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Interactions among biomacromolecules, predominantly noncovalent, underpin biological processes. However, recent advancements in biospecific chemistry have enabled the creation of specific covalent bonds between biomolecules, both in vitro and in vivo. This Review traces the evolution of biospecific chemistry in proteins, emphasizing the role of genetically encoded latent bioreactive amino acids. These amino acids react selectively with adjacent natural groups through proximity-enabled bioreactivity, enabling targeted covalent linkages. We explore various latent bioreactive amino acids designed to target different protein residues, ribonucleic acids, and carbohydrates. We then discuss how these novel covalent linkages can drive challenging protein properties and capture transient protein-protein and protein-RNA interactions in vivo. Additionally, we examine the application of covalent peptides as potential therapeutic agents and site-specific conjugates for native antibodies, highlighting their capacity to form stable linkages with target molecules. A significant focus is placed on proximity-enabled reactive therapeutics (PERx), a pioneering technology in covalent protein therapeutics. We detail its wide-ranging applications in immunotherapy, viral neutralization, and targeted radionuclide therapy. Finally, we present a perspective on the existing challenges within biospecific chemistry and discuss the potential avenues for future exploration and advancement in this rapidly evolving field.

Liquid-liquid phase separation (LLPS) plays a pivotal role in the organization and functionality of living cells. It is imperative to understand the underlying driving forces behind LLPS and to control its occurrence. In this study, we employed coarse-grained (CG) simulations as a research tool to investigate systems comprising oligolysine and adenosine triphosphate (ATP) under conditions of various ionic concentrations and oligolysine lengths. Consistent with experimental observations, our CG simulations captured the formation of LLPS upon the addition of ATP and tendency of dissociating under high ionic concentration. The electrostatic interaction between oligolysine and ATP is of great importance in forming LLPS. An in-depth analysis on the structural properties of LLPS was conducted, where the oligolysine structure remained unchanged with increased ionic concentration and the addition of ATP led to a more pronounced curvature, aligning with the observed enhancement of α-helical secondary structure in experiments. In terms of the dynamic properties, the introduction of ATP led to a significant reduction in translational and vibrational degrees of freedom but not rotational degrees of freedom. Through keeping the total number of charged residues constant and varying their entropic effects, we constructed two systems of similar biochemical significance and further validated the entropy effects on the LLPS formation. These findings provide a deeper understanding of LLPS formation and shed lights on the development of novel bioreactor and primitive artificial cells for synthesizing key chemicals for certain diseases.

Lower back pain continues to be a global epidemic, limiting quality of life and ability to work, due in large part to symptomatic disc degeneration. Development of more effective and less invasive biological strategies are needed to treat disc degeneration. In vitro models such as macro- or micro-bioreactors or mechanically active organ-chips hold great promise in reducing the need for animal studies that may have limited clinical translatability, due to harsher and more complex mechanical loading environments in human discs than in most animal models. This review highlights the complex loading conditions of the disc in situ, evaluates state-of-the-art designs for applying such complex loads across multiple length scales, from macro-bioreactors that load whole discs to organ-chips that aim to replicate cellular or engineered tissue loading. Emphasis was placed on the rapidly evolving more customizable organ-chips, given their greater potential for studying the progression and treatment of symptomatic disc degeneration. Lastly, this review identifies new trends and challenges for using organ-chips to assess therapeutic strategies.

Over the past two decades Biomedical Engineering has emerged as a major discipline that bridges societal needs of human health care with the development of novel technologies. Every medical institution is now equipped at varying degrees of sophistication with the ability to monitor human health in both non-invasive and invasive modes. The multiple scales at which human physiology can be interrogated provide a profound perspective on health and disease. We are at the nexus of creating avatars (herein defined as an extension of digital twins) of human patho/physiology to serve as paradigms for interrogation and potential intervention. Motivated by the emergence of these new capabilities, the IEEE Engineering in Medicine and Biology Society, the Departments of Biomedical Engineering at Johns Hopkins University and Bioengineering at University of California at San Diego sponsored an interdisciplinary workshop to define the grand challenges that face biomedical engineering and the mechanisms to address these challenges. The Workshop identified five grand challenges with cross-cutting themes and provided a roadmap for new technologies, identified new training needs, and defined the types of interdisciplinary teams needed for addressing these challenges. The themes presented in this paper include: 1) accumedicine through creation of avatars of cells, tissues, organs and whole human; 2) development of smart and responsive devices for human function augmentation; 3) exocortical technologies to understand brain function and treat neuropathologies; 4) the development of approaches to harness the human immune system for health and wellness; and 5) new strategies to engineer genomes and cells.

This review comprehensively examines the various applications of microalgae, focusing on their significant potential in producing biodiesel and hydrogen, serving as sustainable food sources, and their efficacy in treating both municipal and food-related wastewater. While previous studies have mainly focused on specific applications of microalgae, such as biofuel production or wastewater treatment, this review covers these applications comprehensively. It examines the potential for microalgae to be applied in various industrial sectors such as energy, food security, and environmental management. By bridging these different application areas, this review differs from previous studies in providing an integrated and multifaceted view of the industrial applications of microalgae. Since it is essential to increase the productivity of the process to utilize microalgae for various industrial applications, research trends in different microalgae cultivation processes, including the culture system (e.g., open ponds, closed ponds) or environmental conditions (e.g., pH, temperature, light intensity) to improve the productivity of biomass and valuable substances was firstly analyzed. In addition, microalgae cultivation technologies that can maximize the biomass and valuable substances productivity while limiting the potential for contamination that can occur when utilizing these systems have been described to maximize CO2 reduction. In conclusion, this review has provided a detailed analysis of current research findings and technological innovations, highlighting the important role of microalgae in addressing global challenges related to energy, food supply, and waste management. It has also provided valuable insights into future research directions and potential commercial applications in several bio-related industries, and illustrated how important continued exploration and development in this area is to realize the full potential of microalgae. [ABSTRACT FROM AUTHOR]

The article discusses the growth and advancements in the use of aerobic bioreactors for producing various bioproducts, with a focus on minimizing shear in the bioreactor process. Topics include the history and evolution of bioreactor use in industrial applications, the ranking of organisms based on their sensitivity to shear, and strategies to reduce shear damage in delicate materials processed in bioreactors.

Microalgae and their bioproducts have diverse applications, including wastewater remediation, CO2 fixation, and the synthesis of nutraceuticals, pharmaceuticals, and biofuels. However, the production of these organisms heavily relies upon environmental conditions, which can significantly impact growth. Furthermore, microalgae cultivation itself can be a source of economic and environmental concerns. Thus, microalgae growth systems have become a critical consideration for both research and industry, to bolster microalgae cultivation and address its accompanying issues. Both open and closed systems, such as raceway ponds and photobioreactors, respectively, are commonly used during the growth process but have their own advantages and drawbacks. However, for microalgae growth, photobioreactors may address most concerns as the system's design lowers the risk of contamination and provides the ability to control the delivery of desired growth factors. To determine the appropriate system for targeted microalgae cultivation, it is crucial to determine factors such as the scale of cultivation and growth and productivity targets. Additionally, efficient usage of these growth systems and carefully selected incubation factors can aid in addressing some of the economic and environmental issues associated with microalgae production. This review will summarize the current applications of bioreactors in both research and industrial capacities and summarize growth and incubation factors for microalgae. [ABSTRACT FROM AUTHOR]

Biotechnological processes are essential for developing economies that aim to stand out in future markets. The use of bioreactors is one of the most important unit operations of biotechnological processes, and real-time monitoring of bioreactors is essential to ensure precise bioprocess control. This review presents different types of bioreactors, sensors, and applications in other sectors. Bioreactors, controlled systems for cultivating microorganisms and cells, are essential tools in various fields, from scientific research to industrial production. The use of a variety of sensors is critical for accurate, real-time monitoring, early problem detection, reproducibility, cost reduction, and increased efficiency. These benefits are being realized in numerous applications, including biofuel production, bioremediation and leaching processes, tissue engineering, and drug manufacturing. Innovations in bioreactor technology are expanding opportunities for a more sustainable and healthier future. By developing new types of bioreactors, integrating advanced sensors, and exploring promising applications, bioreactors are playing a key role in addressing global challenges and sustainably advancing science and technology. [ABSTRACT FROM AUTHOR]

This review discusses the eco-friendly and cost-effective biosynthesis of gold nanoparticles (AuNPs) in viable microorganisms, focusing on microbes-mediated AuNP biosynthesis. This process suits agricultural, environmental, and biomedical applications, offering renewable, eco-friendly, non-toxic, sustainable, and time-efficient methods. Microorganisms are increasingly used in green technology, nanotechnology, and RNAi technology, but several microorganisms have not been fully identified and characterized. Bio-nanotechnology offers eco-friendly and sustainable solutions for nanomedicine, with microbe-mediated nanoparticle biosynthesis producing AuNPs with anti-oxidation activity, stability, and biocompatibility. Ultrasmall AuNPs offer rapid distribution, renal clearance, and enhanced permeability in biomedical applications. The review explores nano-size dependent biosynthesis of AuNPs by bacteria, fungi, and viruses revealing their non-toxic, non-genotoxic, and non-oxidative properties on human cells. AuNPs with varying sizes and shapes, from nitrate reductase enzymes, have shown potential as a promising nano-catalyst. The synthesized AuNPs, with negative charge capping molecules, have demonstrated antibacterial activity against drug-resistant Pseudomonas aeruginosa, and Acinetobacter baumannii strains, and were non-toxic to Vero cell lines, indicating potential antibiotic resistance treatments. A green chemical method for the biosynthesis of AuNPs using reducing chloroauric acid and Rhizopus oryzae protein extract has been described, demonstrating excellent stability and strong catalytic activity. AuNPs are eco-friendly, non-toxic, and time-efficient, making them ideal for biomedical applications due to their antioxidant, antidiabetic, and antibacterial properties. In addition to the biomedical application, the review also highlights the role of microbially synthesized AuNPs in sustainable management of plant diseases, and environmental bioremediation. [ABSTRACT FROM AUTHOR]

Engineering skeletal muscle tissue is crucial for the repair and replacement of damaged or dysfunctional muscle. Despite numerous studies emphasizing the significance of skeletal muscle engineering, challenges persist in effectively replacing or repairing large muscle sections in vivo. Bioreactors that facilitate the rapid expansion of muscle precursor cells present a promising solution for addressing extensive muscle loss. Specifically, bioreactors that mimic the native microenvironment of muscle tissue can induce biomimetic stimuli, selectively promoting the expansion of muscle precursors with optimal myo‐regenerative potential. In this review, the advancements made in utilizing bioreactors to enhance the myo‐regenerative phenotype of cells for skeletal muscle engineering are highlighted. [ABSTRACT FROM AUTHOR]

Microbial biotransformation of lemongrass oil to geraniol and geranic acid, high value compounds of citral biosynthetic pathway has been reported. Biotransformation studies were carried out using a fungus Aspergillus niger strain AUD-C2 isolated from the rhizospheric soil of lemongrass, as catalyst. Three different methodologies using culture broth, spore suspension and cell-free extract, have been utilized for biotransformation and successfully demonstrated at litre scale in bioreactors. Overall 55% geraniol and 75% geranic acid were obtained by biotransformation of lemongrass oil in 48 h using spore suspension and cell free extract, respectively. [ABSTRACT FROM AUTHOR]

Microbial biotransformation is valuable for obtaining pharmaceutical, nutritional, and cosmetical potential molecules. Basically, for its realization, only a parental molecule, a microorganism, and a suitable fermentation system are needed. Regarding the last requirement, the most common resource used for screenings are the shaken flasks (a.k.a., conical flasks or Erlenmeyers). Despite their popularity, several concerning points discussed here limit their utilization. Multiparametric bioreactors give more reliable results but are expensive and the need for many of them for parallelized screenings becomes inaccessible for many research groups. In this review, we present some problems associated with this issue and strategies to solve them. [ABSTRACT FROM AUTHOR]

We evaluated by comparing the performance of three pneumatically-driven bioreactors in the production of L-asparaginase (L-ASNase), an enzyme used to treat leukaemia and lymphoma. A two-step screening process was conducted to detect Cunninghamella spp. strains producing L-ASNase. Cunninghamella echinulata DSM1905 produced the highest levels of L-ASNase during screening assays. Subsequently, fermentations were performed in bubble column (BCR), airlift (ALR), and hybrid fixed-bed airlift (FB-ALR) bioreactors to determine the best upstream bioprocess. Mycelial biomass production was higher in BCR than in ALR and FB-ALR (p ≤ 0.0322). The activity of L-ASNase produced in FB-ALR, in which the fungus grew as a consistent biofilm, was significantly higher (p ≤ 0.022) than that from ALR, which was higher than that of BCR (p = 0.036). The specific activity of ALR and FB-ALR presented no differences (p = 0.073), but it was higher than that of BCR (p ≤ 0.032). In conclusion, C. echinulata DSM1905, grown under the biofilm phenotype, produced the highest levels of L-ASNase, and FB-ALR was the best upstream system for enzyme production. [ABSTRACT FROM AUTHOR]

• Monitored microbial shifts during anaerobic degradation of two types of food waste. • Sampling of both leachate and solids revealed microbial composition differences. • Substrates led to different population dynamics and methanogenic pathways. A key question in anaerobic microbial ecology is how microbial communities develop over different stages of waste decomposition and whether these changes are specific to waste types. We destructively sampled over time 26 replicate bioreactors cultivated on fruit/vegetable waste (FVW) and meat waste (MW) based on pre-defined waste components and composition. To characterize community shifts, we examined 16S rRNA genes from both the leachate and solid fractions of the waste. Waste decomposition occurred faster in FVW than MW, as accumulation of ammonia in MW reactors led to inhibition of methanogenesis. We identified population succession during different stages of waste decomposition and linked specific populations to different waste types. Community analyses revealed underrepresentation of methanogens in the leachate fractions, emphasizing the importance of consistent and representative sampling when characterizing microbial communities in solid waste. [ABSTRACT FROM AUTHOR]

Membrane fouling caused by many direct and indirect triggering factors has become an obstacle to the application of membrane bioreactors (MBRs). The nonlinear relationship between those factors is subject to complex causality or affiliation, which is difficult to clarify for the diagnosis of membrane fouling. To solve this problem, this paper proposes a compressible diagnosis model (CDM) based on transfer entropy to facilitate the fault diagnosis of the root cause for membrane fouling. The novelty of this model includes the following points: Firstly, a framework of a CDM between membrane fouling and causal variables is built based on a feature extraction algorithm and mechanism analysis. The framework can identify fault transfer scenarios following the changes in operating conditions. Secondly, the fault transfer topology of a CDM based on transfer entropy is constructed to describe the causal relationship between variables dynamically. Thirdly, an information compressible strategy is designed to simplify the fault transfer topology. This strategy can eliminate the repetitious affiliation relationship, which contributes to diagnosing the root causal variables speedily and accurately. Finally, the effectiveness of the proposed CDM is verified by the measured data from an actual MBR. The results of experiments demonstrate that the proposed CDM fulfills the diagnosis of membrane fouling. [ABSTRACT FROM AUTHOR]

The impact of orbitally shaking bioreactors (OSRs) on the biopharmaceutical industry is becoming increasingly important. In the preliminary exploration of the orbitally shaking bioreactor performance, the vessel wall shape has a crucial influence on the mixing and mass transfer in the bioreactor. However, the shape of OSRs still maintains a cylindrical structure, significantly limiting the advantages of the orbital shaking mixing. Therefore, in order to further improve the mixing and mass transfer performance of OSRs, a novel wall shape is proposed in this paper. This novel wall shape consists of cylindrical and square parts and looks like a square tank with a large circular chamfer (STCC), which was found could effectively enhance the efficiency of material mixing and mass transfer theoretically. Based on the same specific volumetric power consumption, a comparative analysis was conducted on the mixing time and oxygen transfer efficiency of OSRs with different shape walls using simulation and experimental methods. The results showed that the OSR with STCC was expected to perform higher mixing and oxygen transfer efficiency than the OSR with cylindrical wall. These findings suggested a promising prospect for the future application of the OSRs with STCC. • Developing a novel wall structure (STCC) improving the mixing performance of OSRs. • Both oxygen mass transfer and mixing efficiency were increased with the STCC effect. • Improving the bioreactor performance with low calculated shear stress. • Mixing speed was found significantly lower in the vortex center than other regions. • Promising prospect for the future application of the OSRs with STCC. [ABSTRACT FROM AUTHOR]

Integration of living cells with extrinsic functional entities gives rise to bioaugmented nanobiohybrids, which hold tremendous potential across diverse fields such as cell therapy, biocatalysis, and cell robotics. This study presents a biocompatible method for incorporating multilayered functional liposomes onto the cell surface, creating extracellular artificial organelles or exorganelles. The introduction of various extrinsic functionalities to cells is achieved without comprising their viabilities. The integration of extrinsic enzymatic reactions is exemplified through the cascade reaction involving glucose oxidase and horseradish peroxidase. Furthermore, our protocol offers the design flexibility to customize liposome compositions, thereby providing effective cell modification. The versatility of the liposome‐based exorganelle approach establishes an advanced chemical tool, empowering cells with novel functionalities that surpass or are complementary to their innate capabilities. [ABSTRACT FROM AUTHOR]

There is an increasing demand for cost-effective semi-passive water treatment that can withstand challenging climatic conditions and effectively and sustainably manage mine-impacted water in (sub)arctic regions. This study investigated the ability of four pilot-scale bioreactors inoculated with locally sourced bacteria and affected by a freeze–thaw cycle to remove selenium and antimony. The bioreactors were operated at a Canadian (sub)arctic mine for a year. Two duplicate bioreactors were installed in a heated shed that was maintained at 5 °C over the winter, while two other duplicates were installed outdoors and left to freeze. The removal rate of selenium and antimony was monitored weekly, while a genomic characterization of the microbial populations in the bioreactors was performed monthly. The overall percentage of selenium and antimony removal was similar in the outside (10–93% Se, 20–96% Sb) and inside (35–94% Se, 10–95% Sb) bioreactors, apart from the spring thawing period when removal in the outdoor bioreactors was slightly lower for Se. The dominant taxonomic groups of microbial populations in all bioreactors were Bacteroidota, Firmicutes, Desulfobacterota and Proteobacteria. The microbial population composition was consistent and re-established quickly after spring thaw in the outside bioreactors. This demonstrated that the removal capacity of bioreactors inoculated with locally sourced bacteria was mostly unaffected by a freeze–thaw cycle, highlighting the strength of using local resources to design bioreactors in extreme climatic conditions. [ABSTRACT FROM AUTHOR]

The electrochemical technique was used to investigate the effect of surface corrugations on the rate of mass and heat transfer (by analogy) in a stirred tank reactor. Impeller rotational speed, impeller shape, corrugation peak to valley height, and corrugation orientation (horizontal or vertical) were among the variables investigated. Depending on the operating conditions, surface corrugation increased the volumetric mass transfer coefficient by a factor ranging from 1.16 to 3.7. Mass transfer data were correlated with dimensionless correlations of an average deviation of ±4.2 and ±5.49 for radial and axial flow turbines, respectively. The significance of the dimensionless equations in determining the rate of heat transfer from the corrugated wall to a cooling jacket was emphasized. [ABSTRACT FROM AUTHOR]

Blueberries are high-value fruits. The traditional method of propagation by cuttings cannot supply the modern market with large quantities of seedlings. The method of micropropagation of plants in vitro makes it possible to bring the production of blueberry seedlings to the highest level. Blueberries have not been sufficiently studied in in vitro culture, so the search for the simplest and most cost-effective methods of micropropagation remains relevant. The problem of accelerated micropropagation of blueberries can be solved using rocker-type bioreactors, which differ from other models in terms of simplicity of design and low cost. A study was carried out to evaluate the effectiveness of micropropagation of Vaccinium corymbosum 'Bluecrop' in rocker bioreactors. Two types of bioreactors were compared: the bioreactor of the Platform system and the TIS rocker bioreactor modified by the author. As a control, blueberries were grown on a semi-solid medium. The effectiveness of blueberry micropropagation was evaluated by the following indicators: multiplication coefficient, shoot length, and proportion of vitrified shoots. Experiments were conducted on WPM medium, with zeatin supplementation at a concentration of 1.0 mg/l, resulting in optimal results. It is shown that the rocker bioreactor is slightly inferior to the plantform bioreactor in micropropagation but outperforms the method of micropropagation on semisolid media. The rocker bioreactor can be fully utilized for production purposes. In order to reduce costs and increase technical reliability, the working principle of the mechanical drive of the author's model of a rocker-type bioreactor was changed. [ABSTRACT FROM AUTHOR]

Pleurotus ostreatus (oyster) is a world known-edible mushroom. Its fruit bodies are commercially available in the market due to their high nutritional value and medicinal properties. The production of this mushroom is possible through both solid media and submerged cultivation. Nowadays, bioreactors have attracted researchers' attention due to their ability to control environmental conditions, and provide better nutrition, faster, and higher growth of mycelial biomass. This research aimed to optimize the cultivation factors such as pH, incubation time, and volume of inoculation in the Shake flask via response surface methodology (RSM) in order to increase the mycelial biomass. Then, the effect of aeration on the biomass growth was studied within the bioreactor. The results of RSM showed that, the optimal conditions for tested factors; pH, incubation time and inoculation rate was estimated as 6, 11.84 days, and 10% respectively. Under these conditions, the dry weight of fungal biomass was determined as 10.1 g/L. The cultivation results in the bioreactor showed that the highest dry weight mass was 12.13 g/L at 1 vvm aeration, being significantly higher compared to other levels of aeration or even no aeration (control). Therefore, using a bioreactor with optimized conditions could provide a suitable scaling-up system for more production of P. ostreatus cell biomass in a shorter time. [ABSTRACT FROM AUTHOR]

This experimental study explores the mitigation of membrane fouling in membrane bioreactors (MBRs) through the combined use of granular activated carbon (GAC) and powdered activated carbon (PAC). The research assesses the impact of these materials on the fouling resistance, critical flux, and permeate quality using various mixed liquor suspended solids concentrations and carbon dosages. The results indicate that the GAC-PAC combination significantly reduces the total filtration resistance, particularly the cake layer resistance, by 11.7% to 13.6% compared to setups without activated carbon or with the individual carbon types. The study also reveals that this combination decreased the fouling rate by 15% to 24% at critical flux steps, demonstrating substantial improvements in fouling mitigation and operational efficiency. Furthermore, the GAC-PAC combination, which produces an adsorption process, enhances the permeate quality, achieving the near-complete removal of organic matter, total nitrogen, and turbidity, with total phosphorus removal reaching 99%. These findings demonstrate that the combined use of GAC and PAC not only reduces membrane fouling but also improves the overall MBR performance, making it a viable strategy for enhancing the efficiency of wastewater treatment processes. [ABSTRACT FROM AUTHOR]

The human microbiota impacts a variety of diseases and responses to therapeutics. Due to a lack of robust in vitro models, detailed mechanistic explanations of host‐microbiota interactions cannot often be recapitulated. We describe the design and development of a novel, versatile and modular in vitro system that enables indirect coculture of human epithelial cells with anaerobic bacteria for the characterization of host‐microbe secreted metabolite interactions. This system was designed to compartmentalize anaerobes and human cells in separate chambers conducive to each organism's requisite cell growth conditions. Using perfusion, fluidic mixing, and automated sample collection, the cells continuously received fresh media, while in contact with their corresponding compartments conditioned supernatant. Supernatants from each chamber were collected in a cell‐free time‐resolved fashion. The system sustained low oxygen conditions in the anaerobic chamber, while also supporting the growth of a representative anaerobe (Bacteroides thetaiotaomicron) and a human colonic epithelial cell line (Caco‐2) in the aerobic chamber. Caco‐2 global gene expression changes in response to coculture with B. thetaiotaomicron was characterized using RNA sequencing. Extensive, targeted metabolomics analysis of over 150 central carbon metabolites was performed on the serially collected supernatants. We observed broad metabolite changes in host‐microbe coculture, compared to respective mono‐culture controls. These effects were dependent both on sampling time and the compartment probed (apical vs. basolateral). Coculturing resulted in the depletion of several important metabolites, including guanine, uridine 5'‐monophosphate, asparagine, and thiamine. Additionally, while Caco‐2 cells cultured alone predominantly affected the basolateral metabolite milieu, increased abundance of 2,3‐dihydroxyisovalerate and thymine on the basolateral side, occurred when the cells were cocultured with B. thetaiotaomicron. Thus, our system can capture the dynamic, competitive and cooperative processes between host cells and gut microbes. [ABSTRACT FROM AUTHOR]

Gene therapy using recombinant adeno‐associated virus (rAAV) as delivery vehicles has garnered much interest in recent years. There are still significant gaps in our fundamental understanding of the manufacturing processes to deliver sufficient products. Manufacturing efforts of rAAV using HEK293 cells have commonly relied on fixed bed falling film bioreactors like the iCELLis®. We used computational fluid dynamics (CFD) to validate the operating conditions required for a predictive iCELLis® 500 scale‐down model. The small‐scale and at‐scale systems have different flow paths causing validation of the corresponding agitation rates required to achieve the same linear flow through the fixed bed across scales to be non‐trivial. Therefore, we used CFD to predict the theoretical scaling relationship. In addition, CFD could predict kLa differences between the two systems and the operating conditions required to match kLa between scales. We also confirmed that the location of DO control must be the same in both systems to achieve proper scaling. Experimental runs confirming the validity of the novel scale‐down model showed that based on the modifications to the iCELLis® Nano system, we achieved similar DO, key metabolite, pH, and GC titer trends in both systems. [ABSTRACT FROM AUTHOR]

Single‐use bioreactors (SUB) have made a significant impact on the field of bioprocessing, becoming increasingly popular for biomolecule synthesis due to their many advantages, such as minimizing contamination risks and streamlining processes. Extensive research has been conducted on the hydrodynamic conditions within single‐use bioreactors, with a focus on parameters like mixing time, oxygen transfer rate, and stress levels to improve cell cultivation procedures. Several studies have demonstrated that SUB can effectively nurture various cell types, including those that generate monoclonal antibodies, yielding outcomes similar to conventional bioreactor systems, thus highlighting their adaptability and effectiveness in biomolecule processing. SUB equipped with wave mechanisms have shown to display comparable metabolic behaviors and fermentation consistency to conventional bioreactors, confirming their dependability in supporting fungal growth and metabolite generation. Mechanical stirring for agitation leads to high shear forces alongside enhanced monitoring and control, influencing microbial physiology and macro‐morphologies. This underscores the importance of operational factors such as rocking speed, rocking angle, and gas flow rate. Overall, the integration of single‐use bioreactors in biomolecule synthesis is expected to expand, driven by the need for increased yields and cost‐effective manufacturing solutions. [ABSTRACT FROM AUTHOR]

Prodigiosin is a red bacterial pigment with great potential as a natural dye and drug precursor, while presenting several pharmacological properties, including antimicrobial and anticancer activities. Its commercialization for biomedical applications, however, remains scarce. The major limitations are related to the lack of efficient bioprocesses and scaling up from laboratory to production. In the present work, the upstream process for prodigiosin production was developed using a marine Serratia rubidaea isolated from a sample collected near a shallow-water hydrothermal vent. The yield of product per biomass was found to be influenced by the cell concentration in the inoculum. The system was scaled up to 2 L stirred tank reactors with two different vessel geometries. It was shown that the vessel geometry and a cascade control mode for regulating the dissolved oxygen concentration influenced the volumetric oxygen mass transfer coefficient (kLa) and thus prodigiosin production. To improve product yields, strategies to mimic the aeration conditions found at the sampling site were tested. When the inoculum was grown for 5 h at 200 rpm and for 19 h at 25 rpm, which significantly decreased the oxygen available, the cells produced 588.2 mgproduct/gbiomass, corresponding to a production of 1066.2 mg of prodigiosin in 24 h and a productivity of 36.1 mgproduct/(L.h). This is a 3.7-fold increase in prodigiosin yield and a 4.5-fold increase in productivity in relation to when no particular strategy was promoted. Additionally, it was shown that lipid analysis and flow cytometry may be used as reliable at-line analytical tools, allowing the monitoring of cell condition and prodigiosin production during fermentation. [ABSTRACT FROM AUTHOR]

Abstract This review comprehensively examines the various applications of microalgae, focusing on their significant potential in producing biodiesel and hydrogen, serving as sustainable food sources, and their efficacy in treating both municipal and food-related wastewater. While previous studies have mainly focused on specific applications of microalgae, such as biofuel production or wastewater treatment, this review covers these applications comprehensively. It examines the potential for microalgae to be applied in various industrial sectors such as energy, food security, and environmental management. By bridging these different application areas, this review differs from previous studies in providing an integrated and multifaceted view of the industrial applications of microalgae. Since it is essential to increase the productivity of the process to utilize microalgae for various industrial applications, research trends in different microalgae cultivation processes, including the culture system (e.g., open ponds, closed ponds) or environmental conditions (e.g., pH, temperature, light intensity) to improve the productivity of biomass and valuable substances was firstly analyzed. In addition, microalgae cultivation technologies that can maximize the biomass and valuable substances productivity while limiting the potential for contamination that can occur when utilizing these systems have been described to maximize CO2 reduction. In conclusion, this review has provided a detailed analysis of current research findings and technological innovations, highlighting the important role of microalgae in addressing global challenges related to energy, food supply, and waste management. It has also provided valuable insights into future research directions and potential commercial applications in several bio-related industries, and illustrated how important continued exploration and development in this area is to realize the full potential of microalgae.

Abstract Single‐use bioreactors (SUB) have made a significant impact on the field of bioprocessing, becoming increasingly popular for biomolecule synthesis due to their many advantages, such as minimizing contamination risks and streamlining processes. Extensive research has been conducted on the hydrodynamic conditions within single‐use bioreactors, with a focus on parameters like mixing time, oxygen transfer rate, and stress levels to improve cell cultivation procedures. Several studies have demonstrated that SUB can effectively nurture various cell types, including those that generate monoclonal antibodies, yielding outcomes similar to conventional bioreactor systems, thus highlighting their adaptability and effectiveness in biomolecule processing. SUB equipped with wave mechanisms have shown to display comparable metabolic behaviors and fermentation consistency to conventional bioreactors, confirming their dependability in supporting fungal growth and metabolite generation. Mechanical stirring for agitation leads to high shear forces alongside enhanced monitoring and control, influencing microbial physiology and macro‐morphologies. This underscores the importance of operational factors such as rocking speed, rocking angle, and gas flow rate. Overall, the integration of single‐use bioreactors in biomolecule synthesis is expected to expand, driven by the need for increased yields and cost‐effective manufacturing solutions.

Background: Following an extensive examination of various biofiltration packing materials within a typical bioreactor (a biofilter) is aiming to remove hydrogen sulfide (H2S) in the raw biogas. Methods: Both biochar (pre- and post-pyrolysis at 400, 500, and 600 °C) and cellular concrete (CLC) waste, representing organic and inorganic packing materials, respectively, displayed remarkable removal efficiency (RE) performance under dynamic conditions. Nevertheless, the physical and chemical properties of these packing materials play a crucial role in absorbing and trapping H2S for further filtration from the raw biogas. Key evaluations encompass chemical compositions, porosity, and specific surface area, aligning with contemporary research methodologies (e.g., XRF, Walkley-black, Kjeldahl, BET, T-plot), as analyzed in this study. Results: Subsequently, the modification of these physicochemical properties aimed to demonstrate continued interactions of iron (III) oxide (Fe2O3) with H2S for chemical modification of CLC waste, and enhance the specific surface area of biochar from 12, 22, and 24 m2/g to 235, 433, 475 m2/g, and for porosity from 0.01, 0.42, and 0.025 cm3/g to 0.096, 4, 0.24 cm3/g, respectively, for physical modification of biochar samples after pyrolysis at 400, 500, and 600 °C. Conclusion: In the end, improving the possibility of getting better RE from a laboratory-scale biofilter is possible by modification of the most effective physical (adding KOH to biochar and increasing porosity by 9 times, specific surface area by 19 times) and chemical (adding Fe2O3 to CLC waste) properties of the environment-friendly packing materials.

• Dissolved organic matter characteristics linked to bacterial community succession. • Bacterial community was an important driver of TN removal rates. • Enrichment of copiotroph microbes in N-cycle pathways promoted TN removal. • The increase in local carbon decomposition depressed TN removal. Woodchip bioreactors are an eco-friendly technology for removing nitrogen (N) pollution. However, there needs to be more clarity regarding the dissolved organic matter (DOM) characteristics and bacterial community succession mechanisms and their association with the N removal performance of bioreactors. The laboratory woodchip bioreactors were continuously operated for 360 days under three influent N level treatments, and the results showed that the average removal rate of TN was 45.80 g N/(m3·day) when the influent N level was 100 mg N/L, which was better than 10 mg N/L and 50 mg N/L. Dynamic succession of bacterial communities in response to influent N levels and DOM characteristics was an important driver of TN removal rates. Medium to high N levels enriched a copiotroph bacterial module (Module 1) detected by network analysis, including Phenylobacterium, Xanthobacteraceae, Burkholderiaceae, Pseudomonas , and Magnetospirillaceae , carrying N-cycle related genes for denitrification and ammonia assimilation by the rapid consumption of DOM. Such a process can increase carbon limitation to stimulate local organic carbon decomposition to enrich oligotrophs with fewer N-cycle potentials (Module 2). Together, this study reveals that the compositional change of DOM and bacterial community succession are closely related to N removal performance, providing an ecological basis for developing techniques for N-rich effluent treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

• The removal of 8 gaseous hydrocarbons was evaluated in aerated stirred bioreactors. • Hydrocarbons were removed in the following order: toluene ≈ m-xylene ≈ ethylbenzene > heptane > hexane > cyclohexane > pentane > butane. • Microbial communities were influenced by the type of carbon sourced removed. • Analytical method for online monitoring of complex mixtures of volatile hydrocarbons. The study of microbial hydrocarbons removal is of great importance for the development of future bioremediation strategies. In this study, we evaluated the removal of a gaseous mixture containing toluene, m-xylene, ethylbenzene, cyclohexane, butane, pentane, hexane and heptane in aerated stirred bioreactors inoculated with Rhodococcus erythropolis and operated under non-sterile conditions. For the real-time measurement of hydrocarbons, a novel systematic approach was implemented using Selected-Ion Flow Tube Mass Spectrometry (SIFT-MS). The effect of the carbon source (∼9.5 ppm v) on (i) the bioreactors' performance (BR1: dosed with only cyclohexane as a single hydrocarbon versus BR2: dosed with a mixture of the 8 hydrocarbons) and (ii) the evolution of microbial communities over time were investigated. The results showed that cyclohexane reached a maximum removal efficiency (RE) of 53% ± 4% in BR1. In BR2, almost complete removal of toluene, m-xylene and ethylbenzene, being the most water-soluble and easy-to-degrade carbon sources, was observed. REs below 32% were obtained for the remaining compounds. By exposing the microbial consortium to only the five most recalcitrant hydrocarbons, REs between 45% ± 5% and 98% ± 1% were reached. In addition, we observed that airborne microorganisms populated the bioreactors and that the type of carbon source influenced the microbial communities developed. The abundance of species belonging to the genus Rhodococcus was below 10% in all bioreactors at the end of the experiments. This work provides fundamental insights to understand the complex behavior of gaseous hydrocarbon mixtures in bioreactors, along with a systematic approach for the development of SIFT-MS methods. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, we evaluated the utilization rate of organic substrates contained in sanitary landfill leachates (SLLs) by fixed and suspended biomass reactors. Five bioreactors were designed, constructed, and tested for chemical oxygen demand (COD) removal. We applied three levels of organic loading in the influent for each bioreactor, including (1) a rotating biological contactor (RBC) (12, 20, and 25 g COD/m2/day); (2) a trickling filter (TF) (2.67, 5.33, and 8 kg COD/m3/day); (3) an upflow anaerobic sludge blanket (UASB) (13.31, 15.98, and 18.65 kg COD/m3/day); (4) an upflow anaerobic filter in two separated stages (UAF-2SS) (3.71, 2.76, and 1.8 kg COD/m3/day); and (5) an upflow anaerobic filter in three separated stages (UAF-3SS) (2.25, 3.45, and 4.44 kg COD/m3/day). Two equations for predicting the substrate utilization rate (SUR) of organic compounds by microorganisms were calibrated and validated, modeled under a nonsteady state condition. We modified Monod's equation to obtain the significant organic SUR and COD removal efficiency by the biomasses. These kinetic parameters were performed by the microorganisms fixing controlled experimental conditions for pH (8–9) and temperature for the UAFs (20°C, 27°C, and 34°C) and the remaining reactors (18°C– 20°C). The SUR and COD removal efficiency results were as follows: for UASB, −400 to −800 mg/L/h , 70% to 85%; for UAF-3SS, −100 to −300 mg/L/h , 85% to 95%; for UAF-2SS, −100 to −200 mg/L/h , 70% to 85%; and for RBC and TF, −50 to −250 mg/L/h , 70% to 80%. The results were mainly influenced by the structural arrangement of the organic compounds being biodegraded and the geometric configurations of the bioreactors in multiple separated stages, allowing the influence of the solubility of the recalcitrant substances, which varied from 7 to 14:1 COD dilition, to obtain subinhibitory levels for the microbial metabolism and achieve a high COD removal efficiency. Practical Applications: Two of the five bioreactors evaluated in this study, the upflow anaerobic filter in two separated stages and the upflow anaerobic filter in three separated stages, are proposed and designed as innovative reactors for treating groundwater from tropical aquifers contaminated with hydrocarbons. Additionally, UAFs were configured in a coupled bioreactor arrangement (i.e., a sequencing batch reactor followed by UAFs) to restore water quality by removing organic compounds in tropical rivers. By comparing the five bioreactors, the capacity for the chemical oxygen demand removal was significant related to the organic substrate utilization rate (SUR) for treating sanitary landfill leachates with low recalcitrance levels (i.e., rapidly biodegradable). Rapidly biodegradable SLLs can be associated with La Cortada-SLL percolated from the cells/trenches excavated for the disposal of municipal solid waste (MSW) (i.e., Pamplona Municipality, Colombia) due to the contents of a high fraction of putrescible wastes (67%) and a high biochemical oxygen demand/chemical oxygen demand ratio (62%). This level ratio produced a suitable SUR obtained from the microbial metabolism starting with the upflow anaerobic sludge blanket reactor (−400 to −1,200 mg/L/h) followed by the remaining bioreactors (−150 to −350 mg/L/h). Upflow anaerobic filters in multiple separated stages reactors constitute a feasible technical option for overcoming medium to high recalcitrance levels in SLLs obtained from cells/trenches excavated storing around 25% components fraction (e.g., metals, plastics, rubber, leather, textiles). [ABSTRACT FROM AUTHOR]

Human brain organoids produce anatomically relevant cellular structures and recapitulate key aspects of in vivo brain function, which holds great potential to model neurological diseases and screen therapeutics. However, the long growth time of 3D systems complicates the culturing of brain organoids and results in heterogeneity across samples hampering their applications. An integrated platform is developed to enable robust and long‐term culturing of 3D brain organoids. A mesofluidic bioreactor device is designed based on a reaction‐diffusion scaling theory, which achieves robust media exchange for sufficient nutrient delivery in long‐term culture. This device is integrated with longitudinal tracking and machine learning‐based classification tools to enable non‐invasive quality control of live organoids. This integrated platform allows for sample pre‐selection for downstream molecular analysis. Transcriptome analyses of organoids revealed that the mesofluidic bioreactor promoted organoid development while reducing cell death. This platform thus offers a generalizable tool to establish reproducible culture standards for 3D cellular systems for a variety of applications beyond brain organoids. [ABSTRACT FROM AUTHOR]

Production of large amounts of functional NK and CAR-NK cells represents one of the bottlenecks for NK-based immunotherapy. In this study, we developed a largescale, reliable, and practicable NK and CAR-NK production using G-Rex 100M bioreactors, which depend on a gas-permeable membrane technology. This system holds large volumes of medium with enhanced oxygen delivery, creating conditions conducive to large-scale PBNK and CAR-NK expansions for cancer therapy. Both peripheral blood NK cells (PBNKs) and CAR-NKs expanded in these bioreactors retained similar immunophenotypes and exhibited comparable cytotoxicity towards hepatocellular carcinoma (HCC) cells akin to that of NK and CAR-NK cells expanded in G-Rex 6 well bioreactors. Importantly, cryopreservation minimally affected the cytotoxicity of NK cells expanded using the G-Rex 100M bioreactors, establishing a robust platform for scaled-up NK and CAR-NK cell production. This method is promising for the development of “off-the-shelf” NK cells, supporting the future clinical implementation of NK cell immunotherapy. [ABSTRACT FROM AUTHOR]

Betalains are nitrogen-containing natural pigments that are water soluble and they comprise of the red-violet betacyanin and the yellow betaxanthin which are abundant in plants such as red/yellow beet, amaranth, prickly pear, pitaya, and others. They are widely used as food coloring agents for many centuries. Betalains are used in pharmaceuticals, functional foods, and cosmeceuticals, since they have tremendous potential to scavenge free radicals and prevent diseases, such as hypertension, dyslipidemia, cancer, neurological disorders, and vascular stenosis. Betalains are proven to be toxicologically safe and have health benefits, they have been approved as food additives in the United States of America, and European countries. Although betalains can be found in natural resources, there are differences in their composition, amounts, and seasonality. For this reason, researchers have developed alternative methods of producing these valuable compounds using cell and organ culture techniques. In several plants, cell and organ cultures are established, and bioreactor technologies have been used to produce betalains on a wide scale. In this review, we discuss the varied biotechnological methods and approaches applied for the biosynthesis of betalains including metabolic engineering approaches.Key message: The primary objective of the present research was to present the progress that has been made in the production of betalains in plant cell and organ cultures. [ABSTRACT FROM AUTHOR]

This paper presents a novel method for fabricating fluidic circuits using laser printing technology. The method allows for rapid prototyping of macrofluidic devices with control over fluid manipulation and environmental conditions. We employed a high-resolution laser cutter to etch fluidic channels into various substrates, optimizing parameters such as laser power, speed, and substrate material. Our results demonstrate excellent performance in controlling fluid flow and maintaining environmental conditions, handling a wide range of fluids and flow rates. The devices were tested in multiple settings such as with high school students and in research laboratories in universities. We tested the laser-printed macrofluidcs mechanically for durability. We present previous works in microbiology with plants, microbial, and mammalian cell lines showing reliable operation with minimal leakage and consistent fluid dynamics. The versatility and scalability of this approach make it a promising tool for advancing research and innovation in fluidics, providing a robust platform for growing, manipulating, and experimenting with diverse biological systems from cells to whole organisms. We conclude that laser-printed macrofluidics can significantly contribute to fields such as biomedical research, synthetic biology, tissue engineering, and STEM education. [ABSTRACT FROM AUTHOR]

In recent years, microfluidic bioreactors have become important in chemical production; however, the production cost is high, and it becomes difficult to balance scale, efficiency, and cost. Therefore, a low-cost, efficient, high-delivery-capacity, green-fluid reactor is urgently required. Herein, a cellulose bioreactor with dual-scale directional channels and a porous inner wall is reported for the continuous catalytic conversion of polydatin into resveratrol. The dual-scale directional channel structure endows the reactor with high mass transfer speed and large transport capacity, resulting in fast fluid diffusion rate and more severe "disturbance" inside the reactor. It accelerates the mass transfer state of the whole reaction and further improves the catalytic performance compared to the uniform channel reactor. The reactor can achieve a high conversion rate of 98.58% of resveratrol within 2 h and exhibits excellent stability, owing to which it has broad application prospects in catalytic reactions, and helps derive a new approach for constructing fluid catalysis bioreactors. [ABSTRACT FROM AUTHOR]

Xylitol is one of the value-added polyalcohols with diverse applications in the food, nutraceuticals, cosmetic, and pharmaceutical industries. Commercial xylitol production is extensively carried out via chemical technology through catalytic xylose dehydrogenation under high temperatures and pressure. The biotechnological synthesis of xylitol from lignocellulosic biomass is a promising and sustainable substitute for chemical xylitol synthesis, which requires strong reaction conditions and removal of the undesirable coproducts produced during the process. Numerous reviews target culture conditions and metabolic pathways in recombinant and wild xylitol-producing organisms for enhanced xylitol accretion. However, fewer studies focus on the engineering and bioprocess aspects essential for large-scale xylitol production. This review emphasizes recent advancements in xylitol bioproduction using immobilization methods. Cell immobilization improves biocatalyst reusability, stability, and tolerance against inhibitors, decreases process costs, and denotes a fundamental prerequisite for industrial application. The main immobilization techniques, mode of operations, and bioreactors employed for xylitol bioproduction using immobilization have been comprehensively summarized in this review. [ABSTRACT FROM AUTHOR]

Dissimilatory nitrate reduction to ammonium (DNRA) received more attention for its ability to recover ammonium. This study investigated the possibility of low-frequency infrared electromagnetic field (IR-EMF) to improve DNRA. The optimal IR-EMF intensity of 0.04 μT could effectively improve DNRA activity of nonwoven fabric membrane bioreactors. In the long-term operation, the average ammonium conversion efficiency was enhanced by 117.7% and 62.5% under 0.04 μT and 0.06 μT IR-EMF, respectively. The highest nrfA-gene abundance and potential DNRA rate were obtained under 0.04 μT IR-EMF exposure. Bacteroidetes fragilis, Shewanelle oneidensis MR-1, and Thauera sp. RT1901 were selected to investigate the dynamic response of nitrogen transformation and energy metabolism to IR-EMF. The transcriptome sequencing and RT-qPCR results suggested that IR-EMF could enhance both denitrification and DNRA process, mainly by improving ATP synthesis to boost metabolic activity. This study provided an efficient method for the nitrogen recovery via DNRA process by applying IR-EMF. [ABSTRACT FROM AUTHOR]

The current limitations of commercial microcarriers for mesenchymal stromal cell (MSC) expansion are driving the demand for novel tuneable microcarriers. Novel microcarriers are effective in improving MSC expansion under static and dynamic culture conditions without compromising their stemness and differentiation potential. Integrating microcarrier-based cultures within dynamic bioreactors provides an effective scalable approach for MSC expansion and harvest for downstream clinical translation. The development of good manufacturing practice (GMP)-grade systems, non-xenogenic culture media, and optimised bioreactors, which are compatible with novel microcarriers, is essential to improve cell yield and reproducibility. Microcarrier expansion systems show exciting potential to revolutionise mesenchymal stromal cell (MSC)-based clinical therapies by providing an opportunity for economical large-scale expansion of donor- and patient-derived cells. The poor reproducibility and efficiency of cell expansion on commercial polystyrene microcarriers have driven the development of novel microcarriers with tuneable physical, mechanical, and cell-instructive properties. These new microcarriers show innovation toward improving cell expansion outcomes, although their limited biological characterisation and compatibility with dynamic culture systems suggest the need to realign the microcarrier design pathway. Clear headway has been made toward developing infrastructure necessary for scaling up these technologies; however, key challenges remain in characterising the wholistic effects of microcarrier properties on the biological fate and function of expanded MSCs. [ABSTRACT FROM AUTHOR]

Vascular calcification (VC) is a cardiovascular disease characterized by calcium salt deposition in vascular smooth muscle cells (VSMCs). Standard in vitro models used in VC investigations are based on VSMC monocultures under static conditions. Although these platforms are easy to use, the absence of interactions between different cell types and dynamic conditions makes these models insufficient to study key aspects of vascular pathophysiology. The present study aimed to develop a dynamic endothelial cell–VSMC co-culture that better mimics the in vivo vascular microenvironment. A double-flow bioreactor supported cellular interactions and reproduced the blood flow dynamic. VSMC calcification was stimulated with a DMEM high glucose calcification medium supplemented with 1.9 mM NaH2PO4/Na2HPO4 (1:1) for 7 days. Calcification, cell viability, inflammatory mediators, and molecular markers (SIRT-1, TGFβ1) related to VSMC differentiation were evaluated. Our dynamic model was able to reproduce VSMC calcification and inflammation and evidenced differences in the modulation of effectors involved in the VSMC calcified phenotype compared with standard monocultures, highlighting the importance of the microenvironment in controlling cell behavior. Hence, our platform represents an advanced system to investigate the pathophysiologic mechanisms underlying VC, providing information not available with the standard cell monoculture. [ABSTRACT FROM AUTHOR]

In the past, decisions on wastewater treatment methods have predominantly rested on expert opinions, utilizing the Delphi method. Yet, with an anticipated increase in diversification and customization, especially in the "small-batch and diverse" market over the next decade, addressing the formulation and execution of wastewater treatment for these non-traditional production processes will present substantial challenges. Relying solely on Delphi experts' decision-making within a short and time-constrained production planning window is expected to prove inadequate. Predominantly relies on the authors' over 15 years of industry experience in wastewater treatment, this perspective paper proposes an inventive solution that integrates Membrane Bioreactors (MBRs) with Artificial Intelligence (AI) applications. This approach signifies a more advanced method for industrial wastewater treatment compared to conventional methods, with the intention of garnering increased interest for future research endeavors. [ABSTRACT FROM AUTHOR]

• A stationary model for flow and oxygen transport to design optimal axisymmetric radial-flow packed-bed bioreactors (rPBBs) • A stationary model for flow and oxygen transport in rPBBs accounting for Michaelian cellular consumption and bulk medium-to-cell surface oxygen transport resistance. • The effect of axial radial flux distribution on pericellular and bulk dissolved oxygen concentrations for relevant dimensionless parameters determining rPBB behaviour. • Operating conditions under which varying inlet flow rates relieve non-uniform oxygen concentration distribution and decay at cell surface also starting from non-uniform medium radial flux distribution. • Model predictions and integration runtimes feasible to develop algorithms to control dissolved oxygen concentration at cell surface as tissue matures. Radial flow packed-bed bioreactors (rPBBs) overcome the transport limitations of static and axial-flow perfusion bioreactors and enable development of clinical-scale bioengineered tissues. We developed criteria to design rPBBs with uniform medium radial flux distribution along bioreactor length ensuring uniform construct perfusion. We report a model-based analysis of the effect of non-uniform axial distribution of medium radial flux on pericellular concentration of oxygen and glucose. Albeit pseudo-homogeneous, the model predicts how medium flux, solutes transport and cellular consumption interact and determine the pericellular oxygen and glucose concentrations in the presence of pore transport resistance to design optimal axisymmetric rPBBs and enable control of pericellular environment. Thus, oxygen and glucose supply may match cell requirements as tissue matures. Flow and solute transport in bioreactor empty spaces and construct was described with Navier-Stokes and Darcy-Brinkman equations, and with convection–diffusion and convection–diffusion-reaction equations, respectively. Solute transport in construct accounted for Michaelian cellular consumption and bulk medium-to-cell surface oxygen transport resistance in terms of a transport-equivalent bed of Raschig rings. The effect of relevant dimensionless groups on pericellular and bulk solute concentrations was predicted under typical tissue engineering operation and evaluated against literature data for bone tissue engineering. Axial distribution of medium radial flux influenced the distribution of pericellular solutes concentration, more so at high cell metabolic activity. Increasing medium feed flow rates relieved non-uniform solute concentration distribution and decayed at cell surface for metabolic consumption, also starting from axially non-uniform radial flux distribution. Model predictions were obtained in runtimes compatible with on-line control strategies. [ABSTRACT FROM AUTHOR]

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As the occurrences of cancer rise and the requirement for biotherapeutics increases, there is a growing demand for cost‐efficient methods to manufacture mammalian cell‐based biopharmaceuticals. Currently, the most cost‐efficient manufacturing solution is the cultivation of cells in perfusion mode. Perfusion allows for high cell densities of up to 200 million viable cells per mL (MVC mL−1) to be achieved, resulting in an increase in yield and volumetric productivity, which is the production of product per unit volume and time. However, culturing in perfusion mode requires large volumes of media, which is a significant expense in process development. Therefore, methods that allow rapid optimization of perfusion media are desirable to decrease operating costs and increase productivity. In this work, a quasi‐perfusion methodology using microwell plates (MWP) is used for media optimization to culture CHO‐S cells producing IgG1 monoclonal antibodies (mAb) known as trastuzumab, which have clinical applications treating HER2+ breast cancer. Results show blending glucose‐rich supplements and sodium butyrate with perfusion‐specific base media can lead to an 8‐fold increase in monoclonal antibody titre compared with traditional fed‐batch media. The original and optimized media were then scaled‐up to a custom made, mini bioreactor (MBR) running in perfusion mode. Two‐fold higher cell density is achieved in the MBR compared with the MWP, however, when normalizing for cell density, mAb productivity is comparable between the two methodologies. The combined MWP and 250 mL MBR methodology is an optimization tool that enables process development cost savings due to reduced volume of media utilization. [ABSTRACT FROM AUTHOR]

This study investigated the improvement effect of the addition of exogenous calcium ions on the nitrogen removal efficiency of activated sludge in laboratory scale bioreactors fed various Ca concentrations. The long-term nitrogen removal performance was significantly greater in bioreactors supplemented with 150 mg/L extra Ca than in the no-addition control. The characteristics of the bacterial communities and the abundances of ammonium-oxidizing bacteria and genes related to nitrogen cycling were different between bioreactors with 150 mg/L Ca and those with other Ca concentrations (0, 30, 50 and 200 mg/L). Ca addition caused variations in the microbial abundance and distribution of nitrifiers and denitrifiers and in the synergistic effects of nitrogen functional genes in the activated sludge system, which ultimately affected the removal of nitrogen in the bioreactors. Obviously, adding an appropriate amount of Ca to activated sludge systems modifies the microbial community, which creates a beneficial environment for enhancing the removal of nitrogen from wastewater. [ABSTRACT FROM AUTHOR]

This research proposal aims for the replacement of N2 molecule (instead of O2) as a final electron receptor in micro-organisms so that they can produce NH3, which is important industrially, instead of H2O. This idea is based on the hypothesis that replacement of the central atom in gas-carrying compounds in living organisms such as chlorophyll, heme and hemocyanin would replace the fixed gas. However, NH3 is an expensive product because it is produced using the Haber-Bosch reaction technique which requires high temperature and pressure. Therefore, it is predictable here to produce NH3 so simply in bioreactors which is a great economic benefit. [ABSTRACT FROM AUTHOR]

Oil-degrading bacteria have the ability to degrade alkanes present in crude oil because of a special enzymatic system, the alkane hydroxylase complex (AlkH). The mechanism for the transport and degradation of alkanes present in crude oil remains unclear, especially related to the first step in hydrocarbons oxidation. In this work, we present a novel model of the crude oil biodegradation mechanism by considering the contact between the oil drop and the cell and calculating the mass transfer coefficients in three oleophilic bacteria (B. licheniformis, P. putida and P. glucanolyticus). The mass transfer coefficients are evaluated under critical time conditions, when the kinetics and mass transport are in balance, and the difference in the values obtained (kL α = 1.60 × 10−3, 5.25 × 10−4 and 6.19 × 10−4 m/d, respectively) shows the higher value of the mass transfer coefficient and higher biodegradation potential for B. licheniformis. Because the morphology of the cells has been analyzed by optical and electron microscopy, in the proposed model, the increase in the size of the cells in P. glucanolyticus compared to P. putida exhibits higher values of the mass transfer coefficients and this is attributed, as a novel statement, to a bigger window for alkanes transport (contact area) when the external area of the cell is bigger. [ABSTRACT FROM AUTHOR]

Gerbera represents one of the top five most important traditional cut flowers. A major factor influencing the success of the cut flower industry is vase life which in turn has a significant influence on consumer preference. Therefore, the present study considered the effect of silver nanoparticles (AgNPs) supplied in temporary immersion bioreactors (TIBs) on the growth and subsequent shelf life of gerbera flowers. The results showed an initial lag in the growth of plantlets produced from tissue culture, but this effect was reversed by the end of the study, particularly for plants exposed to AgNPs. Although AgNPs did not shorten the time to flowering (67 d in control plants compared with 73 d in AgNPs-treated plants), flower characteristics were not adversely affected by this delay. A significant finding from this study was the observation of improved vase life of flowers grown from plants treated with AgNPs (9.8 d) relative to control plants (8.2 d). This indicated the potential of AgNPs to sustain the longevity of cut flowers after harvest. [ABSTRACT FROM AUTHOR]