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1.
Biomaterials ; 313: 122764, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39190941

RESUMO

Currently, mitochondrial dysfunction caused by oxidative stress is a growing concern in degenerative diseases, notably intervertebral disc degeneration (IVDD). Dysregulation of the balance of mitochondrial quality control (MQC) has been considered the key contributor, while it's still challenging to effectively harmonize different MQC components in a simple and biologically safe way. Hydrogen gas (H2) is a promising mitochondrial therapeutic molecule due to its bio-reductivity and diffusibility across cellular membranes, yet its relationship with MQC regulation remains unknown. Herein, we propose a mitochondrial 'Birth-Death' coordinator achieved by an intelligent hydrogen nanogenerator (Fe@HP-OD), which can sustainably release H2 in response to the unique microenvironment in degenerated IVDs. Both in vitro and in vivo results prove alleviation of cellular oxidative stress and restoration of nucleus pulposus cells function, thereby facilitating successful IVD regeneration. Significantly, this study for the first time proposes the mitochondrial 'Birth-Death' coordination mechanism: 1) attenuation of overactivated mitochondrial 'Death' process (UPRmt and unselective mitophagy); and 2) activation of Adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling pathway for mitochondrial 'Birth-Death' balance (mitochondrial biogenesis and controlled mitophagy). These pioneering findings can fill in the gaps in molecular mechanisms for H2 regulation on MQC homeostasis, and pave the way for future strategies towards restoring equilibrium of MQC system against degenerative diseases.


Assuntos
Hidrogênio , Degeneração do Disco Intervertebral , Mitocôndrias , Estresse Oxidativo , Hidrogênio/química , Animais , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Regeneração/efeitos dos fármacos , Disco Intervertebral/efeitos dos fármacos , Humanos , Mitofagia/efeitos dos fármacos , Ratos Sprague-Dawley , Masculino , Núcleo Pulposo/metabolismo , Ratos
2.
J Environ Sci (China) ; 149: 535-550, 2025 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39181665

RESUMO

Li6ZnO4 was chemically modified by nickel addition, in order to develop different compositions of the solid solution Li6Zn1-xNixO4. These materials were evaluated bifunctionally; analyzing their CO2 capture performances, as well as on their catalytic properties for H2 production via dry reforming of methane (DRM). The crystal structures of Li6Zn1-xNixO4 solid solution samples were determined through X-ray diffraction, which confirmed the integration of nickel ions up to a concentration around 20 mol%, meanwhile beyond this value, a secondary phase was detected. These results were supported by XPS and TEM analyses. Then, dynamic and isothermal thermogravimetric analyses of CO2 capture revealed that Li6Zn1-xNixO4 solid solution samples exhibited good CO2 chemisorption efficiencies, similarly to the pristine Li6ZnO4 chemisorption trends observed. Moreover, a kinetic analysis of CO2 isothermal chemisorptions, using the Avrami-Erofeev model, evidenced an increment of the constant rates as a function of the Ni content. Since Ni2+ ions incorporation did not reduce the CO2 capture efficiency and kinetics, the catalytic properties of these materials were evaluated in the DRM process. Results demonstrated that nickel ions favored hydrogen (H2) production over the pristine Li6ZnO4 phase, despite a second H2 production reaction was determined, methane decomposition. Thereby, Li6Zn1-xNixO4 ceramics can be employed as bifunctional materials.


Assuntos
Dióxido de Carbono , Hidrogênio , Metano , Hidrogênio/química , Metano/química , Dióxido de Carbono/química , Níquel/química , Catálise , Modelos Químicos
3.
J Environ Sci (China) ; 148: 274-282, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095164

RESUMO

Developing cost-effective and high-performance catalyst systems for dry reforming of methane (DRM) is crucial for producing hydrogen (H2) sustainably. Herein, we investigate using iron (Fe) as a promoter and major alumina support in Ni-based catalysts to improve their DRM performance. The addition of iron as a promotor was found to add reducible iron species along with reducible NiO species, enhance the basicity and induce the deposition of oxidizable carbon. By incorporating 1 wt.% Fe into a 5Ni/10ZrAl catalyst, a higher CO2 interaction and formation of reducible "NiO-species having strong interaction with support" was observed, which led to an ∼80% H2 yield in 420 min of Time on Stream (TOS). Further increasing the Fe content to 2wt% led to the formation of additional reducible iron oxide species and a noticeable rise in H2 yield up to 84%. Despite the severe weight loss on Fe-promoted catalysts, high H2 yield was maintained due to the proper balance between the rate of CH4 decomposition and the rate of carbon deposit diffusion. Finally, incorporating 3 wt.% Fe into the 5Ni/10ZrAl catalyst resulted in the highest CO2 interaction, wide presence of reducible NiO-species, minimum graphitic deposit and an 87% H2 yield. Our findings suggest that iron-promoted zirconia-alumina-supported Ni catalysts can be a cheap and excellent catalytic system for H2 production via DRM.


Assuntos
Óxido de Alumínio , Hidrogênio , Ferro , Metano , Níquel , Zircônio , Metano/química , Zircônio/química , Catálise , Ferro/química , Hidrogênio/química , Óxido de Alumínio/química , Níquel/química
4.
Microb Cell Fact ; 23(1): 247, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39261831

RESUMO

Biofuel can be generated by different organisms using various substrates. The green alga Chlorococcum humicola OQ934050 exhibited the capability to photosynthesize carbonate carbon, maybe via the activity of carbonic anhydrase enzymes. The optimum treatment is C:N ratio of 1:1 (0.2 mmoles sodium carbonate and 0.2 mmoles sodium nitrate) as it induced the highest dry mass (more than 0.5 mg.mL-1). At this combination, biomass were about 0.2 mg/mL-1 carbohydrates, 0.085 mg/mL-1 proteins, and 0.16 mg/mL-1 oil of this dry weight. The C/N ratios of 1:1 or 10:1 induced up to 30% of the Chlorococcum humicola dry mass as oils. Growth and dry matter content were hindered at 50:1 C/N and oil content was reduced as a result. The fatty acid profile was strongly altered by the applied C.N ratios. The defatted leftovers of the grown alga, after oil extraction, were fermented by a newly isolated heterotrophic bacterium, identified as Bacillus coagulans OQ053202, to evolve hydrogen content as gas. The highest cumulative hydrogen production and reducing sugar (70 ml H2/g biomass and 0.128 mg/ml; respectively) were found at the C/N ratio of 10:1 with the highest hydrogen evolution efficiency (HEE) of 22.8 ml H2/ mg reducing sugar. The optimum treatment applied to the Chlorococcum humicola is C:N ratio of 1:1 for the highest dry mass, up to 30% dry mass as oils. Some fatty acids were induced while others disappeared, depending on the C/N ratios. The highest cumulative hydrogen production and reducing sugar were found at the C/N ratio of 10:1.


Assuntos
Bacillus , Biocombustíveis , Biomassa , Carbonatos , Hidrogênio , Nitratos , Hidrogênio/metabolismo , Bacillus/metabolismo , Nitratos/metabolismo , Carbonatos/metabolismo , Fermentação , Clorófitas/metabolismo , Clorófitas/crescimento & desenvolvimento , Fotossíntese , Ácidos Graxos/metabolismo
5.
Sci Rep ; 14(1): 21425, 2024 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-39271809

RESUMO

Oxidative stress in adipose tissue may alter the secretion pattern of adipocytokines and potentially promote atherosclerosis. However, the therapeutic role of hydrogen in adipose tissue under oxidative stress remains unclear. In this study, subcutaneous adipose tissue (SCAT) was collected from the mid-thoracic wounds of 12 patients who underwent open-heart surgery with a mid-thoracic incision. The adipose tissue was then immersed in a culture medium dissolved with hydrogen, which was generated using a hydrogen-generating device. The weight of the adipose tissue was measured before and after hydrogenation, and the tissue was immunostained for nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and superoxide dismutase (SOD), which are markers of oxidative stress. The immunostaining results showed that HO-1 and Nrf2 expression levels were significantly decreased in the hydrogenated group, whereas SOD expression levels increased, but did not attain statistical significance. Image analysis of adipose tissue revealed that a reduction in adipocyte size. Furthermore, hydrogenated adipose tissue showed a trend toward increased gene expression levels of adiponectin and decreased gene expression levels of chemerin, an adipocytokine involved in adipogenesis. These results demonstrated the therapeutic potential of hydrogen gas for oxidative stress in adipose tissue and for reducing adipocyte size.


Assuntos
Tecido Adiposo , Hidrogênio , Estresse Oxidativo , Estresse Oxidativo/efeitos dos fármacos , Humanos , Hidrogênio/farmacologia , Hidrogênio/metabolismo , Masculino , Feminino , Tecido Adiposo/metabolismo , Tecido Adiposo/efeitos dos fármacos , Pessoa de Meia-Idade , Superóxido Dismutase/metabolismo , Heme Oxigenase-1/metabolismo , Heme Oxigenase-1/genética , Idoso , Adiponectina/metabolismo , Adiponectina/genética , Adipócitos/metabolismo , Adipócitos/efeitos dos fármacos , Gordura Subcutânea/metabolismo , Gordura Subcutânea/efeitos dos fármacos , Fator 2 Relacionado a NF-E2
6.
CNS Neurosci Ther ; 30(9): e70021, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39258790

RESUMO

BACKGROUND: Sepsis-associated encephalopathy (SAE) is a neuronal injury with poor prognosis. Mitochondrial dysfunction is critical in SAE development, and hydrogen gas (H2) has a protective effect on septic mice. This study aimed to investigate the effect of high concentration (67%) of H2 on SAE and whether it is related to mitochondrial biogenesis and mitochondrial dynamics. METHODS: A mouse sepsis model was induced by cecal ligation and puncture. The mice inhalated 67% H2 for 1 h at 1 and 6 h post-surgery, respectively. The 7-day survival rate was recorded. Cognitive function was assessed using the Y-maze test and Morris water maze test. Serum inflammatory factors, antioxidant enzymes, as well as mitochondrial function indexes including mitochondrial membrane potential (MMP) and ATP in the hippocampal tissue were evaluated 24 h after surgery. Mitochondrial dynamic proteins (DRP1 and MFN2) and biosynthetic proteins (PGC-1α, NRF2, and TFAM) in the hippocampal tissue were detected. Moreover, the morphology of mitochondria was observed by transmission electron microscopy. RESULTS: Inhalation of 67% H2 improved the 7-day survival rates and recognition memory function of septic mice, alleviated brain antioxidant enzyme activity (SOD and CAT), and reduced serum proinflammatory cytokine levels. H2 inhalation also enhanced the expression of MFN2 and mitochondrial biogenesis-related factors (PGC-1α, NRF2, and TFAM) and decreased the expression of fission protein (DRP1), leading to improvement in mitochondrial function, as evidenced by MMP and ATP levels. CONCLUSIONS: Inhalation of high concentration (67%) of H2 in septic mice improved the survival rate and reduced neuronal injury. Its mechanism might be mediated by enhancing mitochondrial biogenesis and mitochondrial dynamics.


Assuntos
Hidrogênio , Dinâmica Mitocondrial , Encefalopatia Associada a Sepse , Animais , Encefalopatia Associada a Sepse/tratamento farmacológico , Camundongos , Hidrogênio/farmacologia , Hidrogênio/administração & dosagem , Hidrogênio/uso terapêutico , Dinâmica Mitocondrial/efeitos dos fármacos , Masculino , Administração por Inalação , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Sepse/complicações , Sepse/tratamento farmacológico , Sepse/metabolismo , Camundongos Endogâmicos C57BL , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Aprendizagem em Labirinto/efeitos dos fármacos
7.
Bioresour Technol ; 412: 131414, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39226941

RESUMO

Anaerobic electrochemical digestion (AED) is an effective system for recovering biogas from organic wastes. However, the effects of different anode potentials on anaerobic activated sludge remain unclear. This study confirmed that biofilms exhibited the best electroactivity at -0.2 V (vs. Ag/AgCl) compared to -0.4 V and 0 V. Gas was further regulated, with the highest hydrogen content (47 ± 7 %) observed at -0.2 V. The 0 V system produced the largest amount of methane (70 ± 8 %) and exhibited the greatest presence of hydrogen-utilizing microorganisms. The gas yield at -0.4 V was the lowest, with no hydrogen detected. Excess bioelectrohydrogen at -0.2 V and 0 V caused the co-enrichment of Methanobacterium and Acetoanaerobium, establishing a thermodynamically feasible current-acetate-hydrogen electron cycle to improve electrogenesis. These results provide insights into the regulatory strategies of MEC technology during anaerobic digestion, which play a decisive role in determining the composition of biogas.


Assuntos
Eletrodos , Hidrogênio , Metano , Microbiota , Anaerobiose , Hidrogênio/metabolismo , Metano/metabolismo , Microbiota/fisiologia , Gases , Esgotos/microbiologia , Biocombustíveis , Técnicas Eletroquímicas/métodos , Biofilmes
8.
Microbiome ; 12(1): 170, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39252128

RESUMO

BACKGROUND: Clean energy hydrogen (H2) produced from abundant lignocellulose is an alternative to fossil energy. As an essential influencing factor, there is a lack of comparison between constant temperatures (35, 55 and 65 °C) and gradient heating temperature (35 to 65 °C) on the H2 production regulation potential from lignocellulose-rich straw via high-solid anaerobic digestion (HS-AD). More importantly, the microbial mechanism of temperature regulating H2 accumulation needs to be investigated. RESULTS: Constant 65 °C led to the lowest lignin residue (1.93%) and the maximum release of cellulose and hemicellulose, and the highest H2 production (26.01 mL/g VS). H2 production at 35 and 55 °C was only 14.56 and 24.13 mL/g VS, respectively. In order to further explore the potential of ultra-high temperature (65 °C), HS-AD was performed by gradient heating conditions (35 to 65 °C). However, compared to constant 65 °C, gradient heating conditions led to higher lignin residue (2.49%) and lower H2 production (13.53 mL/g VS) than gradient heating conditions (47.98%). In addition, metagenomic analysis showed the cellulose/hemicellulose hydrolyzing bacteria and genes (mainly Thermoclostridium, and xynA, xynB, abfA, bglB and xynD), H2-producing bacteria and related genes (mainly Thermoclostridium, and nifD, nifH and nifK), and microbial movement and metabolic functions were enriched at 65 °C. However, the enrichment of two-component systems under gradient heating conditions resulted in a lack of highly-enriched ultra-high-temperature cellulose/hemicellulose hydrolyzing genera and related genes but rather enriched H2 consumption genera and genes (mainly Acetivibrio, and hyaB and hyaA) resulting in a weaker H2 production. CONCLUSIONS: The lignin degradation process does not directly determine H2 accumulation, which was actually regulated by bacteria/genes contributing to H2 production/consumption. In addition, it is temperature that enhances the hydrolysis process of lignin rather than lignin-degrading enzymes, bacteria and genes by promoting microbial material transfer and metabolism. In terms of temperature, one of the key parameters of HS-AD for H2 production, we developed an important regulatory strategy, enriched the theoretical basis of temperature regulation for H2 production to further expanded the research horizon in this field. Video Abstract.


Assuntos
Hidrogênio , Lignina , Hidrogênio/metabolismo , Lignina/metabolismo , Anaerobiose , Temperatura Alta , Celulose/metabolismo , Polissacarídeos/metabolismo , Metagenômica/métodos , Temperatura , Bactérias/metabolismo , Bactérias/classificação , Bactérias/genética
9.
Bioresour Technol ; 412: 131432, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39236909

RESUMO

In this study, the effect of modulating fulvic acid (FA) concentrations (0, 25 and 50 mg/L) on nitrogen removal in a bioelectrochemical hydrogen autotrophic denitrification system (BHDS) was investigated. Results showed that FA increased the nitrate (NO3--N) removal rate of the BHDSs from 37.8 to 46.2 and 45.2 mg N/(L·d) with a current intensity of 40 mA. The metagenomic analysis revealed that R2 (25 mg/L) was predominantly populated by autotrophic denitrifying microorganisms, which enhanced denitrification performance by facilitating electron transfer. Conversely, R3 (50 mg/L) exhibited an increase in genes related to the heterotrophic process, which improved the denitrification performance through the collaborative action of both autotrophic and heterotrophic denitrification pathways. Besides, the study also identified a potential for nitrogen removal in Serpentinimonas, which have been rarely studied. The interesting set of findings provide valuable reference for optimizing BHDS for nitrogen removal and promoting specific denitrifying genera within the system.


Assuntos
Processos Autotróficos , Benzopiranos , Desnitrificação , Hidrogênio , Hidrogênio/metabolismo , Nitratos/metabolismo , Nitrogênio , Bactérias/metabolismo , Técnicas Eletroquímicas/métodos
10.
Yakugaku Zasshi ; 144(9): 877-886, 2024.
Artigo em Japonês | MEDLINE | ID: mdl-39218655

RESUMO

Nucleosides with a substituent at the 4'-position have received much attention as antiviral drugs and as raw materials for oligonucleotide therapeutics. 4'-Modified nucleosides are generally synthesized using ionic reactions through the introduction of electrophilic or nucleophilic substituents at the 4'-position. However, their synthetic methods have some drawbacks; e.g., (i) it is difficult to control stereoselectivity at the 4'-position; (ii) complex protection-deprotection processes are required; (iii) the range of electrophiles and nucleophiles is limited. With this background, we considered that a carbon radical generated at the 4'-position would be a useful intermediate for the synthesis of 4'-modified nucleosides. In this review, two novel methods for the generation of 4'-carbon radicals are summarized. The first utilizes radical deformylation involving ß-fragmentation of a hydroxymethyl group at the 4'-position. The other utilizes radical decarboxylation and 1,5-hydrogen atom transfer (1,5-HAT), which enables the generation of 4'-carbon radicals while retaining the hydroxymethyl group at the 4'-position. These methods enable the rapid and facile generation of 4'-carbon radicals and provide various 4'-modified nucleosides including 2',4'-bridged structures.


Assuntos
Antivirais , Carbono , Nucleosídeos , Nucleosídeos/síntese química , Nucleosídeos/química , Carbono/química , Radicais Livres/química , Radicais Livres/síntese química , Antivirais/síntese química , Antivirais/química , Técnicas de Química Sintética/métodos , Hidrogênio/química
11.
Front Immunol ; 15: 1444958, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39211045

RESUMO

As a small molecule, hydrogen is colorless, odorless and lightest. Many studies conducted that hydrogen can protect almost every organ, including the brain, heart muscle, liver, small intestine, and lungs. To verify whether high concentrations of hydrogen (HCH) has anti-inflammatory and antioxidant activities on respiratory system, we product a systematic review and meta-analysis. We investigated MEDLINE-PubMed, Cochrane Library, ScienceDirect, Wiley and SpringerLink database and selected in vivo studies related to the anti-inflammatory or antioxidant effects of HCH in the lung diseases which were published until September 2023. We firstly identified 437 studies and only 12 met the inclusion criteria. They all conducted in rodents. The results showed that HCH had a positive effect on the reduction of tumor necrosis factor alpha (TNF-α), interleukin (IL)-1ß, IL-4, IL-8, malondialdehyde (MDA), superoxide dismutase (SOD) and reactive oxygen species (ROS); but there is no effect on IL-6, we speculated that may contribute to the test results for different body fluids and at different points in time. This meta-analysis discovered the protective effects on inflammation and oxidative stress, but whether there exists more effects on reduction of inflammatory and oxidant mediators needs to be further elucidated.


Assuntos
Anti-Inflamatórios , Antioxidantes , Hidrogênio , Pneumopatias , Estresse Oxidativo , Animais , Humanos , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Citocinas/metabolismo , Hidrogênio/análise , Mediadores da Inflamação/metabolismo , Pneumopatias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
12.
ACS Nano ; 18(35): 24162-24172, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39162692

RESUMO

Although the past decade has witnessed a rapid development of oxidoreductase-mimicking nanozymes, the mimicry of cofactors that play key roles in mediating electron and proton transfer remains limited. This study explores how surface Au-H species conjugated to Au nanoparticles (NPs) that imitate formate dehydrogenase (FDH) can serve as cofactors, analogous to NADH in natural enzymes, offering diverse possibilities for FDH-mimicking Au nanozymes to mimic various enzymes. Once O2 is present, Au-H species assist Au NPs to complete the on-demand H2O2 generation for cascade reactions. Alternatively, when oxidizing organic molecules are introduced as substrates, Au-H species confer nitro reductase- and aldehyde reductase-like activities on Au NPs under anaerobic conditions. Furthermore, similar to the dehydrogenase-NADH complex, Au NPs possessing Au-H species are gifted with esterase-like activity for ester hydrolysis. By revealing that Au-H species are prosthetic groups for FDH-mimicking Au nanozymes, this work may inspire explorations into future self-generated cofactor mimics for nanozymes, thereby circumventing the need for exogenous cofactors.


Assuntos
Formiato Desidrogenases , Ouro , Nanopartículas Metálicas , Ouro/química , Formiato Desidrogenases/metabolismo , Formiato Desidrogenases/química , Nanopartículas Metálicas/química , Propriedades de Superfície , Hidrogênio/química , Hidrogênio/metabolismo , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Materiais Biomiméticos/química , Materiais Biomiméticos/metabolismo , Oxirredução
13.
J Environ Manage ; 368: 122189, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39128340

RESUMO

As an alternative to fossil fuels, there is growing interest in using ammonia in combustion systems, particularly in internal combustion engines. As a competent competitor to hydrogen, it has various advantages. However, adding an ignition promoter such as hydrogen is still necessary to maintain combustion stability. Since the engine using ammonia also suffers from high NOx emissions, in this study, the effects of adding different gases on the performance and emissions of an ammonia-hydrogen dual-fuel engine were numerically investigated. The base engine was a diesel engine whose parameters were accustomed to running with ammonia-hydrogen as fuel. Hydrogen was injected via the port in the intake stage at 180 crank angle degrees (CAD) and mixed with the cylinder charge. Ammonia was directly injected into the cylinder at 350-370 CAD. Different gasses, including argon, nitrogen, carbon dioxide, and oxygen, were injected into the cylinder at various crank angles before, during, and after ammonia injection (330-350 CAD, 350-370 CAD, and 370-390 CAD). A MATLAB code was prepared to solve the governing equations, and the combustion mechanism was implemented in Cantera. The results showed that adding CO2 before or concurrent with the ammonia injection timing had undesirable impacts on the peak in-cylinder pressure and NO and NO2 emissions. The O2 addition had a negative on the emissions. Adding N2 and Ar concurrently with the ammonia injection (350-370 CAD) could diminish NO and NO2 emissions without drastically affecting the peak in-cylinder pressure and temperature.


Assuntos
Amônia , Hidrogênio , Emissões de Veículos , Amônia/química , Emissões de Veículos/análise , Dióxido de Carbono/química , Gases , Poluentes Atmosféricos/análise , Oxigênio/química , Nitrogênio/química
14.
Bioresour Technol ; 410: 131280, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151565

RESUMO

Ethanol pre-fermentation of food waste effectively alleviates acidification; however, its effects on interspecies electron transfer remain unknown. This study configured the feed according to COD ratios of ethanol: sodium acetate: sodium propionate: sodium butyrate of 5:2:1.5:1.5 (ethanol-type anaerobic digestion) and 0:5:2.5:2.5 (control), and conducted semi-continuous anaerobic digestion (AD) experiments. The results showed that ethanol-type AD increased maximum tolerable organic loading rate (OLR) to 6.0 gCOD/L/d, and increased the methane production by 1.2-14.8 times compared to the control at OLRs of 1.0-5.0 gCOD/L/d. The abundance of the pilA gene, which was associated with direct interspecies electron transfer (DIET), increased by 5.6 times during ethanol-type AD. Hydrogenase genes related to interspecies hydrogen transfer (IHT), including hydA-B, hoxH-Y, hnd, ech, and ehb, were upregulated during ethanol-type AD. Ethanol-type AD improved methanogenic performance and enhanced microbial metabolism by stimulating DIET and IHT.


Assuntos
Etanol , Hidrogênio , Metano , Metano/metabolismo , Hidrogênio/metabolismo , Anaerobiose , Etanol/metabolismo , Transporte de Elétrons , Reatores Biológicos , Fermentação , Hidrogenase/metabolismo
15.
Bioresour Technol ; 410: 131276, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151564

RESUMO

This study evaluated the dark-fermentative hydrogen (H2) production potential of isolated and identified Shigella flexneri SPD1 from various pure (glucose, fructose, sucrose, lactose, and galactose) and biowastes (coconut coir, cotton fiber, groundnut shells, rice-, and wheat-straws)-derived sugars. Among sugars, S. flexneri SPD1 exhibited high H2 production of up to 3.20 mol/mole of hexose using glucose (5.0 g/L). The pre-treatment of various biowastes using green solvents (choline chloride and lactic acid mixture) and enzymatic hydrolysis resulted in the generation of up to 36.0 g/L of sugars. The maximum H2 production is achieved up to 2.92 mol/mol of hexose using cotton-hydrolysate. Further, the upscaling of bioprocess up to 5 L of capacity resulted in a maximum yield of up to 3.06 mol/mol of hexose. These findings suggested that S. flexneri SPD1, a novel H2-producer, can be employed to develop a circular economy-based approach to produce clean energy.


Assuntos
Fermentação , Hidrogênio , Shigella flexneri , Solventes , Shigella flexneri/metabolismo , Hidrogênio/metabolismo , Solventes/química , Química Verde/métodos , Hidrólise , Açúcares/metabolismo , Escuridão , Resíduos , Biotecnologia/métodos
16.
Bioresour Technol ; 410: 131275, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151570

RESUMO

This article reveals the basic laws of straw supercritical water gasification (SCWG) and provides basic experimental data for the effective utilization of straw. The paper studied the impact of three operational conditions on the production of high-calorific value hydrogen-rich combustible gases through SCWG of straw within a quartz tube reactor. The findings reveal that elevated reaction temperatures, extended residence times, and reduced feedstock concentrations favor the SCWG of straw. When combustible gas contains carbon dioxide, the maximum low heating value (LHV) of the gas is 21 MJ/Nm3. Upon removing carbon dioxide, the LHV of the gas reached 38 MJ/Nm3. Subsequently, a machine learning (ML) model was developed to forecast gas yield and LHV during the SCWG process. The results demonstrate that the model exhibits robust generalization capabilities. ML can be extensively applied to forecast biomass SCWG processes across various operational conditions.


Assuntos
Gases , Hidrogênio , Aprendizado de Máquina , Água , Água/química , Dióxido de Carbono , Biomassa
17.
J Environ Manage ; 368: 122209, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39180821

RESUMO

The current need for the upgradation of biohydrogen generation and contaminant removal in two-chambered microbial electrolysis cells (MECs) compels the design of alternatives i.e. bioelectrochemical systems (BESs) to conventional reactors. In this study, a novel three-chambered design of MEC (BES-1) was developed with a common anodic chamber and a two-cathodic chambers at both ends of the anodic chamber, separated by a membrane (MEC-MEC). To facilitate electricity recovery, a microbial fuel cell (MFC) was integrated with an MEC in BES-2. Cathodic hydrogen recovery of 8.89 and 4.81 mL/L.day, and organic matter removal of 82% and 76% were obtained in BES-1 and BES-2, respectively, demonstrating their capabilities for bioremediation. Electrochemical analyses also revealed that cathodic reduction reactions improved with the effective utilization of protons during integration. Our design regulates H2/O2-associated electrochemical reactions and is beneficial for maintaining pH equilibrium. From cost and energy perspectives, the integrated BES provides a platform for two different reactions simultaneously and is capable of boosting overall hydrogen recovery and organic matter removal. Moreover, the compactness and competitiveness of such an integrated BES increase its scope for real-world applications.


Assuntos
Fontes de Energia Bioelétrica , Hidrogênio , Oxirredução , Águas Residuárias , Águas Residuárias/química , Eletrólise , Biodegradação Ambiental , Eletrodos , Oxigênio/química , Eliminação de Resíduos Líquidos/métodos
18.
Int J Mol Sci ; 25(16)2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39201528

RESUMO

Graphitic carbon nitride (g-C3N4)-based photocatalysts have garnered significant interest as a promising photocatalyst for hydrogen generation under visible light, to address energy and environmental challenges owing to their favorable electronic structure, affordability, and stability. In spite of that, issues such as high charge carrier recombination rates and low quantum efficiency impede its broader application. To overcome these limitations, structural and morphological modification of the g-C3N4-based photocatalysts is a novel frontline to improve the photocatalytic performance. Therefore, we briefly summarize the current preparation methods of g-C3N4. Importantly, this review highlights recent advancements in crafting high-performance g-C3N4-based photocatalysts, focusing on strategies like elemental doping, nanostructure design, bandgap engineering, and heterostructure construction. Notably, sophisticated doping techniques have propelled hydrogen production rates to a 104-fold increase. Ingenious nanostructure designs have expanded the surface area by a factor of 26, concurrently extending the fluorescence lifetime of charge carriers by 50%. Moreover, the strategic assembly of heterojunctions has not only elevated charge carrier separation efficiency but also preserved formidable redox properties, culminating in a dramatic hundredfold surge in hydrogen generation performance. This work provides a reliable and brief overview of the controlled modification engineering of g-C3N4-based photocatalyst systems, paving the way for more efficient hydrogen production.


Assuntos
Grafite , Hidrogênio , Compostos de Nitrogênio , Processos Fotoquímicos , Hidrogênio/química , Catálise , Grafite/química , Compostos de Nitrogênio/química , Luz , Nanoestruturas/química
19.
Proc Natl Acad Sci U S A ; 121(34): e2400267121, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39136990

RESUMO

The fusion of hydrogenases and photosynthetic reaction centers (RCs) has proven to be a promising strategy for the production of sustainable biofuels. Type I (iron-sulfur-containing) RCs, acting as photosensitizers, are capable of promoting electrons to a redox state that can be exploited by hydrogenases for the reduction of protons to dihydrogen (H2). While both [FeFe] and [NiFe] hydrogenases have been used successfully, they tend to be limited due to either O2 sensitivity, binding specificity, or H2 production rates. In this study, we fuse a peripheral (stromal) subunit of Photosystem I (PS I), PsaE, to an O2-tolerant [FeFe] hydrogenase from Clostridium beijerinckii using a flexible [GGS]4 linker group (CbHydA1-PsaE). We demonstrate that the CbHydA1 chimera can be synthetically activated in vitro to show bidirectional activity and that it can be quantitatively bound to a PS I variant lacking the PsaE subunit. When illuminated in an anaerobic environment, the nanoconstruct generates H2 at a rate of 84.9 ± 3.1 µmol H2 mgchl-1 h-1. Further, when prepared and illuminated in the presence of O2, the nanoconstruct retains the ability to generate H2, though at a diminished rate of 2.2 ± 0.5 µmol H2 mgchl-1 h-1. This demonstrates not only that PsaE is a promising scaffold for PS I-based nanoconstructs, but the use of an O2-tolerant [FeFe] hydrogenase opens the possibility for an in vivo H2 generating system that can function in the presence of O2.


Assuntos
Hidrogênio , Hidrogenase , Luz , Oxigênio , Complexo de Proteína do Fotossistema I , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema I/química , Hidrogenase/metabolismo , Hidrogenase/química , Hidrogênio/metabolismo , Oxigênio/metabolismo , Oxigênio/química , Clostridium beijerinckii/metabolismo , Clostridium beijerinckii/genética , Oxirredução , Proteínas Ferro-Enxofre/metabolismo , Proteínas Ferro-Enxofre/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Fotossíntese
20.
Waste Manag ; 187: 306-316, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39089146

RESUMO

Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy.


Assuntos
Café , Hidrogênio , Micro-Ondas , Polietileno , Polipropilenos , Pirólise , Polipropilenos/química , Hidrogênio/química , Café/química , Catálise , Polietileno/química , Eliminação de Resíduos/métodos
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