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1.
Environ Res ; 262(Pt 2): 119912, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39233029

RESUMO

Covalent organic framework (COF) catalytic photocatalysts mediating Fenton-like reactions have been applied to the treatment of organic dyes in printing and dyeing wastewater. However, the photocatalytic performance of original COF is often unsatisfactory. This study investigated the impact of porosity modification strategies on the performance of COF photocatalysts in mediating the removal of organic dyes via Fenton-like reaction. Porosity modification was achieved by increasing the concentration of acetic acid (HAc) catalyst during COF preparation. The modified TAPB-DMTA COF (12M COF) exhibited excellent adsorption and photocatalytic properties. The Fenton-like reaction mediated by 12M COF photocatalysis removed nearly 96% of malachite green (MG) within 20 min, with a rate constant of 0.091 min-1, which was 2.9 and 6.5 times higher than that of g-C3N4 and original COF under the same reaction conditions, respectively. Additionally, the modulation mechanism of porosity modification on COF photocatalysis was explored. The conduction band (CB) of COF was reduced from -0.14 eV to -0.38 eV after porosity modification, facilitating the generation of longer-lived O2•- in the reaction system, which was conducive to efficient MG removal. Anti-interference experiments showed that the photocatalytic Fenton-like reaction system based on 12 M COF was less affected by common anions, cations and dissolved organics, while maintaining a high MG removal rate in tap water, mid-water, secondary clarifier effluent and river water. In summary, porosity modification was an effective strategy to improve the catalytic performance of original COFs. This study presented an efficient metal-free photocatalyst modification strategy for the Fenton-like reaction while avoiding the production of toxic by-products during dye degradation.

2.
J Environ Manage ; 367: 122034, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39098067

RESUMO

With fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), this study evaluated the performance of zero-valent iron (ZVI) enhanced anammox process for treating fulvic acids (FA)-containing wastewater and investigated the fate of dissolved organic nitrogen (DON) at the molecular level. The results showed that ZVI increased the total organic carbon (TOC) removal rate of the anammox system by approximately 10% and reduced the organic matter fluorescence intensity by 21%. Specifically, microbial humic-like C1 and terrestrial humic-like C4 components were preferentially degraded by ZVI among the fluorescence components (C1-C4). Moreover, ZVI significantly altered the transformation pathways of DON molecules in anammox. The number of precursors molecular formulas increased from 1617 to 2002, attributed to the elimination of high molecular weight (MW) (>500 Da) molecules. Specifically, DON molecules with high O/C were degraded under the effect of ZVI, while some high MW were resisted. The original products generated from anammox consortia metabolism and FA degradation underwent secondary reactions with ZVI, thereby decreased the O/C of products molecular formulas. Furthermore, anammox process was subjected to the most carboxylic acid reaction, including decarboxylation and reduction of carboxylic acids. For CHON molecules, a significant number of reactions involving the reduction of nitro groups contributed to the reduction of wastewater toxicity, which improved the overall performance.


Assuntos
Ferro , Nitrogênio , Espectrometria de Fluorescência , Águas Residuárias , Nitrogênio/metabolismo , Ferro/química , Ferro/metabolismo , Águas Residuárias/química , Benzopiranos/química
3.
Environ Sci Technol ; 57(51): 21791-21800, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38079570

RESUMO

Further reducing the organic requirements is essential for the sustainable development of partial denitrification/anammox technology. Here, an innovative mixotrophic partial denitrification/anammox (MPD/A) installation fed with pyrite and few organics was realized, and the average nitrogen and phosphorus removal rates were as high as 96.24 ± 0.11% and 79.23 ± 2.06%, respectively, with a C/N ratio of 0.5. To understand the nature by which MPD/A achieves efficient nitrogen removal and organic conservation, the electron transfer-dependent nitrogen escape and energy metabolism were first elucidated using multiomics analysis. Apart from heterotrophic denitrification and anammox, the results revealed some unexpected metabolic couplings of MPD/A systems, in particular, putative nitrate-dependent organic and pyrite oxidation among nominally heterotrophic Denitratisoma (PRO3) strains, which accelerated nitrate gasification with a low-carbon supply. Additionally, Candidatus Brocadia (AMX) employed extracellular solid-state electron acceptors as terminal electron sinks for high-rate ammonium removal. AMX transported ammonium electrons to extracellular γFeO(OH) (generated from pyrite oxidation) through the transient storage of menaquinoline pools, cytoplasmic migration via multiheme cytochrome(s), and OmpA protein/nanowires-mediated electron hopping on cell surfaces. Further investigation observed that extracellular electron flux resulted in the transfer of more energy from the increased oxidation of the electron donor to the ATP, supporting nitrite-independent ammonium removal.


Assuntos
Compostos de Amônio , Águas Residuárias , Desnitrificação , Esgotos , Nitratos , Oxidação Anaeróbia da Amônia , Reatores Biológicos , Compostos de Amônio/metabolismo , Sulfetos , Oxirredução , Nitrogênio
4.
Environ Sci Technol ; 57(46): 17910-17919, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37463493

RESUMO

This study introduced photogenerated electrons into the anammox system by coupling them to a g-C3N4 nanoparticle photocatalyst. A high nitrogen removal efficiency (94.25%) was achieved, exceeding the biochemical limit of 89% imposed by anammox stoichiometry. Photogenerated electrons boosted anammox metabolic activity by empowering key enzymes (NIR, HZS, and WLP-related proteins) and triggered rapid algal enrichment by enhancing the algal Calvin cycle, thus developing multiple anammox-algae synergistic nitrogen removal processes. Remarkably, the homologous expression of cbb3-type cytochrome c oxidase (CcO) in anammox bacteria was discovered and reported in this study for the first time. This conferred aerobic respiration capability to anammox bacteria and rendered them the principal oxygen consumer under 7.9-19.8 mg/L dissolved oxygen, originating from algal photosynthesis. Additionally, photogenerated electrons selectively targeted the cb1 complex and cbb3-type CcO as activation sites while mobilizing the RegA/B regulatory system to activate the expression of cbb3-type CcO. Furthermore, cbb3-type CcO blocked oxidative stress in anammox by depleting intracellular oxygen, a substrate for reactive oxygen species synthesis. This optimized the environmental sensitivity of anammox bacteria and maintained their high metabolic activity. This study expands our understanding of the physiological aptitudes of anammox bacteria and provides valuable insights into applying solar energy for enhanced wastewater treatment.


Assuntos
Desnitrificação , Complexo IV da Cadeia de Transporte de Elétrons , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Nitrogênio/metabolismo , Oxidação Anaeróbia da Amônia , Oxirredução , Bactérias/metabolismo , Oxigênio , Respiração , Reatores Biológicos/microbiologia , Esgotos/microbiologia
5.
J Environ Sci (China) ; 124: 952-962, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182197

RESUMO

The long-term impact of fulvic acid (FA) on partial nitritation (PN) system was initially examined in this study. The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulation rate (NAR nearly 100%) and ammonium removal rate (ARR 56.85%), while FA over 50 mg/L decreased ARR from 56.85% to 0.7%. Sludge characteristics analysis found that appropriate FA (<50 mg/L) exposure promoted the settling performance and granulation of PN sludge by removing Bacteroidetes and accumulating Chloroflexi. The analysis of metagenomics suggested that the presence of limited FA (0-50 mg/L) stimulated the generation of NADH, which favors the denitrification and nitrite reduction. The negative impact of FA on the PN system could be divided into two stages. Initially, limited FA (50-120 mg/L) was decomposed by Anaerolineae to stimulate the growth and propagation of heterotrophic bacteria (Thauera). Increasing heterotrophs competed with AOB (Nitrosomonas) for dissolved oxygen, causing AOB to be eliminated and ARR to declined. Subsequently, when FA dosage was over 120 mg/L, Anaerolineae were inhibited and heterotrophic bacteria reduced, resulting in the abundance of AOB recovered. Nevertheless, the ammonium transformation pathway was suppressed because genes amoABC and hao were obviously reduced, leading to the deterioration of reactor performance. Overall, these results provide theoretical guidance for the practical application of PN for the treatment of FA-containing sewage.


Assuntos
Compostos de Amônio , Esgotos , Compostos de Amônio/metabolismo , Bactérias/genética , Bactérias/metabolismo , Benzopiranos , Reatores Biológicos/microbiologia , Metagenômica , NAD/metabolismo , Nitritos/metabolismo , Nitrogênio/metabolismo , Oxirredução , Oxigênio/metabolismo , Esgotos/microbiologia
6.
Environ Sci Technol ; 56(22): 16115-16124, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36215419

RESUMO

Significant progress in understanding the key enzymes or species of anammox has been made; however, the nitrogen removal mechanism in complex coupling systems centered on anammox remains limited. In this study, by the combination of metagenomics-metatranscriptomics analyses, the nitrogen removal in the anammox-centered coupling system that entails partial denitrification (PD) and hydrolytic acidification (HA, A-PDHA) was elucidated to be the nitrogen transformation driven by the electron generation-transport-consumption process. The results showed that a total nitrogen (TN) removal efficiency of >98%, with a TN effluence of <1 mg/L and a TN removal contribution via anammox of >98%, was achieved after 59 days under famine operation and alkaline conditions during the start-up process. Further investigation confirmed that famine operation promoted the activity of genes responsible for electron generation in anammox, and increased the abundance or expression of genes related to electron consumption. Alkaline conditions enhanced the electron generation for PD by upregulating the activity of glyceraldehyde 3-phosphate dehydrogenase and strengthened electron transfer by increasing the gene encoding quinone pool. Altogether, these variations in the electron flow led to efficient nitrogen removal. These results improve our understanding of the nitrogen removal mechanism and application of the anammox-centered coupling systems in treating nitrogen wastewater.


Assuntos
Desnitrificação , Nitrogênio , Nitrogênio/metabolismo , Reatores Biológicos , Elétrons , Oxidação Anaeróbia da Amônia , Oxirredução , Águas Residuárias , Esgotos
7.
Cell Physiol Biochem ; 39(2): 740-50, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27459514

RESUMO

BACKGROUND/AIMS: The cell surface protein transmembrane 4 L6 family member 1 (TM4SF1) has been detected in various tumors and plays a major role in the development of cancer. We aimed to investigate the effects of TM4SF1 on the migration and invasion of pancreatic cancer in vitro and in vivo and explore its related molecular mechanisms. METHODS: qRT-PCR and immunohistochemical analyses were used to measure the expression of TM4SF1 in pancreatic cancer tissues and adjacent tissues. TM4SF1 was silenced using siRNA and shRNA to investigate the role of this protein in the proliferation and metastasis of pancreatic cancer cells. MTS and Transwell assays were used to examine the effect of TM4SF1 on pancreatic cancer cell lines. The expression and activity of MMP-2 and MMP-9 were determined by qRT-PCR, western blots and gelatin zymography. In vivo, orthotopic pancreatic tumor models were used to examine the formation of metastasis. RESULTS: qRT-PCR and immunohistochemical analyses showed that TM4SF1 was highly expressed in pancreatic cancer tissues compared with the adjacent tissues. In in vitro experiments the silencing of TM4SF1 reduced cell migration and invasion and down-regulated the expression and activity of MMP-2 and MMP-9. However, no significant difference in cell proliferation was detected after silencing TM4SF1. Additionally, knocking down TM4SF1 decreased the formation of lung and liver metastases in orthotopic pancreatic tumor models. CONCLUSION: Our results demonstrate that the expression of TM4SF1 is higher in pancreatic cancer tissues and pancreatic cancer cell lines than controls. Knockdown of TM4SF1 inhibited the migration and invasion of pancreatic cancer cells by regulating the expression and activity of MMP-2 and MMP-9, which suggests that TM4SF1 may play a significant role in metastasis in pancreatic cancer.


Assuntos
Antígenos de Superfície/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/genética , Animais , Antígenos de Superfície/metabolismo , Linhagem Celular Tumoral , Humanos , Imuno-Histoquímica , Masculino , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Nus , Invasividade Neoplásica , Metástase Neoplásica , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/terapia , Interferência de RNA , Terapêutica com RNAi , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(11): 3608-14, 2016 Nov.
Artigo em Zh | MEDLINE | ID: mdl-30199153

RESUMO

UV-Vis absorbance, fluorescence, and Gas Chromatography Mass Spectrometry (GC-MS) were applied to the comparative study on sediment dissolved organic nitrogen (DON) in five typical lakes (Erhai lake, Dianchilake, Poyang lake, Wuhan Dong lake, and Taihu lake) in different lake regions with different nutrition status, revealing the relationship between structural and compositional characteristics of sediment DON and trophic level of lakes. The obtained results showed that: ①Structure of lake sediment DON in Yungui Plateau region is more stable, compared with those in Eastern Plain region, indicating its lower bioavailability. ②In Yungui Plateau region, the source and compositional characteristics of sediment DON weremore complex in Dianchi lake (a seriously polluted lake), and its sediment DON bioavailabilitywas relatively higher. While, with respect to the less polluted Erhai lake, the source of sediment DON is more simple with a higher stability in DON structure and composition, which is beneficial for maintaining its good water quality. ③In Eastern Plain region, nutrition status of Taihu lake was similer to Donghu lake. The structure and composition of sediment DON was complex. But the lower aromaticityand fewer Aromatic ring substituents abundance made their relatively weak nutrient retention ability, posing risk to water quality. With regard to Poyang Lake, the structure and composition of sediment DON was relatively simple, but nutrient retention ability was relatively strong, which played a positive role in maintaining good water quality. ④P(Ⅲ+Ⅴ, n)/P(Ⅰ+Ⅱ, n) values(the content ratio of humic-like substanceto protein-like substances)were in sequence of Dianchi Lake (33.14)>Erhai Lake(21.49)>Taihu Lake(9.06)>Donghu Lake(7.04)>Poyang Lake(4.83), while E(4)/E(6) values (the ratio of UV-Vis absorbance at 465 and 665 nm) were in sequence of Dianchi Lake (27.00)>Donghu Lake(6.65)>Poyang Lake(5.47)>Taihu(3.50)>Erhai Lake(2.31). In addition, P(Ⅲ+Ⅴ, n)/P(Ⅰ+Ⅱ, n) and E(4)/E(6) valueswere positively correlated with thecontents of the different nitrogen (N) forms in the sediments. The above information suggested that P(Ⅲ+Ⅴ, n)/P(Ⅰ+Ⅱ, n) and E(4)/E(6) values exhibited good discrimination degree among different trophic status lakes, and they were considered to indirectly indicate the nutrition levels of lakes to a certain extent.

9.
Bioresour Technol ; 403: 130882, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38788805

RESUMO

This study successfully established Iron Sulfide-Mediated mixotrophic Partial Denitrification/Anammox system, achieving nitrogen and phosphorus removal efficiency of 97.26% and 78.12%, respectively, with COD/NO3--N of 1.00. Isotopic experiments and X-ray Photoelectron Spectroscopy analysis confirmed that iron sulfide enhanced autotrophic Partial Denitrification performance. Meanwhile, various sulfur valence states functioned as electron buffers, reinforcing nitrogen and sulfur cycles. Microbial community analysis indicated reduced heterotrophic denitrifiers (OLB8, OLB13) under lower COD/NO3--N, creating more niche space for autotrophic bacteria and other heterotrophic denitrifiers. The prediction of functional genes illustrated that iron Sulfide upregulated genes related to carbon metabolism, denitrification, anammox and sulfur oxidation-reduction, facilitating the establishment of carbon-nitrogen-sulfur cycle. Furthermore, this cycle primarily produced electrons via nicotinamide adenine dinucleotide and sulfur oxidation-reduction processes, subsequently utilized within the electron transfer chain. In summary, the Partial Denitrification/Anammox system under the influence of iron sulfide achieved effient nitrogen removal by expediting electron transfer through the carbon-nitrogen-sulfur cycle.


Assuntos
Carbono , Desnitrificação , Nitrogênio , Oxirredução , Enxofre , Enxofre/metabolismo , Nitrogênio/metabolismo , Carbono/metabolismo , Reatores Biológicos , Bactérias/metabolismo , Compostos Ferrosos/metabolismo , Compostos Ferrosos/química , Anaerobiose
10.
J Hazard Mater ; 473: 134626, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38759403

RESUMO

This study innovated constructed an activated carbon-loaded nano-zero-valent iron (nZVI-C) enhanced membrane aerated biofilm reactor (MABR) coupled partial nitritation/anammox (PN/A) system for optimizing nitrogen and antibiotics removal. Results showed that nitrogen and antibiotic removal efficiencies of 88.45 ± 0.14% and 89.90 ± 3.07% were obtained by nZVI-C, respectively. nZVI-C hastened Nitrosomonas enrichment (relative abundance raised from 2.85% to 12.28%) by increasing tryptophan content in EPS. Furthermore, nZVI-C proliferated amo gene by 3.92 times and directly generated electrons, stimulating Ammonia monooxygenase (AMO) co-metabolism activity. Concurrently, via antibiotic resistance genes (ARGs) horizontal transfer, Nitrosomonas synergized with Arenimonas and Comamonadaceae for efficient antibiotic removal. Moreover, nZVI-C mitigated antibiotics inhibition of electron transfer by proliferating genes for PN and anammox electron production (hao, hdh) and utilization (amo, hzs, nir). That facilitated electron transfer and synergistic substrate conversion between ammonia oxidizing bacteria (AOB) and anaerobic ammonia oxidizing bacteria (AnAOB). Finally, the high nitrogen removal efficiency of the MABR-PN/A system was achieved.


Assuntos
Antibacterianos , Biofilmes , Reatores Biológicos , Ferro , Nitrogênio , Nitrogênio/metabolismo , Ferro/metabolismo , Ferro/química , Poluentes Químicos da Água/metabolismo , Membranas Artificiais , Amônia/metabolismo , Oxirredução , Nanopartículas Metálicas/química , Carvão Vegetal/química , Eliminação de Resíduos Líquidos/métodos , Oxirredutases
11.
Water Res ; 255: 121532, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38564893

RESUMO

Photocatalytic materials-microbial biohybrid systems pave the way for solar-driven wastewater nitrogen removal. In this study, interspecies cooperation in photogenerated electron transfer and efficient nitrogen removal mechanism in the g-C3N4-anammox consortia biohybrid system were first deciphered. The results indicated that the essential extracellular electron carriers (cytochrome c and flavin) for anammox genomes were provided by associated bacteria (BACT3 and CHLO2). This cooperation, regulated by the ArcAB system and electron transfer flavoprotein, made anammox bacteria the primary photogenerated electron sink. Furthermore, an efficient photogenerated electron harness was used to construct a reductive glycine pathway (rGlyP) in anammox bacteria inventively, which coexisted with the Wood-Ljungdahl pathway (WLP), constituting a dual-pathway carbon fixation model, rGlyP-WLP. Carbon fixation products efficiently contributed to the tricarboxylic acid cycle, while inhibiting electron diversion in anabolism. Photogenerated electrons were targeted channeled into nitrogen metabolism-available electron carriers, enhancing anammox and dissimilatory nitrate reduction to ammonium (DNRA) processes. Moreover, ammonia assimilation by the glycine cleavage system in rGlyP established an alternative ammonia removal route. Ultimately, multi-pathway nitrogen removal involving anammox, DNRA, and rGlyP achieved 100 % ammonia removal and 94.25 % total nitrogen removal efficiency. This study has expanded understanding of anammox metabolic diversity, enhancing its potential application in carbon-neutral wastewater treatment.

12.
Bioresour Technol ; 407: 131100, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38992478

RESUMO

The sludge fermentation-coupled denitrification process, utilized for sludge reduction and nitrogen removal from wastewater, is frequently hindered by its hydrolysis step's efficacy. This study addresses this limitation by extending the sludge retention time (SRT) to 120 days. As a result, the nitrate removal efficiency (NRE) of the nitrification-sludge fermentation coupled denitrification (NSFD) pilot system increased from 67.1 ± 0.2 % to 96.7 ± 0.1 %, and the sludge reduction efficiency (SRE) rose from 40.2 ± 0.5 % to 62.2 ± 0.9 %. Longer SRT enhanced predation and energy dissipation, reducing intact cells from 99.2 % to 78.0 % and decreasing particle size from 135.2 ± 4.6 µm and 19.4 ± 2.1 µm to 64.5 ± 3.5 µm and 15.5 ± 1.6 µm, respectively. It also created different niches by altering the biofilm's adsorption capacity, with interactions between these niches driving improved performance. In conclusion, extending SRT optimized the microbial structure and enhanced the performance of the NSFD system.


Assuntos
Desnitrificação , Fermentação , Nitrificação , Esgotos , Esgotos/microbiologia , Projetos Piloto , Reatores Biológicos , Nitratos/metabolismo , Biofilmes , Fatores de Tempo , Nitrogênio , Purificação da Água/métodos , Tamanho da Partícula
13.
Bioresour Technol ; 394: 130280, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38176594

RESUMO

Anaerobic ammonium oxidation (anammox) is an efficient nitrogen removal process; however, nitrate byproducts hampered its development. In this study, extracellular polymeric substances (EPS) were embedded into NH2-MIL-101(Fe), creating NH2-MIL-101(Fe)@EPS to reduce nitrate. Results revealed that chemical nitrate reduction efficiency of NH2-MIL-101(Fe)@EPS surpassed that of NH2-MIL-101(Fe) by 17.3 %. After adding 0.5 g/L NH2-MIL-101(Fe)@EPS within the anammox process, nitrate removal efficiency reached63.9 %, consequently elevating the total nitrogen removal efficiency to 92.4 %. 16S rRNA sequencing results elucidated the predominant role of Candidatus Brocadia within NH2-MIL-101(Fe)@EPS-anammox system. Concurrently, sufficient photogenerated electrons were transferred to microorganisms, promoting the growth of Desnitratisoma and OLB17. Additionally, photogenerated electrons activated flavin and Complex III, thereby up-regulating crucial genes involved in intra/extracellular electron transfer. Subsequently, denitrification and dissimilatory nitrate reduction to ammonium were activated to reduce nitrate. In summary, this study achieved a notable rate of photocatalytic nitrate reduction within anammox process through the NH2-MIL-101(Fe)@EPS photocatalysts.


Assuntos
Compostos de Amônio , Estruturas Metalorgânicas , Nitratos , Matriz Extracelular de Substâncias Poliméricas , RNA Ribossômico 16S , Oxidação Anaeróbia da Amônia , Oxirredução , Reatores Biológicos , Compostos de Amônio/química , Nitrogênio , Desnitrificação
14.
Bioresour Technol ; 402: 130808, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38723724

RESUMO

The substantial discharge of ferroferric oxide nanoparticles (Fe3O4 NPs) into sewage threatens the survival of functional microorganisms in wastewater treatment. This study elucidated responses of anaerobic ammonium oxidation (anammox) consortia to inhibition from high Fe3O4 NPs concentration and recovery mechanisms. The nitrogen removal efficiency decreased by 20.3 % and recovered after 55 days under 1000 mg/L Fe3O4 NPs concentration. Toxicity was attributed to reactive oxygen species (ROS) production. The excessive ROS damaged membrane integrity, nitrogen metabolism, and DNA synthesis, resulting in the inhibition of anammox bacteria activity. However, recovery mechanisms of anammox consortia activity were activated in response to 1000 mg/L Fe3O4 NPs. The increase of heme oxygenase-1, thioredoxin, and nicotinamide adenine dinucleotide-quinone oxidoreductase genes alleviated oxidative stress. Furthermore, the activation of metabolic processes associated with membrane and DNA repair promoted recovery of anammox bacteria activity. This study provided new insights into NPs contamination and control strategies during anammox process.


Assuntos
Oxirredução , Espécies Reativas de Oxigênio , Espécies Reativas de Oxigênio/metabolismo , Compostos de Amônio/metabolismo , Anaerobiose , Nitrogênio , Bactérias/metabolismo , Consórcios Microbianos , Estresse Oxidativo/efeitos dos fármacos , Águas Residuárias/química
15.
Bioresour Technol ; 395: 130390, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38301944

RESUMO

In this study, H2O2 (0.1 ‰) and NH2-MIL-101(Fe)-driven (150 mg/L) photo-Fenton-coupled anammox were proposed to simultaneously improve the removal efficiency of nitrogen and humic acid. Long-term experiments showed that the total nitrogen removal efficiency was increased by the photo-Fenton reaction to 91.9 ± 1.5 % by altering the bioavailability of refractory organics. Correspondingly, the total organic carbon removal efficiency was significantly increased. Microbial community analyses indicated that Candidatus_Brocadia maintained high activity during photo-Fenton reaction and was the most abundant genus in the reactor. Dissimilatory nitrate reduction to ammonium process and denitrification process were enhanced, resulting in reduced NO3--N production. The establishment of electron transfer between microorganisms and NH2-MIL-101 (Fe) improved the charge separation efficiency of the quantum dots and increased the intracellular adenosine triphosphate content of anammox bacteria. These results indicated that photo-Fenton-anammox process promoted the removal of nitrogen and refractory organics in one reactor which had good economic value and application prospects.


Assuntos
Compostos de Amônio , Desnitrificação , Estruturas Metalorgânicas , Oxirredução , Nitrogênio , Peróxido de Hidrogênio , Oxidação Anaeróbia da Amônia , Elétrons , Reatores Biológicos/microbiologia , Esgotos
16.
World J Gastroenterol ; 30(19): 2575-2602, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38817665

RESUMO

BACKGROUND: Lactate, previously considered a metabolic byproduct, is pivotal in cancer progression and maintaining the immunosuppressive tumor microenvironment. Further investigations confirmed that lactate is a primary regulator, introducing recently described post-translational modifications of histone and non-histone proteins, termed lysine lactylation. Pancreatic adenocarcinomas are characterized by increased glycolysis and lactate accumulation. However, our understanding of lactylation-related genes in pancreatic adenocarcinomas remains limited. AIM: To construct a novel lactylation-related gene signature to predict the survival of patients with pancreatic cancer. METHODS: RNA-seq and clinical data of pancreatic adenocarcinoma (PDAC) were obtained from the GTEx (Genotype-Tissue Expression) and TCGA (The Cancer Genome Atlas) databases via Xena Explorer, and GSE62452 datasets from GEO. Data on lactylation-related genes were obtained from publicly available sources. Differential expressed genes (DEGs) were acquired by using R package "DESeq2" in R. Univariate COX regression analysis, LASSO Cox and multivariate Cox regressions were produced to construct the lactylation-related prognostic model. Further analyses, including functional enrichment, ESTIMATE, and CIBERSORT, were performed to analyze immune status and treatment responses in patients with pancreatic cancer. PDAC and normal human cell lines were subjected to western blot analysis under lactic acid intervention; two PDAC cell lines with the most pronounced lactylation were selected. Subsequently, RT-PCR was employed to assess the expression of LRGs genes; SLC16A1, which showed the highest expression, was selected for further investigation. SLC16A1-mediated lactylation was analyzed by immunofluorescence, lactate production analysis, colony formation, transwell, and wound healing assays to investigate its role in promoting the proliferation and migration of PDAC cells. In vivo validation was performed using an established tumor model. RESULTS: In this study, we successfully identified 10 differentially expressed lactylation-related genes (LRGs) with prognostic value. Subsequently, a lactylation-related signature was developed based on five OS-related lactylation-related genes (SLC16A1, HLA-DRB1, KCNN4, KIF23, and HPDL) using Lasso Cox hazard regression analysis. Subsequently, we evaluated the clinical significance of the lactylation-related genes in pancreatic adenocarcinoma. A comprehensive examination of infiltrating immune cells and tumor mutation burden was conducted across different subgroups. Furthermore, we demonstrated that SLC16A1 modulates lactylation in pancreatic cancer cells through lactate transport. Both in vivo and in vitro experiments showed that decreasing SLC16A1 Level and its lactylation significantly inhibited tumor progression, indicating the potential of targeting the SLC16A1/Lactylation-associated signaling pathway as a therapeutic strategy against pancreatic adenocarcinoma. CONCLUSION: We constructed a novel lactylation-related prognostic signature to predict OS, immune status, and treatment response of patients with pancreatic adenocarcinoma, providing new strategic directions and antitumor immunotherapies.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Pancreáticas , Microambiente Tumoral , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/metabolismo , Prognóstico , Linhagem Celular Tumoral , Microambiente Tumoral/imunologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Transportadores de Ácidos Monocarboxílicos/genética , Transportadores de Ácidos Monocarboxílicos/metabolismo , Processamento de Proteína Pós-Traducional , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adenocarcinoma/mortalidade , Adenocarcinoma/imunologia , Adenocarcinoma/metabolismo , Ácido Láctico/metabolismo , Simportadores/genética , Simportadores/metabolismo , Proliferação de Células/genética , Perfilação da Expressão Gênica , Masculino , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/mortalidade , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/terapia , Feminino , Animais , Transcriptoma
17.
J Hazard Mater ; 452: 131035, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-36958165

RESUMO

In this study, activated carbon-loaded nano-zero-valent iron (nZVI-C) composites were added to anaerobic ammonium oxidation bacteria (AnAOB) to overcome the inhibition of tetracycline hydrochloride (TCH). Results showed that 500 mg L-1 nZVI-C effectively mitigated the long-term inhibition of 1.5 mg L-1 TCH on AnAOB and significantly improved the total nitrogen removal efficiency (TNRE) (from 65.27% to 86.99%). Spectroscopic analysis revealed that nZVI-C increased the content of N-H and CO groups in EPS, which contributed to the adsorption of TCH. The accumulation of humic acid-like substances in EPS was also conducive to strengthening the extracellular defense level. In addition, TCH-degrading bacteria (Clostridium and Mycobacterium) were enriched in situ, and the abundance of Ca. Brocadia was significantly increased (from 10.69% to 18.59%). Furthermore, nZVI-C increased the abundance of genes encoding tetracycline inactivation (tetX), promoted mineralization of TCH by 90%, weakening the inhibition of TCH on microbial nitrogen metabolism. nZVI-C accelerated the electron consumption of anammox bacteria by upregulating the abundance of electron generation genes (nxrA, hdh) and providing electrons directly.


Assuntos
Microbiota , Tetraciclina , Tetraciclina/farmacologia , Tetraciclina/metabolismo , Matriz Extracelular de Substâncias Poliméricas , Ferro/química , Oxidação Anaeróbia da Amônia , Anaerobiose , Bactérias/genética , Bactérias/metabolismo , Esgotos/química , Nitrogênio/metabolismo , Reatores Biológicos , Oxirredução
18.
Water Sci Technol ; 65(10): 1826-33, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22546798

RESUMO

Completely autotrophic nitrogen removal over nitrite (CANON) is a cost-effective nitrogen removal process. Implementation of the CANON process relies on the cooperation of ammonium-oxidizing and Anammox bacteria, as well as the inhibition of nitrite-oxidizing bacteria. Strict limitations on dissolved oxygen (DO) concentration in the reactor, and the addition of sufficient inorganic carbon in the influent, were adopted as the main operational strategies. The reactor was fed with synthetic inorganic wastewater composed mainly of NH(4)(+)-N, and operated for 106 days. Stable nitrogen removal rates (NRR) of around 1.4 kg N m(-3) d(-1) were obtained at ambient temperature. Morphological characteristics and analysis of bacterial community confirmed the formation of functional outer aerobic and inner anaerobic granular sludge, providing evidence of stable nitrogen removal.


Assuntos
Bactérias Anaeróbias/química , Nitrogênio/química , Eliminação de Resíduos Líquidos/métodos , Poluição Química da Água/prevenção & controle , Nitritos/química , Nitrogênio/isolamento & purificação , Esgotos/química , Esgotos/microbiologia , Temperatura , Purificação da Água/métodos
19.
Sci Total Environ ; 827: 154289, 2022 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35247414

RESUMO

The complex relationships between the molecular composition of dissolved organic matter (DOM) and microbial communities are essential for maintaining the stability of aquatic ecosystems. This study comprehensively analyzed the characteristics and potential effects of DOM molecular composition as well as the relationship between microbial communities and DOM molecular composition in sediments from the Beiyun River, Beijing, China. The results showed that the content of DOM in Beiyun River sediments was 9.93-41.57 g/kg, mainly composed of lignin-like (36.75%) and protein-like (17.79%) substances. Compared with other rivers affected by anthropogenic activities, the higher content of labile substances in the Beiyun River increased the risk of nutrient release. At the same time, 1402 molecules remained stable in each sample, most of which were refractory lignin-like substances and protein-like substances carrying ester groups. The agricultural section contained more common DOM molecules than the urban section, mainly tannin-like and lignin-like substances with unsaturated or cyclic structures. And, the intensity of anthropogenic activities was the main reason affecting the diversity of unique DOM molecular in each sample. Moreover, Dechloromonas as the dominant genus of Proteobacteria was closely related to the biological modification of low unsaturated (DBE < 15) condensed aromatic compounds (P < 0.05). Anaerolineaceae and Anaerolineae belonging to the Chloroflexi phylum have the potential to degrade medium and high molecular weight (M/Z > 400) liable substances (P < 0.05) and release lignin-like substances. In addition, the proportion of protein-like substances can indirectly reflect the risk of nutrient release in sediments affected by urbanization. Thus, the results of this study further reveal the impact of urbanization on rivers, and provide theoretical basis and guidance for pollution control of the Beiyun River and other urbanized rivers worldwide.


Assuntos
Matéria Orgânica Dissolvida , Rios , Ecossistema , Lignina , Rios/química
20.
Bioresour Technol ; 362: 127844, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36031131

RESUMO

The mechanisms of Fe2+ on nitrogen and phosphorus removal and functional bacterial competition in anammox systems was investigated. Under 0.12 mM Fe2+, the performance of nitrogen and phosphorus removal increased by 10.08 % and 151.91 %, respectively, compared with the control stage. Phosphorus removal was achieved through extracellular polymeric substance (EPS) induced biomineralization to form Fe-P minerals, and functional group COC in EPS played a critical role. T-EPSs was the major nucleation site due to it maintaining the supersaturated state (saturation index > 0) of Fe-P minerals for a long time. Population succession showed that Fe2+ weakened the competition between heterotrophic denitrifier (Denitrasoma) and anammox microbe (Candidatus Brocadia) for space and substrates, which was favorable for the enrichment of anammox biomass. Moreover, the variation in gene abundance (such as Hao, Cyt c, and Nir) indicated that Fe2+ improved electron behaviors (generation, transport, and consumption) during the nitrogen metabolism of anammox systems.


Assuntos
Nitrogênio , Fósforo , Oxidação Anaeróbia da Amônia , Reatores Biológicos/microbiologia , Desnitrificação , Matriz Extracelular de Substâncias Poliméricas/química , Ferro , Nitrogênio/análise , Oxirredução , Esgotos
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