy conversion efficiency and energy recovery is accomplished. In MFC-MBR hybrid system, the MBR improves the effluent quality to a high level, while the energy consumption and membrane fouling of MBR are alleviated by MFC. The hybrid processes benefit from MFCs as an online low cost efficient biosensor as well. Current trends, purposes and progresses in respect of these two cardinal hybrid processes are discussed and tables comprised of a wide range of researches within the scope of the integrations are provided in full details to gather a comprehensive literature. Finally, a multilateral evaluation plan, required to make integrated MFC processes competitive against the practically implemented ones, is proposed.

关键词： Bioreactor   Cyclic stretching   Mechanical stimulation   Tissues engineering   Cardiac tissue maturation  

摘要： Physical stimuli are crucial for the structural and functional maturation of tissues both in vivo and in vitro. In tissue engineering applications, bioreactors have become fundamental and effective tools for providing biomimetic culture conditions that recapitulate the native physical stimuli. In addition, bioreactors play a key role in assuring strict control, automation, and standardization in the production process of cell-based products for future clinical application. In this study, a compact, easy-to-use, tunable stretch bioreactor is proposed. Based on customizable and low-cost technological solutions, the bioreactor was designed for providing tunable mechanical stretch for biomimetic dynamic culture of different engineered tissues. In-house validation tests demonstrated the accuracy and repeatability of the imposed mechanical stimulation. Proof of concepts biological tests performed on engineered cardiac constructs, based on decellularized human skin scaffolds seeded with human cardiac progenitor cells, confirmed the bioreactor Good Laboratory Practice compliance and ease of use, and the effectiveness of the delivered cyclic stretch stimulation on the cardiac construct maturation. (C) 2020 IPEM. Published by Elsevier Ltd. All rights reserved.

关键词： Fouling   Membrane bioreactor   Microbial fuel cell   Wastewater treatment  

摘要： Membrane bioreactors (MBR) have gained much attention due to their ability to achieve higher treatment efficiency. However, high external energy consumption in aeration for membrane fouling mitigation has been limiting their application. Microbial fuel cells (MFC) can ideally extract energy from wastewater in the form of electricity and reduce membrane fouling. Thus, the use of MFC-MBR is rapidly expanding. However, the MFC-MBR design and operation is not fully mature and further research is needed to optimize the process efficiency and enhance the applicability. This review gives an overview of recent studies on the performances of MFC-MBR systems, regarding the design and configuration of the integrated system, irrespective of whether optimization was done or not in the operating system.

关键词： Packed bed bioreactor   Naphthalene   Removal efficiency   External mass transfer   Inlet flow rate  

摘要： The biodegradation of naphthalene using low-density polyethylene (LOPE) immobilized Exiguobacterium sp. RKS3 (MG696729) in a packed bed bioreactor (PBBR) was studied. The performance of a continuous PBBR was evaluated at different inlet flow rates (IFRs) (20-100 mL/h) under 64 days of operation. The maximum naphthalene removal efficiency (RE) was found at low IFR, and it further decreased with increasing IFRs. In a continuous PBBR, the external mass transfer (EMT) aspect was analysed at various IFRs, and experimental data were interrelated between Colburn factor (J(D)) and Reynolds number (N-Re) as J(D) = KNRe(n-1). A new correlation J(D) = 5.71N(Re)(-0.1) was obtained to predict the EMT aspect of naphthalene biodegradation. Andrew-Haldane model was used to evaluate the bio-kinetic parameters of naphthalene degradation, and kinetic constant a v(max), J(s), and J(i) were found as 0.386 per day, 13.6 mg/L, and 20.54 mg/L, respectively.

关键词： AnMBR   Anaerobic digestion   Emerging contaminants   Antibiotic resistance genes   Biodegradation  

摘要： Emerging contaminants (ECs) are synthetic organic chemicals that released into the environment, which pose a serious threat to the ecosystem and human health. Due to the high costs of physicochemical methods and the possibility of secondary pollution, and conventional biological treatment techniques are not efficient to remove ECs. Thus, there is a need to develop novel technologies to treat ECs. Anaerobic digestion (AD) is reported to degrade most ECs. Anaerobic membrane bioreactor (AnMBR) is an upgraded AD technology that has high system stability and microbial community abundance. The biogas production and EC biodegradation efficiency in the AnMBR system are markedly higher than those in the traditional AD system. In recent years, AnMBR is widely used to remove environmental ECs. This review analyzes the feasibility and challenges of AnMBR in the treatment of ECs and provides useful insights for improving the performance and efficiency of AnMBR to treat ECs.

关键词： Micro-bioreactor   Mixing   k(L)a   Oscillation   Capillary waves   Droplets  

摘要： For high-throughput cell culture and associated analytics, droplet-based cultivation systems open up the opportunities for parallelization and rapid data generation. In contrast to microfluidics with continuous flow, sessile droplet approaches enhance the flexibility for fluid manipulation with less operational effort. Generating biologically favorable conditions and promoting cell growth in a droplet, however, is particularly challenging due to mass transfer limitations, which has to be solved by implementing an effective mixing technique. Here, capillary waves induced by vertical oscillation are used to mix inside a sessile droplet micro-bioreactor (MBR) avoiding additional moving parts inside the fluid. Depending on the excitation frequency, different patterns are formed on the oscillating liquid surface, which are described by a model of a vibrated sessile droplet. Analyzing mixing times and oxygen transport into the liquid, a strong dependency of mass transfer on the oscillation parameters, especially the excitation frequency, is demonstrated. Oscillations at distinct capillary wave resonant frequencies lead to rapid homogenization with mixing times of 2 s and volumetric liquid-phase mass transfer coefficients of more than 340 h(-1) . This shows that the mass transfer in a droplet MBR can be specifically controlled via capillary waves, what is subsequently demonstrated for cultivations of Escherichia coli BL21 cells. Therefore, the presented MBR with vertical oscillation mixing is a promising analytical tool to perform cellular assays and experiments in parallel with intensified and tailored mass transfer.

关键词： Human   Umbilical cord matrix derived mesenchymal stromal cells (hUCM-MSCs)   Wave-Induced Motion Bioreactor (WIMB)   Stirred bioreactor   hUCM-MSC post-expansion evaluation   Gene expression pattern  

摘要： Mesenchymal Stromal Cells (MSCs) are being targeted for diverse cell-therapies applications. The MSC expansion in bioreactor is necessary to achieve the cell number required for clinical applications in accordance with cGMP guidelines. Since the culture conditions may influence the post-expansion MSC outcomes, in this work, human Umbilical Cord Matrix derived Mesenchymal Stromal Cells (hUCM-MSCs) were evaluated during and after expansion using CulliSpher-S (R) microcarrier with different bioreactor hydrodynamics: the single-use Wave-Induced Motion Bioreactor (WIMB) with a modified cellbag design proposed by our laboratory, and the conventional spinner flask. WIMB cultures showed longer cell culture times and lower cell yields than spinner flask culture, positioning the WIMB as a less suitable bioreactor than conventional stirred-based systems for high-yield MSC expansion bioprocess. Regarding cell biological functions, hUCM-MSCs harvested from the CultiSpher-S (R)/WIMB and the CultiSpher-S (R)/spinner kept determining major MSC molecular and biological characteristics according to immunophenotyping and multilineage differentiation assays. Moreover, biological processes were not regulated differently when hUCM-MSCs were cultivated in WIMB or spinner flask, indicating that post-expansion hUCM-MSCs characteristics are similar in both bioreactor systems.

关键词： AnMBR   Fouling   Quorum quenching   Ultrasonic   Wastewater  

摘要： This review summarizes the recent development and studies of anaerobic membrane bioreactor (AnMBR) to control fouling issues. AnMBR is an emerging waste water treatment technology mainly because of its low sludge residual, high volumetric organic removal rate, complete liquid-solid separation, better effluent quality, efficient resource recovery and the small footprint. This paper surveys the fundamental aspects of AnMBRs, including its applications, membrane configurations, and recent progress for enhanced reactor performance. Furthermore, the membrane fouling, a major restriction in the practical application of AnMBR, its mechanism and antifouling strategies like membrane cleaning, quorum quenching, ultrasonic treatment, membrane modifications, and antifouling agents are briefly discussed. Based on the review, the key issues that require urgent attention to facilitate large scale and integrated application of AnMBR technology are identified and future research perspectives relating to the prevalent issues are proposed.

关键词： Bioreactor   Microparticle-enhanced cultivation   Filamentous fungi   Image analysis  

摘要： Species-dependent mechanisms of morphological development affect filamentous fungi cultivations. In order to influence fungal morphology microparticle-enhanced cultivations (MPEC) were used towards four species exhibiting various mechanisms of morphology formation: a spore agglomerative Aspergillus terreus, hyphae agglomerative Penicillium rubens, spore and hyphae agglomerative Chaetomium globosum and non-agglomerative Mucor racemosus. The experiments were performed in stirred tank bioreactors as one-stage (inoculation with spores) and two-stage (inoculation with 24 -h shake flask preculture) MPEC and standard processes. Fungal morphology was quantified with the use of image analysis. The addition of Al2O3 microparticles to the bioreactor cultures changed the size and shape of mycelial objects of spore agglomerating A. terreus and non-agglomerating M. racemosus the most. The simultaneous action of microparticles and mechanical forces was the strongest for C. globosum, the fungus that combines both hyphae and spore agglomeration mechanisms of morphological development. The weakest effect of microparticles was observed for P. rubens, whose mechanism is hyphae agglomerative. Ultimately, MPEC was more effective in two-stage processes.

关键词： PHA   MBR   Hollow fibers   Ceramic   Immersed   Diffusion  

摘要： One of the factors limiting the economic viability of polyhydroxyalkanoates (PHA) is the low volumetric productivity obtained with second-generation feedstocks, resulting from their low carbon concentration. In the present study, the use of membrane bioreactors (MBRs) was evaluated as a strategy to retain the microbial cells in the reactor and to enable a repeated supply of substrate without increasing the reactor volume. Two immersed MBR systems were studied: classical pressure-driven MBRs (hollow fibers and ceramic fillers), and a novel diffusion-based MBR. In the latter, the rate of volatile fatty acid (VFA) diffusion across the membranes was lower than the VFA consumption rate of the culture, and thus, not suitable to attain high productivities. Possible research directions to increase substrate diffusion are suggested. On the other hand, pressure-driven configurations led to high values of productivity (0.87-1.44 g/(L.h)) during a fed-batch PHA accumulation using mixed microbial consortia. No flux reduction was observed in a 24 h fed-batch process, which allowed for a reduction of up to 82 % of the reactor volume, demonstrating the potential of this strategy. Hollow fibers and ceramic filters offered similar results during the fed-batch, but they presented different limitations and advantages.