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Microplastics (MPs) pollution poses a global environmental challenge with significant concerns regarding its potential impact on human health. Toxicological investigations have revealed multi-system impairments caused by MPs in various organisms. However, the specific reproductive hazards in human contexts remain elusive, and understanding the transgenerational reproductive toxicity of MPs remains limited. This study delves into the reproductive toxicity resulting from lactational exposure to polystyrene MPs (PS-MPs) in female mice, extending the inquiry to assess the reproductive effects on their offspring bred by rigorous natural mating. The MPs dosage corresponds to the detected concentration in infant formula prepared using plastic bottles. By systematically evaluating the reproductive phenotypes of F0 female mice from birth to adulthood, we found that female mice exposed to PS-MPs exhibited delayed puberty, disturbed estrous cyclicity, diminished fertility, elevated testosterone, abnormal follicle development, disrupted ovarian steroidogenesis, and ovarian inflammation. Importantly, the observed inheritable reproductive toxicity manifested with gender specificity, showcasing more pronounced abnormalities in male offspring. Specifically, reproductive disorders did not manifest in female offspring; however, a significant decrease in sperm count and viability was observed in PS-MPs-exposed F1 males. Testicular transcriptomics analysis of F1 males significantly enriched pathways associated with reproductive system development and epigenetic modification, such as male germ cell proliferation, DNA methylation, and histone modification. In summary, real-life exposure to PS-MPs impaired the reproductive function of female mice and threateningly disrupted the spermatogenesis of their F1 male offspring, which raises serious concerns about inter- and trans-generational reproductive toxicities of MPs in mammals. These findings underscore the potential threats of MPs to human reproductive health, emphasizing the need for continued vigilance and research in this critical area.
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Lactação , Microplásticos , Reprodução , Animais , Feminino , Camundongos , Microplásticos/toxicidade , Reprodução/efeitos dos fármacos , Masculino , Exposição Materna/efeitos adversosRESUMO
Methanogenic archaea, characterized by their cell membrane lipid molecules consisting of isoprenoid chains linked to glycerol-1-phosphate via ether bonds, exhibit exceptional adaptability to extreme environments. However, this distinct lipid architecture also complicates the interactions between methanogenic archaea and nanoparticles. This study addresses this challenge by exploring the interaction and transformation of selenium nanoparticles (SeNPs) within archaeal Methanosarcina acetivorans C2A. We demonstrated that the effects of SeNPs are highly concentration-dependent, with chemical stimulation of cellular processes at lower SeNPs concentrations as well as oxidative stress and metabolic disruption at higher concentrations. Notably, we observed the formation of a protein corona on SeNPs, characterized by the selective adsorption of enzymes critical for methylotrophic methanogenesis and those involved in selenium methylation, suggesting potential alterations in protein function and metabolic pathways. Furthermore, the intracellular transformation of SeNPs into both inorganic and organic selenium species highlighted their bioavailability and dynamic transformation within archaea. These findings provide vital insights into the nano-bio interface in archaeal systems, contributing to our understanding of archaeal catalysis and its broader applications.
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Methanosarcina , Nanopartículas , Selênio , Selênio/química , Selênio/metabolismo , Methanosarcina/metabolismo , Nanopartículas/química , Nanopartículas/metabolismo , Estresse OxidativoRESUMO
Addressing the challenge of understanding how cellular interfaces dictate the mechanical resilience and adhesion of archaeal cells, this study demonstrates the role of the surface layer (S-layer) in methanogenic archaea. Using a combination of atomic force microscopy and single-cell force spectroscopy, we quantified the impact of S-layer disruption on cell morphology, mechanical properties, and adhesion capabilities. We demonstrate that the S-layer is crucial for maintaining cell morphology, where its removal induces significant cellular enlargement and deformation. Mechanical stability of the cell surface is substantially compromised upon S-layer disruption, as evidenced by decreased Young's modulus values. Adhesion experiments revealed that the S-layer primarily facilitates hydrophobic interactions, which are significantly reduced after its removal, affecting both cell-cell and cell-bubble interactions. Our findings illuminate the S-layer's fundamental role in methanogen architecture and provide a chemical understanding of archaeal cell surfaces, with implications for enhancing methane production in biotechnological applications.
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Microscopia de Força Atômica , Análise de Célula Única , Propriedades de Superfície , Archaea/química , Archaea/metabolismo , Adesão Celular , Interações Hidrofóbicas e HidrofílicasRESUMO
Addressing the challenge of accurately monitoring polycyclic aromatic hydrocarbons (PAHs) in aquatic systems, this study employed diffusive gradients in thin-films (DGT) technique to achieve methods detection limits as low as 0.02 ng L-1 to 0.05 ng L-1 through in situ preconcentration and determination of time-integrated concentrations. The efficacy of the developed DGT samplers was validated under diverse environmental conditions, demonstrating independence from factors such as pH (5.03-9.01), dissolved organic matter (0-20 mg L-1), and ionic strength (0.0001-0.6 M). Notably, the introduction of a novel theoretical approach to calculate diffusion coefficients based on solvent-accessible volume tailored for PAHs significantly enhanced the method's applicability, particularly for organic pollutants with low solubility. Field deployments in coastal zones validated the DGT method against traditional grab sampling, with findings advocating a 4 to 7-day optimal deployment duration for balancing sensitivity and mitigating lag time effects. These results provide a sophisticated, efficient solution to the persistent challenge of monitoring hydrophobic organic pollutants in aquatic environments, broadening the scope and applicability of DGT in environmental science and providing a robust tool for researchers.
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As essential primary producers, cyanobacteria play a major role in global carbon and nitrogen cycles. Though the influence of nanoplastics on the carbon metabolism of cyanobacteria is well-studied, little is known about how nanoplastics affect their nitrogen metabolism, especially under environmentally relevant nitrogen concentrations. Here, we show that nitrogen forms regulated growth inhibition, nitrogen consumption, and the synthesis and release of microcystin (MC) in Microcystis aeruginosa exposed to 10 µg/mL amino-modified polystyrene nanoplastics (PS-NH2) with a particle size of 50 nm under environmentally relevant nitrogen concentrations of nitrate, ammonium, and urea. We demonstrate that PS-NH2 inhibit M. aeruginosa differently in nitrate, urea, and ammonium, with inhibition rates of 51.87, 39.70, and 36.69%, respectively. It is caused through the differences in impairing cell membrane integrity, disrupting redox homeostasis, and varying nitrogen transport pathways under different nitrogen forms. M. aeruginosa respond to exposure of PS-NH2 by utilizing additional nitrogen to boost the production of amino acids, thereby enhancing the synthesis of MC, extracellular polymeric substances, and membrane phospholipids. Our results found that the threat of nanoplastics on primary producers can be regulated by the nitrogen forms in freshwater ecosystems, contributing to a better understanding of nanoplastic risks under environmentally relevant conditions.
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Microcystis , Nitrogênio , Microcystis/efeitos dos fármacos , Microcystis/metabolismo , Microcystis/crescimento & desenvolvimento , Nitrogênio/química , Nitrogênio/metabolismo , Microcistinas/metabolismo , Poliestirenos/química , Tamanho da Partícula , Microplásticos/metabolismo , Nanopartículas/química , Nitratos/metabolismo , Nitratos/química , Ureia/metabolismo , Ureia/química , Ureia/farmacologiaRESUMO
Hydroxyl radicals (·OH) produced in subsurface sediments play an important role in biogeochemical cycles. One of the major sources of·OH in sediments is associated with reduced compounds (e.g., iron and organic matter) oxygenation. Moreover, the properties of iron forms and dissolved organic matter (DOM) components varied significantly across redox-fluctuation zones of estuaries. However, the influence of these variations on mechanisms of·OH production in estuaries remains unexplored. Herein, sediments from riparian zones, wetlands, and rice fields in the Yellow River Estuary were collected to systematically explore the diverse mechanisms of·OH generation. Rhythmic continuous·OH production (82-730 µmol/kg) occurred throughout the estuary, demonstrating notable spatial heterogeneity. The amorphous iron form and humic-like DOM components were the key contributors to·OH accumulation in estuary wetlands and freshwater restoration wetlands, respectively. The crystalline iron form and protein-like DOM components influenced the capabilities of iron reduction and continuous·OH production. Moreover, the orthogonal partial least squares models outperformed various multivariate models in screening crucial factors and predicting the spatiotemporal production of·OH. This study provides novel insights into varied mechanisms of·OH generation within distinct redox-fluctuation zones in estuaries and further elucidates elemental behavior and contaminant fate in estuarine environments. ENVIRONMENTAL IMPLICATION: Given that estuaries serve as sinks for anthropogenic pollutants, various organic pollutants (e.g., emerging contaminants such as antibiotics) have been widely detected in estuarine environments. The production of·OH in sediments has been proven to affect the fate of contaminants. Therefore, the varied mechanisms of·OH in estuarine environments, dominated by diverse iron forms and DOM components, were explored in this study. MLR and OPLS models exhibited good performance in screening crucial factors and predicting·OH production. Our work highlights that in estuarine subsurface environments, the presence of·OH potentially leads to a natural degradation of pollutants.
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Integration of methanogenic archaea with photocatalysts presents a sustainable solution for solar-driven methanogenesis. However, maximizing CH4 conversion efficiency remains challenging due to the intrinsic energy conservation and strictly restricted substrates of methanogenic archaea. Here, we report a solar-driven biotic-abiotic hybrid (biohybrid) system by incorporating cadmium sulfide (CdS) nanoparticles with a rationally designed methanogenic archaeon Methanosarcina acetivorans C2A, in which the glucose synergist protein and glucose kinase, an energy-efficient route for glucose transport and phosphorylation from Zymomonas mobilis, were implemented to facilitate nonnative substrate glucose for methanogenesis. We demonstrate that the photo-excited electrons facilitate membrane-bound electron transport chain, thereby augmenting the Na+ and H+ ion gradients across membrane to enhance adenosine triphosphate (ATP) synthesis. Additionally, this biohybrid system promotes the metabolism of pyruvate to acetyl coenzyme A (AcCoA) and inhibits the flow of AcCoA to the tricarboxylic acid (TCA) cycle, resulting in a 1.26-fold augmentation in CH4 production from glucose-derived carbon. Our results provide a unique strategy for enhancing methanogenesis through rational biohybrid design and reprogramming, which gives a promising avenue for sustainably manufacturing value-added chemicals.
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Trifosfato de Adenosina , Metano , Metano/metabolismo , Transporte de Elétrons , Trifosfato de Adenosina/metabolismo , Metabolismo Energético , Transporte Biológico , Methanosarcina/metabolismoRESUMO
Synthetic musks (SMs) have gained widespread utilization in daily consumer products, leading to their widespread dissemination in aquatic environments through various pathways. Over the past few decades, the production of SMs has consistently risen, prompting significant concern over their potential adverse impacts on ecosystems and human health. Although several studies have focused on the development of analytical techniques for detecting SMs in biological samples and cosmetic products, a comprehensive evaluation of their global distribution in diverse aquatic media and biological matrices remains lacking. This review aims to provide an up-to-date overview of the occurrence of SMs in both aquatic and various biological matrices, investigating their worldwide distribution trends, assessing their ecological toxicity, and comparing different methodologies for processing and analysis of SMs. The findings underscore the prevalence of polycyclic musks as predominant SMs, with consumption of various products in different countries leading to contrasting distribution of contaminants. Furthermore, the migration of SMs from sediments to the water phase is investigated, indicating the role of solid-phase reservoirs. Incomplete degradation of SMs in the environment could contribute to their accumulation in aquatic systems, impacting the growth and oxidative stress of aquatic organisms, and having a possibility of genotoxicity to them. Human exposure data highlight substantial risks for vulnerable populations such as pregnant women and infants. Moreover, contemporary methods for SMs analysis are presented in this review, particularly focusing on advancements made in the last five years. Finally, research enhancement and critical questions regarding the analysis of SMs are provided, offering suggestions for future research endeavors.
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Cosméticos , Poluentes Químicos da Água , Gravidez , Humanos , Feminino , Ecossistema , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise , Organismos AquáticosRESUMO
Nanoplastics (NPs) are a prevalent type of emerging pollutant in marine environment. However, their fouling behavior and impact on reverse osmosis (RO) membrane performance remain unexplored. We investigated the relationship between polystyrene (PS), one of the most abundant NPs, with silica scaling and humic acid (HA) fouling in RO. The results demonstrated that the surface potential of NPs played an important role in the combined scaling and fouling process. Compared with the negatively charged NPs (original PS and carboxyl group modified PS, PS-COOH), the amino-functionalized PS (PS-NH2) with positive surface charge significantly accelerated membrane scaling/fouling and induced a synergistic water flux decline, due to the strong electrostatic attraction between PS-NH2, foulants, and the membrane surface. The amino groups acted as binding sites, which promoted the heterogeneous nucleation of silica and adsorption of HA, then formed stable composite pollutants. Thermodynamic analysis via isothermal titration calorimetry (ITC) further confirmed the spontaneous formation of stable complexes between PS-NH2 and silicates/HA. Our study provides new insights into the combined NPs fouling with other scalants or foulants, and offers guidance for the accurate prediction of RO performance in the presence of NPs.
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Microplásticos , Purificação da Água , Osmose , Purificação da Água/métodos , Membranas Artificiais , Dióxido de Silício , Poliestirenos , Substâncias HúmicasRESUMO
The toxicity of nanoparticles to freshwater microalgae is of significant importance in maintaining the overall stability of aquatic ecosystems. However, the transport mechanism and toxicity response of microalgae towards nanoplastics (NPs) remain to be further investigated. In this study, we examined the toxicity and internalization mechanisms of polystyrene nanoplastics (PS-NPs) in the microalga Chlorella sorokiniana. The results revealed that the PS-NPs inhibited algal cells' growth and disrupted cell integrity upon contact, leading to cell shrinkage or rupture. Moreover, amino-modified PS-NPs (Nano-PS-NH2) exhibited greater toxicity to C. sorokiniana than carboxyl-modified PS-NPs (Nano-PS-COOH). Furthermore, significant inhibition of PS-NPs internalization was observed when four different endocytosis-related inhibitors were used, indicating that internalized PS-NPs can enter algal cells through endocytic pathways. More importantly, C. sorokiniana exposed to Nano-PS-NH2 responded to the reduction in carbon sources and energy resulting from the suppression of photosynthesis by regulating the metabolism of carbohydrates. These findings elucidate the effects of PS-NPs on C. sorokiniana, including their impact on cell morphology and metabolism, while shedding light on the internalization mechanisms of NPs by C. sorokiniana which deepen our understanding of the toxicity of nanoplastics on algae and provide important theoretical support for solving such aquatic ecological environment problems.
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Chlorella , Microalgas , Nanopartículas , Poluentes Químicos da Água , Microplásticos/toxicidade , Poliestirenos/toxicidade , Ecossistema , Poluentes Químicos da Água/toxicidade , Nanopartículas/toxicidadeRESUMO
Microbiologically influenced corrosion (MIC) caused by sulfate reducing bacteria (SRB) is a serious challenge in many industries, but biofilm greatly decreases the toxicity of bactericides to cell inside. d-amino acids are potential enhancers for bactericides due to their excellent performance on biofilm inhibition. However, the mechanism of d-amino acid cooperating with bactericides for MIC inhibition is still unknown. In this study, d-tyrosineï¼D-Tyrï¼and disoctyl dimethyl ammonium chloride (DDAC) were selected as the typical d-amino acid and bactericide, respectively, to evaluate their synergetic inhibition on the corrosion caused by Desulfovibrio vulgaris. D-Tyr obviously enhanced the role of DDAC in inhibiting corrosion with high corrosion inhibition efficiency at 77.23 %. The attachment of EPS and live cells on the coupon surface decreased in the presence of D-Try, leading to more cells directly exposed to DDAC. Besides, D-Try decreased the amount of live cells on the surface and thus reduced the utilization of Fe by SRB and corrosion current. Moreover, dead cells settling to the coupon surface may form a protective lay to retard the contact between live SRB and Fe, leading to slow cathode reaction and less corrosion. Therefore, D-Tyr can reduce the coverage of biofilm, thereby reducing its protective effect on SRB and achieving better corrosion inhibition effect. This work provides a new strategy for improving bactericides and inhibiting MIC.
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Although microbial humus respiration plays a critical role in organic matter decomposition and biogeochemical cycling of elements in diverse anoxic environments, the role of methane-producing species (methanogens) is not well defined. Here we report that a major fraction of humus, humic acid reduction enhanced the growth of Methanosarcina acetivorans above that attributed to methanogenesis when utilizing the energy sources methanol or acetate, results which showed both respiratory and fermentative modes of energy conservation. Growth characteristics with methanol were the same for an identically cultured mutant deleted for the gene encoding a multi-heme cytochrome c (MmcA), results indicating MmcA is not essential for respiratory electron transport to humic acid. Transcriptomic analyses revealed that growth with humic acid promoted the upregulation of genes annotated as cell surface pyrroloquinoline quinone (PQQ)-binding proteins. Furthermore, PQQ isolated from the membrane fraction was more abundant in humic acid-respiring cells, and the addition of PQQ improved efficiency of the extracellular electron transport. Given that the PQQ-binding proteins are widely distributed in methanogens, the findings extend current understanding of microbial humus respiration in the context of global methane dynamics.
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Substâncias Húmicas , Metanol , Metanol/metabolismo , Cofator PQQ/metabolismo , Methanosarcina/metabolismo , Metano/metabolismoRESUMO
Anaerobic marine environments are the third largest producer of the greenhouse gas methane. The release to the atmosphere is prevented by anaerobic 'methanotrophic archaea (ANME) dependent on a symbiotic association with sulfate-reducing bacteria or direct reduction of metal oxides. Metagenomic analyses of ANME are consistent with a reverse methanogenesis pathway, although no wild-type isolates have been available for validation and biochemical investigation. Herein is reported the characterization of methanotrophic growth for the diverse marine methanogens Methanosarcina acetivorans C2A and Methanococcoides orientis sp. nov. Growth was dependent on reduction of either ferrihydrite or humic acids revealing a respiratory mode of energy conservation. Acetate and/or formate were end products. Reversal of the well-characterized methanogenic pathways is remarkably like the consensus pathways for uncultured ANME based on extensive metagenomic analyses.
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Euryarchaeota , Respiração , Archaea/genética , Atmosfera , ConsensoRESUMO
The occurrence of 25 multi-class pollutants comprising phthalate esters (PAEs), polycyclic aromatic hydrocarbons (PAHs), and synthetic musks (SMs) were studied in PM2.5 samples collected at an industrial/commercial/residential/traffic mixed area in Shanghai during four seasons. During the whole period, a slight exceedance of the PM2.5 annual limit was observed, with an average of 36.8 µg/m3, and PAEs were the most predominant, accounting for >70 % of the studied organic pollutants in PM2.5, followed by PAHs and SMs. Statistically significant differences were observed for the concentrations of PM2.5, PAEs, PAHs, and SMs in winter and summer. This seasonal variation could be derived from anthropogenic activities and atmospheric dynamics. Principal component analysis (PCA) and PAHs ratios suggested a mixed source mainly derived from vehicle emissions and industrial processes. Moreover, gaseous pollutants were also accounted for, indicating the emission of PAHs might accompany the NO2 emission process. Finally, inhalation of PM2.5-bound organic pollutants for carcinogenic and non-carcinogenic risks were estimated as average values for each season, showing outside the safe levels in autumn and winter in some cases, suggesting that new policies should be to developed to reduce their emissions and protect human health in this area.
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Studies on the adverse effects of nanoplastics (NPs, particle diameter <1000 nm) including physical damage, oxidative stress, impaired cell signaling, altered metabolism, developmental defects, and possible genetic damage have intensified in recent years. However, the analytical detection of NPs is still a bottleneck. To overcome this bottleneck and obtain a reliable and quantitative distribution analysis in complex freshwater ecosystems, an easily applicable NP tracer to simulate their fate and behavior is needed. Here, size- and surface charge-tunable core-shell Au@Nanoplastics (Au@NPs) were synthesized to study the environmental fate of NPs in an artificial freshwater system. The Au core enables the quantitative detection of NPs, while the polystyrene shell exhibits NP properties. The Au@NPs showed excellent resistance to environmental factors (e.g., 1% hydrogen peroxide solution, simulating gastric fluid, acids, and alkalis) and high recovery rates (>80%) from seawater, lake water, sewage, waste sludge, soil, and sediment. Both positively and negatively charged NPs significantly inhibited the growth of duckweed (Lemna minor L.) but had little effect on the growth of cyanobacteria (Microcystis aeruginosa). In addition, the accumulation of positively and negatively charged NPs in cyanobacteria occurred in a concentration-dependent manner, with positively charged NPs more easily taken up by cyanobacteria. In contrast, negatively charged NPs were more readily internalized in duckweed. This study developed a model using a core-shell Au@NP tracer to study the environmental fate and behavior of NPs in various complex environmental systems.
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Cianobactérias , Microplásticos , Bioacumulação , Ecossistema , Água Doce , Água do Mar , PoliestirenosRESUMO
Diets comprising selenium-deficient crops have been linked to immune disorders and cardiomyopathy. Selenium nanoparticles (SeNPs) have emerged as a promising nanoplatform for selenium-biofortified agriculture. However, SeNPs fail to reach field-scale applications due to a poor understanding of the fundamental principles of its behavior. Here, we describe the transport, transformation, and bioavailability of SeNPs through a combination of in vivo and in vitro experiments. We show synthesized amorphous SeNPs, when sprayed onto the leaves of Arabidopsis thaliana, are rapidly biotransformed into selenium(IV), nonspecifically incorporated as selenomethionine (SeMet), and specifically incorporated into two selenium-binding proteins (SBPs). The SBPs identified were linked to stress and reactive oxygen species (mainly H2O2 and O2-) reduction, processes that enhance plant growth and primary root elongation. Selenium is transported both upwards and downwards in the plant when SeNPs are sprayed onto the leaves. With the application of Silwet L-77 (a common agrochemical surfactant), selenium distributed throughout the whole plant including the roots, where pristine SeNPs cannot reach. Our results demonstrate that foliar application of SeNPs promotes plant growth without causing nanomaterial accumulation, offering an efficient way to obtain selenium-fortified agriculture.
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Nanopartículas , Selênio , Proteínas de Plantas , Peróxido de Hidrogênio , AntioxidantesRESUMO
The Roseobacter clade bacteria are of great significance in marine ecology and biogeochemical cycles, and they are potential microbial chassis for marine synthetic biology due to their versatile metabolic capabilities. Here, we adapted a CRISPR-Cas-based system, base editing, with the combination of nuclease-deactivated Cas9 and deaminase for Roseobacter clade bacteria. Taking the model roseobacter Roseovarius nubinhibens as an example, we achieved precise and efficient genome editing at single-nucleotide resolution without generating double-strand breaks or requesting donor DNAs. Since R. nubinhibens can metabolize aromatic compounds, we interrogated the key genes in the ß-ketoadipate pathway with our base editing system via the introduction of premature STOP codons. The essentiality of these genes was demonstrated, and for the first time, we determined PcaQ as a transcription activator experimentally. This is the first report of CRISPR-Cas-based genome editing in the entire clade of Roseobacter bacteria. We believe that our work provides a paradigm for interrogating marine ecology and biogeochemistry with direct genotype-and-phenotype linkages and potentially opens a new avenue for the synthetic biology of marine Roseobacter bacteria.
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Roseobacter , Roseobacter/genética , Roseobacter/metabolismo , Edição de Genes , Fenótipo , Sistemas CRISPR-Cas/genéticaRESUMO
Understanding the fundamental interaction of nanoparticles at plant interfaces is critical for reaching field-scale applications of nanotechnology-enabled plant agriculture, as the processes between nanoparticles and root interfaces such as root compartments and root exudates remain largely unclear. Here, using iron deficiency-induced plant chlorosis as an indicator phenotype, we evaluated the iron transport capacity of Fe3O4 nanoparticles coated with citrate (CA) or polyacrylic acid (PAA) in the plant rhizosphere. Both nanoparticles can be used as a regulator of plant hormones to promote root elongation, but they regulate iron deficiency in plant in distinctive ways. In acidic root exudates secreted by iron-deficient Arabidopsis thaliana, CA-coated particles released fivefold more soluble iron by binding to acidic exudates mainly through hydrogen bonds and van der Waals forces and thus, prevented iron chlorosis more effectively than PAA-coated particles. We demonstrate through roots of mutants and visualization of pH changes that acidification of root exudates primarily originates from root tips and the synergistic mode of nanoparticle uptake and transformation in different root compartments. The nanoparticles entered the roots mainly through the epidermis but were not affected by lateral roots or root hairs. Our results show that magnetic nanoparticles can be a sustainable source of iron for preventing leaf chlorosis and that nanoparticle surface coating regulates this process in distinctive ways. This information also serves as an urgently needed theoretical basis for guiding the application of nanomaterials in agriculture.
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Anemia Hipocrômica , Arabidopsis , Deficiências de Ferro , Nanopartículas de Magnetita , Ferro/metabolismo , Transporte Biológico , Anemia Hipocrômica/metabolismo , Arabidopsis/metabolismo , Raízes de Plantas/metabolismoRESUMO
Antibiotic resistance is a global health challenge, and the COVID-19 pandemic has amplified the urgency to understand its airborne transmission. The bursting of bubbles is a fundamental phenomenon in natural and industrial processes, with the potential to encapsulate or adsorb antibiotic-resistant bacteria (ARB). However, there is no evidence to date for bubble-mediated antibiotic resistance dissemination. Here, we show that bubbles can eject abundant bacteria to the air, form stable biofilms over the air-water interface, and provide opportunities for cell-cell contact that facilitates horizontal gene transfer at and over the air-liquid interface. The extracellular matrix (ECM) on bacteria can increase bubble attachment on biofilms, increase bubble lifetime, and, thus, produce abundant small droplets. We show through single-bubble probe atomic force microscopy and molecular dynamics simulations that hydrophobic interactions with polysaccharides control how the bubble interacts with the ECM. These results highlight the importance of bubbles and its physicochemical interaction with ECM in facilitating antibiotic resistance dissemination and fulfill the framework on antibiotic resistance dissemination.
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Antagonistas de Receptores de Angiotensina , COVID-19 , Humanos , Pandemias , Inibidores da Enzima Conversora de Angiotensina , Bactérias , Resistência Microbiana a MedicamentosRESUMO
Elevated CO2 emissions have substantially altered the worldwide climate, while the excessive reliance on fossil fuels has exacerbated the energy crisis. Therefore, the conversion of CO2 into fuel, petroleum-based derivatives, drug precursors, and other value-added products is expected. Cupriavidus necator H16 is the model organism of the "Knallgas" bacterium and is considered to be a microbial cell factory as it can convert CO2 into various value-added products. However, the development and application of C. necator H16 cell factories has several limitations, including low efficiency, high cost, and safety concerns arising from the autotrophic metabolic characteristics of the strains. In this review, we first considered the autotrophic metabolic characteristics of C. necator H16, and then categorized and summarized the resulting problems. We also provided a detailed discussion of some corresponding strategies concerning metabolic engineering, trophic models, and cultivation mode. Finally, we provided several suggestions for improving and combining them. This review might help in the research and application of the conversion of CO2 into value-added products in C. necator H16 cell factories.