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There are numerous reviews of the various bioelectrochemical models, but few focus only on the microbial electrolysis cell for biohydrogen production from organic wastewater. Neglecting the dynamic interactions of the bioelectrochemical factors at the microbial level in the bulk liquid reduces the complexity of the model. Still, the optimization for scaling up to industrial performance stagnates. Therefore, a comprehensive analysis of the existing mathematical models critically evaluates the assumptions related to the reactor conditions, including metabolic reaction kinetics, electrode reaction kinetics, biofilm dynamics, and hydraulic dynamics. A comparative study between different models with different substrate inputs shows the significance of the assumptions made in predicting the model performances. A unified modeling framework integrates substrate diversity, microbial community dynamics, biofilm behavior, electrochemical interactions, and hydrodynamics with the requirement of experimental validation to enable robust prediction of MEC performance. The framework facilitates the scalability and practical application of MEC technology and thus contributes to the progress of sustainable biohydrogen production. [Display omitted] • Critical evaluation of assumptions in microbial electrolysis cell modeling. • Unified framework for robust and scalable hydrogen production modeling. • Advances in biofilm and electrochemical interaction modeling for MECs. • Predictive modeling integrates complex microbial and electrochemical dynamics. • Enhanced scalability of MEC technology for sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

Membrane fouling is one of the most important issues in membrane studies and remains a current challenge. Therefore, developing composite membranes to reduce fouling is essential. In this study, delafossite-type CuMnO2 and CuMnO2-NH2 nanostructures were synthesized and characterized in detail using various instrumental tools, including SEM, SEM-Elemental Mapping, P-XRD, BET, and FTIR. The biological properties of CuMnO2 and CuMnO2-NH2 nanostructures, including antioxidant, antimicrobial, cell viability, antidiabetic activity, antibiofilm activity, and DNA fragmentation, were examined. Both materials exhibited good antioxidant, antimicrobial, and antibiofilm properties. The highest antioxidant activity for CuMnO2 was 75.93% at 100 mg/L, while the highest antioxidant activity for CuMnO2-NH2 was 92.35% at 100 mg/L. The most effective MIC value of 16 mg/L was obtained for CuMnO2 against Enterococcus hirae and Enterococcus faecalis. The highest amylase activity, at 165.2%, was observed at 100 mg/L for CuMnO2. Both CuMnO2 and CuMnO2-NH2 exhibited complete inhibition of microbial cell viability (100%) at 100 mg/L. Additionally, they demonstrated excellent biofilm inhibition activities against S. aureus and P. aureginosa. Furthermore, the use of polyethersulfone (PES) membranes coated with CuMnO2 and CuMnO2-NH2 compounds for the eradication of Escherichia coli was investigated, along with the antibacterial activities of the membrane surface and permeate. [ABSTRACT FROM AUTHOR]

Specific cellular microenvironment, multi-enzyme complex and expensive essential cofactor make the biological manufacturing of plant chloroplast natural products (PCNPs) extremely challenging. The above difficulties have hampered the biosynthesis of capsanthin and capsorubin in the past 30 years. Here, we take capsanthin and capsorubin as examples to design an innovative microbial factory to promote the heterologous synthesis of PCPNs. Our main strategy is mimicking the microenvironment of chloroplasts in microbial factory. First, accumulation of violaxanthin, which is the key precursor, was increased by 587.9%, through introducing oxidative microenvironment and thioredoxin. The initial capsanthin-producing strain with 0.28 mg g−1 DCW were obtained by introducing capsanthin/capsorubin synthase (CCS). Subsequently, chloroplast-derived chaperones Cpn60α, Cpn60β and Cpn20 created a folding-promoting microenvironment for CCS. At the same time, by imitating the quasi -natural CCS, an artificial homotrimer was constructed and obtained 5.15 mg g−1 DCW capsanthin, and 1.62 mg g−1 DCW capsorubin. Finally, sufficient FADH 2 was provided for CCS by feeding 20 mM formate. This process was realized by the continuous catalysis of formate dehydrogenase and flavin reductase. The engineered strain accumulated 6.77 mg g−1 DCW of capsanthin and 2.18 mg g−1 DCW of capsorubin. Compared with the initial strain, the yield of capsanthin was increased by 24.18 times, and 13.54 times of the highest yield reported so far. Artificially designed microbial cell factory and low-cost cofactor supply methods are in line with the current sustainable and green wave of biochemicals. This work not only provides a platform strain for low-cost and sustainable biosynthesis, but also provides a paradigm for heterologous expression of chloroplast-derived enzymes. [Display omitted] • High redox potential promoted zeaxanthin epoxidase to form highly active oligomer. • Chloroplast-derived chaperones effectively promote the folding of capsanthin/capsorubin synthase (CCS). • The artificial homotrimer located in the plasma membrane can be used for efficient synthesis of capsanthin and capsanthin. • Releasing the reducing power of formate provides sufficient FADH 2 for CCS, which is low-cost and green. [ABSTRACT FROM AUTHOR]

Microbial cell factories have emerged as a sustainable alternative to traditional chemical synthesis and plant extraction methods for producing aromatic compounds. However, achieving economically viable production of these compounds in microbial systems remains a significant challenge. This review summarizes the latest advancements in metabolic flux regulation during the microbial production of aromatic compounds, providing an overview of its applications and practical outcomes. Various strategies aimed at improving the utilization of extracellular substrates, enhancing the efficiency of synthetic pathways for target products, and rewiring intracellular metabolic networks to boost the titer, yield, and productivity of aromatic compounds are discussed. Additionally, the persistent challenges in this field and potential solutions are highlighted. • Aromatic compound production depends on the metabolic flux directed toward final products in cell factories. • The metabolic flux assimilated from substrates is fundamental for the high production of aromatic compounds. • Optimizing metabolic flux conversion into the aromatic compound pathway reduces flux losses. • Directing metabolic flux from central and branch pathways into aromatic compounds increases titers and yields. [ABSTRACT FROM AUTHOR]

The accumulation of byproducts is a major challenge in bioproduction, reducing yields and increasing downstream costs. We created a framework to avoid byproduct formation based on a synthetic microbial community. Engineering and evolution created the 'upcycler' strain able to upcycle byproducts into biomass and/or the product of interest As a proof-of-concept, we used Yarrowia lipolytica , the byproduct citric acid, and the product β-carotene. The presence of the upcycler strain improved growth by 135% and production by 104%, while achieving a total bioconversion of byproducts. Microbial cell factories, which convert feedstocks into a product of value, have the potential to help transition toward a bio-based economy with more sustainable ways to produce food, fuels, chemicals, and materials. One common challenge found in most bioconversions is the co-production, together with the product of interest, of undesirable byproducts or overflow metabolites. Here, we designed a strategy based on synthetic microbial communities to address this issue and increase overall production yields. To achieve our goal, we created a Yarrowia lipolytica co-culture comprising a wild-type (WT) strain that consumes glucose to make biomass and citric acid (CA), and an 'upcycler' strain, which consumes the CA produced by the WT strain. The co-culture produced up to two times more β-carotene compared with the WT monoculture using either minimal medium or hydrolysate. The proposed strategy has the potential to be applied to other bioprocesses and organisms. [Display omitted] Biotechnology processes often face reduced production yields due to the presence of byproducts. In this work, we developed a system based on the use of synthetic microbial communities to reduce byproduct formation. This was achieved by creation of an 'upcycler' strain that converts byproducts into products of interest. Synthetic microbial communities with the capacity to upcycle fermentation byproducts have the potential to address major challenges associated with bioproduction. Our study demonstrated the advantages of synthetic microbial communities containing byproduct-upcycling strains in bioproduction processes compared with monocultures at the laboratory scale. When both the producer and the upcycler strains were engineered to make the desired product (β-carotene), both biomass and product yield increased in both defined medium and lignocellulosic hydrolysate. Currently, our technology is at an experimental proof-of-concept stage and has been validated at the laboratory scale [Technology Readiness Level (TRL4)]. Successful completion of TRL4 indicates that our strategy has the potential for further scale-up, considering appropriate strategies to maintain the functionality and efficiency of co-cultures. [ABSTRACT FROM AUTHOR]

Sialic acid (SA) is widely present at the end of the sugar chain of glycoproteins and glycolipids on the surface of animal and microbial cells and is involved in many physiological activities between microbial and host cells. Notably, these functions are attributed to the diversity of these SA types, their different transformation pathways, and their metabolic actions within the host, which are considered potential targets for affecting various diseases. However, developing disease mitigation strategies is often limited by an unclear understanding of the mechanisms of interaction of the causative agents with their hosts. This review mainly focuses on three types of SA: Neu5Ac, Neu5Gc, and KDN. The sources, main types, and distribution of these SAs are discussed in detail, emphasizing the metabolic processes of different SAs and their interaction mechanisms with the host. This review will help lay a foundation for developing functional foods and SA-targeted intervention strategies. [ABSTRACT FROM AUTHOR]

Biocatalysis using whole cell biotransformation presents an alternative approach to producing complex molecules when compared to traditional synthetic chemical processes. This method offers several advantages, including scalability, self-contained co-factor recycling systems, the use of cost-effective raw materials, and reduced purification costs. Notably, biotransformation using microbial consortia provides benefits over monocultures by enhancing biosynthesis efficiency and productivity through division of labor and a reduction in metabolic burden. However, reliably controlling microbial cell populations within a consortium remains a significant challenge. In this work, we address this challenge through mechanical constraints. We describe the encapsulation and immobilization of cells in a hyper-porous hydrogel block, using methods and materials that are designed to be amenable to industrial scale-up. The porosity of the block provides ample nutrient access to ensure good cell viability, while the mechanical properties of the hydrogel matrix were optimized for Escherichia coli encapsulation, effectively limiting their proliferation while sustaining recombinant protein production. We also demonstrated the potential of this method for achieving stable co-cultivation of microbes by maintaining two different microbial strains spatially in a single porous hydrogel block. Finally, we successfully applied encapsulation to enable biotransformation in a mixed culture. Unlike its non-encapsulated counterpart, encapsulated E. coli expressing RadH halogenase achieved halogenation of the genistein substrate in a co-culture with genistein-producing Streptomyces. Overall, our strategy of controlling microbial cell populations through physical constraints offers a promising approach for engineering synthetic microbial consortia for biotransformation at an industrial scale. [ABSTRACT FROM AUTHOR]

Background: Odd chain fatty acids (OCFAs) are gaining attention for their valuable medical and nutritional applications. Microbial fermentation offers a sustainable and environmentally friendly alternative for OCFA production compared to traditional extraction or chemical synthesis methods. To achieve an economically feasible OCFA production process, it is essential to identify and develop microbial cell factories capable of producing OCFAs with high titers and yields. Results: We selected 19 yeast species, including both oleaginous yeasts and representatives from the Ascomycota and Basidiomycota phyla, based on their known or potential ability to produce OCFAs. These species were screened under various growth conditions to evaluate their OCFA production potential. In glucose-based, nitrogen-limited media, the strains produced fatty acids to varying extents, with OCFAs comprising 0.5–5% of the total fatty acids. When using the OCFAs precursor propionic acid as the sole carbon source, only eight strains exhibited growth, with tolerance to propionic acid concentrations between 5 and 29 g/L. The strains also displayed varying efficiencies in converting propionic acid into fatty acids, yielding between 0.16 and 1.22 g/L of fatty acids, with OCFAs constituting 37–89% of total fatty acids. Among the top performing strains, Cutaneotrichosporon oleaginosus produced the highest OCFA titers and yields (0.94 g/L, 0.07 g/g), Yarrowia lipolytica demonstrated superior growth rates even at elevated propionic acid concentrations, and Rhodotorula toruloides achieved the highest proportion of OCFAs relative to total fatty acids (89%). Conclusions: Our findings highlight the diverse capacities of the selected yeast species for OCFA production, identifying several promising strains for further optimization as microbial cell factories in sustainable OCFA production processes. [ABSTRACT FROM AUTHOR]

Intestinal stem cells are crucial for maintaining intestinal homeostasis, yet their transformation into tumor stem cells in the context of microbial infection remains poorly understood. Fusobacterium nucleatum is frequently associated with the onset and progression of colorectal cancer (CRC). In this study, we uncovered that F. nucleatum colonized the depths of gut crypts in both patients with CRC and mouse models. Through single-cell sequencing analysis, we demonstrated that F. nucleatum infection reprogrammed crypt cells and activated lymphocyte antigen 6 complex, locus A+ ( LY6A+, also known as stem cell antigen 1 [Sca-1]) revival stem cells (RSCs), promoting their hyperproliferation and subsequent transformation into tumor stem cells, which accelerated intestinal carcinogenesis. Mechanistically, we identified LY6A as a glycosylphosphatidylinositolanchored (GPI-anchored) membrane receptor for F. nucleatum. Upon binding, F. nucleatum induced the upregulation of ribosomal protein S14 (RPS14) via the LY6A receptor, driving RSC hyperactivity and tumorigenic conversion. Functional studies showed that genetic ablation of Ly6a in intestinal epithelial cells or Rps14 in LY6A+ RSCs substantially reduced F. nucleatum colonization and tumorigenesis. Moreover, analysis of clinical CRC cohorts revealed a strong correlation between F. nucleatum infection, RSC expansion, and elevated RPS14 expression in tumor tissues. These findings highlight an alternative F. nucleatum/LY6A/RPS14 signaling axis as a critical driver of CRC progression and propose potential therapeutic targets for effective CRC intervention. [ABSTRACT FROM AUTHOR]

End-of-life (EoL) mobile phones represent a valuable reservoir of critical raw materials at higher concentrations compared to primary ores. This review emphasizes the critical need to transition from single-material recovery approaches to comprehensive, holistic strategies for recycling EoL mobile phones. In response to the call for sustainable techniques with reduced energy consumption and pollutant emissions, biohydrometallurgy emerges as a promising solution. The present work intends to review the most relevant studies focusing on the exploitation of microbial consortia in bioleaching and biorecovery processes. All living organisms need macro- and micronutrients for their metabolic functionalities, including some of the elements contained in mobile phones. By exploring the interactions between microbial communities and the diverse elements found in mobile phones, this paper establishes a microbial-centric perspective by connecting each element of each layer to their role in the microbial cell system. A special focus is dedicated to the concepts of ecodesign and modularity as key requirements in electronics to potentially increase selectivity of microbial consortia in the bioleaching process. By bridging microbial science with sustainable design, this review proposes an innovative roadmap to optimize metal recovery, aligning with the principles of the circular economy and advancing scalable biotechnological solutions for electronic waste management. [ABSTRACT FROM AUTHOR]

Ce-MOFs with ferrocenedicarboxylic acid ligands (Ce-FcDC) as a bifunctional nanozyme exhibited high peroxidase (POD)-mimicking activity and superoxide dismutase (SOD)-mimicking activity. H2O2 was produced from catalytic hydrolysis of peroxymonosulfate (PMS) using Ce-FcDC as a catalyst. The growth of E. coli and S. aureus were synergistically and more effectively suppressed by PMS in the presence of Ce-FcDC, in comparison with the sole use of PMS or Ce-FcDc. Under the catalysis of Ce-FcDC as the POD-mimicking nanozyme, PMS could be activated by Ce-FcDC to produce SO4•− and •OH and H2O2 from the hydrolysis of PMS was further derivatized to O2•− and •OH. Ce-FcDC as the SOD-mimicking nanozyme causes O2•− to form H2O2. The generation of O2•− and •OH were confirmed using p-benzoquinone and isopropanol alcohol as the scavengers. The resulted SO4•−, O2•−, and •OH from combination of PMS with Ce-FcDC as an activator may have key roles for suppressing the growth of E. coli and S. aureus. This strategy could be an effective approach for suppressing the growth and preventing infections or pollutions of some other microbial cells as well. [ABSTRACT FROM AUTHOR]

3-Hydroxypropionic acid (3-HP) is a C3-based versatile platform chemical offering significant industrial and environmental advantages over petrochemical derivatives. Microbial cell factories are commonly employed to produce 3-HP from various carbon sources, with glycerol being a key substrate via CoA-dependent and -independent pathways. However, challenges such as inhibited growth and reduced productivity, often due to substrate inhibition and toxic byproducts like 3-hydroxypropionaldehyde (3-HPA), limit the efficiency of glycerol-based microbial 3-HP production and its industrial scalability. To address these challenges, we propose an alternative in vitro approach for 3-HP production from glycerol through a coupled enzymatic reaction. We optimized the recombinant production of glycerol dehydratase (GDHt) and alpha-ketoglutaric semialdehyde dehydrogenase (KGSADH), two key enzymes from Escherichia coli. After purification, GDHt and KGSADH showed 23.4 ± 4.6 s−1 mM−1 and 28.7 ± 5.0 s−1 mM−1 of k cat /K m , respectively. We then systematically varied enzyme concentrations, reaction temperature, and pH to determine the optimal conditions for 3-HP biosynthesis. The chain reaction, conducted with 100 nM of each enzyme, produced 43.5 μg/mL of 3-HP within 20 min under optimal conditions of 45 ºC and pH 9.0. This approach demonstrated the potential for a clean and efficient in vitro system for 3-HP production from renewable sources. [Display omitted] • Glycerol dehydratase (GHDt) was produced from Escherichia coli. • α-ketoglutaric semialdehyde dehydrogenase (KSGADH) was produced from Escherichia coli. • In vitro coupling of GDHt to KGSADH enabled the bioconversion of glycerol to 3-HP. • Condition optimization improved the biocatalytic efficiency for 3-HP production. • In vitro system would allow facile extraction of 3-HP for downstream applications. [ABSTRACT FROM AUTHOR]

The acquisition of microbial plant cell wall-degrading enzymes coincided with the main independent origins of specialized herbivory in beetles. Secondary loss of beetle-encoded digestive enzymes was offset by the recruitment of functionally convergent digestive symbionts. Tyrosine-supplementing symbionts were repeatedly recruited by herbivorous beetles, thereby aiding in cuticle biosynthesis. A symbiotically enforced cuticle allows herbivorous beetles to overcome biotic and abiotic challenges. Synthetic symbioses developed to tractably reconstitute natural infections in beetles. The ecological radiation of herbivorous beetles is among the most successful in the animal kingdom. It coincided with the rise and diversification of flowering plants, requiring beetles to adapt to a nutritionally imbalanced diet enriched in complex polysaccharides and toxic secondary metabolites. In this review, we explore how beetles overcame these challenges by coopting microbial genes, enzymes, and metabolites, through both horizontal gene transfer (HGT) and symbiosis. Recent efforts revealed the functional convergence governing both processes and the unique ways in which microbes continue to shape beetle digestion, development, and defense. The development of genetic and experimental tools across a diverse set of study systems has provided valuable mechanistic insights into how microbes spurred metabolic innovation and facilitated an herbivorous transition in beetles. [ABSTRACT FROM AUTHOR]

Peracetic acid (PAA) oxidation, which is a kind of chemical method for sludge pretreatment, has been verified to be valid for promoting sludge anaerobic digestion performance. However, the methane production is still limited at certain levels by this method, because excess PAA has negative effects on methanogens. This work selected a freezing method combined with PAA to form a composite sludge pretreatment technology for synergistically improving the biomethane production. According to the experimental data, the methane yield was largely enhanced from 166.4 ± 5.6 mL/g volatile suspended solids (VSS) in the control to 261.5 ± 7.3 mL/g VSS by the combined freezing (−10 °C) and PAA (0.08 g/g TSS) pretreatment, with a 57.2% increase rate. Kinetic analysis showed that the methane production potential, methane production rate, and hydrolysis rate were promoted, respectively, from 159.4 mL/g VSS, 17.18 mL/g VSS/d, and 0.104 d−1 to 254.9 mL/g VSS, 25.69 mL/g VSS/d, and 0.125 d−1 by the freezing + PAA pretreatment. Mechanism analysis revealed that the freezing + PAA pretreatment destroyed both extracellular polymeric substances (EPS) and microbial cells in the sludge, resulting in the increase in hydrolysis efficiency. Gene analysis showed that the hydrolytic microbes (Hyphomicrobium and norank_f_Caldilineaceae), acidogens (e.g., Petrimonas, Tissierella, and Mycobacerium) and methanogens (Methanosaeta, Methanosarcina, and Methanobacterium) were all enriched by the freezing + PAA pretreatment, with the total abundances calculated to be 10.65% and 22.07% in the control and pretreated reactors, respectively. Considering both technical and economic factors, the freezing + PAA method is feasible for sludge pretreatment. [ABSTRACT FROM AUTHOR]

The co-contamination of nitrate nitrogen (NO3−-N) and tetracycline (TC) in aquaculture water has caused serious environmental and health problems. Bioremediation is a promising approach for the removal of NO3−-N and TC. However, free bacteria are sensitive to environmental variation, limiting its application. In this study, a bacterial strain with high NO3−-N and TC degradation ability, Bacillus cereus W2, was isolated and immobilized on wheat straw biochar by an adsorption method. The effect of immobilization conditions, including biochar dosage, inoculum amount, and immobilization time on NO3−-N and TC removal was explored. The degradation abilities of the biochar-immobilized Bacillus cereus W2 under different nitrate and TC concentrations was investigated. Results showed that the prepared biochar had abundant functional groups such as -COOH, -OH, -C=C-OH, etc., which have good affinity for microbial cell membranes and are conducive to the adhesion and proliferation of microbial cells. The highest NO3−-N and TC removal efficiencies of 99.50% and 78.60% after 24 h were obtained under a biochar dosage of 4 mg·mL−1, microbe inoculation amount of 40%, and immobilization time of 24 h. The immobilized Bacillus cereus W2 performed better NO3−-N and TC removal than the free cells under different initial NO3−-N and TC concentrations. The enhanced removal of NO3−-N by the biochar-immobilized Bacillus cereus W2 may be attributed to the promoted expression level of functional genes involved in denitrification (nirS, norB, and nosZ). The biochar-immobilized Bacillus cereus W2 demonstrates potential for treating various nitrate-antibiotic co-contaminated wastewaters, including those from livestock farming, aquaculture systems, and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Due to the problems of high difficulty and cost of sludge treatment and disposal, the residual sludge with high water content was treated by lysis to realize the reduction. The sludge lysis was conducted by ultravio-sonication (UVS). The effects of wavelength and power of ultraviolet (UV), and sludge concentration and alkali treatment were investigated. The results found that the power of the UV impacted the sludge lysis degree (DDCOD) more strongly than the wavelength, which could increase the amount of TP, PO43−-P, TN, NH4+-N, protein and polysaccharides in the supernatant but reduce the percentage of carbon, nitrogen and phosphorus. During the lysis by UV-ultrasound, DDCOD increased slightly as the sludge concentration increased, and alkali treatment was more conducive to the dissolution of substances. Under the conditions of ultrasonic power 400 W and frequency 40 kHz, UV power 16 W and wavelength 185 nm, sludge concentration 12,000 mg·L−1, pH = 11 (alkali treatment), the contents of TP, PO43−-P, TN, NH4+-N were 297.1 mg·L−1, 183.9 mg·L−1, 522.3 mg·L−1, and 58.9 mg·L−1, respectively, with DDCOD reaching up to 63.02%. The improvement of sludge lysis degree was conducive to the release of substances and the reduction the moisture content, which facilitated the subsequent sludge disposal and resource utilization. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) is one of the most challenging diseases in the 21st century, and more than 10 million people around the world suffer from IBD. Because of the limitations and adverse effects associated with conventional IBD therapies, there has been increased scientific interest in microbial‐derived biomolecules, known as postbiotics. Postbiotics are defined as the preparation of inanimate microorganisms and/or their components that confer a health benefit on the host, comprising inactivated microbial cells, cell fractions, metabolites, etc. Postbiotics have shown potential in enhancing IBD treatment by reducing inflammation, modulating the immune system, stabilizing intestinal flora and maintaining the integrity of intestinal barriers. Consequently, they are considered promising adjunctive therapies for IBD. Recent studies indicate that postbiotics offer distinctive advantages, including spanning clinical (safe origin), technological (easy for storage and transportation) and economic (reduced production costs) dimensions, rendering them suitable for widespread applications in functional food/pharmaceutical. This review offers a comprehensive overview of the definition, classification and applications of postbiotics, with an emphasis on their biological activity in both the prevention and treatment of IBD. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Life is invasive, occupying all physically accessible scales, stretching between almost nothing (protons, electrons, and photons) and almost everything (the whole biosphere). Motivated by seventeenth-century insights into this infinity, this paper proposes a language to discuss life as an infinite double cascade of machines making machines. Using this simplified language, we first discuss the micro-cascade proposed by Leibniz, which describes how the self-reproducing machine of the cell is built of smaller submachines down to the atomic scale. In the other direction, we propose that a macro-cascade builds from cells larger, organizational machines, up to the scale of the biosphere. The two cascades meet at the critical point of 10³ s in time and 1 micron in length, the scales of a microbial cell. We speculate on how this double cascade evolved once a self-replicating machine emerged in the salty water of prebiotic earth. [ABSTRACT FROM AUTHOR]

Fermented sugarcane vinasse is a volatile fatty acids-rich wastewater with great potential to supply electrons in microbial electrolysis cells (MEC). This work reports the hydrogen production in a single-chambered MEC started-up with voltage of 0.8 V at 37 °C using activated sludge as inoculum. Electroactive microbes were established with current production of 0.2 ± 0.07 A m−2 and consequent hydrogen production, reaching 90% of molar fraction of hydrogen and volumetric production rate of 12.7 L m−2 d−1. The gradual increase of the voltage to 1.0 V and 1.2 V led to the increase of current production up to density of ca. 2.7 and 4.5 A m−2, respectively. However, hydrogen production was unstable due to the concomitant use of electrons and/or hydrogen by possible synthesis reactions. The identification of Thermoanaerobacterium and Caproidiproducens as the main microorganisms during the operation suggested the establishment of a co-culture in which hydrogen entered a loop of production and consumption in the single-chambered MEC. [Display omitted] • Maximum hydrogen production rate of 12.7 L m−2 d−1 from fermented sugarcane vinasse. • Hydrogen was reused for homoacetogenesis and carbon-chain elongation reactions. • Electroactive microorganisms acted as electrogens and electrotrophs concomitantly. • Hydrogen was produced and utilized by Thermoanaerobacterium and Caproiciproducens. [ABSTRACT FROM AUTHOR]

Hydrogen (H2) remains a pivotal clean energy source, and the emergence of Solar-powered Microbial Photoelectrochemical Cells (MPECs) presents promising avenues for H2 production while concurrently aiding organic matter degradation. This study introduces an MPEC system employing a g-C3N4/CQDs/BiOBr photocathode and a bioanode, successfully achieving simultaneous H2 production and sludge reduction. The research highlights the effective formation of a Z-type heterojunction in the g-C3N4/CQDs/BiOBr photocathode, substantially enhancing the photocurrent response under light conditions. Operating at – 0.4 V versus RHE, it demonstrated a current density of – 3.25 mA·cm−2, surpassing that of g-C3N4/BiOBr (−2.25 mA·cm−2) by 1.4 times and g-C3N4 (−2.04 mA·cm−2) by 1.6 times. When subjected to visible light irradiation and a 0.8 V applied bias voltage, the MPEC system achieved a current density of 1.0 mA·cm−2. The cumulative H2 production of the MPEC system reached 8.9 mL, averaging a production rate of 0.13 mL·h−1. In the anode chamber, the degradation rates of total chemical oxygen demand (TCOD), soluble chemical oxygen demand (SCOD), total suspended solids (TSS), volatile suspended solids (VSS), proteins, polysaccharides, and volatile fatty acids (VFA) in the sludge were recorded at 57.18%, 82.64%, 64.98%, 86.39%, 42.81%, 67.34%, and 29.01%, respectively. [ABSTRACT FROM AUTHOR]

We investigated the metabolome of the iron- and sulfur-oxidizing, extremely thermoacidophilic archaeon Metallosphaera sedula grown on mineral pyrite (FeS2). The extraction of organic materials from these microorganisms is a major challenge because of the tight contact and interaction between cells and mineral materials. Therefore, we applied an improved protocol to break the microbial cells and separate their organic constituents from the mineral surface, to extract lipophilic compounds through liquid–liquid extraction, and performed metabolomics analyses using MALDI-TOF MS and UHPLC-UHR-Q/TOF. Using this approach, we identified several molecules involved in central carbon metabolism and in the modified Entner-Doudoroff pathway found in Archaea, sulfur metabolism-related compounds, and molecules involved in the adaptation of M. sedula to extreme environments, such as metal tolerance and acid resistance. Furthermore, we identified molecules involved in microbial interactions, i.e., cell surface interactions through biofilm formation and cell–cell interactions through quorum sensing, which relies on messenger molecules for microbial communication. Moreover, we successfully extracted and identified different saturated thiophene-bearing quinones using software for advanced compound identification (MetaboScape). These quinones are respiratory chain electron carriers in M. sedula , with biomarker potential for life detection in extreme environmental conditions. [ABSTRACT FROM AUTHOR]

Monoterpene α -pinene exhibits significant potential as an alternative fuel, widely recognized for its affordability and eco-friendly nature. It demonstrates multiple biological activities and has a wide range of applications. However, the limited supply of pinene extracted from plants poses a challenge in meeting the needs of the aviation industry and other sectors. Considering this, the microbial cell factory is the only viable option for achieving sustainable pinene production. This study employed a rational design model to optimize the copy number and integration site for the heterogenous pinene expression pathway in Escherichia coli (E. coli). The integrated strain with the best pinene pathway PG1 was selected. Subsequently, the resulting strain, E. coli HSY009, accumulated 49.01 mg/L of pinene after 24 h fermentation in the flask culture. To further enhance production, pinene expression cassette PG1 was sequentially integrated into three non-essential regions (44th, 58th, 23rd), resulting in an improved pinene titer. Then, the fermentation process under optimized conditions enhanced the production of pinene to 436.68 mg/L in a 5 L batch fermenter with a mean productivity of 14.55 mg/L/h. To the best of our knowledge, this work represents the maximum mean pinene productivity based on the currently available literature. The findings of this work provide valuable insights for optimizing E. coli to produce other valuable terpenoids that share the same intermediates, IPP and DMAPP. Conclusively, this research validates the model's universality and highlights its potential for application as cutting-edge biofuel precursors. [ABSTRACT FROM AUTHOR]

Measurements during episodes of African dust, made with two wideband integrated bioaerosol spectrometers (WIBSs), one on the northeastern coast of Puerto Rico and the other in the city of León, Spain, show unmistakable, bioaerosol-like fluorescing aerosol particles (FAPs) that can be associated with these dust episodes. The Puerto Rico event occurred during a major incursion of African dust during June 2020. The León event occurred in the late winter and spring of 2022, when widespread, elevated layers of dust inundated the Iberian Peninsula. Satellite and back-trajectory analyses confirm that dust from northern Africa was the source of the particles during both events. The WIBSs measure the size of individual particles in the range from 0.5 to 30 µm , derive a shape factor, and classify seven types of fluorescence from the FAPs. In general, it is not possible to directly determine the specific biological identity from fluorescence signatures; however, measurements of these types of bioaerosols in laboratory studies allow us to compare ambient fluorescence patterns with whole microbial cells measured under controlled conditions. Here we introduce some new metrics that offer a more quantitative approach for comparing FAP characteristics derived from particles measured under different environmental conditions. The analysis highlights the similarities and differences at the two locations and reveals differences that can be attributed to the age and history of the dust plumes, e.g., the amount of time that the air masses were in the mixed layer and the frequency of precipitation along the air mass trajectory. [ABSTRACT FROM AUTHOR]

Cervicovaginal (CV) microbiota is critical for the well-being of host. We investigated the relationship between the ratio of Lactobacilli (LB) and cocci/coccobacilli (C/CB)-type microbial cells with biofilm formation of CV mixed cultures of women with no inflammation/infection or any epithelial abnormalities in Pap-stained smears Group 1 (G1) corresponds to the flora with LB-type cells alone, whereas G2 corresponds to the LB-dominated flora. G3 contains balanced LB and C/CB cells and G4 is dominated with C/CB. G5 corresponds to a flora with C/CB-type cells alone. Biofilm formation of CV mixed cultures was assessed by crystal violet binding assay and optical density (OD)≥0.8 were defined as biofilm producers. G1 and G3 exist in higher frequencies compared to the other smear groups. However, although the frequency of G5 dominated with C/CB-type cells were the lowest (4%); biofilm formation in that group was observed in the highest frequency (42.9%). The least biofilm formation frequency was observed in G3 smears with balanced flora (1%). Biofilm formation in healthy CV flora increases when there becomes an imbalance between LB and C/CB-type cells and an increase in C/CB-type cells. Our approach may enable early detection of vaginal dysbiosis in healthy flora prone to biofilm-associated CV infections such as bacterial vaginosis (BV). [ABSTRACT FROM AUTHOR]

Metabolic engineering is a rapidly evolving field that involves optimizing microbial cell factories to overproduce various industrial products. To achieve this, several tools, leveraging constraint-based stoichiometric models and metaheuristic algorithms like particle swarm optimization (PSO), have been developed. However, PSO can potentially get trapped in local optima. Quantum-behaved PSO (QPSO) overcomes this limitation, and our study further enhances its binary version (BQPSO) with a neighborhood topology, leading to the advanced neighborhood-based BQPSO (NBQPSO). Combined with flux balance analysis (FBA), this forms an innovative approach, NBQPSO-FBA, for identifying optimal knockout strategies to maximize the desired metabolite production. Additionally, we introduced a novel encoding strategy suitable for large-scale genome-scale metabolic models (GSMMs). Evaluated on four E. coli GSMMs (iJR904, iAF1260, iJO1366, and iML1515), NBQPSO-FBA matches or surpasses established bi-level linear programming (LP) and heuristic methods in metabolite production optimization. Notably, it achieved 90.69% realization of the theoretical maximum in acetate production and demonstrated comparable performance with leading algorithms in lactate production. The efficiency of NBQPSO-FBA, which requires fewer knockouts, makes it a practical and effective tool for optimizing microbial cell factories. This addresses the rising demand for microbial products across various industries. [ABSTRACT FROM AUTHOR]

Survivability and tolerance of polycyclic aromatic hydrocarbon (PAH)- degrading bacteria in harsh environments, especially under varying temperatures, are a bottleneck for the effective application of in situ bioremediation. In this study, a temperature adaptation system (TAS) was constructed by combining a customized thermotolerant system with a customized cold-resistant system to realize the temperature-responsive regulation of the PAH-degrading mesophilic bacterium Novosphingobium pentaromativorans US6-1. The innovative dual-pronged TAS strategy enabled the chassis strain to effectively tackle conditions under varying temperatures, ensuring robust biological activities across a broadened temperature spectrum and exhibiting the potential to realize the high-efficiency PAH degradation of N. pentaromativorans US6-1 in in situ bioremediation. Furthermore, the temperature-responsive regulation achieved using the TAS circuit is likely promising for creating intelligent microbial cell factories and avoiding precise temperature maintenance, making it highly useful for industrial applications. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is considered one of the most challenging, drug-resistant, opportunistic pathogens partly due to its ability to synthesize robust biofilms. Biofilm is a mixture of extracellular polymeric substances (EPS) that encapsulates microbial cells, leading to immune evasion, antibiotic resistance, and thus higher risk of infection. In the cystic fibrosis lung environment, P. aeruginosa undergoes a mucoid transition, defined by overproduction of the exopolysaccharide alginate. Alginate encapsulation results in bacterial resistance to antibiotics and the host immune system. Given its role in airway inflammation and chronic infection, alginate is an obvious target to improve treatment for P. aeruginosa infection. Previously, we demonstrated polysaccharide lyase Smlt1473 from Stenotrophomonas maltophilia strain k279a can catalyze the degradation of multiple polyuronides in vitro, including D-mannuronic acid (poly-ManA). Poly-ManA is a major constituent of P. aeruginosa alginate, suggesting that Smlt1473 could have potential application against multidrug-resistant P. aeruginosa and perhaps other microbes with related biofilm composition. In this study, we demonstrate that Smlt1473 can inhibit and degrade alginate from P. aeruginosa. Additionally, we show that tested P. aeruginosa strains are dominant in acetylated alginate and that all but one have similar M-to-G ratios. These results indicate that variation in enzyme efficacy among the isolates is not primarily due to differences in total EPS or alginate chemical composition. Overall, these results demonstrate Smlt1473 can inhibit and degrade P. aeruginosa alginate and suggest that other factors including rate of EPS production, alginate sequence/chain length, or non-EPS components may explain differences in enzyme efficacy. [ABSTRACT FROM AUTHOR]

Bioaugmentation with electrochemically active bacteria (EAB) has been suggested useful for improving the performance of bioelectrochemical systems (BESs) for sustainable energy generation, while its success is dependent on EAB introduced into the systems. Here we report on the isolation of a novel EAB, Geobacter sulfurreducens strain 60473, from microbes that colonized on an anode of a sediment microbial fuel cell. This strain is highly adhesive to graphite electrodes, forms dense biofilms on electrode surfaces, and generates high current densities in BESs. When microbial electrolysis cells (MECs) inoculated with paddy-field soil and fed starch as the major organic substrate were augmented with strain 60473, Geobacter bacteria predominantly colonized on anodes, and MEC performances, including current generation, hydrogen production and organics removal, were substantially improved compared to non-bioaugmented controls. Results suggest that bioaugmentation with electrode-adhesive EAB, such as strain 60473, is a promising approach for improving the performance of BESs, including MECs treating fermentable organics and biomass wastes. [ABSTRACT FROM AUTHOR]

Sourdough fermentation of bran can overcome the technological problems encountered in bread making but favors the activity of endogenous β-glucanase leading to a degradation of β-glucans. This study investigated the effects of high-intensity ultrasound (US) pretreatment of oat bran (OB) and barley bran (BB) on its β-glucans content, properties, and preservation in processing, as well as on the acidification kinetics of bran sourdough fermentation and on its application in flatbread. To reduce β-glucanase activity, OB and BB (15% water suspensions) were US-pretreated prior to sourdough fermentation. The acidification kinetics, the microbial viable cell count, and the total titratable acidity (TTA) of the sourdough were determined. The total β-glucans content of bran, sourdough, and bread, as well as water solubility and the molecular weight (Mw) of untreated and US-pretreated bran, were investigated. The physical properties of control wheat and composite flatbreads were compared. The US-pretreatment increased the acidification rate (30%) and TTA (51%) of OB sourdough, however, decreased the acidification rate of BB (18%). After the US-pretreatment of OB and BB, the total (11.5–12.3%) and water-soluble β-glucans (31–40%) increased while their Mw decreased (7–21.7%). In sourdough and flatbread prepared with US-pretreated OB/BB, 93–95% and 90–98% of β-glucans were retained, respectively, compared to 64–72% and 82–92% in control samples. The US-pretreatment and/or sourdough fermentation of OB and BB resulted in flatbreads of higher specific volume (8–22%) and cohesiveness (11–20%) while reduced hardness (40–55%) and chewiness (51–73%) compared to their control bread. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phenolic compounds are industrially versatile chemicals that have been successfully produced in microbial cell factories. Unfortunately, most phenolic compounds are highly toxic to cells in specific cellular environments or above a particular concentration because they form a complex with iron and promote hydroxyl radical production in Fenton reactions, resulting in the ferroptosis of cells. Here, we demonstrated that overexpression of efflux pumps and porins, including porins LamB and OmpN, and efflux pumps EmrAB, MdtABC, and SrpB, can enhance Escherichia coli phloroglucinol (PG) tolerance by inhibiting the generation of hydroxyl radicals. In addition, LamB and OmpN overexpression improved the bioproduction of PG. Furthermore, efflux pumps and porins can enhance bacterial tolerance to various phenolic compounds, including phenol, catechol, resorcinol, pyrogallol, and 2-naphthol. LamB and MdtABC confer a generalized tolerance to phenols. However, EmrAB, OmpN, and SrpB showed inconsistent effects of bacterial tolerance to different phenolic compounds. Our results will theoretically support the construction of phenolic compound-tolerant bacteria strains, which should be more efficient in the biosynthesis of phenols. [ABSTRACT FROM AUTHOR]

The introduction of heterologous pathways into microbial cell compartments offers several potential advantages, including increasing enzyme concentrations and reducing competition with native pathways, making this approach attractive for producing complex metabolites like fatty acids and fatty alcohols. However, measuring subcellular concentrations of these metabolites remains technically challenging. Here, we explored 3-hydroxypropionic acid (3-HP), readily quantifiable and sharing the same precursors—acetyl-CoA, NADPH, and ATP—with the above-mentioned products, as a reporter metabolite for peroxisomal engineering in the yeast Komagataella phaffii. To this end, the malonyl-CoA reductase pathway for 3-HP production was targeted into the peroxisome of K. phaffii using the PTS1-tagging system, and further tested with different carbon sources. Thereafter, we used compartmentalized 3-HP production as a reporter system to showcase the impact of different strategies aimed at enhancing the peroxisomal NADPH pool. Co-overexpression of genes encoding a NADPH-dependent redox shuttle from Saccharomyces cerevisiae (IDP2/IDP3) significantly increased 3-HP yields across all substrates, whereas peroxisomal targeting of the S. cerevisiae NADH kinase Pos5 failed to improve 3-HP production. This study highlights the potential of using peroxisomal 3-HP production as a biosensor for evaluating peroxisomal acetyl-CoA and NAPDH availability by simply quantifying 3-HP, demonstrating its potential for peroxisome-based metabolic engineering in yeast. [ABSTRACT FROM AUTHOR]

Bacteria can be engineered to manufacture chemicals, but it is unclear how to optimally engineer a single cell to maximise production performance from batch cultures. Moreover, the performance of engineered production pathways is affected by competition for the host's native resources. Here, using a 'host-aware' computational framework which captures competition for both metabolic and gene expression resources, we uncover design principles for engineering the expression of host and production enzymes at the cell level which maximise volumetric productivity and yield from batch cultures. However, this does not break the fundamental growth-synthesis trade-off which limits production performance. We show that engineering genetic circuits to switch cells to a high synthesis-low growth state after first growing to a large population can further improve performance. By analysing different circuit topologies, we show that highest performance is achieved by circuits that inhibit host metabolism to redirect it to product synthesis. Our results should facilitate construction of microbial cell factories with high and efficient production capabilities. Engineering microbial cell factories for chemical manufacture remains challenging due to trade-offs between production and growth. Here, the authors uncover how to design genetic circuits in bacteria that maximise volumetric productivity and yield. [ABSTRACT FROM AUTHOR]

This study presents a novel approach, the Supercapacitor Microbial Electrolysis Cell (SC-MEC), which utilizes a supercapacitor as an external power source to enhance the efficiency of autotrophic nitrogen removal in low C/N ratio wastewater. The results demonstrated that the SC-MEC system, operating under anaerobic conditions and devoid of any organic carbon source, exhibited exceptional performance in ammonia oxidation and total nitrogen (TN) removal when solely relying on ammonia nitrogen as the electron donor. Operating at a voltage of 1.8 V with a capacitance capacity of 30 F, ammonium oxidation rated up to 56.51 mg/L/day and TN removal rated up to 54.64 mg/L/day, in which 97% of ammonium nitrogen was converted to gaseous nitrogen. Furthermore, the charging and discharging process of supercapacitors autonomously regulated the bipolar potentials. Cyclic voltammetry (CV) analysis showed the significantly enhanced electrochemical activity of the SC-MEC system during the reaction process. Based on in-situ CV test results, it was inferred that this enhancement was associated with extracellular electron transfer mediators. The microbial community analysis revealed a process of synchronous nitrification and denitrification (SND) coupled with anammox, involving multiple genera, such as Candidatus Kuenenia, Nitrosomonas, Truepera , and Bosea. In conclusion, this study highlights the tremendous potential of SC-MEC in achieving efficient autotrophic nitrogen removal, offering more feasible and economical solutions for addressing low C/N water pollution issues. [ABSTRACT FROM AUTHOR]

In subterranean estuaries (STE), fresh and saline groundwater introduce dissolved organic matter (DOM) of different origin. This DOM serves as substrate for microorganisms that thrive in the STE. In high-energy beaches with dynamic porewater advection, microbial communities face frequent changes in groundwater composition, even at several meters depth. It is unknown how DOM from deep STE groundwater (> 5 m depth) is transformed by prevailing microbial communities. To address this question, we performed sediment incubations in flow-through reactors (FTRs) with deep (6 m depth) STE groundwater of low (1.6) and high salinity (29.1). FTR setups were sampled daily for quantification of dissolved organic carbon (DOC), and at start and end (day 13) of the incubation for analysis of DOM composition, microbial cell numbers and community composition. Solid-phase extracted DOM was molecularly characterized via ultrahigh-resolution Fourier-transform ion cyclotron resonance mass spectrometry. Both groundwater types contained mainly reworked DOM. Corroborating its presumed origin, the fresh groundwater had a more terrestrial DOM signature with a higher proportion of aromatic compounds compared to the saline groundwater. Over the course of the incubation, DOC concentrations increased primarily due to leaching of sedimentary organic matter, providing an additional source of DOM. In all setups, the DOM composition changed significantly from start to end, and similarly for fresh and saline groundwater. From the ~2700 molecular formulae (MF) detected on day 0, 34-35% were removed during the incubations, demonstrating the potential of deep STE microbial communities to degrade recalcitrant DOM that is supplied with the advective porewater flow. However, a substantial portion of MF (63-64%) was retained in both groundwater types, indicating that a fraction of deep STE-DOM is resistant to removal. Properties of MF that were newly detected on day 13 (26-28%) were indicative of labile DOM. Some of these newly detected MF were also identified in sediment-leachates, suggesting that beach sediments are a source of fresh DOM for the STE microbial communities. It is likely that due to longer groundwater residence time in the STE, continuous leaching and microbial processing shift the molecular composition of released DOM from more labile to more recalcitrant DOM. [ABSTRACT FROM AUTHOR]

Bacterial contamination is a major public health concern on a global scale. Treatment resistance in bacterial infections is becoming a significant problem that requires solutions. We were interested in obtaining new polymeric functionalized compounds with antibacterial properties. Three components (polymeric amine, aldehyde, and phosphite) were used in the paper in a modified "one-pot" Kabachnik–Fields reaction, in tetrahydrofuran at 60 °C, to create the N-C-P skeleton in aminophosphonate groups. Two copolymers were thus prepared starting from an acrylonitriledivinylbenzene (AN-15%DVB) copolymer containing pendant primary amine groups modified by grafting aminophosphonate groups, i.e., aminobenzylphosphonate (Bz-DVB-AN) and aminoethylphosphonate (Et-DVB-AN). The two copolymers were characterized by FT-IR spectroscopy, SEM-EDX, TGA, and antibacterial properties. It was shown that the novel products have antibacterial qualities against S. aureus and E. coli bacteria. The sample with the strongest antibacterial activity was Et-DVB-AN. We assessed how well the Weibull model and the first-order kinetic model represent the inactivation of microbial cells in our samples. The main advantage of the new antibacterial agents developed in this work is their easy recovery, which helps to avoid environmental contamination. [ABSTRACT FROM AUTHOR]

Stainless steel mesh (SSM) is a cost-effective, readily available catalyst and conductive substrate for large-scale hydrogen production in microbial electrolysis cells (MEC). This study reveals that variations in wire diameter and aperture size of SSM affect both the electroactive area for hydrogen evolution reaction (HER) and the formation and diffusion of hydrogen micro-nano bubbles, impacting MEC performance. In-situ hydrogen microbubble observation shows that 60-mesh SSM provides optimal hydrogen evolution due to its large electrochemical active area and many nucleation sites, minimizing the "bubble shielding effect". The SSM-60 MEC achieves the highest hydrogen recovery (75 ± 5.1%) and energy recovery efficiency (85 ± 6.2%). This study combines electroactivity testing with microscopic in-situ reaction observation to provide a novel strategy for understanding efficient hydrogen evolution catalysts. [Display omitted] • HER activity of SSM with varying mesh numbers in neutral media was investigated. • In-situ observation analyzed effects of SSM mesh number on H 2 bubble formation. • Smaller bubbles and quick detachment improved hydrogen evolution efficiency. • SSM-60 MEC achieved highest hydrogen recovery and energy recovery efficiency. [ABSTRACT FROM AUTHOR]

The article reviews the main achievements of the Gause Institute of New Antibiotics over the past 10 years in the area of developing antibiotics and related compounds that are promising for the use in medical practice and/or are of theoretical interest. Particular attention is focused on original structures that circumvent resistance of microbial or tumor cells. For new compounds with high biological activity, the structure—activity relationships was studied, which is an important requirement in the design of new compounds. The main areas of research are nominally grouped by potential practical action: antibacterial, antifungal, and/or antitumor. The main approaches used in the synthesis of modern antimicrobial or antitumor agents are reviewed: microbiological, synthetic, and combined (semi-synthetic). [ABSTRACT FROM AUTHOR]

Propanethiol oxidoreductase (PTO) is a novel thiol-oxidizing enzyme from Pseudomonas putida S-1 that utilizes thiols as the sole nutrition source. This enzyme has shown application potential in the bioremediation of thiols, its substrate selectivity, however, has not yet been elucidated. This study reveals that PTO exhibits catalytic activity towards ethanethiol, propanethiol, and butanethiol, but not methanethiol or phenylmethanethiol, indicating unique substrate specificity. Through directed evolution and semi-rational design, we engineered a PTO mutant (A54V&G316T) with twice the specific activity towards propanethiol than the wild type (from 17.3 to 40.7 μg/mg/h). Applying voltage in electrode bioreactors enhanced the microbial degradation of propanethiol, with the mutant PTO further accelerating this process. Both non-native expression in E. coli and native expression in engineered P. putida S-1 demonstrated the mutant PTO's effectiveness in increasing PT removal rates. The PT degradation efficiency of engineered P. putida S-1 increases by 3-fold compared to the wild-type in the first 5 hours. These findings highlight the potential of combining metabolic and electrochemical engineering to enhance bioremediation of toxic compounds. The engineered PTO mutant improves PT degradation efficiency and broadens its application in practical bioremediation strategies. [Display omitted] • Propanethiol oxidoreductase oxidizes ethanethiol, propanethiol, and butanethiol. • A propanethiol oxidoreductase mutant showed increased activity to propanethiol. • The mutant included two amino acid changes and named as A54V&G316T. • The bacteria with mutant (A54V&G316T) showed enhanced propanethiol degradation. • Applying voltage in bioreactor enhances microbial propanethiol degradation. [ABSTRACT FROM AUTHOR]

The possibility of biofilms on otitis media with effusion was reviewed. A systematic literature review was conducted using PubMed, Medline, Google, and Google Scholar search engines between 1975 and 2024. Articles dealing with "otitis media with effusion", "children", "treatment", "pathophysiology", "ventilation tube", or "biofilms" were located through a search engine and retrieved through a query. A middle ear effusion, which can be either mucoid or serous and is not purulent, is a hallmark of OME. The eustachian tube disruption, age, and environmental factors have all been linked to OME. Inflammation, infection, effusion, and tissue hyperplasia are common pathways that might lead to OME, suggesting that it is a complex disorder. Whether attached to living or nonliving surfaces, biofilms comprise a collection of microbial cells surrounded by a matrix formed by the cells. This matrix accounts for about 90% of the dry mass of the biofilm. Microbiological biofilms evade both the host immune system and antibiotics. The fact that 70% of OME cultures are sterile has been known for a long time. Numerous data point to the ineffectiveness of antibiotic treatment in OME, suggesting that biofilm is responsible for the disease's chronic nature. The present high rate of further surgery can be reduced by exploring new therapeutic options made possible by comprehending the function of biofilms in the genesis of OME. The most effective way to eliminate biofilms in the middle ear is to provide antibiotics locally. [ABSTRACT FROM AUTHOR]

Microorganisms, particularly extremophiles, have evolved multiple adaptation mechanisms to address diverse stress conditions during survival in unique environments. Their responses to environmental coercion decide not only survival in severe conditions but are also an essential factor determining bioproduction performance. The design of robust cell factories should take the balance of their growing and bioproduction into account. Thus, mining and redesigning stress-tolerance elements to optimize the performance of cell factories under various extreme conditions is necessary. Here, we reviewed several stress-tolerance elements, including acid-tolerant elements, saline-alkali-resistant elements, thermotolerant elements, antioxidant elements, and so on, providing potential materials for the construction of cell factories and the development of synthetic biology. Strategies for mining and redesigning stress-tolerance elements were also discussed. Moreover, several applications of stresstolerance elements were provided, and perspectives and discussions for potential strategies for screening stress-tolerance elements were made. [ABSTRACT FROM AUTHOR]

Plant natural products (PNPs) exhibit a wide range of biological activities and have essential applications in various fields such as medicine, agriculture, and flavors. Given their natural limitations, the production of highvalue PNPs using microbial cell factories has become an effective alternative in recent years. However, host metabolic burden caused by its massive accumulation has become one of the main challenges for efficient PNP production. Therefore, it is necessary to strengthen the transmembrane transport process of PNPs. This review introduces the discovery and mining of PNP transporters to directly mediate PNP transmembrane transportation both intracellularly and extracellularly. In addition to transporter engineering, this review also summarizes several auxiliary strategies (such as small molecules, environmental changes, and vesicles assisted transport) for strengthening PNP transportation. Finally, this review is concluded with the applications and future perspectives of transportation engineering in the construction and optimization of PNP microbial cell factories. [ABSTRACT FROM AUTHOR]

In this research, the emulsification method was used to encapsulate Lactobacillus reuteri in microparticles of whey protein concentrate (WPC) at different levels (1%, 2%, and 4%) and gum Arabic (GA) at three levels (0/5%, 1%, and 1/5%) and a constant level of sunflower oil (5%). The results showed that emulsions with higher quantities of wall materials exhibited better encapsulation efficiency (67%/57%) and preservation ability at different temperatures, different pH, and presence of 1% bile salt. During the storage time, the droplet size of the emulsion increased more than two times (from 2.2 to 4.6 μm) and the absolute zeta potential of the optimal emulsion decreased (from −19/63 to −16/76 mV). Encapsulating Lactobacillus reuteri in the stabilized emulsion with the highest concentration of wall material improved the cells' protection during storage. The study also observed a decline in the number of primary encapsulated live cells in the gastrointestinal tract (from 4/32 to 3/58 Log CFU/mL) after 90 days of storage. In the case of the nonencapsulated sample, the initial live population decreased from 2.8 to 1 Log CFU/mL after 90 days of storage. The electron microscope images showed that the emulsions became unstable after 30, 60, and 90 days of storage, but the microbial cells were still visible in the continuous phase. Overall, encapsulating Lactobacillus reuteri using emulsification technique can preserve the probiotics during storage and "in vitro" gastrointestinal digestion. [ABSTRACT FROM AUTHOR]

We recently identified that the cerebral mRNA expression of inducible costimulator (ICOS) and its ligand, ICOSL, both significantly increase during the elimination of Toxoplasma gondii cysts from the brains of infected mice by the perforin-mediated cytotoxic activity of CD8+ T cells. In the present study, we examined the role of ICOS in activating the effector activity of CD8+ T cells in response to the presence of cysts in infected mice. Following the adoptive transfer of splenic CD8+ T cells from chronically infected ICOS-deficient (ICOS−/−) and wild-type (WT) mice to infected SCID mice, fewer CD8+ T cells were detected in the brains of the recipients of ICOS−/− CD8+ T cells than the recipients of WT CD8+ T cells. Interestingly, even with the lower migration rate of the ICOS−/− CD8+ T cells, those T cells eliminated T. gondii cysts more efficiently than WT CD8+ T cells did in the brains of the recipient mice. Consistently, the ICOS−/− CD8+ T cells secreted greater amounts of granzyme B in response to T. gondii antigens in vitro than WT CD8+ T cells did. We identified that CD8+ T cells of infected ICOS−/− mice express significantly greater levels of CD28 on their surface than CD8+ T cells of infected WT mice, and the relative expression of CD28 mRNA to CD8β mRNA levels in the brains of the recipients of those CD8+ T cells were strongly correlated with their relative expression levels of mRNA for T-bet transcription factors and perforin. Furthermore, blocking CD28 signaling using a combination of anti-CD80 and anti-CD86 antibodies eliminated the increased cytotoxic activity of the ICOS−/− CD8+ T cells in vitro. The present study uncovered notable compensatory interactions between ICOS and CD28, which protected the cytotoxic effector activity of CD8+ T cells against microbial infection in a murine model of chronic infection with T. gondii. [ABSTRACT FROM AUTHOR]

The discovery of bacteriophages allowed the development of new ways to control the bacterial number and to assess bacterial viability. The most obvious application of bacteriophages is the treatment of human bacterial infections (phage therapy). The advantage of phage therapy is the extreme specificity of phages, since they interact with and infect only certain bacteria without affecting other bacteria or cell lines of other organisms. The advances in phage biology led to the widespread use of specific phage–host interactions in medicine and the agricultural and food industries. Thus, bacteriophages are an alternative to antibiotics for fighting infections and destroying pathogenic bacteria. This work has demonstrated for the first time the potential of a compact acoustic sensor system for assessing the impact of bacteriophages on microbial cells and the bacteriophage sensitivity of the latter. It has been shown that the developed system can be used to evaluate the activity of bacteriophages against microbial cells within 5 min without taking into account the time of cultivation of microbial cells for analysis. The results obtained are promising for further development of the acoustic sensory system in phage therapy. [ABSTRACT FROM AUTHOR]

Biofilm formation is a widespread phenomenon in the microbial world. They may affect human and animal health and cause damage to various industries; at the same time, they can be useful in such fields as wastewater treatment or improving bioavailability of nutrients for plants. This fact actualizes the development of methods for studying biofilms. The present work is the first report on an optical sensor technique for the indication of bacterial biofilm formation with regard to biological variability, using plant growth-promoting rhizobacteria of the genus Azospirillum as a model. The correlation was found between the changes in electrophysical parameters recorded by the sensor system and the morphological features of bacteria from planktonic and/or biofilm cultures: the presence of motile organelles (flagella), polymorphism, and ultrastructure of cellular forms. It was established that the profiles of microbial cells recorded by the optical system were significantly different in planktonic and biofilm forms. When comparing the cells of different strains (the parental strain and its derivatives), or planktonic and biofilm bacteria, the variables recorded by the electro-optical sensor system were in agreement with the changes in bacterial micro- and ultrastructure recorded by other techniques. The results of analysis of the electrophysical profiles of A. baldaniorum Sp245 can be used as reference for revealing specific interactions between biofilm cells of this strain and various root surface components of a putative plant partner using an optical sensor system. [ABSTRACT FROM AUTHOR]

Bioremediation is traditionally performed using free bacterial cells; however, immobilised bacterial cells have gained attention recently as a promising technique due to the numerous benefits presented. Removing dyes by biological processes is gaining apparent interest because it is profitable and environmentally friendly. Azo dyes, released into the environment, have dangerous effects on aquatic and human life, and their persistence and discharge into the environment are becoming a global concern. Considering the importance of the aspects involved in the bioremediation of azo dyes by immobilised microbial cells and the growing number of publications on the subject, this review aimed to survey state-of-the-art and make a bibliometric mapping of these studies in the period from 2013 to 2023. The analysis of articles was selected from the Science Direct database. The bibliometric mapping provided relevant data to understand the evolution of research in the area and the main bottlenecks that must be overcome for future advances to be achieved. [ABSTRACT FROM AUTHOR]

Myricitrin is a member of flavonols, natural phenolic compounds extracted from plant resources. It has gained great attention for various biological activities, such as anti-inflammatory, anti-cancer, anti-diabetic, as well as cardio-/neuro-/hepatoprotective activities. These effects have been demonstrated in both in vitro and in vivo models, making myricitrin a favorable candidate for the exploitation of novel functional foods with potential protective or preventive effects against diseases. This review summarized the health benefits of myricitrin and attempted to uncover its action mechanism, expecting to provide a theoretical basis for their application. Despite enormous bioactive potential of myricitrin, low production, high cost, and environmental damage caused by extracting it from plant resources greatly constrain its practical application. Fortunately, innovative, green, and sustainable extraction techniques are emerging to extract myricitrin, which function as alternatives to conventional techniques. Additionally, biosynthesis based on synthetic biology plays an essential role in industrial-scale manufacturing, which has not been reported for myricitrin exclusively. The construction of microbial cell factories is absolutely an appealing and competitive option to produce myricitrin in large-scale manufacturing. Consequently, state-of-the-art green extraction techniques and trends in biosynthesis were reviewed and discussed to endow an innovative perspective for the large-scale production of myricitrin. [ABSTRACT FROM AUTHOR]

Natural pigments are increasingly in demand over synthetic pigments due to their beneficial biological activities and environmentally friendly process. Recent advances in metabolic engineering and synthetic biology enabled the sustainable bioproduction of natural pigments from microorganisms. Metabolic engineering strategies, including modulation of metabolic flux, enzyme engineering, subcellular compartmentalization, and co-cultures, allowed the improvement in production of natural pigments from yeasts. Optimization of fermentation and downstream process helped to achieve high titer and yield of target pigment compounds. System-based engineering strategies, a quantitative assessment of sustainability, and a quality analysis of pigments will contribute to accelerate the commercialization of bio-based pigments. Pigments are widely used in the food, cosmetic, textile, pharmaceutical, and materials industries. Demand for natural pigments has been increasing due to concerns regarding potential health problems and environmental pollution from synthetic pigments. Microbial production of natural pigments is a promising alternative to chemical synthesis or extraction from natural sources. Here, we discuss yeasts as promising chassis for producing natural pigments with their advantageous traits such as genetic amenability, safety, rapid growth, metabolic diversity, and tolerance. Metabolic engineering strategies and optimizing strategies in downstream process to enhance production of natural pigments are thoroughly reviewed. We discuss the challenges, including expanding the range of natural pigments and improving their feasibility of industrial scale-up, as well as the potential strategies for future development. [ABSTRACT FROM AUTHOR]