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1.
Opt Lett ; 48(6): 1355-1358, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36946926

RESUMEN

A novel frequency-tunable microwave signal generation method is proposed by incorporating parity-time (PT) symmetry in period-one (P1) laser dynamics in an optically injected semiconductor laser. In this method, P1 oscillation enables a large frequency tuning range and PT symmetry leads to excellent side-mode suppression and low phase noise. In an experimental demonstration, the side-mode suppression ratio reaches 58.4 dB and the phase noise is -126.2 dBc/Hz at 10 kHz offset when generating a 6.98 GHz signal, which are improved by 44.5 dB and 13.5 dB, respectively, compared with the previously reported optoelectronic oscillator-based P1 oscillation. By simply adjusting the optical injection strength, the frequency of the microwave signal generated by PT symmetry P1 dynamics is tuned from 5.07 GHz to 15.22 GHz, in which the phase noise is kept below 120 dBc/Hz at 10 kHz offset. The proposed method is expected to find applications in high-performance wireless communication and radar systems.

2.
Mol Psychiatry ; 27(5): 2414-2424, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35449295

RESUMEN

The lysine-63 deubiquitinase cylindromatosis (CYLD) is long recognized as a tumor suppressor in immunity and inflammation, and its loss-of-function mutations lead to familial cylindromatosis. However, recent studies reveal that CYLD is enriched in mammalian brain postsynaptic densities, and a gain-of-function mutation causes frontotemporal dementia (FTD), suggesting critical roles at excitatory synapses. Here we report that CYLD drives synapse elimination and weakening by acting on the Akt-mTOR-autophagy axis. Mice lacking CYLD display abnormal sociability, anxiety- and depression-like behaviors, and cognitive inflexibility. These behavioral impairments are accompanied by excessive synapse numbers, increased postsynaptic efficacy, augmented synaptic summation, and impaired NMDA receptor-dependent hippocampal long-term depression (LTD). Exogenous expression of CYLD results in removal of established dendritic spines from mature neurons in a deubiquitinase activity-dependent manner. In search of underlying molecular mechanisms, we find that CYLD knockout mice display marked overactivation of Akt and mTOR and reduced autophagic flux, and conversely, CYLD overexpression potently suppresses Akt and mTOR activity and promotes autophagy. Consequently, abrogating the Akt-mTOR-autophagy signaling pathway abolishes CYLD-induced spine loss, whereas enhancing autophagy in vivo by the mTOR inhibitor rapamycin rescues the synaptic pruning and LTD deficits in mutant mice. Our findings establish CYLD, via Akt-mTOR signaling, as a synaptic autophagy activator that exerts critical modulations on synapse maintenance, function, and plasticity.


Asunto(s)
Macroautofagia , Proteínas Proto-Oncogénicas c-akt , Animales , Enzimas Desubicuitinizantes/metabolismo , Mamíferos/metabolismo , Ratones , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/fisiología , Sinapsis/metabolismo , Serina-Treonina Quinasas TOR/metabolismo
3.
Environ Res ; 212(Pt C): 113356, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35489476

RESUMEN

Metagenomic approach was applied to simultaneously reveal the antibiotic resistance genes (ARGs) and antibacterial biocide & metal resistance genes (BMRGs), and the corresponding microbial hosts with high mobility during aerobic granular sludge (AGS) formation process. The results showed that the relative abundance of BMRGs was 88-123 times that of ARGs. AGS process was easier to enrich BMRGs, leading to a greater risk of drug resistance caused by BMRGs than that by ARGs. The enrichments of ARGs and BMRGs in AGS were closely related to several enhanced microbial metabolisms (i.e., cell motility, transposase and ATP-binding cassette transporters) and their corresponding regulatory genes. Several enhanced KEGG Orthologs (KO) functions, such as K01995, K01996, K01997 and K02002, might cause a positive impact on the spread of ARGs and BMRGs, and the main contributors were the largely enriched glycogens accumulating organisms. The first dominant ARGs (adeF) was carried by lots of microbial hosts, which might be enriched and propagated mainly through horizontal gene transfer. Candidatus Competibacter denitrificans simultaneously harbored ARG (cmx) and Cu related RGs (corR). Many enriched bacteria contained simultaneously multiple BMRGs (copR and corR) and mobile genetic elements (integrons and plasmids), granting them high mobility capabilities and contributing to the spread of BMRGs. This study might provide deeper understandings of the proliferation and mobility of ARGs and BMRGs, importantly, highlighted the status of BMRGs, which laid the foundation for the controlling widespread of resistance genes in AGS.


Asunto(s)
Desinfectantes , Metales Pesados , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Genes Bacterianos , Aguas del Alcantarillado
4.
Environ Res ; 206: 112606, 2022 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-34954146

RESUMEN

The partial nitrification-anammox (PN/A) process is a promising method for the treatment of municipal wastewater. It is necessary to clarify the responses of PN/A system to antimicrobial agent triclosan (TCS) widely existed in the influent of wastewater treatment plants. In this study, it was found that PN/A system was robust to cope with 0.5 mg/L TCS. Specifically, the control reactor reached 80% total nitrogen removal efficiency (TNRE) on day 107, while the reactor feeding with 0.5 mg/L TCS reached the same TNRE on day 84. The results of the activity test, high-throughput sequencing and DNA-based stable isotope probing showed that 0.5 mg/L TCS did not impede the performance of ammonia oxidizing archaea, ammonia oxidizing bacteria (Nitrosomonas) and anammox bacteria (Candidatus Brocadia and Ca. Kuenenia), but significant inhibited the nitrite oxidizing bacteria (Nitrospira and Ca. Nitrotoga) and denitrifying bacteria. The influent TCS led to the increase of EPS content and enrichment of four resistance genes (RGs) (intI1, sul1, mexB, and tnpA), which might be two principal mechanisms by which PN/A can resist TCS. In addition, functional bacteria carrying multiple RGs also contributed to the maintenance of PN/A system function. These findings improved the understandings of antimicrobial effects on the PN/A system.


Asunto(s)
Nitrificación , Triclosán , Oxidación Anaeróbica del Amoníaco , Reactores Biológicos , Matriz Extracelular de Sustancias Poliméricas , Nitrógeno , Oxidación-Reducción , Aguas del Alcantarillado , Triclosán/farmacología , Aguas Residuales
5.
J Environ Sci (China) ; 92: 211-223, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32430124

RESUMEN

Triclosan (TCS) is commonly found in wastewater treatment plants, which often affects biological treatment processes. The responses of nitrification, antibiotic resistome and microbial community under different TCS concentrations in activated sludge system were evaluated in this study. The experiment was conducted in a sequencing batch reactor (SBR) for 240 days. Quantitative PCR results demonstrated that the abundance of ammonium oxidizing bacteria could be temporarily inhibited by 1 mg/L TCS and then gradually recovered. And the abundances of nitrite oxidizing bacteria (NOB) under 2.5 and 4 mg/L TCS were three orders of magnitude lower than that of seed sludge, which accounted for partial nitrification. When the addition of TCS was stopped, the abundance of NOB increased. The mass balance experiments of TCS demonstrated that the primary removal pathway of TCS changed from adsorption to biodegradation as TCS was continuously added into the SBR system. Moreover, TCS increased the abundance of mexB, indicating the efflux pump might be the main TCS-resistance mechanism. As a response to TCS, bacteria could secrete more protein (PN) than polysaccharide. Three-dimensional excitation-emission matrix revealed that tryptophan PN-like substances might be the main component in PN to resist TCS. High-throughput sequencing found that the relative abundances of Paracoccus, Pseudoxanthomonas and Thauera increased, which could secrete extracellular polymeric substances (EPS). And Sphingopyxis might be the main TCS-degrading bacteria. Overall, TCS could cause partial nitrification and increase the relative abundances of EPS-secreting bacteria and TCS-degrading bacteria.


Asunto(s)
Nitrificación , Triclosán , Reactores Biológicos , Nitritos , Aguas del Alcantarillado , Aguas Residuales
6.
Soft Matter ; 15(11): 2391-2399, 2019 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-30776045

RESUMEN

In this work, we study the plane-strain deformations of hyperelastic plates induced by differential growth, aiming to derive some analytical formulas for 2D shape-programming of hyperelastic plates. First, we present a plate equation system with the growth functions incorporated, which is derived from the 3D governing system through a series expansion and truncation approach. By proposing a novel analytical method, the plate equation system is solved explicitly. The obtained solutions can reveal the dependence of the current configurations of the hyperelastic plates on the differential growth fields. By solving an inverse problem, some analytical formulas are obtained, which can be used to identify the growth functions for generating arbitrary 2D geometrical shapes of the hyperelastic plates. To demonstrate the efficiency of these formulas, some representative examples are studied, which show good consistency with the numerical simulations. The obtained analytical formulas have wide potential applications in the design of intelligent soft devices.

7.
Phys Rev Lett ; 120(21): 215503, 2018 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-29883155

RESUMEN

Instability patterns of rolling up a sleeve appear more intricate than the ones of walking over a rug on floor, both characterized as systems of uniaxially compressed soft film on stiff substrate. This can be explained by curvature effects. To investigate pattern transitions on a curved surface, we study a soft shell sliding on a rigid cylinder by experiments, computations and theoretical analyses. We reveal a novel postbuckling phenomenon involving multiple successive bifurcations: smooth-wrinkle-ridge-sagging transitions. The shell initially buckles into periodic axisymmetric wrinkles at the threshold and then a wrinkle-to-ridge transition occurs upon further axial compression. When the load increases to the third bifurcation, the amplitude of the ridge reaches its limit and the symmetry is broken with the ridge sagging into a recumbent fold. It is identified that hysteresis loops and the Maxwell equal-energy conditions are associated with the coexistence of wrinkle-ridge or ridge-sagging patterns. Such a bifurcation scenario is inherently general and independent of material constitutive models.

8.
Micromachines (Basel) ; 15(6)2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38930754

RESUMEN

Microfabrication technology with quartz crystals is gaining importance as the miniaturization of quartz MEMS devices is essential to ensure the development of portable and wearable electronics. However, until now, there have been no reports of dimension compensation for quartz device fabrication. Therefore, this paper studied the wet etching process of Z-cut quartz crystal substrates for making deep trench patterns using Au/Cr metal hard masks and proposed the first quartz fabrication dimension compensation strategy. The size effect of various sizes of hard mask patterns on the undercut developed in wet etching was experimentally investigated. Quartz wafers masked with initial vias ranging from 3 µm to 80 µm in width were etched in a buffered oxide etch solution (BOE, HF:NH4F = 3:2) at 80 °C for prolonged etching (>95 min). It was found that a larger hard mask width resulted in a smaller undercut, and a 30 µm difference in hard mask width would result in a 17.2% increase in undercut. In particular, the undercuts were mainly formed in the first 5 min of etching with a relatively high etching rate of 0.7 µm/min (max). Then, the etching rate decreased rapidly to 27%. Furthermore, based on the etching width compensation and etching position compensation, new solutions were proposed for quartz crystal device fabrication. And these two kinds of compensation solutions were used in the fabrication of an ultra-small quartz crystal tuning fork with a resonant frequency of 32.768 kHz. With these approaches, the actual etched size of critical parts of the device only deviated from the designed size by 0.7%. And the pattern position symmetry of the secondary lithography etching process was improved by 96.3% compared to the uncompensated one. It demonstrated significant potential for improving the fabrication accuracy of quartz crystal devices.

9.
bioRxiv ; 2023 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-37781625

RESUMEN

Deubiquitinases present locally at synapses regulate synaptic development, function, and plasticity. It remains largely unknown, however, whether deubiquitinases localized outside of the synapse control synapse remodeling. Here we identify ubiquitin specific protease 48 (USP48; formerly USP31) as a nuclear deubiquitinase mediating robust synapse removal. USP48 is expressed primarily during the first postnatal week in the rodent brain and is virtually restricted to nuclei, mediated by a conserved, 13-amino acid nuclear localization signal. When exogenously expressed, USP48, in a deubiquitinase and nuclear localization-dependent manner, induces striking filopodia elaboration, marked spine loss, and significantly reduced synaptic protein clustering in vitro, and erases ~70% of functional synapses in vivo. USP48 interacts with the transcription factor NF-κB, deubiquitinates NF-κB subunit p65 and promotes its stability and activation, and up-regulates NF-κB target genes known to inhibit synaptogenesis. Depleting NF-κB prevents USP48-dependent spine pruning. These findings identify a novel nucleus-enriched deubiquitinase that plays critical roles in synapse remodeling.

10.
Nat Prod Res ; 37(14): 2335-2341, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35212249

RESUMEN

Starting from L-tryptophan, 19 new N-substituted chiral indole analogs were synthesized. The prepared compounds were evaluated for biological activity against Sclerotinia sclerotiorum, Alternaria solani, Verticillium dahliae, Colletotrichum orbiculare, Cytospora juglandis and Curvularia lunata. The preliminary bioassays showed that most of the synthesized compounds exhibited fungicidal activity. Compound b13 in particular exhibited significant antifungal activity against Verticillium dahliae and Sclerotinia sclerotiorum, with the MIC value of 1.95 µg mL-1. Compound b13 also showed excellent activity against six plant pathogen fungi, and was identified as the most active on the biological assays, and will be studied further.


Asunto(s)
Antifúngicos , Ascomicetos , Antifúngicos/farmacología , Hongos , Indoles/farmacología , Relación Estructura-Actividad
11.
Sci Total Environ ; 855: 158916, 2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36155029

RESUMEN

Anaerobic ammonium oxidation (anammox) is well-known to be an environmental and promising biotechnology. However, the natural enrichment of anammox bacteria is still a challenging topic. In this study, partial S(0)-driven autotrophic denitrification (PSAD) was developed to stably supply nitrite, and natural enrichment of anammox bacteria was rapidly realized in a single sequencing moving bed biofilm reactor at room temperature. With the initiation of PSAD, anammox bacteria spontaneously emerged within 12 days, and PSAD-anammox coupling system was realized successfully. And then, the influent concentration of ammonium continuously increased to the same concentration as the nitrate, and the mean total nitrogen removal efficiency reached 92.77 %, which was mainly contributed by anammox. Moreover, the coupling of PSAD and anammox reduced the risk of sulfate emissions. cDNA high throughput sequencing revealed that the relative abundance of Candidatus Brocadia and Thiobacillus reached 39.03 % and 13.48 % at the 88th day. Oligotyping analysis illustrated that GATTTAAT and GTCCCA were the dominant Ca. Brocadia and Thiobacillus oligotypes in PSAD-anammox coupling system, respectively. DNA-based stable isotope probing further deciphered that Thiobacillus was the actual performer of PSAD and supported the nitrite for anammox bacteria in PSAD-anammox coupling system. Overall, this work provided a new strategy to naturally enrich anammox bacteria.


Asunto(s)
Compuestos de Amonio , Desnitrificación , Reactores Biológicos/microbiología , Nitritos , Oxidación Anaeróbica del Amoníaco , Temperatura , Oxidación-Reducción , Bacterias/genética
12.
Nat Prod Res ; 37(19): 3261-3266, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37682697

RESUMEN

In this work, a total of 19 novel naphthalene hybrids with chimonanthine scaffolds were efficiently synthesised from indole-3-acetonitrile in good yields. The prepared compounds were evaluated for biological activity against Cryptococcus neoformans, Escherichia coli, Shigella spp, Candida albicans, Salmonella spp, and Staphylococcus aureus. The preliminary bioassays showed that most of the synthesised compounds exhibited significant antibacterial or antifungal activity. Notably, compound 8 showed potent activity against Cryptococcus neofonmans, Escherichia coli, Shigella spp, and Candida albicans than the positive control, all with the same MIC value of 3.53 µM. Compound 8 had a broad spectrum of antibacterial or antifungal activity, and will be studied further.


Asunto(s)
Antifúngicos , Cryptococcus neoformans , Antifúngicos/farmacología , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Candida albicans , Escherichia coli , Naftalenos/farmacología , Relación Estructura-Actividad
13.
Neuron ; 111(6): 797-806.e6, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36638803

RESUMEN

Empathic function is essential for the well-being of social species. Empathy loss is associated with various brain disorders and represents arguably the most distressing feature of frontotemporal dementia (FTD), a leading form of presenile dementia. The neural mechanisms are unknown. We established an FTD mouse model deficient in empathy and observed that aged somatic transgenic mice expressing GGGGCC repeat expansions in C9orf72, a common genetic cause of FTD, exhibited blunted affect sharing and failed to console distressed conspecifics by affiliative contact. Distress-induced consoling behavior activated the dorsomedial prefrontal cortex (dmPFC), which developed profound pyramidal neuron hypoexcitability in aged mutant mice. Optogenetic dmPFC inhibition attenuated affect sharing and other-directed consolation in wild-type mice, whereas chemogenetically enhancing dmPFC excitability rescued empathy deficits in mutant mice, even at advanced ages when substantial cortical atrophy had occurred. These results establish cortical hypoexcitability as a pathophysiological basis of empathy loss in FTD and suggest a therapeutic strategy.


Asunto(s)
Enfermedad de Alzheimer , Esclerosis Amiotrófica Lateral , Demencia Frontotemporal , Ratones , Animales , Demencia Frontotemporal/genética , Empatía , Expansión de las Repeticiones de ADN , Enfermedad de Alzheimer/genética , Ratones Transgénicos , Proteína C9orf72/genética , Esclerosis Amiotrófica Lateral/genética
14.
Foods ; 11(19)2022 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-36230185

RESUMEN

The effects of cysteine addition (0%, 0.05%, 0.10%, 0.15%, 0.20%, 0.25%) on the physicochemical properties of plant-based extrudates by high-moisture extrusion were investigated. The texturization degree, rheological properties, hardness, springiness and chewiness of the extrudates significantly improved with the addition of cysteine (<0.15%). Analysis of the microstructure showed that the addition of cysteine (<0.15%) improved the formation of the fiber structure in the extrudates. Cysteine (<0.15%) promoted the formation of new disulfide bonds and non-covalent bonds by changing the disulfide bonds of protein molecules and enhanced the cross-linking degree between proteins. However, the excessive addition of cysteine (>0.15%) had a negative impact on the formation of fiber structure. Analysis of secondary structure suggested that the ordered ß-sheet structures gradually converted to the disordered ß-turn and random coil structures with the addition of cysteine (>0.15%). In addition, analysis of odor properties with the addition of cysteine using an electronic nose showed the difference in volatile components of the extrudates mainly existed in halides, hydrocarbons, sulfides and amines. On the whole, the addition of cysteine could improve the quality of plant-based extrudates.

15.
Water Res ; 210: 118011, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34979468

RESUMEN

Granule-based partial denitrification (PD) is a technology that can supply stable nitrite for applying anaerobic ammonia oxidation in wastewater treatment, and triclosan (TCS) is a frequently detected antibacterial agent in wastewater treatment plants, therefore it is possible that TCS could enter into wastewater that is treated using PD technology. However, the active microorganisms responsible for PD and TCS removing in granule-based PD system have not been clearly identified and it is currently not clear how TCS affects the PD process. In this study, the impacts of TCS on PD performance, PD microbial community, antibiotic resistance genes (ARGs), active PD bacteria and TCS-degrading bacteria in a granule-based PD system were investigated. 3 mg/L TCS had adverse influence on PD process, but PD system could recover gradually after inhibiting of 10 days. After a period of domestication, PD granular sludge could achieve 10.66% of TCS degradation efficiency and 43.62% of TCS adsorption efficiency. Microbes might increase their resistance to TCS by increasing the secretion of extracellular polymeric substances, and the secretion of protein might play a more pivotal role than the secretion of polysaccharides in resisting TCS. The short-term shock of TCS might cause the propagation of acrA-03, while the long-term operation of TCS could propagate fabK and intI1. DNA stable isotope probing assay indicated that Thauera was active PD bacteria and TCS-degrading bacteria in the granule-based PD system, and it could contribute to nitrite accumulation and TCS degradation, simultaneously.


Asunto(s)
Triclosán , Oxidación Anaeróbica del Amoníaco , Bacterias/genética , ADN , Desnitrificación , Isótopos
16.
Sci Total Environ ; 839: 156330, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-35640752

RESUMEN

Knowledge gaps still surround the question of what biofilms form on contaminated microplastics (MPs) in the antibiotics and (or) heavy metals polluted sewage. In this work, the clean polyethylene microplastics (PE MPs) and triclocarban (TCC)-contaminated PE MPs were cultured in the sewage containing only ampicillin (AMP), only copper (Cu) and both AMP and Cu for 28 days. The results showed that the TCC on PE MPs (with concentration of 2.48 mg/g PE MPs) did not impede the adhesion of the bacteria and the formation of biofilm. Moreover, many potential pathogenic bacteria (Aquabacterium and Pseudoxanthomonas) and potential resistant bacteria (Stenotrophomonas) were more likely to attach on TCC-contaminated PE MPs compared with clean PE MPs. In addition, biofilms of TCC-contaminated PE MPs had highest potential pathogenic functions. TCC-contaminated PE MPs also caused the increases of various resistance genes in both biofilm and sewage. The co-occurrence of TCC, AMP and Cu might exert a stronger selective pressure on bacterial communities and promote the co-selection of resistance genes. In addition, TCC-contaminated PE MPs resulted in higher abundance of five mobile genetic elements (MGEs) (intI1, intI3, tnpA-04, IS613 and trb-C) in sewage, which might further promote the transmission of resistance genes.


Asunto(s)
Metales Pesados , Microplásticos , Antibacterianos , Bacterias/genética , Carbanilidas , Genes Bacterianos , Plásticos , Polietileno , Aguas del Alcantarillado
17.
Sci Total Environ ; 815: 152871, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-34998773

RESUMEN

Triclosan (TCS) and copper (Cu2+) were exposed to aerobic granular sludge (AGS) system treating wastewater containing environmental tetracycline, respectively, to explore the different biochemical responses, more importantly, the fates of resistance genes (RGs) in AGS system. The results showed that TCS and Cu2+ could significantly inhibit the N and P removal in AGS system by reducing several key functional genes, including amoA gene of ammonia-oxidizing bacteria, Nitrospira and phosphorus accumulating organisms 16S rRNA genes. TCS caused higher degree of RGs' enrichment than Cu2+, which made the average total relative abundance of RGs of 1.38 ± 0.73 and 0.78 ± 0.24 in TCS and Cu system, respectively. Cu2+ could induce a wider range of horizontal gene transfer than TCS, leading to the detections of more potential hosts harboring RGs in Cu system. Cu system seemed to have stronger repair, immunity and defense ability than TCS system, which enabled it to have sufficient ability to trigger protection mechanism to realize self-protection, eventually the RGs also were controlled. Integron (intI1 and intI3) and plasmids (trb-C and IncQ) might cooperate with microorganisms and water quality parameters to enhance the enrichment of RGs in TCS system, however this interaction among various environmental factors was not obvious in Cu system, which might be responsible for the lower abundance of RGs. The increasing levels of TCS and Cu2+ in wastewater should be paid more attentions during the treatment of wastewater containing environmental tetracycline by AGS system. Especially for TCS, it had the ability to enrich RGs more easily than Cu2+, which should be prevented from entering wastewater treatment plants as far as possible, to avoid more serious proliferation and dissemination of various RGs.


Asunto(s)
Aguas del Alcantarillado , Triclosán , Cobre/toxicidad , ARN Ribosómico 16S , Tetraciclina , Triclosán/toxicidad , Aguas Residuales
18.
Water Res ; 217: 118395, 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35429877

RESUMEN

Hexadecyl trimethyl ammonium chloride (ATMAC-C16) is a kind of quaternary ammonium compound (QACs) which is extensively consumed as disinfectants, antimicrobials and surfactants. Here, the partial nitrification/anammox (PN/A) system was exposed to different levels of ATMAC-C16 (0-10 mg/L) and the main objective was to reveal the long-term microbiological responses of PN/A system to ATMAC-C16, importantly, explore the tolerance of PN/A to ATMAC-C16 and the key resistant strain. Nitrogen removal efficiency was influenced by environmental and extreme levels of ATMAC-C16 through mainly affecting the anammox (hzsB) gene. Two types of anammox, Candidatus Jettenia and Candidatus Kuenenia, were enriched under the pressure of ATMAC-C16, which allowed PN/A system to maintain good nitrogen removal performance. ATMAC-C16 might cause the hormesis of entire microbial population in PN/A system, leading to the enhancement of cell viability. ATMAC-C16 decreased the relative abundances of most antibiotics resistance genes (ARGs) but significantly enriched QACs resistance genes (QRGs). The tolerance of PN/A system to ATMAC-C16 might be strengthened by inducing the efflux pumps encoding genes (qacH-01/02). Microbial hosts dynamic and co-selection mechanism among ARGs and QRGs resulted in the opposite trends of qacEdeltal-01/02 and qacH-01/02. Pseudoxanthomonas mexicana was identified as the ATMAC-C16 resistant strain, and its resistance to 10 mg/L ATMAC-C16 might not only obtain by capturing the qacH gene, but also benefit from its own efflux pump system. Therefore, from the perspective of the transmission of resistance genes, especially for QRGs, the spread risk of QRGs and ATMAC-C16 resistant strain in PN/A technique should be taken seriously.


Asunto(s)
Compuestos de Amonio , Nitrificación , Cloruro de Amonio , Oxidación Anaeróbica del Amoníaco , Reactores Biológicos/microbiología , Desnitrificación , Nitrógeno , Oxidación-Reducción , Compuestos de Amonio Cuaternario/farmacología , Aguas del Alcantarillado
19.
Bioresour Technol ; 347: 126429, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34838974

RESUMEN

Triclocarban (TCC) is in great market demand especially after the outbreak of COVID-19 pandemic, becoming an emerging pollutant. However, the impacts of TCC on the performance of nitrifying granular sludge system and the occurrence of antibiotic resistance genes (ARGs) were still unknown. This work explored the impacts of different concentrations of TCC on nitrifying granular sludge. Results showed that TCC suppressed the activities of ammonia-oxidizing microorganisms and decreased the abundance of Nitrospira. Adsorption was the main way for the removal of TCC and the biodegradation efficiency of TCC increased to 28.00% under 19.70 mg/L TCC addition. TCC enriched the ARGs and promoted the risks of their transferring in microorganisms. Pseudomonas might not only have strong resistance to TCC, but also propagate ARGs. The removal process of TCC and bacterial communities were important factors to promote the spread of ARGs. Thus, the existence of TCC presented a great environmental risk.


Asunto(s)
COVID-19 , Microbiota , Antibacterianos/farmacología , Carbanilidas , Farmacorresistencia Microbiana , Genes Bacterianos/genética , Humanos , Pandemias , SARS-CoV-2 , Aguas del Alcantarillado
20.
J Hazard Mater ; 438: 129465, 2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-35785744

RESUMEN

Chloroxylenol (PCMX), an antibacterial agent, has been widely detected in water environment and has toxic effects on biology and ecology. During 270 d, the influence of PCMX on the performance of three nitrification systems was investigated, including floc-based sequencing batch reactor (FSBR), aerobic granule-based SBR (AGSBR) and biofilm SBR (BSBR). The nitrification capability of three systems was inhibited by PCMX, but recovered after domestication, and PCMX made three systems realize partial nitrification for 10, 100 and 35 days, respectively. The extracellular polymeric substances of three systems increased first and then decreased with the increment of PCMX. The granular structure of AGSBR may be conducive to the enrichment of antibiotic resistance genes (ARGs), and almost all ARGs of BSBR were reduced during the addition of 5.0 mg/L PCMX. The microbial community results showed that Rhodococcus as potential degrading bacteria was continuously enriched in three systems. Piscinibacter was regarded as the potential antibiotic resistant bacteria, which was positively associated with multiple ARGs in three systems. Additionally, quaternary ammonium compounds resistance genes had a variety of positive correlations with bacteria in three systems. This study provided a new perspective for the usage and treatment of PCMX.


Asunto(s)
Microbiota , Aguas del Alcantarillado , Antibacterianos/farmacología , Bacterias/genética , Biopelículas , Reactores Biológicos/microbiología , Farmacorresistencia Microbiana/genética , Nitrificación , Aguas del Alcantarillado/química , Xilenos
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