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1.
Biosens Bioelectron ; 260: 116462, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38833834

RESUMO

Design and intelligent use renewable natural bioenergy is an important challenge. Electric microorganism-based materials are being serve as an important part of bioenergy devices for energy release and collection, calling for suitable skeleton materials to anchor live microbes. Herein we verified the feasibility of constructing bio-abiotic hybrid living materials based on the combination of gelatin, Li-ions and exoelectrogenic bacteria Shewanella oneidensis manganese-reducing-1 (MR-1). The gelatin-based mesh contains abundant pores, allowing microbes to dock and small molecules to diffuse. The hybrid materials hold plentiful electronegative groups, which effectively anchor Li-ions and facilitate their transition. Moreover, the electrochemical characteristics of the materials can be modulated through changing the ratios of gelatin, bacteria and Li-ions. Based on the gelatin-Li-ion-microorganism hybrid materials, a bifunctional device was fabricated, which could play dual roles alternatively, generation of electricity as a microbial fuel cell and energy storage as a pseudocapacitor. The capacitance and the maximum voltage output of the device reaches 68 F g-1 and 0.67 V, respectively. This system is a new platform and fresh start to fabricate bio-abiotic living materials for microbial electron storage and transfer. We expect the setup will extend to other living systems and devices for synthetic biological energy conversion.


Assuntos
Fontes de Energia Bioelétrica , Técnicas Biossensoriais , Hidrogéis , Shewanella , Fontes de Energia Bioelétrica/microbiologia , Shewanella/química , Shewanella/metabolismo , Hidrogéis/química , Técnicas Biossensoriais/métodos , Gelatina/química , Lítio/química , Técnicas Eletroquímicas/métodos , Desenho de Equipamento , Capacitância Elétrica
2.
PLoS One ; 19(6): e0305037, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38837976

RESUMO

Bacteria use various motility mechanisms to explore their environments. Chemotaxis is the ability of a motile bacterial cell to direct its movement in response to chemical gradients. A number of methods have been developed and widely used to study chemotactic responses to chemoeffectors including capillary, agar plug, microscopic slide, and microfluidic assays. While valuable, these assays are primarily designed to monitor rapid chemotactic responses to chemoeffectors on a small scale, which poses challenges in collecting large quantities of attracted bacteria. Consequently, these setups are not ideal for experiments like forward genetic screens. To overcome this limitation, we developed the Large Scale Bacterial Attraction assay (LSBA), which relies on the use of a Nalgene™ Reusable Filter Unit and other materials commonly found in laboratories. We validate the LSBA by investigating chemoeffector kinetics in the setup and by using chemoattractants to quantify the chemotactic response of wild-type, and motility impaired strains of the plant pathogenic bacterium Xanthomonas campestris pv. campestris and the environmental bacterium Shewanella oneidensis. We show that the LSBA establishes a long lasting chemoeffector gradient, that the setup can be used to quantify bacterial migration over time and that the LSBA offers the possibility to collect high numbers of attracted bacteria, making it suitable for genetic screens.


Assuntos
Quimiotaxia , Shewanella , Quimiotaxia/genética , Shewanella/genética , Shewanella/fisiologia , Xanthomonas campestris/genética , Testes Genéticos/métodos , Fatores Quimiotáticos/farmacologia , Bioensaio/métodos
3.
Biochemistry (Mosc) ; 89(4): 701-710, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38831506

RESUMO

Many microorganisms are capable of anaerobic respiration in the absence of oxygen, by using different organic compounds as terminal acceptors in electron transport chain. We identify here an anaerobic respiratory chain protein responsible for acrylate reduction in the marine bacterium Shewanella woodyi. When the periplasmic proteins of S. woodyi were separated by ion exchange chromatography, acrylate reductase activity copurified with an ArdA protein (Swoo_0275). Heterologous expression of S. woodyi ardA gene (swoo_0275) in Shewanella oneidensis MR-1 cells did not result in the appearance in them of periplasmic acrylate reductase activity, but such activity was detected when the ardA gene was co-expressed with an ardB gene (swoo_0276). Together, these genes encode flavocytochrome c ArdAB, which is thus responsible for acrylate reduction in S. woodyi cells. ArdAB was highly specific for acrylate as substrate and reduced only methacrylate (at a 22-fold lower rate) among a series of other tested 2-enoates. In line with these findings, acrylate and methacrylate induced ardA gene expression in S. woodyi under anaerobic conditions, which was accompanied by the appearance of periplasmic acrylate reductase activity. ArdAB-linked acrylate reduction supports dimethylsulfoniopropionate-dependent anaerobic respiration in S. woodyi and, possibly, other marine bacteria.


Assuntos
Acrilatos , Shewanella , Shewanella/enzimologia , Shewanella/genética , Shewanella/metabolismo , Transporte de Elétrons , Acrilatos/metabolismo , Anaerobiose , Oxirredutases/metabolismo , Oxirredutases/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética
4.
Sci Total Environ ; 935: 173443, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-38782281

RESUMO

Fulvic acid (FA) and iron oxides often play regulating roles in the geochemical behavior and ecological risk of arsenic (As) in terrestrial ecosystems. FA can act as electron shuttles to facilitate the reductive dissolution of As-bearing iron (hydr)oxides. However, the influence of FA from different sources on the sequential conversion of Fe/As in As-bearing iron oxides under biotic and abiotic conditions remains unclear. In this work, we exposed prepared As-bearing iron oxides to FAs derived from lignite (FAL) and plant peat (FAP) under anaerobic conditions, tracked the fate of Fe and As in the aqueous phase, and investigated the reduction transformation of Fe(III)/As(V) with or without the presence of Shewanella oneidensis MR-1. The results showed that the reduction efficiency of Fe(III)/As(V) was increased by MR-1, through its metabolic activity and using FAs as electron shuttles. The reduction of Fe(III)/As(V) was closely associated with goethite being more conducive to Fe/As reduction compared to hematite. It is determined that functional groups such as hydroxy, carboxy, aromatic, aldehyde, ketone and aliphatic groups are the primary electron donors. Their reductive capacities rank in the following sequence: hydroxy> carboxy, aromatic, aldehyde, ketone> aliphatic group. Notably, our findings suggest that in the biotic reduction, Fe significantly reduction precedes As reduction, thereby influencing the latter's reduction process across all incubation systems. This work provides empirical support for understanding iron's role in modulating the geochemical cycling of As and is of significant importance for assessing the release risk of arsenic in natural environments.


Assuntos
Arsênio , Benzopiranos , Compostos Férricos , Oxirredução , Shewanella , Compostos Férricos/metabolismo , Compostos Férricos/química , Arsênio/metabolismo , Shewanella/metabolismo , Ferro/química , Ferro/metabolismo
5.
Biosens Bioelectron ; 259: 116422, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38797034

RESUMO

The biology-material hybrid method for chemical-electricity conversion via microbial fuel cells (MFCs) has garnered significant attention in addressing global energy and environmental challenges. However, the efficiency of these systems remains unsatisfactory due to the complex manufacturing process and limited biocompatibility. To overcome these challenges, here, we developed a simple bio-inorganic hybrid system for bioelectricity generation in Shewanella oneidensis (S. oneidensis) MR-1. A biocompatible surface display approach was designed, and silver-binding peptide AgBP2 was expressed on the cell surface. Notably, the engineered Shewanella showed a higher electrochemical sensitivity to Ag+, and a 60 % increase in power density was achieved even at a low concentration of 10 µM Ag+. Further analysis revealed significant upregulations of cell surface negative charge intensity, ATP metabolism, and reducing equivalent (NADH/NAD+) ratio in the engineered S. oneidensis-Ag nanoparticles biohybrid. This work not only provides a novel insight for electrochemical biosensors to detect metal ions, but also offers an alternative biocompatible surface display approach by combining compatible biomaterials with electricity-converting bacteria for advancements in biohybrid MFCs.


Assuntos
Fontes de Energia Bioelétrica , Técnicas Biossensoriais , Shewanella , Prata , Shewanella/metabolismo , Shewanella/química , Fontes de Energia Bioelétrica/microbiologia , Técnicas Biossensoriais/métodos , Prata/química , Materiais Biocompatíveis/química , Nanopartículas Metálicas/química , Eletricidade , Técnicas Eletroquímicas/métodos
6.
Carbohydr Res ; 541: 109148, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38795397

RESUMO

Shewanella vesiculosa HM13 is a Gram-negative bacterium able to produce a large amount of extracellular membrane vesicles. These nanoparticles carry a major protein P49, the loading of which seems to be influenced by the glycans decorating the membrane. Here we report the structural characterization, using chemical analyses and NMR spectroscopy, of the capsular polysaccharides isolated from the nfnB-mutant strain of S. vesiculosa HM13, which is unable to load P49 on the membrane vesicles. In addition to the polysaccharide corona isolated and characterized from the parental strain, the nfnB-mutant strain released another polysaccharide composed of disaccharide repeating units having the following structure. →4)-ß-D-Glc-(1 â†’ 3)-ß-D-GlcNAc-(1→.


Assuntos
Mutação , Polissacarídeos Bacterianos , Shewanella , Shewanella/química , Shewanella/genética , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/isolamento & purificação , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética , Configuração de Carboidratos , Polissacarídeos/química
7.
Anal Chem ; 96(24): 9756-9760, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38781095

RESUMO

Although interaction between organisms and nonorganisms is vital in environmental processes, it is difficult to characterize at nanoscale resolution. Biosynthesis incorporates intracellular and extracellular processes involving crucial interfacial functions and electron and substance transfer processes, especially on the inorganic-organic interface. This work chooses the biosynthesis of iron-based nanoparticles (nFe) as a model for biomaterial interaction and employs Cryo-AEM (i.e., S/TEM, EELS, and EDS analysis based on sample preparation with cryo-transfer holder system), combined with CV, Raman, XPS, and FTIR to reveal the inorganic-organic interface process. The inorganic-organic interactions in the biosynthesis of iron-based nanoparticles by Shewanella oneidensis MR-1 (M-nFe) were characterized by changes in electron cloud density, and the corresponding chemical shifts of Fe and C EELS edges confirm that M-nFe acquires electrons from MR-1 on the interface. Capturing intact filamentous-like, slightly curved, and bundled structure provides solid evidence of a "circuit channel" for electron transfer between organic and inorganic interface. CV results also confirm that adding M-nFe can enhance electron transfer from MR-1 to ferric ions. A mechanism for the synthesis of M-nFe with MR-1 based on intracellular and extracellular conditions under facultative anaerobic was visualized, providing a protocol for investigating the organic-inorganic interface.


Assuntos
Ferro , Shewanella , Shewanella/metabolismo , Shewanella/química , Ferro/química , Ferro/metabolismo , Microscopia Crioeletrônica , Nanopartículas Metálicas/química
8.
Environ Geochem Health ; 46(6): 185, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38695908

RESUMO

Microplastics (MPs), as emerging contaminants, usually experience aging processes in natural environments and further affect their interactions with coexisted contaminants, resulting in unpredictable ecological risks. Herein, the effect of MPs aging on their adsorption for coexisting antibiotics and their joint biotoxicity have been investigated. Results showed that the adsorption capacity of aged polystyrene (PS, 100 d and 50 d) for ciprofloxacin (CIP) was 1.10-4.09 times higher than virgin PS due to the larger BET surface area and increased oxygen-containing functional groups of aged PS. Following the increased adsorption capacity of aged PS, the joint toxicity of aged PS and CIP to Shewanella Oneidensis MR-1 (MR-1) was 1.03-1.34 times higher than virgin PS and CIP. Combined with the adsorption process, CIP posed higher toxicity to MR-1 compared to aged PS due to the rapid adsorption of aged PS for CIP in the first 12 h. After that, the adsorption process tended to be gentle and hence the joint toxicity to MR-1 was gradually dominated by aged PS. A similar transformation between the adsorption rate and the joint toxicity of PS and CIP was observed under different conditions. This study supplied a novel perception of the synergistic effects of PS aging and CIP on ecological health.


Assuntos
Ciprofloxacina , Poliestirenos , Shewanella , Ciprofloxacina/química , Ciprofloxacina/toxicidade , Poliestirenos/toxicidade , Poliestirenos/química , Adsorção , Shewanella/efeitos dos fármacos , Microplásticos/toxicidade , Microplásticos/química , Antibacterianos/química , Antibacterianos/toxicidade , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/química
9.
Artigo em Inglês | MEDLINE | ID: mdl-38728177

RESUMO

Two Gram-stain-negative, rod-shaped bacteria, designated as strains KJ10-1T and KJ40-1T, were isolated from marine brown algae. Both strains were catalase-positive, oxidase-positive, and facultative aerobic. Strain KJ10-1T exhibited optimal growth at 25 °C, pH 7.0, and 3 % NaCl, whereas strain KJ40-1T showed optimal growth at 25 °C, pH 7.0, and 2 % NaCl. The respiratory quinones of strain KJ10-1T were ubiquinone-8, ubiquinone-7, menaquinone-7, and methylated menaquinone-7, while the respiratory quinone of strain KJ40-1T was only ubiquinone-8. As major fatty acids, strain KJ10-1T contained C16 : 0, C17 : 1 ω8c, iso-C15 : 0, and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and strain KJ40-1T contained C16 : 0 and summed features 3 and 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The major polar lipids in strain KJ10-1T were phosphatidylethanolamine, phosphatidylglycerol, and an unidentified aminolipid, whereas those in strain KJ40-1T were phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The DNA G+C contents of strains KJ10-1T and KJ40-1T were 42.1 and 40.8 mol%, respectively. Based on 16S rRNA gene sequences, strains KJ10-1T and KJ40-1T exhibited the closest relatedness to Shewanella saliphila MMS16-UL250T (98.6 %) and Vibrio rumoiensis S-1T (95.4 %), respectively. Phylogenetic analyses, based on both 16S rRNA and 92 housekeeping genes, showed that the strains formed distinct phylogenic lineages within the genera Shewanella and Vibrio. Digital DNA-DNA hybridization and orthologous average nucleotide identity values between strain KJ10-1T and other Shewanella species, as well as between strain KJ40-1T and other Vibrio species, were below the thresholds commonly accepted for prokaryotic species delineation. Based on the phenotypic, chemotaxonomic, and phylogenetic data, strains KJ10-1T and KJ40-1T represent novel species of the genera Shewanella and Vibrio, respectively, for which the names Shewanella phaeophyticola sp. nov. and Vibrio algarum sp. nov. are proposed, respectively. The type strains of S. phaeophyticola and V. algarum are KJ10-1T (=KACC 22589T=JCM 35409T) and KJ40-1T (=KACC 22588T=JCM 35410T), respectively.


Assuntos
Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Ácidos Graxos , Phaeophyceae , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , Shewanella , Ubiquinona , Vibrio , Vitamina K 2 , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Vibrio/genética , Vibrio/classificação , Vibrio/isolamento & purificação , Ubiquinona/análogos & derivados , Shewanella/genética , Shewanella/isolamento & purificação , Shewanella/classificação , Phaeophyceae/microbiologia , Vitamina K 2/análogos & derivados , Fosfolipídeos , Hibridização de Ácido Nucleico , Água do Mar/microbiologia
10.
ACS Synth Biol ; 13(5): 1467-1476, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38696739

RESUMO

Optogenetics is a powerful tool for spatiotemporal control of gene expression. Several light-inducible gene regulators have been developed to function in bacteria, and these regulatory circuits have been ported to new host strains. Here, we developed and adapted a red-light-inducible transcription factor for Shewanella oneidensis. This regulatory circuit is based on the iLight optogenetic system, which controls gene expression using red light. A thermodynamic model and promoter engineering were used to adapt this system to achieve differential gene expression in light and dark conditions within a S. oneidensis host strain. We further improved the iLight optogenetic system by adding a repressor to invert the genetic circuit and activate gene expression under red light illumination. The inverted iLight genetic circuit was used to control extracellular electron transfer within S. oneidensis. The ability to use both red- and blue-light-induced optogenetic circuits simultaneously was also demonstrated. Our work expands the synthetic biology capabilities in S. oneidensis, which could facilitate future advances in applications with electrogenic bacteria.


Assuntos
Luz , Optogenética , Regiões Promotoras Genéticas , Shewanella , Shewanella/genética , Shewanella/metabolismo , Optogenética/métodos , Transporte de Elétrons , Regiões Promotoras Genéticas/genética , Regulação Bacteriana da Expressão Gênica , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Redes Reguladoras de Genes/genética , Biologia Sintética/métodos
11.
Metab Eng ; 83: 206-215, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38710300

RESUMO

Shewanella oneidensis MR-1 has found widespread applications in pollutant transformation and bioenergy production, closely tied to its outstanding heme synthesis capabilities. However, this significant biosynthetic potential is still unexploited so far. Here, we turned this bacterium into a highly-efficient bio-factory for green synthesis of 5-Aminolevulinic Acid (5-ALA), an important chemical for broad applications in agriculture, medicine, and the food industries. The native C5 pathway genes of S. oneidensis was employed, together with the introduction of foreign anti-oxidation module, to establish the 5-ALA production module, resulting 87-fold higher 5-ALA yield and drastically enhanced tolerance than the wild type. Furthermore, the metabolic flux was regulated by using CRISPR interference and base editing techniques to suppress the competitive pathways to further improve the 5-ALA titer. The engineered strain exhibited 123-fold higher 5-ALA production capability than the wild type. This study not only provides an appealing new route for 5-ALA biosynthesis, but also presents a multi-dimensional modularized engineering strategy to broaden the application scope of S. oneidensis.


Assuntos
Ácido Aminolevulínico , Engenharia Metabólica , Shewanella , Shewanella/genética , Shewanella/metabolismo , Ácido Aminolevulínico/metabolismo
12.
Molecules ; 29(10)2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38792137

RESUMO

Bioelectrochemical systems (BESs) are an innovative technology for the efficient degradation of antibiotics. Shewanella oneidensis (S. oneidensis) MR-1 plays a pivotal role in degrading sulfamethoxazole (SMX) in BESs. Our study investigated the effect of BES conditions on SMX degradation, focusing on microbial activity. The results revealed that BESs operating with a 0.05 M electrolyte concentration and 2 mA/cm2 current density outperformed electrolysis cells (ECs). Additionally, higher electrolyte concentrations and elevated current density reduced SMX degradation efficiency. The presence of nutrients had minimal effect on the growth of S. oneidensis MR-1 in BESs; it indicates that S. oneidensis MR-1 can degrade SMX without nutrients in a short period of time. We also highlighted the significance of mass transfer between the cathode and anode. Limiting mass transfer at a 10 cm electrode distance enhanced S. oneidensis MR-1 activity and BES performance. In summary, this study reveals the complex interaction of factors affecting the efficiency of BES degradation of antibiotics and provides support for environmental pollution control.


Assuntos
Fontes de Energia Bioelétrica , Shewanella , Sulfametoxazol , Sulfametoxazol/metabolismo , Shewanella/metabolismo , Eletrodos , Biodegradação Ambiental , Antibacterianos/farmacologia , Antibacterianos/química , Eletrólise , Técnicas Eletroquímicas
13.
Org Lett ; 26(20): 4346-4350, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38722236

RESUMO

Here we report the first total synthesis of the conjugation-ready tetrasaccharide repeating unit of Shewanella japonica type strain KMM 3299T. The presence of rare deoxyamino sugars and installation of three consecutive 1,2-cis glycosidic linkages makes the synthesis formidable. The challenging late-stage oxidation was overcome by using a galacturonate donor. The total synthesis was completed via a longest linear sequence of 22 steps in an overall yield of 3.5% starting from d-mannose.


Assuntos
Oligossacarídeos , Shewanella , Shewanella/química , Oligossacarídeos/química , Oligossacarídeos/síntese química , Estrutura Molecular , Sequência de Carboidratos , Manose/química , Oxirredução
14.
Bioelectrochemistry ; 158: 108723, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38733720

RESUMO

Bidirectional electron transfer is about that exoelectrogens produce bioelectricity via extracellular electron transfer at anode and drive cytoplasmic biochemical reactions via extracellular electron uptake at cathode. The key factor to determine above bioelectrochemical performances is the electron transfer efficiency under biocompatible abiotic/biotic interface. Here, a graphene/polyaniline (GO/PANI) nanocomposite electrode specially interfacing exoelectrogens (Shewanella loihica) and augmenting bidirectional electron transfer was conducted by in-situ electrochemical modification on carbon paper (CP). Impressively, the GO/PANI@CP electrode tremendously improved the performance of exoelectrogens at anode for wastewater treatment and bioelectricity generation (about 54 folds increase of power density compared to blank CP electrode). The bacteria on electrode surface not only showed fast electron release but also exhibited high electricity density of extracellular electron uptake through the proposed direct electron transfer pathway. Thus, the cathode applications of microbial electrosynthesis and bio-denitrification were developed via GO/PANI@CP electrode, which assisted the close contact between microbial outer-membrane cytochromes and nanocomposite electrode for efficient nitrate removal (0.333 mM/h). Overall, nanocomposite modified electrode with biocompatible interfaces has great potential to enhance bioelectrochemical reactions with exoelectrogens.


Assuntos
Fontes de Energia Bioelétrica , Eletrodos , Grafite , Grafite/química , Transporte de Elétrons , Fontes de Energia Bioelétrica/microbiologia , Compostos de Anilina/química , Compostos de Anilina/metabolismo , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Shewanella/metabolismo , Nanocompostos/química , Técnicas Eletroquímicas/métodos
15.
Nat Commun ; 15(1): 4365, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38778052

RESUMO

Biotic-abiotic hybrid photocatalytic system is an innovative strategy to capture solar energy. Diversifying solar energy conversion products and balancing photoelectron generation and transduction are critical to unravel the potential of hybrid photocatalysis. Here, we harvest solar energy in a dual mode for Cu2-xSe nanoparticles biomineralization and seawater desalination by integrating the merits of Shewanella oneidensis MR-1 and biogenic nanoparticles. Photoelectrons generated by extracellular Se0 nanoparticles power Cu2-xSe synthesis through two pathways that either cross the outer membrane to activate periplasmic Cu(II) reduction or are directly delivered into the extracellular space for Cu(I) evolution. Meanwhile, photoelectrons drive periplasmic Cu(II) reduction by reversing MtrABC complexes in S. oneidensis. Moreover, the unique photothermal feature of the as-prepared Cu2-xSe nanoparticles, the natural hydrophilicity, and the linking properties of bacterium offer a convenient way to tailor photothermal membranes for solar water production. This study provides a paradigm for balancing the source and sink of photoelectrons and diversifying solar energy conversion products in biotic-abiotic hybrid platforms.


Assuntos
Biomineralização , Cobre , Água do Mar , Shewanella , Energia Solar , Shewanella/metabolismo , Cobre/química , Cobre/metabolismo , Água do Mar/microbiologia , Água do Mar/química , Salinidade , Purificação da Água/métodos , Nanopartículas/química , Catálise/efeitos da radiação
16.
ACS Appl Bio Mater ; 7(5): 2734-2740, 2024 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-38651321

RESUMO

3D printing of a living bioanode holds the potential for the rapid and efficient production of bioelectrochemistry systems. However, the ink (such as sodium alginate, SA) that formed the matrix of the 3D-printed bioanode may hinder extracellular electron transfer (EET) between the microorganism and conductive materials. Here, we proposed a biomimetic design of a 3D-printed Shewanella bioanode, wherein riboflavin (RF) was modified on carbon black (CB) to serve as a redox substance for microbial EET. By introducing the medicated EET pathways, the 3D-printed bioanode obtained a maximum power density of 252 ± 12 mW/m2, which was 1.7 and 60.5 times higher than those of SA-CB (92 ± 10 mW/m2) and a bare carbon cloth anode (3.8 ± 0.4 mW/m2). Adding RF reduced the charge-transfer resistance of a 3D-printed bioanode by 75% (189.5 ± 18.7 vs 47.3 ± 7.8 Ω), indicating a significant acceleration in the EET efficiency within the bioanode. This work provided a fundamental and instrumental concept for constructing a 3D-printed bioanode.


Assuntos
Materiais Biocompatíveis , Teste de Materiais , Impressão Tridimensional , Riboflavina , Shewanella , Riboflavina/química , Riboflavina/metabolismo , Shewanella/metabolismo , Transporte de Elétrons , Materiais Biocompatíveis/química , Fontes de Energia Bioelétrica , Eletrodos , Fuligem/química , Tamanho da Partícula , Tinta
17.
Indian J Med Microbiol ; 49: 100574, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38561026

RESUMO

PURPOSE: The Shewanella genus is a rare pathogen of marine origin. In recent years, there has been a continuous increase in infection cases caused by this bacterium, and we have observed the uniqueness of infections caused by this microorganism. MATERIALS AND METHODS: This study conducted a retrospective analysis of the medical history and laboratory examination data of patients infected with the Shewanella genus over the past decade. Additionally, it employed bioinformatics methods to analyze the relevant virulence factors and antibiotic resistance genes associated with the Shewanella genus. RESULTS: Over the past 10 years, we have isolated 51 cases of Shewanella, with 68.82% being Shewanella putrefaciens (35/51 cases) and 31.37% being Shewanella algae (16/51 cases). Infected individuals often had underlying diseases, with 39.22% (20/51) having malignant tumors and 25.49% (13/51) having liver and biliary system diseases primarily characterized by stones. The majority of patients, 62.74% (32/51), exhibited mixed infections, including one case with a combination of infections from three other types of bacteria and five cases with a combination of infections from two other types of bacteria. The identified microorganisms were commonly resistant to ticarcillin-clavulanic acid (23.5%), followed by cefoperazone-sulbactam (19.6%), ciprofloxacin (17.6%), and cefotaxime (17.6%). Bioinformatics analysis indicates that Shewanella can express bile hydrolysis regulators and fatty acid metabolism regulators that aid in adapting to the unique environment of the biliary tract. Additionally, it expresses abundant catalase, superoxide dismutase, and two-component signal transduction system proteins, which may be related to environmental adaptation. Shewanella also expresses various antibiotic resistance genes, including beta-lactamases and aminoglycoside modification enzymes. Iron carriers may be one of its important virulence factors. CONCLUSIONS: We speculate that the Shewanella genus may exist as a specific colonizer in the human body, and under certain conditions, it may act as a pathogen, leading to biliary infections in the host.


Assuntos
Infecções por Bactérias Gram-Negativas , Shewanella , Fatores de Virulência , Humanos , Shewanella/genética , Shewanella/classificação , Shewanella/isolamento & purificação , Shewanella/patogenicidade , Estudos Retrospectivos , Infecções por Bactérias Gram-Negativas/microbiologia , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Fatores de Virulência/genética , Idoso , Farmacorresistência Bacteriana/genética , Antibacterianos/farmacologia , Adulto Jovem , Adolescente , Shewanella putrefaciens/genética , Shewanella putrefaciens/isolamento & purificação , Shewanella putrefaciens/classificação
18.
Environ Pollut ; 351: 124008, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38641038

RESUMO

Dissimilatory iron-reducing bacteria (DIRB) affect the geochemical cycling of redox-sensitive pollutants in anaerobic environments by controlling the transformation of Fe morphology. The anaerobic oxidation of antimonite (Sb(III)) driven by DIRB and Fe(III) oxyhydroxides interactions has been previously reported. However, the oxidative species and mechanisms involved remain unclear. In this study, both biotic phenomenon and abiotic verification experiments were conducted to explore the formed oxidative intermediates and related processes that lead to anaerobic Sb(III) oxidation accompanied during dissimilatory iron reduction. Sb(V) up to 2.59 µmol L-1 combined with total Fe(II) increased to 188.79 µmol L-1 when both Shewanella oneidensis MR-1 and goethite were present. In contrast, no Sb(III) oxidation or Fe(III) reduction occurred in the presence of MR-1 or goethite alone. Negative open circuit potential (OCP) shifts further demonstrated the generation of interfacial electron transfer (ET) between biogenic Fe(II) and goethite. Based on spectrophotometry, electron spin resonance (ESR) test and quenching experiments, the active ET production labile Fe(III) was confirmed to oxidize 94.12% of the Sb(III), while the contribution of other radicals was elucidated. Accordingly, we proposed that labile Fe(III) was the main oxidative species during anaerobic Sb(III) oxidation in the presence of DIRB and that the toxicity of antimony (Sb) in the environment was reduced. Considering the prevalence of DIRB and Fe(III) oxyhydroxides in natural environments, our findings provide a new perspective on the transformation of redox sensitive substances and build an eco-friendly bioremediation strategy for treating toxic metalloid pollution.


Assuntos
Antimônio , Compostos Férricos , Compostos de Ferro , Minerais , Oxirredução , Shewanella , Shewanella/metabolismo , Antimônio/metabolismo , Compostos de Ferro/metabolismo , Compostos de Ferro/química , Minerais/metabolismo , Minerais/química , Compostos Férricos/metabolismo , Anaerobiose , Biodegradação Ambiental , Ferro/metabolismo
19.
Fish Shellfish Immunol ; 149: 109588, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38677630

RESUMO

In aquaculture, fluctuating water temperatures can act as a potent stressor, influencing the virulence and transmission dynamics of pathogenic bacteria, potentially triggering outbreaks and impacting fish health. The purpose of this work was to examine the impact of Shewanella spp. infection on hematological, biochemical, and antioxidant-immune parameters of Nile tilapia (Oreochromis niloticus) under different water temperatures. For this purpose, 180 fish were divided into 6 groups in triplicate (30 fish per group; 10 fish per replicate). Group 1 (G1), G2, and G3 were reared at varying water temperatures (22 °C, 28 °C, and 31 °C, respectively) without infection. While G4, G5, and G6 were IP-injected with 0.2 mL of Shewanella spp. (0.14 × 105) and reared at 22 °C, 28 °C, and 31 °C, respectively. Shewanella spp. infection induced significant lowering (p < 0.05) in hematological parameters (red and white blood cells, hemoglobin, and packed cell volume%) and immune-antioxidant responses (phagocytic activity%, phagocytic index, lysozyme, nitric oxide), total antioxidant capacity, catalase, and reduced glutathione, especially at 22 °C. Moreover, a significant increase (p < 0.05) in the hepato-renal function indicators (alanine aminotransferase, aspartate aminotransferase, urea, and creatinine), stress biomarkers (glucose and cortisol), malondialdehyde, and pro-inflammatory cytokines (interleukin-1ß and tumor necrosis factor-α) were the consequences of the Shewanella spp. infection, especially at 22 °C. The Shewanella spp. infection exhibited marked histopathological changes in the hepatic and renal tissues. Worthily, Shewanella spp. can cause detrimental alterations in Nile tilapia's hematological, biochemical, and antioxidant-immune parameters at various water temperatures, but the major detrimental changes were observed at a water temperature of 22 °C. Consequently, we can conclude that the infection dynamics of Shewanella spp. are exaggerated at 22 °C. These outcomes could help in understanding the nature of such an infection in Nile tilapia.


Assuntos
Antioxidantes , Ciclídeos , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Shewanella , Temperatura , Animais , Shewanella/fisiologia , Ciclídeos/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Infecções por Bactérias Gram-Negativas/imunologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Antioxidantes/metabolismo , Imunidade Inata
20.
Commun Biol ; 7(1): 498, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38664541

RESUMO

Siderophore-dependent iron uptake is a mechanism by which microorganisms scavenge and utilize iron for their survival, growth, and many specialized activities, such as pathogenicity. The siderophore biosynthetic system PubABC in Shewanella can synthesize a series of distinct siderophores, yet how it is regulated in response to iron availability remains largely unexplored. Here, by whole genome screening we identify TCS components histidine kinase (HK) BarA and response regulator (RR) SsoR as positive regulators of siderophore biosynthesis. While BarA partners with UvrY to mediate expression of pubABC post-transcriptionally via the Csr regulatory cascade, SsoR is an atypical orphan RR of the OmpR/PhoB subfamily that activates transcription in a phosphorylation-independent manner. By combining structural analysis and molecular dynamics simulations, we observe conformational changes in OmpR/PhoB-like RRs that illustrate the impact of phosphorylation on dynamic properties, and that SsoR is locked in the 'phosphorylated' state found in phosphorylation-dependent counterparts of the same subfamily. Furthermore, we show that iron homeostasis global regulator Fur, in addition to mediating transcription of its own regulon, acts as the sensor of iron starvation to increase SsoR production when needed. Overall, this study delineates an intricate, multi-tiered transcriptional and post-transcriptional regulatory network that governs siderophore biosynthesis.


Assuntos
Proteínas de Bactérias , Regulação Bacteriana da Expressão Gênica , Shewanella , Sideróforos , Shewanella/metabolismo , Shewanella/genética , Sideróforos/biossíntese , Sideróforos/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Fosforilação , Ferro/metabolismo
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