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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]

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]

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]

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]

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]

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]

The importance of a single-use bioreactor (SUB) is continuously increasing in research and industrial fields for biopharmaceutical production. In this study, a newly developed SUB system, the CELBIC® system, applied with the unique agitation method is introduced, and its physical properties and biological applications are evaluated. The mixing time was in the range of 11.0–129.0 s, and the volumetric mass transfer coefficient, kLa, measured through surface aeration, was in the range of 2.7–15.5 h−1 at a working volume of 1–10 L. Biological evaluations using two Chinese hamster ovary (CHO) cell lines, CHO-DG44 and CHO-S cell, were carried out in the CELBIC® systems in 1 and 50 L scales, showing similar cell culture performance as that from stirred tank-type bioreactors. These results support the CELBIC® system as a new SUB system applicable to cell cultures for biopharmaceutical production. [ABSTRACT FROM AUTHOR]

Modular tissue engineering (TE) is based on the design, fabrication, and arrangement of replicated microtissue constructs to generate functional tissues. The advantage of this strategy is to produce tissues that more closely mimic the complex structure of native tissues/organs. High-precision technologies such as microfluidics, 3D bioprinting, and electrospinning, which support both cell- and scaffold-based biofabrication methods, are implemented in a bottom-up TE strategy. Bioreactors are used in the last step of the tissue production process. Packed bed perfusion bioreactors are widely applied in bottom-up tissue engineering due to their ability to control perfusion to tissues. Modeling and simulation software packages are used as powerful tools to predict the perfusion and flow distribution to the tissues and to design robust bioreactors. This review imparts on the recent advances in the field of bottom-up TE process and provides comprehensive insights into the cell-based and scaffold-based strategies used for the biofabrication/assembly of tissue building blocks (BBs). Microfluidic devices and 3D-bioprinting technology are mentioned as precise controlling tools in this regard, the promoted applications of which are swiftly growing. [ABSTRACT FROM AUTHOR]

Quorum quenching (QQ) is an efficient way to mitigate membrane biofouling in a membrane bioreactor (MBR) during wastewater treatment. A QQ bacterium, Lysinibacillus sp. A4, was isolated and used to mitigate biofouling in an MBR during the treatment of wastewater containing metals. A QQ enzyme (named AilY) was cloned from A4 and identified as a metallo-β-lactamase-like lactonase. The QQ activity of A4 and that of Escherichia coli BL21 (DE3) overexpressing AilY could be promoted by Fe2+, Mn2+, and Zn2+ while remaining unaffected by other metals tested. The two bacteria effectively mitigated biofouling by reducing the transmembrane pressure from around 30 to 20 kPa without negative influence on the COD, NH4+-N, or total phosphorus of the effluent. The relative abundance of Lysinibacillus sp. A4 increased greatly from 0.04 to 8.29% in the MBR with metal-containing wastewater, suggesting that Lysinibacillus sp. A4 could multiply quickly and adapt to this environment. Taken together, the findings suggested that A4 could tolerate metal to a certain degree, and this property could allow A4 to adapt well to metal-containing wastewater, making it a valuable strain for mitigating biofouling in MBR during the treatment of metal-containing wastewater. [ABSTRACT FROM AUTHOR]

Here, a comparative study was designed to survey the treatment efficiency of pharmaceutical wastewater containing Naproxen by Membrane bioreactor (MBR) and MBR with fixed-bed packing media (FBMBR). To this end, the performance of MBR and FBMBR in different aeration conditions including average DO (1.9–3.8 mg/L), different organic loading (OLR) (0.86, 1.14 and 1.92 kg COD per cubic meter per day), and Naproxen removal efficiency. The BOD5 removal efficiency, effluent quality and membrane fouling were monitored within 140 days. The results obtained from the present study indicated that COD removal efficiency for FBMBR (96.46%) was higher than that for MBR (95.33%). In addition, a high COD removal efficiency was experienced in both MBR and FBMBR in operational conditions 3 and 4, even where OLR increased from 1.14 to 1.92 kgCOD/m3 d and DO decreased from 4 to < 1 mg/L. Furthermore, the higher Naproxen removal efficiency was observed in FBMBR (94.17%) compared to that for MBR (92.76%). Therefore, FBMBR is a feasible and promising method for efficient treatment of pharmaceuptical wastewater with high concentrations of emerging contaminant, especially, the Naproxen. [ABSTRACT FROM AUTHOR]

Understanding the intricate ecological interactions within the gut microbiome and unravelling its impact on human health is a challenging task. Bioreactors are valuable tools that have contributed to our understanding of gut microbial ecology. However, there is a lack of studies describing and comparing the microbial diversity cultivated in these models. This knowledge is crucial for refining current models to reflect the gastrointestinal microbiome accurately. In this study, we analysed the microbial diversity of 1512 samples from 18 studies available in public repositories that employed cultures performed in batches and various bioreactor models to cultivate faecal microbiota. Community structure comparison between samples using t-distributed stochastic neighbour embedding and the Hellinger distance revealed a high variation between projects. The main driver of these differences was the inter-individual variation between the donor faecal inocula. Moreover, there was no overlap in the structure of the microbial communities between studies using the same bioreactor platform. In addition, α-diversity analysis using Hill numbers showed that highly complex bioreactors did not exhibit higher diversities than simpler designs. However, analyses of five projects in which the samples from the faecal inoculum were also provided revealed an amplicon sequence variants enrichment in bioreactors compared to the inoculum. Finally, a comparative analysis of the taxonomy of the families detected in the projects and the GMRepo database revealed bacterial families exclusively found in the bioreactor models. These findings highlight the potential of bioreactors to enrich low-abundance microorganisms from faecal samples, contributing to uncovering the gut microbial "dark matter". [ABSTRACT FROM AUTHOR]

Ilex paraguariensis St. Hil. is cultivated in South America to prepare a tea-like infusion with pharmacological properties. Its recalcitrant character has hindered the development of a suitable method for propagating selected genotypes. This study aimed to produce in vitro plantlets from axillary shoots of adult plants using a temporary immersion bioreactor. During the elongation phase, the impact of ammonium and nitrate concentration on Murashige and Skoog quarter-strength (¼MS) formulation, macronutrient uptake, hormone supplementation, and explant density (5–30 explants) were analysed. In addition, during the induction and expression stages of root formation, the effect of indole-3-butyric acid (IBA), cadaverine, quercetin, and chlorogenic acid supplementation was studied. As a result, we propose a protocol for in vitro plantlet production of I. paraguariensis adult plants in bioreactors. Twenty-day-old stem segments established in semisolid ¼MS medium plus sucrose 30 g·L− 1 and indole-3-acetic acid (IAA) 0.5 µM are transferred to the elongation phase during 40 days in 300 cc BIT bioreactor (20 explants per flask) containing 100 mL of ¼MS modified with double ammonium and nitrate content and N6-benzyladenine (BA) 20 µM. Then, shoots longer than one centimetre are removed from the explant and placed into a rooting medium consisting of ¼MS with sucrose 30 g·L− 1 and supplemented with IBA 7.5 µM, cadaverine 20 µM, quercetin 20 µM, and chlorogenic acid 20 µM. Finally, the in vitro 30-day-old plantlets are acclimatised on 150 cc pots filled with non-sterile composted pine bark and controlled-release micro-fertiliser. An inter-simple sequence repeat assessment revealed no difference between in vitro plantlets and mother plants.Key message: This report presents a protocol for producing Ilex paraguariensis in vitro plantlets from adult plants by combining semisolid and liquid mediums in a temporary immersion system. [ABSTRACT FROM AUTHOR]

Purpose: 3D cell culture and hypoxia have been demonstrated to increase the therapeutic effects of mesenchymal stem/stromal cells (MSCs)-derived extracellular vesicles (EVs). In this study, a process for the production of MSC-EVs in a novel 3D bioreactor system under normoxic and hypoxic conditions was established and the resulting EVs were characterized. Methods: Human adipose-derived MSCs were seeded and cultured on a 3D membrane in the VITVO® bioreactor system for 7 days. Afterwards, MSC-EVs were isolated and characterized via fluorescence nanoparticle tracking analysis, flow cytometry with staining against annexin V (Anx5) as a marker for EVs exposing phosphatidylserine, as well as CD73 and CD90 as MSC surface markers. Results: Cultivation of MSC in the VITVO® bioreactor system demonstrated a higher concentration of MSC-EVs from the 3D bioreactor (9.1 × 109 ± 1.5 × 109 and 9.7 × 109 ± 3.1 × 109 particles/mL) compared to static 2D culture (4.2 × 109 ± 7.5 × 108 and 3.9 × 109 ± 3.0 × 108 particles/mL) under normoxic and hypoxic conditions, respectively. Also, the particle-to-protein ratio as a measure for the purity of EVs increased from 3.3 × 107 ± 1.1 × 107 particles/µg protein in 2D to 1.6 × 108 ± 8.3 × 106 particles/µg protein in 3D. Total MSC-EVs as well as CD73−CD90+ MSC-EVs were elevated in 2D normoxic conditions. The EV concentration and size did not differ significantly between normoxic and hypoxic conditions. Conclusion: The production of MSC-EVs in a 3D bioreactor system under hypoxic conditions resulted in increased EV concentration and purity. This system could be especially useful in screening culture conditions for the production of 3D-derived MSC-EVs. [ABSTRACT FROM AUTHOR]

The development of carbon dioxide removal methods, coupled with decreased CO2 emissions, is fundamental to achieving the targets outlined in the Paris Agreement limiting global warming to 1.5 °C. Here we are investigating the importance of the organic carbon feedstock to support silicate mineral weathering in small-scale flow through bioreactors and subsequent CO2 sequestration. Here, we combine two bacteria and two fungi, widely reported for their weathering potential, in simple flow through bioreactors (columns) consisting of forsterite and widely available, cheap organic carbon sources (wheat straw, bio-waste digestate of pig manure and biowaste, and manure compost), over six weeks. Compared to their corresponding abiotic controls, the inoculated straw and digestate columns release more total alkalinity (~2 times more) and produce greater dissolved and solid inorganic carbon (29% for straw and 13% for digestate), suggesting an increase in CO2 sequestration because of bio-enhanced silicate weathering. Microbial biomass is higher in the straw columns compared to the digestate and manure compost columns, with a phospholipid fatty acid derived total microbial biomass 10 x greater than the other biotic columns. Scanning Electron Microscopy imaging shows the most extensive colonisation and biofilm formation on the mineral surfaces in the straw columns. The biotic straw and digestate columns sequester 50 and 14 mg C more than their abiotic controls respectively, while there is no difference in the manure columns. The selection of organic carbon sources to support microbial communities in the flow through bioreactors controlls the silicate weathering rates and CO2 sequestration. [ABSTRACT FROM AUTHOR]

Due to the limitations of conventional ultrafiltration/microfiltration-based membrane bioreactors (UF/MF-MBRs) in removing trace organic compounds (TrOCs), the concept of high-retention membrane bioreactors (HR-MBRs) was introduced. Despite the benefits, HR-MBRs still suffer several drawbacks. Therefore, this paper critically reviews the effectiveness and feasibility of the proposed strategies to alleviate fouling, salinity build-up and incomplete biodegradation of TrOCs during wastewater treatment by HR-MBRs. The severity of each challenge is compared amongst the various configurations together with the associated capital and operational expenditure to determine the most cost-effective set-up. Guidance is provided on strategies and/or lessons that could be adopted from well-established processes used at municipal scale. Chemical cleaning as mitigation for fouling degrades membranes leading to poor TrOCs removal, while pre-treatment and membrane surface modification increase operational expenditure (OpEX). However, there are other environmentally-friendly pretreatment and cleaning options which hold great potential for future application. These options such as advanced oxidation processes (AOPs) are critically discussed in this work. Further, in-depth discussion is made on the pros and cons of the various approaches (such as frequent sludge withdrawal, intermittent UF/MF filtration and using organic salts) to alleviate salt build-up. Finally, incomplete biodegradation of rejected TrOCs in the bioreactor transfers problems of toxic pollutants from wastewater treatment to sludge management. Herein mitigation strategies including using stronger biological agents and coupling HR-MBRs with other techniques are debated. Despite the challenges, HR-MBRs are a promising solution for clean water production from TrOCs impaired wastewater. Therefore, more research is needed to improve the performance of HR-MBRs. [ABSTRACT FROM AUTHOR]

This study aimed to determine the photomixotrophic and physiological responses using different temporary immersion systems (TIS) during in vitro multiplication of agave Tobalá. The culture systems were SETIS™ bioreactor, Temporary Immersion Bioreactor (TIB), Monobloc Advance Temporary Immersion System, and semisolid culture medium as the control. At six weeks of culture, different physiological variables were evaluated: chlorophyll content, stomatal index, percentage of closed stomata, Phosphoenolpyruvate (PEP) and Rubisco during the multiplication stage, and survival percentage in the acclimatization stage. TIS increased multiplication rate (41%), stomatal index (44%), percentage of closed stomata (11%) and chlorophyll content (45%) with respect to the semisolid culture medium system. The highest PEP content (> 35%) was observed in temporary immersion (TI), whereas, Rubisco content, showed no differences among the culture systems evaluated. Regarding survival percentage during acclimatization, the highest shoot survival was obtained in TI, and all regenerate shoots were rooted ex vitro. This study shows that in vitro photomixotrophism was induced in TIS during the multiplication stage. In conclusion, SETIS™ bioreactor and TIB systems are an alternative for mass multiplication of A. potatorum; however, all TIS evaluated guarantee a high survival rate during acclimatization. [ABSTRACT FROM AUTHOR]

The constant surge in nitric oxide in the atmosphere results in severe environmental degradation, negatively impacting human health and ecosystems, and is presently a global concern. Widely used physicochemical technologies for nitric oxide (NO) removal comes with high installation and operational costs and the production of secondary pollutants. Thus, biological treatment has been emphasized over the last two decades, but the poor solubility of NO in water makes it a challenging issue. The present article reviews the various technical aspects of biological treatment of nitric oxide, including the removal pathways and reactor configurations involved in the process. The most widely used technologies in this regard are chemical adsorption processes followed by biological reactors like biofilters, biotrickling filters and membrane bioreactors that enhance NO solubility and offer the flexibility and scope of further improvement in process design. The effect of various experimental and operational parameters on NO removal, including pH, carbon source, gas flow rate, gas residence time and presence of inhibitory components in the flue gas, is also discussed along with the developed mathematical models for predicting NO removal in a biological treatment system. There is an extensive scope of investigation regarding the development of an economical system to remove NO, and an exhaustive model that would optimize the process considering maximum practical parameters encountered during such operation. A detailed discussion made in this article gives a proper insight into all these areas. [ABSTRACT FROM AUTHOR]

The Turiaçu pineapple cultivar produces fruits of high organoleptic value but has few biotechnological studies on seedling production. However, conventional in vitro propagation can affect the photosynthetic potential of plants when transferred to the field, thus mitigating measures should be undertaken to solve this limitation, for example by decreasing carbohydrate concentration in the growth medium, adopting bioreactors of temporary immersion with forced ventilation, and using gas permeable membranes in the culture flask. The present work focused on evaluating the growth and development of plantlets from Ananas comosus [L]. Merr. cultivar Turiaçu, an important but neglected pineapple cultivar, under different sucrose concentrations and cultivation systems. For that, the impact of the photomixotrophic and photoautotrophic growth on morphophysiological responses of plants and survival during the ex vitro acclimatization was assessed. The plants were grown in four cultivation systems: permanent immersion system with sealed flasks (PIS-SF); permanent immersion system with natural ventilation (PIS-NV); single-flask temporary immersion bioreactors (TIS-PF); and twin-flasks temporary immersion bioreactors (TIS-RALM), combined with sucrose concentrations (0, 5.0, 15.0, and 30.0 g L−1). The results indicate that Turiaçu plants have photoautotrophic potential in vitro, as the photochemical efficiency of the plants increased in cultivation systems with TIS –RALM gas exchange without the addition of sucrose. Furthermore, it also improved the performance and hardening of plants in ex vitro conditions, which constitutes a crucial step towards the diffusion of this cultivar. [ABSTRACT FROM AUTHOR]

An in situ microscope based on pulsed transmitted light illumination via optical fiber was combined to artificial-intelligence to enable for the first time an online cell classification according to well-known cellular morphological features. A 848 192-image database generated during a lab-scale production process of antibodies was processed using a convolutional neural network approach chosen for its accurate real-time object detection capabilities. In order to induce different cell death routes, hybridomas were grown in normal or suboptimal conditions in a stirred tank reactor, in the presence of substrate limitation, medium addition, pH regulation problem or oxygen depletion. Using such an optical system made it possible to monitor real-time the evolution of different classes of animal cells, among which viable, necrotic and apoptotic cells. A class of viable cells displaying bulges in feast or famine conditions was also revealed. Considered as a breakthrough in the catalogue of process analytical tools, in situ microscopy powered by artificial-intelligence is also of great interest for research. [ABSTRACT FROM AUTHOR]

Endocrine-disrupting phthalates (EDPs) are widely used as plasticizers for the manufacture of different plastics and polyvinyl chloride by providing flexibility and mechanical strength. On the other hand, they are categorized under priority pollutants list due to their threat to human health and the environment. This study examined biodegradation of a mixture of dimethyl, diethyl, dibutyl, benzyl butyl, di-2-ethylhexyl, and di-n-octyl phthalates using a CSTB (continuous stirred tank bioreactor) operated under batch, fed-batch, continuous, and continuous with biomass recycle operation modes. For operating the CSTB under biomass recycle mode, microfiltration using an indigenous tubular ceramic membrane was employed. Ecotoxicity assessment of the treated water was carried out to evaluate the toxicity removal efficiency by the integrated bioreactor system. From the batch experiments, the EDPs cumulative degradation values were 90 and 75% at 1250 and 1500 mg/L total initial concentration of the mixture, respectively, whereas complete degradation was achieved at 750 mg/L. In the fed-batch study, 93% degradation was achieved at 1500 mg/L total initial concentration of the mixture. In continuous operation mode, 94 and 85% degradation efficiency values were achieved at 43.72 and 52.08 mg/L⋅h inlet loading rate of phthalate mixture. However, continuous feeding with 100% biomass recycle revealed complete degradation at 41.67 mg/L⋅h inlet loading rate within the 84 h operation period. High seed germination index and low mortality percentage of brine shrimps observed with phthalate degraded water from the integrated bioreactor system revealed its excellent potential in the treatment and toxicity removal of phthalates contaminated environment. [ABSTRACT FROM AUTHOR]

Microalgae are excellent sources of biomass containing several important compounds for human and animal nutrition—proteins, lipids, polysaccharides, pigments and antioxidants as well as bioactive secondary metabolites. In addition, they have a great biotechnological potential for nutraceuticals, and pharmaceuticals as well as for CO2 sequestration, wastewater treatment, and potentially also biofuel and biopolymer production. In this review, the industrial production of the most frequently used microalgae genera—Arthrospira, Chlorella, Dunaliella, Haematococcus, Nannochloropsis, Phaeodactylum, Porphyridium and several other species is discussed as concerns the applicability of the most widely used large-scale systems, solar bioreactors (SBRs)—open ponds, raceways, cascades, sleeves, columns, flat panels, tubular systems and others. Microalgae culturing is a complex process in which bioreactor operating parameters and physiological variables closely interact. The requirements of the biological system—microalgae culture are crucial to select the suitable type of SBR. When designing a cultivation process, the phototrophic production of microalgae biomass, it is necessary to employ SBRs that are adequately designed, built and operated to satisfy the physiological requirements of the selected microalgae species, considering also local climate. Moreover, scaling up microalgae cultures for commercial production requires qualified staff working out a suitable cultivation regime. Key points: • Large-scale solar bioreactors designed for microalgae culturing. • Most frequently used microalgae genera for commercial production. • Scale-up requires suitable cultivation conditions and well-elaborated protocols. [ABSTRACT FROM AUTHOR]

Cytochromes P450 are a unique family of enzymes found in all Kingdoms of living organisms (animals, bacteria, plants, fungi, and archaea), whose main function is biotransformation of exogenous and endogenous compounds. The review discusses approaches to enhancing the efficiency of electrocatalysis by cytochromes P450 for their use in biotechnology and design of biosensors and describes main methods in the development of reconstituted and electrochemical catalytic systems based on the biochemical mechanism of cytochromes P450, as well as and modern trends for their practical application. [ABSTRACT FROM AUTHOR]

Pharmaceuticals are of concern to our planet and health as they can accumulate in the environment. The impact of these biologically active compounds on ecosystems is hard to predict, and information on their biodegradation is necessary to establish sound risk assessment. Microbial communities are promising candidates for the biodegradation of pharmaceuticals such as ibuprofen, but little is known yet about their degradation capacity of multiple micropollutants at higher concentrations (100 mg/L). In this work, microbial communities were cultivated in lab-scale membrane bioreactors (MBRs) exposed to increasing concentrations of a mixture of six micropollutants (ibuprofen, diclofenac, enalapril, caffeine, atenolol, paracetamol). Key players of biodegradation were identified using a combinatorial approach of 16S rRNA sequencing and analytics. Microbial community structure changed with increasing pharmaceutical intake (from 1 to 100 mg/L) and reached a steady-state during incubation for 7 weeks on 100 mg/L. HPLC analysis revealed a fluctuating but significant degradation (30–100%) of five pollutants (caffeine, paracetamol, ibuprofen, atenolol, enalapril) by an established and stable microbial community mainly composed of Achromobacter, Cupriavidus, Pseudomonas and Leucobacter. By using the microbial community from MBR1 as inoculum for further batch culture experiments on single micropollutants (400 mg/L substrate, respectively), different active microbial consortia were obtained for each single micropollutant. Microbial genera potentially responsible for degradation of the respective micropollutant were identified, i.e. Pseudomonas sp. and Sphingobacterium sp. for ibuprofen, caffeine and paracetamol, Sphingomonas sp. for atenolol and Klebsiella sp. for enalapril. Our study demonstrates the feasibility of cultivating stable microbial communities capable of degrading simultaneously a mixture of highly concentrated pharmaceuticals in lab-scale MBRs and the identification of microbial genera potentially responsible for the degradation of specific pollutants. Key points: • Multiple pharmaceuticals were removed by stable microbial communities. • Microbial key players of five main pharmaceuticals were identified. [ABSTRACT FROM AUTHOR]

Biofilm cells have a different physiology than planktonic cells, which has been the focus of most research. Biofilms are complex biostructures that form on any surface that comes into contact with water on a regular basis. They are dynamic, structurally complex systems having characteristics of multicellular animals and multiple ecosystems. The three themes covered in this review are biofilm ecology, biofilm reactor technology and design, and biofilm modeling. Membrane-supported biofilm reactors, moving bed biofilm reactors, granular sludge, and integrated fixed-film activated sludge processes are all examples of biofilm reactors used for water treatment. Biofilm control and/or beneficial application in membrane processes are improving. Biofilm models have become critical tools for biofilm foundational research as well as biofilm reactor architecture and design. At the same time, the differences between biofilm modeling and biofilm reactor modeling methods are acknowledged. [ABSTRACT FROM AUTHOR]

A conventional activated sludge (CAS) system has traditionally been used for secondary treatment in wastewater treatment plants. Due to the high cost of aeration and the problem of sludge treatment, researchers are developing alternatives to the CAS system. A membrane bioreactor (MBR) is a technology with higher solid-liquid separation efficiency. However, the use of MBR is limited due to inevitable membrane fouling and high energy consumption. Membrane fouling requires frequent cleaning, and MBR components must be replaced, which reduces membrane lifetime and operating costs. To overcome the limitations of the MBR system, a microbial fuel cell-membrane bioreactor (MFC-MBR) coupling system has attracted the interest of researchers. The design of the novel bioelectrochemical membrane reactor (BEMR) can effectively couple microbial degradation in the microbial electrochemical system (MES) and generate a microelectric field to reduce and alleviate membrane fouling in the MBR system. In addition, the coupling system combining an MES and an MBR can improve the efficiency of COD and ammonium removal while generating electricity to balance the energy consumption of the system. However, several obstacles must be overcome before the MFC-MBR coupling system can be commercialised. The aim of this study is to provide critical studies of the MBR, MES and MFC-MBR coupling system for wastewater treatment. This paper begins with a critical discussion of the unresolved MBR fouling problem. There are detailed past and current studies of the MES-MBR coupling system with comparison of performances of the system. Finally, the challenges faced in developing the coupling system on a large scale were discussed. [ABSTRACT FROM AUTHOR]

In recent years, great breakthroughs have been made in basic research and clinical applications of stem cells in regenerative medicine and other fields, which continue to inspire people to explore the field of stem cells. With nearly unlimited self-renewal ability, stem cells can generate at least one type of highly differentiated daughter cell, which provides broad development prospects for the treatment of human organ damage and other diseases. In the field of stem cell research, related technologies for inducing or isolating stem cells are relatively mature, and a variety of stable stem cell lines have been successfully constructed. To realize the full clinical application of stem cells as soon as possible, it is more and more important to further optimize each stage of stem cell research while conforming to Current Good Manufacture Practices (cGMP) standards. Here, we synthesized recent developments in stem cell research and focus on the introduction of xenogenicity in the preclinical research process and the remaining problems of various cell bioreactors. Our goal is to promote the development of technologies for xeno-free culture and clinical expansion of stem cells through in-depth discussion of current research. This review will provide new insight into stem cell research protocols and will contribute to the creation of efficient and stable stem cell expansion systems. [ABSTRACT FROM AUTHOR]

Secondary metabolites from plants are ubiquitous and have applications in medicines, food additives, scents, colorants, and natural pesticides. Biotechnological production of secondary metabolites that have economic benefits is an attractive alternative to conventional methods. Cell, adventitious, and hairy root suspension cultures are typically used to produce secondary metabolites. According to recent studies, somatic embryos in suspension culture are useful tools for the generation of secondary metabolites. Somatic embryogenesis is a mode of regeneration in several plant species. This review provides an update on the use of somatic embryogenesis in the production of valuable secondary metabolites. The factors influencing the generation of secondary metabolites using somatic embryos in suspension cultures, elicitation methods, and prospective applications are also discussed in this review. [ABSTRACT FROM AUTHOR]

Microbial bioemulsifiers are molecules of amphiphilic nature and high molecular weight that are efficient in emulsifying two immiscible phases such as water and oil. These molecules are less effective in reducing surface tension and are synthesized by bacteria, yeast and filamentous fungi. Unlike synthetic emulsifiers, microbial bioemulsifiers have unique advantages such as biocompatibility, non-toxicity, biodegradability, efficiency at low concentrations and high selectivity under different conditions of pH, temperature and salinity. The adoption of microbial bioemulsifiers as alternatives to their synthetic counterparts has been growing in ongoing research. This article analyzes the production of microbial-based emulsifiers, the raw materials and fermentation processes used, as well as the scale-up and commercial applications of some of these biomolecules. The current trend of incorporating natural compounds into industrial formulations indicates that the search for new bioemulsifiers will continue to increase, with emphasis on performance improvement and economically viable processes. [ABSTRACT FROM AUTHOR]

Sulfate is a key component in the textile industry and sulfate-reducing conditions could enhance dye reduction in the treatment of textile industry wastewater. In this study, a sulfidogenic up flow anaerobic reactors fed with different organic substrates (ethanol and acetate) were operated to treat textile wastewater and Remazol Brilliant Violet 5R was used as a model dyestuff. The reactors were operated for 192 days at 7 operational periods at 1 day HRT. Throughout the study, 2000 mg/L SO42− and 1340–1540 mg/L COD were added to the feed, corresponding to COD/SO42− ratios of 0.67 and 0.77, respectively. Remazol Brilliant Violet 5R was added to feed at a concentration of 50 mg/L on day 148 and its concentration was gradually increased to 1000 mg/L. The maximum dye removal rate was over 990 mg/(L.d) for both reactors. Although high-rate dye removal was achieved, an increase in the dye concentration resulted in a decreased sulfate reduction and COD oxidation for both reactors. In addition to the continuous process, biotic and abiotic batch reactors were operated to identify the dye removal mechanism. Batch reactors showed that biogenic sulfide produced in the sulfate reduction can be used to reduce Remazol Brilliant Violet 5R. Batch reactors also indicated that although abiotic sulfide-based Remazol Brilliant Violet 5R reduction is possible, the presence of microorganisms increased its reduction rate. [ABSTRACT FROM AUTHOR]

Nitrogen (N) and phosphorus (P) losses to surface and coastal waters are still critically high across Europe and globally. Measures to mitigate and reduce these losses are being implemented both at the cultivated land surface and at the edge-of-fields. Woodchip bioreactors represent a new alternative in Denmark for treating agricultural drainage water, and the present study—based on two years of data from five Danish field-based bioreactors—determined N removal rates varying from 1.49 to 5.37 g N m−3 d−1 and a mean across all bioreactors and years of 2.90 g N m−3 d−1. The loss of phosphorus was relatively high the first year after bioreactor establishment with rates varying from 298.4 to 890.8 mg P m−3 d−1, but in the second year, the rates ranged from 12.2 to 77.2 mg P m−3 d−1. The investments and the costs of the bioreactors were larger than expected based on Danish standard investments. The cost efficiency analysis found the key issues to be the need for larger investments in the bioreactor itself combined with higher advisory costs. For the four woodchip bioreactors considered in the cost efficiency analysis, the N removal cost was around DKK 350 per kg N ($50 per kg N), which is ca. 50% higher than the standard costs defined by the Danish authorities. Based on the estimated costs of the four bioreactor facilities included in this analysis, a bioreactor is one of the most expensive nitrogen reduction measures compared to other mitigation tools. [ABSTRACT FROM AUTHOR]

Hepatic sinusoids play a key role in maintaining high activities of liver cells in the hepatic acinus. However, the construction of hepatic sinusoids has always been a challenge for liver chips, especially for large-scale liver microsystems. Herein, we report an approach for the construction of hepatic sinusoids. In this approach, hepatic sinusoids are formed by demolding a self-developed microneedle array from a photocurable cell-loaded matrix in a large-scale liver-acinus-chip microsystem with a designed dual blood supply. Primary sinusoids formed by demolded microneedles and spontaneously self-organized secondary sinusoids can be clearly observed. Benefiting from significantly enhanced interstitial flows by formed hepatic sinusoids, cell viability is witnessed to be considerably high, liver microstructure formation occurs, and hepatocyte metabolism is enhanced. In addition, this study preliminarily demonstrates the effects of the resulting oxygen and glucose gradients on hepatocyte functions and the application of the chip in drug testing. This work paves the way for the biofabrication of fully functionalized large-scale liver bioreactors. [ABSTRACT FROM AUTHOR]

Different species of microorganisms colonize the plastic surfaces and form biofilms depending on the aquatic environment. In the current investigation, characteristics of the plastic surface after exposure to three different aquatic environments based on visualization using scanning electron microscopy (SEM) and spectroscopic (diffuse reflectance (DR) and infrared (IR)) techniques were examined in laboratory bioreactors with time. For both materials, there were no differences observed in the ultraviolet (UV) region among the reactors and several peaks were observed with fluctuating intensities and without any trends. For light density polyethylene (LDPE), peaks indicating the presence of biofilm could be observed in the visible region for activated sludge bioreactor, and for polyethylene terephthalate (PET), freshwater algae biofilm was also visible. PET in freshwater bioreactor is the most densely populated sample both under the optical microscope and SEM. Based on the DR spectra, different visible peaks for LDPE and PET were observed but, in both cases, the visible region peaks (~ 450 and 670 nm) correspond to the peaks found in the water samples of the bioreactors. The difference on these surfaces could not be identified with IR but the fluctuations observed in the UV wavelength region were also detectable using indices obtained from the IR spectra such as keto, ester, and vinyl. For instance, the virgin PET sample shows higher values in all the indices than the virgin LDPE sample [(virgin LDPE: ester Index (I) = 0.051, keto I = 0.039, vinyl I = 0.067), (virgin PET: ester I = 3.5, keto I = 19, vinyl I = 0.18)]. This suggests that virgin PET surface is hydrophilic as expected. At the same time, for all the LDPE samples, all the indices demonstrated higher values (especially for R2) than the virgin LDPE. On the other hand, ester and keto indices for PET samples demonstrated lower values than virgin PET. In addition, DRS technique was able to identify the formation of the biofilm both on wet and dry samples. Both DRS and IR can describe changes in the hydrophobicity during the initial formation of biofilm but DRS can better describe the fluctuations of biofilm in the visible spectra region. [ABSTRACT FROM AUTHOR]

Cynanchumwilfordii is a traditional Chinese herb and has various pharmacological effects. However, its raw plant material is insufficient to meet the market demand. Adventitious roots (ARs) are a novel alternative material for producing plant products. Herein, C. wilfordii ARs were cultured in 5-L bioreactors to produce bioactive compounds and the effects of salt strength and sucrose concentration were investigated in this study. Furthermore, the kinetic study was implemented for confirming a suitable culture period. Finally, the culture efficiency of different size bioreactors was compared. The full salt strength of Murashige and Skoog medium supplemented with 30 g L−1 sucrose was most favorable for AR biomass and the production of flavonoids, ρ-hydroxyacetophenone, 2,5-dihydroxyacetophenone, and total acetophenone derivatives, whereas the media with 50 and 70 g L−1 sucrose were optimal for the production of 2,4-dihydroxyacetophenone and total polysaccharides, respectively. The accumulation of AR biomass and three acetophenone derivatives peaked on day 25, but those of total polysaccharide and flavonoids peaked on day 30, indicating that the selection of culture period should depend on the target compound to be produced. Among 5-, 10-, and 20 L-bioreactors, the 20-L bioreactor exhibited good culture efficiency. The findings suggest that bioactive compounds of C. wilfordii can be mass produced through AR culture in an established bioreactor system, and the produced ARs can be used as promising raw material in the production of plant products. [ABSTRACT FROM AUTHOR]

Since ancient times, Morinda species, particularly Morinda citrifolia, have been used for their therapeutic benefits. Iridoids, anthraquinones, coumarins, flavonoids, lignans, phytosterols, and carotenoids are examples of natural substances with bioactivity. Anthraquinone derivatives are the most significant of these chemicals since they are utilized as natural coloring agents and have a wide range of medicinal functions. Utilizing cell and organ cultures of Morinda species, various biotechnological methods have been developed for the bioproduction of anthraquinone derivatives. The generation of anthraquinone derivatives in cell and organ cultures is summarized in this article. The methods used to produce these chemicals in bioreactor cultures have also been examined. Key points: • This review investigates the potential of cell and organ cultures for anthraquinone synthesis. • The overproduction of anthraquinones has been addressed using a variety of techniques. • The use of bioreactor technologies for anthraquinone manufacturing is highlighted. [ABSTRACT FROM AUTHOR]

Culture medium heterogeneity is inherent in industrial bioreactors. The loss of mixing efficiency in a large-scale bioreactor yields to the formation of concentration gradients. Consequently, cells face oscillatory culture conditions that may deeply affect their metabolism. Herein, cell response to transient perturbations, namely high methanol concentration combined with hypoxia, has been investigated using a two stirred-tank reactor compartiments (STR-STR) scale-down system and a Pichia pastoris strain expressing the gene encoding enhanced green fluorescent protein (eGFP) under the control of the alcohol oxidase 1 (AOX1) promoter. Cell residence times under transient stressing conditions were calculated based on the typical hydraulic circulation times of bioreactors of tens and hundreds cubic metres. A significant increase in methanol and oxygen uptake rates was observed as the cell residence time was increased. Stressful culture conditions impaired biomass formation and triggered cell flocculation. More importantly, both expression levels of genes under the control of pAOX1 promoter and eGFP specific fluorescence were higher in those oscillatory culture conditions, suggesting that those a priori unfavourable culture conditions in fact benefit to recombinant protein productivity. Flocculent cells were also identified as the most productive as compared to ovoid cells. Key points: • Transient hypoxia and high methanol trigger high level of recombinant protein synthesis • In Pichia pastoris, pAOX1 induction is higher in flocculent cells • Medium heterogeneity leads to morphological diversification [ABSTRACT FROM AUTHOR]

The microalga Chlamydopodium fusiforme MACC-430 was cultured in two types of outdoor pilot cultivation units—a thin-layer cascade (TLC) and a raceway pond (RWP) placed in a greenhouse. This case study aimed to test their potential suitability for cultivation scale-up to produce biomass for agriculture purposes (e.g., as biofertilizer or biostimulant). The culture response to the alteration of environmental conditions was evaluated in "exemplary" situations of good and bad weather conditions using several photosynthesis measuring techniques, namely oxygen production, and chlorophyll (Chl) fluorescence. Validation of their suitability for online monitoring in large-scale plants has been one of the objectives of the trials. Both techniques were found fast and robust reliable to monitor microalgae activity in large-scale cultivation units. In both bioreactors, Chlamydopodium cultures grew well in the semi-continuous regime using daily dilution (0.20—0.25 day−1). The biomass productivity calculated per volume was significantly (about 5 times) higher in the RWPs compared to the TLCs. The measured photosynthesis variables showed that the build-up of dissolved oxygen concentration in the TLC was higher, up to 125–150% of saturation (%sat) as compared to the RWP (102–104%sat). As only ambient CO2 was available, its shortage was indicated by a pH increase due to photosynthetic activity in the thin-layer bioreactor at higher irradiance intensities. In this setup, the RWP was considered more suitable for scale-up due to higher areal productivity, lower construction and maintenance costs, the smaller land area required to maintain large culture volumes, as well as lower carbon depletion and dissolved oxygen build-up. Key points: • Chlamydopodium was grown in both raceways and thin-layer cascades in pilot-scale. • Various photosynthesis techniques were validated for growth monitoring. • In general, raceway ponds were evaluated as more suitable for cultivation scale-up. [ABSTRACT FROM AUTHOR]

Mine water containing copper and zinc exceeding the permissible discharge limit has been discharged from the S mine site in South Korea. To evaluate the feasibility of applying passive treatment methods for treating water discharged from this mine, bench-scale experiments were conducted by using columns simulating successive alkalinity-producing systems (SAPS) and bioreactors. As substrate materials, limestone and spent mushroom compost (SMC) were applied, with their structures and mixing ratios varied. The efficiency of metal removal for each column was then evaluated. SAPS (column B) and bioreactors (columns C and D) exhibited Cu removal efficiencies of 99.7%, 98.0%, and 97.1%, respectively, while the limestone reactor (column A) had an average removal efficiency of 81.3%. Except for the re-dissolution events, Zn removal efficiencies were 99.5%, 97.6%, and 88.4%, respectively, while the limestone reactor had an average removal efficiency of 29.2%. Facilitated by a pH increase caused by the dissolution of limestone, the bacterial sulfate reduction (BSR) reaction was shown to be effective at removing metal in the SAPS and bioreactor columns; the process was revealed through the presence of sulfide in the effluent. When comparing bioreactors with different compost mixing ratios, columns with greater SMC ratios had higher removal efficiencies, as well as higher alkalinity, which shows the importance of SMC in metal removal. Overall, this study will be helpful in determining on-site treatment methods for Cu- and Zn-rich mine water by reusing waste materials, SMC, through bacterial metal reduction reactions, as well as considering the potential lifespan of the treatment facility. [ABSTRACT FROM AUTHOR]

Since water hyacinth (WH) spreads quickly and adversely affects the development of both animals and plants by robbing water bodies of their nutrients and oxygen, WH is widely regarded as a noxious weed around the world. Therefore, turning this undesirable weed into valuable chemicals and fuels aids in developing countries' ability to sustain themselves. Hence, the present work aims to optimize average biogas production (ABP), cumulative methane yield (CMY), and methane concentration (MC) during biomethanation of WH using cow dung. The investigations were conducted in a semi-batch digester at various pH (6–8), temperature (30–50 °C) and cow dung dosage (0.0143–0.0429 m3/m3 WH slurry). The central composite design (CCD) of response surface method was used to optimize the pH, temperature, and cow dung dosage. The effects of studied process parameters on the ABP, CMY and MC were significant. The predicted and experimental responses showed goodness of quadratic fit. The optimum ABP of 0.058 m3/kg WH, CMY of 0.055 m3/kg WH, and MC of 83.38% were achieved at the pH, temperature and cow dung dosage of 7.2, 47.5 °C and 0.0428 m3/m3 WH slurry. In addition, anaerobic biodegradability was found to be between 14.7 and 72.6% in all tests. Hence, Eichhornia crassipes could be a potential substrate to produce maximum biogas using cow dung. [ABSTRACT FROM AUTHOR]

We evaluated the effects of a periphyton bioreactor on phytoplankton by experimentally simulating oligotrophication in a shallow eutrophic system. The experiment had two 50% diluted treatments with and without a periphyton bioreactor. Sampling was performed on days 6, 9, 12, 15, and 20 of the experimental period. The periphyton bioreactor accumulated biomass (chlorophyll-a, AFDM) and TP during the experimental period. Despite the biomass and TP loss due to periphyton detachment from the substrate after community reaching the algal biomass peak, the gains exceeded the losses, and the net rate was positive for all attributes in the bioreactor. Based on the average, our findings suggest that periphyton bioreactors negatively affected the phytoplankton total biovolume. Cyanobacteria were the most abundant phytoplankton group. However, the periphyton bioreactor caused the biomass loss of the Raphidiopsis raciborskii in phytoplankton. Our results suggest that bioreactor influenced the phytoplankton structure, reducing cyanobacterial biomass, especially Raphidiopsis raciborskii. However, the bioreactor did not reflect a significant increase in the epipelon biomass during the experimental period. We conclude that the periphyton bioreactor has the potential to assist in the maintenance of restored shallow lakes and reservoirs, especially in controlling phytoplankton growth. [ABSTRACT FROM AUTHOR]

The use of mixed microbial cultures (MMCs) is seen as an attractive strategy for polyhydroxyalkanoate (PHA) production. In order to optimize the MMC-PHA production process, tools are required to improve our understanding of the physiological state of the PHA-storing microorganisms within the MMC. In the present study, we explored the use of flow cytometry to analyse the metabolic state and polyhydroxybutyrate (PHB) content of the microorganisms from an MMC-PHA production process. A sequencing batch reactor under a feast and famine regime was used to enrich an MMC with PHB-storing microorganisms. Interestingly, once the PHB-storing microorganisms are selected, the level of PHB accumulation depends largely on the metabolic state of these microorganisms and not exclusively on the consortium composition. These results demonstrate that flow cytometry is a powerful tool to help to understand the PHA storage response of an MMC-PHA production process. Key points: • Flow cytometry allows to measure PHB content and metabolic activity over time. • Microorganisms showing high PHB content also have high metabolic activity. • PHB producers with low metabolic activity show low PHB content. [ABSTRACT FROM AUTHOR]

Taking into account difficulties in exhaustive simultaneous decarbonation and denitrogenation in biological treatment of coking wastewater (CWW), a novel full-scale CWW biological treatment sequentially combining anaerobic, aerobic, hydrolytic, and aerobic reactors (A/O1/H/O2) was designed performing excellent removal of carbon-containing pollutants in the bioreactors A and O1, while the nitrogen-containing compounds in the bioreactors H and O2. To provide an effective tool for the CWW treatment monitoring and control, the succession of microbial community in this unique toxic CWW habitat should be established and characterized in detail. The results of 16S rRNA genes revealed Acidobacteria dominating in the unique CWW habitat. The dominant groups in bioreactors A and O1 include Proteobacteria, Firmicutes, and Acidobacteria, while Proteobacteria, Acidobacteria, Nitrospirae, and Planctomycetes dominate in reactors H and O2. The genera of Rhodoplanes, Bacillus, and Leucobacter are rich in genes responsible for the xenobiotics biodegradation and metabolism pathway. The Mantel test and PCA results showed the microbial communities of A/O1/H/O2 sequence correlating strongly with SRT, and COD load and removal. The co-occurrence network analysis indicated decarbonation and denitrogenation driven by two network modules having the keystone taxa belonging to the Comamonadaceae and Hyphomicrobiaceae families. The results significantly expanded the knowledge on the diversity, structure, and function of the CWW active sludge differentiating the relationships between bacterial communities and environmental variables in CWW treatment. [ABSTRACT FROM AUTHOR]

This study investigated the performance of a novel integrated bio-electrochemical system for synergistic hydrogen production from a process combining a dark fermentation reactor and a galvanic cell. The operating principle of the system is based on the electrochemical conversion of protons released upon dissociation of the acid metabolites of the biological process and is mediated by the electron flow from the galvanic cell, coupling biochemical and electrochemical hydrogen production. Accordingly, the galvanic compartment also generates electricity. Four different experimental setups were designed to provide a preliminary assessment of the integrated bio-electrochemical process and identify the optimal configuration for further tests. Subsequently, dark fermentation of cheese whey was implemented both in a stand-alone biochemical reactor and in the integrated bio-electrochemical process. The integrated system achieved a hydrogen yield in the range 75.5–78.8 N LH2/kg TOC, showing a 3 times improvement over the biochemical process. [ABSTRACT FROM AUTHOR]

Meet the biotech startups brewing milk in bioreactors to improve on baby formula. [ABSTRACT FROM AUTHOR]

A comprehensive assessment of oxygen transfer rate (OTR) measurement techniques in the bubble environment of large-scale industrial fermenters is presented. Specifically, we focus on the sodium sulfite and hydrogen peroxide methods, two of the most commonly used approaches for measuring OTR in high oxygen-demand systems, and compare them with the nitrogen degassing method. A theoretical review of these methods is conducted and supplemented with experimental data collected from a 5-l stirred-tank fermenter. Through this comparative analysis, the key differences between the methods are highlighted, including the enhancement factor effect, their applicability to industrial bioreactors with high volumetric mass transfer coefficients (kLa\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$k_{\text{L}}a$$\end{document}), and the challenges associated with scaling these techniques to industrial systems. Results underscore the critical role of OTR in determining mass transfer efficiency in aerobic bioreactors, while also outlining the relationship of OTR to biochemical reactions in the environment. [ABSTRACT FROM AUTHOR]

Surfactants represent a large group of industrial relevant substances and can be generated chemically, but also biologically. Important microbial producers are several Pseudomonas species, mainly known for their ability to produce rhamnolipids. For safety reasons, recombinant Pseudomonas putida is preferred for heterologous production of rhamnolipids as well as its precursor 3-(3-hydroxyalkanoyloxy) alkanoic acid (HAA), which is a promising platform substance. The surface-active properties of HAA combined with classical submerged aeration cause strong foam formation making biotechnological production in stirred tank bioreactors challenging. Therefore, a foam-free bioprocess for HAA production was developed in this study. The combination of headspace aeration, overpressure up to 8 bar, and temperature reduction prevented oxygen limitation, shortened process time, and enhanced the maximum HAA concentration to 1.71 g l− 1 with a space-time yield of 0.08 g l− 1 h− 1. [ABSTRACT FROM AUTHOR]

Lycaste aromatica (Graham) Lindl. orchid is known for its outstanding cinnamon aroma, which has caused its illegal and accelerated extraction from its natural habitat. For this reason, procedures were developed for asymbiotic seed germination and seedling development in a gravity immersion bioreactor (GIB) system. Four culture media were tested for in vitro germination: ½ Murashige and Skoog (MS) containing 15 g L−1 sucrose, MS, ½ Knudson C containing 15 g L−1 sucrose, and Knudson C. The efficiency of in vitro culture protocol using semi-solid medium was compared to four immersion frequencies of the GIB system in a liquid medium using 30 mL of ½ MS medium per seedling. Germination began at 8 wk and lasted for 6 wk. The best treatment was ½ MS with 81% seed germination. In 90 d, the GIB did not result in significant effects on most growth parameters, including number of leaves; number of roots and seedling height were not significantly different to those of seedlings developed in the semi-solid medium. However, seedlings developed in the semi-solid medium reported a higher number of shoots (1.6 shoots) and root length (2 cm). The GIB showed the highest photosynthesis rate (0.74 μmol CO2 g−1 s−1). The GIB could be an alternative to develop this species due to its increased photosynthesis and having stomatal function. [ABSTRACT FROM AUTHOR]

Environmental contamination from pharmaceuticals has received increased attention from researchers in the past 20 years. As such, numerous lab-scale studies have sought to characterize the effects of these contaminants on various targets, as well as determine improved removal methods. Many studies have used lab-scale bioreactors to investigate pharmaceutical effects on wastewater bacteria, as wastewater treatment plants often act as reservoirs for pharmaceuticals. However, few—if any—of these studies report the specific lab materials used during testing, such as tubing or pipette tip type. In this study, the pharmaceuticals erythromycin, diclofenac, and gemfibrozil were exposed to different micropipette tips, syringe filters, and tubing types, and losses over time were evaluated. Losses to tubing and syringe filters were particularly significant and neared 100%, depending on the pharmaceutical compound and length of exposure time. Results discussed herein indicate that pharmaceutical sorption to various lab supplies results in decreases to both dosed and quantified pharmaceutical concentrations. Studies that fail to consider this source of loss may therefore draw inaccurate conclusions about pharmaceutical effects or removal efficiencies. [ABSTRACT FROM AUTHOR]

Diesel oil is known to be one of the major petroleum products that can pollute water and soil. Soil pollution caused by petroleum hydrocarbons has substantially impacted the environment, especially in the Middle East. In this study, modeling and optimization of hexadecane removal from soil was performed using two pure cultures of Acinetobacter and Acromobacter and consortium culture of both bacterial species using artificial neural network (ANN) method. Then the best ANN structure was proposed based on mean square error (MSE) as well as correlation coefficient (R) for pure cultures of Acinetobacter and Acromobacter as well as their consortium. The results showed that the correlations between the actual data and the data predicted by ANN (R2) in Acromobacter, Acinetobacter and consortium of both cultures were 0.50, 0.47 and 0.63, respectively. Despite the low correlation between the experimental data and the data predicted by the ANN, the correlation coefficient and the precision of ANN for the consortium was higher. As a result, ANN had desirable precision to predict hexadecan removal by the cobsertium culture of Ochromobater and Acintobacter. [ABSTRACT FROM AUTHOR]

State of the art and possibilities of improvement of chemical reactors and bioreactors for the synthesis of organic and inorganic chemicals are considered. Various approaches to intensification are discussed, both those based on equipment miniaturization and those based on the reduction of the diffusion resistance in flows in macroscale apparatuses. Taylor vortices arising in two-phase laminar flows favor the process intensification. In one-phase flows, favorable conditions are created owing to the concentration of the kinetic energy of the flow in a small volume (no more than 1 mL), which ensures high quality of micromixing and hence the stoichiometric ratio of the atoms in the product being synthesized. Modern microreactors allow rigorous control of the temperature and pH in the reaction zone. Because several such zones can be arranged in one apparatus, the use of microreactors is promising for the synthesis of composite materials. Macroscale reactors of the new type are characterized by increased coefficients of heat and mass exchange. The volume of a pulsation resonance apparatus can be completely sealed during the process, which is particularly valuable in operation with dangerously explosive and inflammable substance, and a flow-through pulsation apparatus can be a good alternative to standard implementation of polymerization processes. [ABSTRACT FROM AUTHOR]