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1.
Environ Int ; 190: 108846, 2024 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-38925006

RESUMEN

Natural environments play a crucial role in transmission of antimicrobial resistance (AMR). Development of methods to manage antibiotic resistance genes (ARGs) in natural environments are usually limited to the laboratory or field scale, partially due to the complex dynamics of transmission between different environmental compartments. Here, we conducted a nine-year longitudinal profiling of ARGs at a watershed scale, and provide evidence that restrictions on livestock farms near water bodies significantly reduced riverine ARG abundance. Substantial reductions were revealed in the relative abundance of genes conferring resistance to aminoglycosides (42%), MLSB (36%), multidrug (55%), tetracyclines (53%), and other gene categories (59%). Additionally, improvements in water quality were observed, with distinct changes in concentrations of dissolved reactive phosphorus, ammonium, nitrite, pH, and dissolved oxygen. Antibiotic residues and other pharmaceuticals and personal care products (PPCPs) maintain at a similarly low level. Microbial source tracking demonstrates a significant decrease in swine fecal indicators, while human fecal pollution remains unchanged. These results suggest that the reduction in ARGs was due to a substantial reduction in input of antibiotic resistant bacteria and genes from animal excreta. Our findings highlight the watershed as a living laboratory for understanding the dynamics of AMR, and for evaluating the efficacy of environmental regulations, with implications for reducing environmental risks associated with AMR on a global scale.

2.
Environ Sci Pollut Res Int ; 31(19): 28321-28340, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38538998

RESUMEN

The presence of heavy metal ions in water environments has raised significant concerns, necessitating practical solutions for their complete removal. In this study, a combination of adsorption and electrocoagulation (ADS + EC) techniques was introduced as an efficient approach for removing high concentrations of nickel ions (Ni2+) from aqueous solutions, employing low-cost sunflower seed shell biochar (SSSB). The combined techniques demonstrated superior removal efficiency compared to individual methods. The synthesized SSSB was characterized using SEM, FT-IR, XRD, N2-adsorption-desorption isotherms, XPS, and TEM. Batch processes were optimized by investigating pH, adsorbent dosage, initial nickel concentration, electrode effects, and current density. An aluminum (Al) electrode electrocoagulated particles and removed residual Ni2+ after adsorption. Kinetic and isotherm models examined Ni2+ adsorption and electrocoagulation coupling with SSSB-based adsorbent. The results indicated that the kinetic data fit well with a pseudo-second-order model, while the experimental equilibrium adsorption data conformed to a Langmuir isotherm under optimized conditions. The maximum adsorption capacity of the activated sunflower seed shell was determined to be 44.247 mg.g-1. The highest nickel ion removal efficiency of 99.98% was observed at initial pH values of 6.0 for ADS and 4.0 for ADS/EC; initial Ni2+ concentrations of 30.0 mg/L and 1.5 g/L of SSSB; initial current densities of 0.59 mA/cm2 and 1.32 kWh/m3 were also found to be optimal. The mechanisms involved in the removal of Ni2+ from wastewater were also examined in this research. These findings suggest that the adsorption-assisted electrocoagulation technique has a remarkable capacity for the cost-effective removal of heavy metals from various wastewater sources.


Asunto(s)
Carbón Orgánico , Níquel , Aguas Residuales , Contaminantes Químicos del Agua , Níquel/química , Adsorción , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Carbón Orgánico/química , Cinética , Purificación del Agua/métodos , Helianthus/química , Electrocoagulación/métodos
3.
Chemosphere ; 356: 141795, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38548078

RESUMEN

Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) are persistent pollutants that have been introduced into the environment as a result of human activities. They are produced when PAHs undergo oxidation and are highly resistant to degradation, resulting in prolonged exposure and significant health risks for wildlife and humans. Nitro-PAHs' potential to induce cancer and mutations has raised concerns about their harmful effects. Furthermore, their ability to accumulate in the food chain seriously threatens the ecosystem and human health. Moreover, nitro-PAHs can disrupt the normal functioning of the endocrine system, leading to reproductive and developmental problems in humans and other organisms. Reducing nitro-PAHs in the environment through source management, physical removal, and chemical treatment is essential to mitigate the associated environmental and human health risks. Recent studies have focused on improving nitro-PAHs' phytoremediation by incorporating microorganisms and biostimulants. Microbes can break down nitro-PAHs into less harmful substances, while biostimulants can enhance plant growth and metabolic activity. By combining these elements, the effectiveness of phytoremediation for nitro-PAHs can be increased. This study aimed to investigate the impact of introducing microbial and biostimulant agents on the phytoremediation process for nitro-PAHs and identify potential solutions for addressing the environmental risks associated with these pollutants.


Asunto(s)
Biodegradación Ambiental , Restauración y Remediación Ambiental , Hidrocarburos Policíclicos Aromáticos , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/metabolismo , Restauración y Remediación Ambiental/métodos , Humanos , Ecosistema , Nitrocompuestos/toxicidad
4.
Environ Res ; 249: 118344, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38311200

RESUMEN

More and more previously designed wastewater treatment plants (WWTPs) are upgraded to tertiary treatment to meet the higher effluent discharge standards of conventional pollutants. Contaminants of emerging concern (CECs) can cause adverse effects on organisms and usually flow into WWTPs along with urban sewage. How the retrofitted WWTPs targeting conventional pollutants will influence the treatment efficiency of CECs is seldom discussed. This study investigates the removal of CECs in two full-scale newly retrofitted WWTPs (CD and JM WWTPs), containing high-efficiency sedimentation tank and denitrification deep bed filter for enhancing total nitrogen removal. The overall CEC removal efficiencies in the CD and JM WWTPs were 73.79 % and 93.63 %, respectively. Mass balance results indicated that CD WWTP and JM WWTP release a total of 36.89 and 88.58 g/d of CECs into the environment through effluent and excess sludge, respectively. Analysis of the concentration of CECs along the treatment process revealed most CECs were removed in the biological treatment units. The incorporation of newly constructed tertiary treatment proved beneficial for CEC removal and removed 2.93 % and 2.36 % CECs, corresponding to CEC removal of 2.92 and 27.49 g/d in the CD and JM WWTPs, respectively. The data of this study were further used to evaluate the suitability of the SimpleTreat model for simulating the fate of CECs in WWTPs. The predicted fraction of CECs discharged through the biological treatment effluent were generally within ten-fold difference from the measured results, highlighting its potential for estimating CEC removal in WWTPs.


Asunto(s)
Nitrógeno , Eliminación de Residuos Líquidos , Aguas Residuales , Contaminantes Químicos del Agua , Contaminantes Químicos del Agua/análisis , Nitrógeno/análisis , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Aguas Residuales/análisis
5.
Environ Pollut ; 344: 123303, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38199486

RESUMEN

Neonicotinoid insecticides are among the most used insecticides and their residues are frequently found in surface water due to their persistence and mobility. Neonicotinoid insecticides exhibit toxicity to a wide range of aquatic invertebrates at environmentally relevant levels, and therefore their contamination in surface water is of significant concern. In this study, we investigated the spatiotemporal distribution of six neonicotinoids in a large wetland system, the Prado Wetlands, in Southern California, and further evaluated the wetlands' efficiency at removing these insecticides. Total neonicotinoid concentrations in water ranged from 3.17 to 46.9 ng L-1 at different locations within the wetlands, with imidacloprid and dinotefuran among the most detected. Removal was calculated based on concentrations as well as mass flux. The concentration-based removal values for a shallow pond (vegetation-free), moderately vegetated cells, densely vegetated cells, and the entire wetland train were 16.9%, 34.2%, 90.2%, and 61.3%, respectively. Principal component analysis revealed that pH and temperature were the primary factors affecting neonicotinoids removal. Results from this study demonstrated the ubiquitous presence of neonicotinoids in surface water impacted by urban runoff and wastewater effluent and highlighted the efficiency of wetlands in removing these trace contaminants due to concerted effects of uptake by wetland plants, photolysis, and microbial degradation.


Asunto(s)
Insecticidas , Contaminantes Químicos del Agua , Insecticidas/toxicidad , Humedales , Contaminantes Químicos del Agua/análisis , Neonicotinoides/toxicidad , Nitrocompuestos , Agua
6.
J Dermatolog Treat ; 34(1): 2276044, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37905433

RESUMEN

THE PURPOSE OF THE ARTICLE: Pyoderma gangrenosum (PG) is an ulcerating neutrophilic dermatosis with an incidence of 3-10 patients per million. PG equally affects patients of both sexes and of any age. Of these patients, 50-75% are associated with auto-immune disease. The lower extremities are the most commonly affected body parts. Minor trauma to the skin may result in the development of new lesions. Patients complain of chronic, nonhealing ulcers with associated pain. Treatment starts with systemic or intralesional corticosteroids, however, no official treatment protocol currently exists. Recent success has been found with biologic agents such as TNF-a inhibitor, although the treatment efficacy in these reports is limited. As for the pregnant patient, the drug selection is difficult. In this report, we want to assess the efficiency of certolizumab in the pregnant patient. RESULTS: We report a case of a patient with PG, who responded well to certolizumab, 400 mg as a booster dose, followed by 200 mg biweekly for 8 weeks. The lesions gradually resolved and followed up for 5months without side effect. In addition, we reviewed the literature and compared the current treatment efficiency in the treatment of PG. CONCLUSION: Certolizumab may be a promising therapeutic option for patients with severe PG.


Asunto(s)
Piodermia Gangrenosa , Masculino , Embarazo , Femenino , Humanos , Piodermia Gangrenosa/tratamiento farmacológico , Piodermia Gangrenosa/patología , Certolizumab Pegol/uso terapéutico , Piel/patología , Corticoesteroides/uso terapéutico , Resultado del Tratamiento , Inhibidores del Factor de Necrosis Tumoral/uso terapéutico
7.
Chemosphere ; 341: 140045, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37683947

RESUMEN

The outbreak of toxic cyanobacteria blooms is hazardous to water safety. Ozonation has been used to treat cyanobacteria-laden source water. Generally, cyanobacterial blooms enter into a long-term maintenance stage from the bloom development, but how the changed bloom stage affects ozonation is still unknow. Herein, influences of ozonation on cell inactivation and microcystin removal of Microcystis at the development and maintenance stage, were investigated. Then, ozonation-assisted coagulation for Microcystis removal at the two stages was compared. Results showed no significant difference in the photosynthetic inactivation of Microcystis at both stages. Microcystis at the maintenance stage exhibited a lower loss of membrane integrity (268-480 M-1 s-1) than that at the development stage (413-596 M-1 s-1). However, the extracellular microcystin increased by 30-410% at the maintenance stage at a lower ratio of [O3: DOC] (0.10-0.80) compared to the development stage (0.21-1.68), mainly ascribed to a decrease in the ozonation efficiency for microcystin removal. This finding might result from the elevated biomass and N-containing organics as competitors to reduce microcystin ozonation. Meanwhile, it was possible to generate fewer hydroxyl radicals to oxidize microcystin at the maintenance stage than that at the development stage. Besides, the removal ratio of Microcystis after ozonation-assisted coagulation, was reduced by 46-230% at the maintenance stage, due to the insufficient modification of cellular surface or elevated organics of 3-30 kDa. This work indicated that ozonation is effective to treat Microcystis at the development stage of a bloom whist pre-ozonation might be an inappropriate choice at the long-term maintenance stage.


Asunto(s)
Cianobacterias , Microcystis , Ozono , Microcystis/metabolismo , Microcistinas/metabolismo , Agua/metabolismo , Cianobacterias/metabolismo
8.
iScience ; 26(7): 107193, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37485353

RESUMEN

Azoospermia is a significant cause of male infertility, with non-obstructive azoospermia (NOA) being the most severe type of spermatogenic failure. NOA is mostly caused by congenital factors, but our understanding of its genetic causes is very limited. Here, we identified a frameshift variant (c.201_202insAC, p.Tyr68Thrfs∗17) and two nonsense variants (c.1897C>T, p.Gln633∗; c.2005C>T, p.Gln669∗) in KCTD19 (potassium channel tetramerization domain containing 19) from two unrelated infertile Chinese men and a consanguineous Pakistani family with three infertile brothers. Testicular histological analyses revealed meiotic metaphase I (MMI) arrest in the affected individuals. Mice modeling KCTD19 variants recapitulated the same MMI arrest phenotype due to severe disrupted individualization of MMI chromosomes. Further analysis showed a complete loss of KCTD19 protein in both Kctd19 mutant mouse testes and affected individual testes. Collectively, our findings demonstrate the pathogenicity of the identified KCTD19 variants and highlight an essential role of KCTD19 in MMI chromosome individualization.

9.
Environ Sci Technol ; 57(30): 11267-11278, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37477285

RESUMEN

The widespread occurrence of tire tread particles (TPs) has aroused increasing concerns over their impacts. However, how they affect the soil fauna remains poorly understood. Here, based on systematically assessing the toxicity of TPs on soil model speciesEnchytraeus crypticusat environmentally relevant concentrations through both soil and food exposure routes, we reported that TPs affected gut microbiota, intestinal histopathology, and metabolites of the worms both through particulate- and leachate-induced effects, while TP leachates exerted stronger effects. The dominant role of TP leachates in TP toxicity was further explained by the findings that worms did not ingest TPs with a particle size of over 150 µm and actively avoided consuming TP particles. Moreover, by comparing the effects of different brands of TPs as well as new and aged TPs, we demonstrated that it was mainly TP leachates that resulted in the ubiquity of the disturbance in the worm's gut microbiota among different brands of TPs. Notably, the large variations in leachate compositions among different brands of TPs provided us a unique opportunity to identify the determinants of TP toxicity. These results provide novel insights into the toxicity of TPs to soil fauna and a reference for toxicity reduction of tires.


Asunto(s)
Microbioma Gastrointestinal , Polvo , Tamaño de la Partícula , Suelo
10.
J Environ Manage ; 341: 117986, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37172350

RESUMEN

Increased urbanization and anthropogenic activities can alter dissolved organic matter (DOM) and complicate its interaction with bacteria in rivers' ecosystems, however, there is limited information about how bacterial communities respond to DOM components in rivers with different urbanization levels. Here, we combined spectroscopy-based DOM analysis and 16S rRNA gene amplicon sequencing to investigate the associations of bacterial taxa and DOM properties as well as the impacts of DOM on bacterial niche breadth in North River (NR) and West River (WR) of Jiulong River watershed, southern China, which had low and high urbanization levels, respectively. Spectroscopy analysis showed that hydrophilic DOM was predominant in both rivers whereas chromophoric DOM was higher in WR. Network analysis indicated that only seven bacterial genera (i.e., hg clade, chthoniobacter, Geobacter, Acidibacter, Alphal Cluster, Fluviicola, and Lacunisphaera) showed strong associations with DOM optical variables in both rivers, whereas more than 85% of DOM-bacterial genera associations were different between rivers. These results suggest that the relationship between DOM and bacterial communities had different responses in rivers with different urbanization levels. The partial least square path model indicated that the total standardized effect of physico-chemicals on bacterial niche breadth was higher in NR (0.62) than in WR (0.35), whereas humic substances showed an opposite pattern (NR: -0.42; WR: 1.67). The distinct effects of physico-chemicals and DOM on bacterial niche breadths between rivers could be due to the different effects of urbanization and human activities on the environmental conditions of riverine ecosystems. Our findings revealed a huge dissimilarity in the bacteria-DOM co-occurrence networks between rivers with different urbanization levels and provide a novel insight that urbanization may enhance DOM's importance to bacterial niche breadths.


Asunto(s)
Materia Orgánica Disuelta , Ríos , Humanos , Ríos/química , Ecosistema , Urbanización , ARN Ribosómico 16S/genética , Bacterias/genética , Espectrometría de Fluorescencia
11.
Water Res ; 237: 119992, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37099873

RESUMEN

Recent studies have reported conflicting results on the effects of biofouling on the adsorption behavior of microplastics (MPs). However, the underlying mechanisms driving the adsorption of MPs undergoing biofouling in aquatic environments remain unclear. This study examined the interactions between polyamide (PA), polyvinyl chloride (PVC) and polyethylene (PE) with two phytoplankton, namely cyanobacteria Microcystis aeruginosa and microalgae Chlorella vulgaris. Results indicated that MP effects on phytoplankton were dose- and crystalline-type dependent, with M. aeruginosa being more sensitive to MP exposure than C. vulgaris in the inhibitory order PA > PE > PVC. Analysis of antibiotic adsorption of the MPs showed significant contributions from CH/π interactions on PE and PVC and hydrogen bonding on PA, which decreased with phytoplankton biofouling and aging. Meanwhile, higher levels of extracellular polymeric substances on microalgae-aged MPs compared to cyanobacteria-aged MPs were conducive to adsorption of antibiotics, mainly through hydrophobic interactions. Overall, promotional and anti-promotional adsorption of antibiotics on MPs was induced by biofouling and aging of microalgae and cyanobacteria, respectively. This study provides deep insights into the specific mechanisms by which biofouling affects MP adsorption in aquatic environments, thus advancing our understanding of this critical environmental issue.


Asunto(s)
Incrustaciones Biológicas , Chlorella vulgaris , Cianobacterias , Microalgas , Contaminantes Químicos del Agua , Microplásticos , Fitoplancton , Plásticos/química , Antibacterianos/farmacología , Adsorción , Polietileno , Contaminantes Químicos del Agua/química
12.
Materials (Basel) ; 16(5)2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36902984

RESUMEN

Carbon nanotube-based derivatives have attracted considerable research interest due to their unique structure and fascinating physicochemical properties. However, the controlled growth mechanism of these derivatives remains unclear, and the synthesis efficiency is low. Herein, we proposed a defect-induced strategy for the efficient heteroepitaxial growth of single-wall carbon nanotubes (SWCNTs)@hexagonal boron nitride (h-BN) films. Air plasma treatment was first performed to generate defects on the wall of SWCNTs. Then, atmospheric pressure chemical vapor deposition was conducted to grow h-BN on the surface of SWCNTs. Controlled experiments combined with first-principles calculations revealed that the induced defects on the wall of SWCNTs function as nucleation sites for the efficient heteroepitaxial growth of h-BN.

13.
Front Microbiol ; 14: 1109311, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36846800

RESUMEN

As an important ecological system on the earth, rivers have been influenced by the rapid development of urbanization, industrialization, and anthropogenic activities. Increasingly more emerging contaminants, such as estrogens, are discharged into the river environment. In this study, we conducted river water microcosmic experiments using in situ water to investigate the response mechanisms of microbial community when exposed to different concentrations of target estrogen (estrone, E1). Results showed that both exposure time and concentrations shaped the diversity of microbial community when exposed to E1. Deterministic process played a vital role in influencing microbial community over the entire sampling period. The influence of E1 on microbial community could last for a longer time even after the E1 has been degraded. The microbial community structure could not be restored to the undisturbed state by E1, even if disturbed by low concentrations of E1(1 µg/L and 10 µg/L) for a short time. Our study suggests that estrogens could cause long-term disturbance to the microbial community of river water ecosystem and provides a theoretical basis for assessing the environmental risk of estrogens in rivers.

14.
Artículo en Inglés | MEDLINE | ID: mdl-36790415

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) have been recognized as a potential health risk and are widespread in nature due to their intrinsic chemical stability and high recalcitrance to degradation. A taxonomic study was carried out on strain P9T, which was isolated from a PAH-degrading consortium, enriched from the mangrove sediment from Zhangzhou, PR China. The isolate was chemoheterotrophic, aerobic, Gram-stain-negative, short-rod shaped, and motile by one polar flagellum. Growth was observed at salinities from 0.5-6.0 % (optimum, 3 %), at pH 4-9 (optimum, pH 7) and at 10-41 °C (optimum, 25-30 °C). It did not synthesize bacteriochlorophyll a. Catalase and oxidase activities were positive. Acid was produced from starch, amygdalin, arbutin, cellobiose, d-fructose, maltose, d-mannitol, melezitose, melibiose, raffinose, d-ribose, sucrose, trehalose, d-xylose, aesculin ferric citrate, gentiobiose, glycogen, l-arabinose, l-rhamnose, methyl α-d-glucopyranoside, methyl ß-d-xylopyranoside, N-acetylglucosamine and salicin, and weakly positive for d-arabitol, d-galactose, lactose, turanose and glycerol. Phylogenetic analysis revealed that strain P9T fell within the clade comprising the type strains of Salipiger species and formed an independent cluster with Salipiger profundus, which was distinct from other members of the family Rhodobacteraceae. The 16S rRNA gene sequence comparisons showed that strain P9T was most closely related to Salipiger bermudensis HTCC 260T (96.7 %), and other species of the genus Salipiger (95.7-94.2 %). Strain P9T had the highest digital DNA-DNA hybridization value with S. profundus CGMCC 1.12377T (25.0 %) and the highest average nucleotide identity (ANIb and ANIm) values with S. profundus CGMCC 1.12377T(80.3 and 85.8 %, respectively). The sole respiratory quinone was quinone 10. The dominant fatty acids were C18 : 1 ω7c (61.4 %), C16 : 0 (17.5 %) and C19 : 0 ω8c cyclo (7.6 %). The G+C content of the chromosomal DNA was 65.8 mol%. In the polar lipid profile, phospholipid, phosphatidylglycerol, aminolipid, glycolipid and phosphatidylethanolamine were the major compounds. Based on the phenotypic and phylogenetic data, strain P9T represents a novel species of the genus Salipiger, for which the name Salipiger pentaromativorans sp. nov. is proposed. The type strain is P9T (=CCTCC AB 209290T=LMG 25701T=MCCC 1F01055T).


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Rhodobacteraceae , Ácidos Grasos/química , Agua de Mar/microbiología , Filogenia , ARN Ribosómico 16S/genética , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Composición de Base , Análisis de Secuencia de ADN , Fosfolípidos/química , Quinonas
15.
Biosens Bioelectron ; 226: 115119, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36764128

RESUMEN

By introducing the computer numerical control (CNC) engraving technology, this study fabricated the reusable CNC-fabricated membrane-less laminar flow microfluidic MFC (LMMFC) to develop the bioelectrochemical sensor and power source simultaneously. To verify its applicability, optimization of electroactive bacteria (EAB) cultivation and laminar-flow formation, performance of power density and long-term operation, and detection of Cr(VI) were evaluated. Results of EAB optimization showed under lower external resistance, shorter start-up time of current production, larger oxidation current, denser microbial distribution, and a higher percentage of Geobacter spp. were observed. Results of the laminar-flow operation indicated that increasing the density difference between two solutions and raising the anode flow velocity can minimize the interference of the diffusion zone. The power output of LMMFC could reach 2085 mW m-2 and achieve long-term stability for current production (∼150 h). Regarding the detection of Cr(VI), low-concentration (0.1∼1 ppm) and high-concentration (1-10 ppm) ranges reached the linear coefficient of determination of 0.98 and 0.97, respectively. Overall, these results suggest that an LMMFC which can both act as the power source and biosensor was successfully developed, showing potential for future self-power application.


Asunto(s)
Fuentes de Energía Bioeléctrica , Técnicas Biosensibles , Fuentes de Energía Bioeléctrica/microbiología , Microfluídica , Cromo , Electrodos , Bacterias
16.
Environ Sci Ecotechnol ; 13: 100223, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36437887

RESUMEN

Antibiotic resistance genes (ARGs) are a well-known environmental concern. Yet, limited knowledge exists on the fate and transport of ARGs in deep freshwater reservoirs experiencing seasonal hydrological changes, especially in the context of particle-attached (PA) and free-living (FL) lifestyles. Here, the ARG profiles were examined using high-throughput quantitative PCR in PA and FL lifestyles during four seasons representing two hydrological phenomena (vertical mixing and thermal stratification) in the Shuikou Reservoir (SR), Southern China. The results indicated that seasonal hydrological dynamics were critical for influencing the ARGs in PA and FL and the transition of ARGs between the two lifestyles. ARG profiles both in PA and FL were likely to be shaped by horizontal gene transfer. However, they exhibited distinct responses to the physicochemical (e.g., nutrients and dissolved oxygen) changes under seasonal hydrological dynamics. The particle-association niche (PAN) index revealed 94 non-conservative ARGs (i.e., no preferences for PA and FL) and 23 and 16 conservative ARGs preferring PA and FL lifestyles, respectively. A sharp decline in conservative ARGs under stratified hydrologic suggested seasonal influence on the ARGs transition between PA and FL lifestyles. Remarkably, the conservative ARGs (in PA or FL lifestyle) were more closely related to bacterial OTUs in their preferred lifestyle than their counterparts, indicating lifestyle-dependent ARG enrichment. Altogether, these findings enhanced our understanding of the ARG lifestyles and the role of seasonal hydrological changes in governing the ARG transition between the lifestyles in a typical deep freshwater ecosystem.

17.
J Environ Manage ; 326(Pt B): 116737, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36403459

RESUMEN

Dissolved organic matter (DOM), known as a key to the aquatic carbon cycle, is influenced by abiotic and biotic factors. However, the compositional variation and these factors' effects on fluorescence DOM (FDOM) in urban rivers undergoing different anthropogenic pressure are poorly investigated. Herein, using fluorescence excitation-emission matrix and parallel factor analysis (EEM-PARAFAC), four FDOM components (C1, C2, C3, and C4) were identified in a less urbanized north river (NR) and a more urbanized west river (WR) of Jiulong River Watershed in Fujian province, China. C1, C2, and C4 were related to humic-like substances (HLS) and C3 to protein-like substances (PLS). HLS (63.9% in WR and 36.4% in NR) and PLS (62.7% in WR and 37.3% in NR) exhibited higher fluorescence in the more urbanized river. We also found higher PLS in winter, but higher HLS in summer for both rivers. Although the coefficient of variation indicated a difference in FDOM components stability to some extent between the two rivers, the typhoon event that occurred in summer had a stronger disruptive impact on the CDOM and FDOM of a more urbanized river than that of a less urbanized river. We explore abiotic and biotic factors' effects on FDOM using the partial least squares path model (PLS-PM). PLS-PM results revealed higher significant influences of biotic factors on FDOM in the more urbanized river. This study enhances our understanding of FDOM dynamics of rivers with different anthropogenic pressure together with the abiotic and biotic factors driving them.


Asunto(s)
Materia Orgánica Disuelta , Ríos , Sustancias Húmicas/análisis , Análisis Factorial , Estaciones del Año , China , Espectrometría de Fluorescencia
18.
Int J Syst Evol Microbiol ; 72(11)2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36367518

RESUMEN

An aerobic denitrifying bacterium, designated as strain CPY4T, was isolated from activated sludge treating urban sewage under alternating aerobic/anaerobic conditions by an enrichment culture technique. Cells of strain CPY4T were Gram-stain-negative, aerobic, long rod-shaped, motile by means of single polar flagellum and capable of aerobic denitrification with citrate as the carbon source. Growth of strain CPY4T was observed at 10-45 °C (optimum, 30-35 °C), at pH 6.0-10.5 (optimum, pH 8.0-8.5) and in 0-5 % NaCl (optimum, 0-3 %; w/v). The 16S rRNA gene sequence of strain CPY4T showed the highest similarity to Zobellella denitrificans ZD1T (97.9 %), followed by Zobellella endophytica 59N8T (97.6 %), Zobellella aerophila JC2671T (97.2 %), Zobellella taiwanensis ZT1T (97.1 %) and Zobellella maritima 102-Py4T (96.3 %). Genome comparisons between CPY4T and other Zobellella species showed highest digital DNA-DNA hybridization with Z. denitrificans ZD1T (43.8 %) and highest average nucleotide identity (ANIb and ANIm) of genome nucleotide sequences with Z. denitrificans ZD1T(90.7 and 92 %, respectively). Phylogenetic analysis revealed that strain CPY4T fell within the clade comprising the type strains of Zobellella species and formed a phyletic line with them, which was distinct from other members of the family Aeromonadaceae. The sole respiratory ubiquinone was quinone 8. The predominant fatty acids (>10 % of the total fatty acids) of strain CPY4T were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) and C16 : 0. The genomic DNA G+C content was 62.7 mol %. In the polar lipid profile, diphosphatidylglycerol, phosphatidylglycerol, phosphatidyl ethanolamine, phospholipids and aminolipids were the major compounds. Based on the genotypic and phenotypic data, strain CPY4T represents a novel species of the genus Zobellella, for which the name Zobellella iuensis sp. nov. is proposed. The type strain is CPY4T (=JCM 34456T=CGMCC 1.18722T).


Asunto(s)
Aeromonadaceae , Aguas del Alcantarillado/microbiología , ARN Ribosómico 16S/genética , Filogenia , Composición de Base , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/química , Análisis de Secuencia de ADN , Fosfolípidos/química , Ubiquinona/química
19.
Nat Commun ; 13(1): 7001, 2022 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-36385095

RESUMEN

An acute inflammatory response needs to be properly regulated to promote the elimination of pathogens and prevent the risk of tumorigenesis, but the relevant regulatory mechanism has not been fully elucidated. Here, we report that Ras guanine nucleotide-releasing protein 1 (RasGRP1) is a bifunctional regulator that promotes acute inflammation and inhibits inflammation-associated cancer. At the mRNA level, Rasgrp1 activates the inflammatory response by functioning as a competing endogenous RNA to specifically promote IL-6 expression by sponging let-7a. In vivo overexpression of the Rasgrp1 3' untranslated region enhances lipopolysaccharide-induced systemic inflammation and dextran sulphate sodium-induced colitis in Il6+/+ mice but not in Il6-/- mice. At the protein level, RasGRP1 overexpression significantly inhibits the tumour-promoting effect of IL-6 in hepatocellular carcinoma progenitor cell-like spheroids. Examination of the EGFR signalling pathway shows that RasGRP1 inhibits inflammation-associated cancer cell growth by disrupting the EGFR-SOS1-Ras-AKT signalling pathway. Tumour patients with high RasGRP1 expression have better clinical outcomes than those with low RasGRP1 expression. Considering that acute inflammation rarely leads to tumorigenesis, this study suggests that RasGRP1 may be an important bifunctional regulator of the acute inflammatory response and tumour growth.


Asunto(s)
Factores de Intercambio de Guanina Nucleótido , Interleucina-6 , Ratones , Animales , Interleucina-6/genética , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Transformación Celular Neoplásica/genética , Inflamación/genética , Sinapsinas , Receptores ErbB
20.
Crit Rev Biotechnol ; : 1-16, 2022 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36424845

RESUMEN

Bioelectrochemical systems such as microbial fuel cells (MFCs) have gained extensive attention due to their abilities to simultaneously treat wastewater and generate renewable energy resources. Recently, to boost the system performance, the photoelectrode has been incorporated into MFCs for effectively exploiting the synergistic interaction between light and microorganisms, and the resultant device is known as photo-assisted microbial fuel cells (photo-MFCs). Combined with the metabolic reaction of organic compounds by microorganisms, photo-MFCs are capable of simultaneously converting both chemical energy and light energy into electricity. This article aims to systematically review the recent advances in photo-MFCs, including the introduction of specific photosynthetic microorganisms used in photo-MFCs followed by the discussion of the fundamentals and configurations of photo-MFCs. Moreover, the materials used for photoelectrodes and their fabrication approaches are also explored. This review has shown that the innovative strategy of utilizing photoelectrodes in photo-MFCs is promising and further studies are warranted to strengthen the system stability under long-term operation for advancing practical application.

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