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The construction and precise synthesis of materials based on functional and structural orientations have emerged as a pivotal platform in the field of environmental management. In this paper, an efficient and stable catalyst (RuLDH) was constructed to achieve this goal. RuLDH comprises individual Ru atoms that are uniformly dispersed on ZnAl-LDH, achieved by room temperature stirring. Remarkably, RuLDH exhibits exceptional performance under visible light, effectively triggering the photocatalytic degradation of tetracycline hydrochloride (TC) via peroxymonosulfate (PMS) with a remarkable efficiency of 100%, all while avoiding the generation of highly toxic intermediates. In addition, RuLDH0.2 demonstrated its utility in fluorescence detection of TC, showcasing commendable analytical performance characterized by rapid response, low detection limit, and robust resistance to environmental interferences (with a detection limit of 1.0 mg/L). Notably, the RuLDH0.2/PMS/Vis system exhibited remarkable efficacy in treating actual pesticide wastewater, effectively exerting bactericidal and disinfectant effects. This study serves as a source of inspiration for the design of multifunctional single-atom catalysts, thereby pushing the boundaries of "integration of diagnosis and treatment" in environmental management and control.
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Desinfetantes , Rutênio , Antibacterianos/farmacologia , Tetraciclina , PeróxidosRESUMO
The purpose of this article is to evaluate the clinical effect of clinical practice guideline on traditional Chinese medicine therapy alone or combined with antibiotics for acute tonsillitis. The applicability and application of the Guideline were evaluated based on the clinicians by using the electronic questionnaire. Questionnaires about 538 on application evaluation and 502 questionnaires on applicability evaluation were completed from April 28 to July 9, 2018. The subjects in the questionnaires include the clinicians with junior title, intermediate title, and senior title that have used this Guideline. The descriptive statistical analysis of the collected questionnaire was carried out. In the applicability evaluation, according to the classification of professional titles, the application rate was highest in intermediate title clinicians (26.77%), followed by junior (23.98%) and deputy senior (19.33%) professional title clinicians. In the quality evaluation, the rationality of application scope (98.61%) and the terminology accuracy (98.81%) scores were higher, and the rationality of differentiation and classification (96.05%) was the lowest. The applicability evaluation suggested that clinicians believed this Guideline had high safety (98.42%), reasonable content (98.03%), significant effect (99.6%), reduced use of antibiotics in Western medicine (93.89%), and a high applicability ratio (96.44%). In the application evaluation, Department of lung disease showed the highest application rate (44.24%); rationality of the Guideline was more than 97% in treatment rules and prophylaxis except the syndrome differentiation (92.75%); a high ratio of clinicians believed the recommended scheme was good: curative effect 97.4%, safety 97.59%, and economy 93.87%. The study shows that the clinical practice guideline on traditional Chinese medicine therapy alone or combined with antibiotics for acute tonsillitis is of good quality, high clinical use and good effect. It can be used as a standardized treatment scheme for acute tonsillitis in traditional Chinese medicine. But there are some unsuitable contents and need to be further improved. The Guideline should strengthen the revision on differentiation of symptoms and signs as well as prophylaxis.
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Medicina Tradicional Chinesa , Tonsilite , Antibacterianos , Humanos , Guias de Prática Clínica como Assunto , Inquéritos e Questionários , Síndrome , Tonsilite/tratamento farmacológicoRESUMO
Though evaluation and analysis on the relevant literatures at home and abroad in recent years, the total number of retrieved literature was 2 664. According to the inclusion criteria and exclusion criteria,the literatures were screened out, and the results were as followsï¼374 literatures. To analyse the advantages and evidence of Chinese medicine in the prevention and treatment of adult acute tonsillitis. It is found to be effective, convenient and practical for the treatment of acute tonsillitis by traditional Chinese medicine (TCM) like treatment according to syndrome differentiation, Chinese patent drug, self Chinese medicine prescription and external treatment. TCM has obvious advantages in the prevention and treatment of acute tonsillitis, has the function of supplementing or substituting antibiotics, and has the function of regulating the defense function of organism.
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Medicina Tradicional Chinesa , Tonsilite/prevenção & controle , Tonsilite/terapia , Adulto , Medicamentos de Ervas Chinesas/uso terapêutico , HumanosRESUMO
Clinical practice guideline (CPG) should be concise and readability, which can be possible to implement CPG into practice smoothly. A formal published CPG can't load its developing process and details. An editorial explanation of CPG is much useful to show details and logic process of developing CPG. Although there are many different standards for developing CPG, being nothing to do with process management of CPG. By referring to editorial explanation on international standards, a request for CPG was investigated in this study. An editorial explanation for clinical practice guideline should be transparency, logic and traceable. A good editorial explanation could make users or readers to learn what goes on behind the scenes. A standardized editorial explanation could supervise the GCP developing and improve the quality of GCP.
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Políticas Editoriais , Guias de Prática Clínica como Assunto/normasRESUMO
Due to the emerging environmental issues related to heavy metals, concern about the soil quality of farming lands near manufacturing district is increasing. Investigating the function of soil microorganisms exposed to long-term heavy metal contamination is meaningful and important for agricultural soil utilization. This article studied the potential influence of several heavy metals on microbial biomass, activity, abundance, and community composition in arable soil near industrial estate in Zhuzhou, Hunan province, China. The results showed that soil organic contents (SOC) were significantly positive correlated with heavy metals, whereas dehydrogenase activity (DHA) was greatly depressed by the heavy metal stress. Negative correlation was found between heavy metals and basal soil respiration (BSR), and no correlation was found between heavy metals and microbial biomass content (MBC). The quantitative PCR (QPCR) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis could suggest that heavy metal pollution has significantly decreased abundance of bacteria and fungi and also changed their community structure. The results could contribute to evaluate heavy metal pollution level in soil. By combining different environmental parameters, it would promote the better understanding of heavy metal effect on the size, structure, and activity of microbial community in arable soil.
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Bactérias/efeitos dos fármacos , Biodiversidade , Fungos/efeitos dos fármacos , Metais Pesados/farmacologia , Poluentes do Solo/farmacologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biomassa , China , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Metais Pesados/análise , Rizosfera , Solo/química , Microbiologia do Solo , Poluentes do Solo/análiseRESUMO
Increasing molecular evidence points to a wide occurrence of laccase-like multicopper oxidase (LMCO)-encoding genes in bacteria. Most researches mainly focused on the bacterial LMCO diversity, whereas the processes and the environmental factors responsible for structuring bacterial LMCO communities remain relatively unknown in a composting system. Six gene libraries were constructed from samples in representative stages during composting. A total of 185 sequences obtained from sample DNA extracts were classified to 59 operational taxonomic units (OTUs) based on 10 % cutoff. The distribution profile of bacterial LMCO genes showed that proteobacterial- and actinobacterial-associated species were the dominant communities during composting. Pearson correlation analysis indicated that the pile temperature and water-soluble carbon (WSC) content were significantly positively correlated with bacterial LMCO gene OTU numbers, Chao1 and Shannon index, whereas the humic acid (HA)-like carbon content had the most significant effect on the distribution of the bacterial LMCO genes during composting by redundancy analysis. These findings will improve the understanding of the mutual relationship between environmental factors and bacterial LMCO community compositions in composting.
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Biota , Lacase/genética , Monofenol Mono-Oxigenase/genética , Microbiologia do Solo , Solo , Carbono/análise , Solo/química , TemperaturaRESUMO
Traditional three-domain fungal and bacterial laccases have been extensively studied for their significance in various biotechnological applications. Growing molecular evidence points to a wide occurrence of more recently recognized two-domain laccase-like multicopper oxidase (LMCO) genes in Streptomyces spp. However, the current knowledge about their ecological role and distribution in natural or artificial ecosystems is insufficient. The aim of this study was to investigate the diversity and composition of Streptomyces two-domain LMCO genes in agricultural waste composting, which will contribute to the understanding of the ecological function of Streptomyces two-domain LMCOs with potential extracellular activity and ligninolytic capacity. A new specific PCR primer pair was designed to target the two conserved copper binding regions of Streptomyces two-domain LMCO genes. The obtained sequences mainly clustered with Streptomyces coelicolor, Streptomyces violaceusniger, and Streptomyces griseus. Gene libraries retrieved from six composting samples revealed high diversity and a rapid succession of Streptomyces two-domain LMCO genes during composting. The obtained sequence types cluster in 8 distinct clades, most of which are homologous with Streptomyces two-domain LMCO genes, but the sequences of clades III and VIII do not match with any reference sequence of known streptomycetes. Both lignocellulose degradation rates and phenol oxidase activity at pH 8.0 in the composting process were found to be positively associated with the abundance of Streptomyces two-domain LMCO genes. These observations provide important clues that Streptomyces two-domain LMCOs are potentially involved in bacterial extracellular phenol oxidase activities and lignocellulose breakdown during agricultural waste composting.
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Variação Genética , Lignina/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Streptomyces/enzimologia , Streptomyces/genética , Agricultura , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , Dados de Sequência Molecular , Análise de Sequência de DNA , Homologia de Sequência , Solo , Microbiologia do Solo , Streptomyces/crescimento & desenvolvimento , Gerenciamento de ResíduosRESUMO
The input of microplastics (MPs) and warming interfere with soil carbon (C) or nitrogen (N) cycles. Although the effects of warming and/or MPs on the cycles have been well studied, the biological coupling of microbial-driven cycles was neglected. Here, the synergistic changes of the cycles were investigated using batch incubation experiments. As results, the influences of MPs were not significant at 15, 20, and 25 °C, and yet, high temperature (i.e., 30 °C) reduced the respiration of high-concentration MPs-amended soil by 9.80%, and increased dissolved organic carbon (DOC) by 14.74%. In contrast, high temperature did not change the effect of MPs on N. The decrease of microbial biomass carbon (MBC) and the constant of microbial biomass nitrogen (MBN) indicated that microbial N utilization was enhanced, which might be attributed to the enrichments of adapted populations, such as Conexibacter, Acidothermus, and Acidibacter. These observations revealed that high temperature and MPs drove the differential response of soil C and N cycles. Additionally, the transcriptomic provided genomic evidence of the response. In summary, the high temperature was a prerequisite for the MPs-driven response, which underscored new ecological risks of MPs under global warming and emphasized the need for carbon emission reduction and better plastic product regulation.
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Microplásticos , Plásticos , Solo , Carbono , Microbiologia do Solo , Nitrogênio/análise , Ciclo do NitrogênioRESUMO
This research was conducted to distinguish between the separate effects of the Phanerochaete chrysosporium inoculation and sample property heterogeneity induced by different inoculation regimes on the indigenous bacterial communities during agricultural waste composting. P. chrysosporium was inoculated during different phases. The bacterial community abundance and structure were determined by quantitative PCR and denaturing gradient gel electrophoresis analysis, respectively. Results indicated a significant stimulatory effect of P. chrysosporium inoculation on the bacterial community abundance. The bacterial community abundance significantly coincided with pile temperature, ammonium, and nitrate (P<0.006). Variance partition analysis showed that the P. chrysosporium inoculation directly explained 20.5% (P=0.048) of the variation in the bacterial communities, whereas the sample property changes induced by different inoculation regimes indirectly explained up to 35.1% (P=0.002). The bacterial community structure was significantly related to pile temperature, water-soluble carbon (WSC), and C/N ratio when P. chrysosporium were inoculated. The C/N ratio solely explained 7.9% (P=0.03) of the variation in community structure, whereas pile temperature and WSC explained 7.7% (P=0.026) and 7.5% (P=0.034) of the variation, respectively. P. chrysosporium inoculation affected the indigenous bacterial communities most probably indirectly through increasing pile temperature, enhancing the substrate utilizability, and changing other physico-chemical factors.
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Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Biota , Phanerochaete/crescimento & desenvolvimento , Microbiologia do Solo , Solo/química , Carbono/análise , DNA Bacteriano/genética , Eletroforese em Gel de Gradiente Desnaturante , Nitratos/análise , Compostos de Amônio Quaternário/análise , Reação em Cadeia da Polimerase em Tempo Real , TemperaturaRESUMO
The rapid recombination of photogenerated electrons and holes, low utilization of visible light and weak oxidation capacity significantly limit the photocatalytic activity for the degradation of organic pollutants. Doping is used as a conventional strategy for regulating the electronic structure of photocatalysts to obtain a wider light absorption, but also suffers from the problems of reduced charge mobility and oxidation capacity, which is not conducive to photocatalytic degradation of pollutants. To address this issue, a nitrogen self-doped hollow nanotubes g-C3N4 (N-PCN) was synthesized by synergistic self-doping and quantum confinement effects. The N-PCN exhibits excellent efficiency in photocatalytic degradation of TC compared to the pristine g-C3N4. The synthesized N-PCN has a more positive conduction band minimum and can generate more photogenerated electrons to reduce oxygen to superoxide radicals. In addition, experimental and theoretical evidence shows that N-self-doping not only suppresses the recombination of photogenerated charge carriers but also facilitates the adsorption of oxygen molecules. Consequently, more superoxide radicals and singlet oxygen are generated through oxygen activation process.
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Poluentes Ambientais , Catálise , Nanotubos de Carbono/química , Nitrogênio , Oxigênio/química , SuperóxidosRESUMO
Emerging evidence from genomics gives us a glimpse into the potential contribution of lysogenic bacteriophages (phages) to the environmental adaptability of their hosts. However, it is challenging to quantify this kind of contribution due to the lack of appropriate genetic markers and the associated controllable environmental factors. Here, based on the unique transformable nature of arsenic (the controllable environmental factor), a series of flooding microcosms was established to investigate the contribution of arsM-bearing lysogenic phages to their hosts' adaptation to trivalent arsenic [As(III)] toxicity, where arsM is the marker gene associated with microbial As(III) detoxification. In the 15-day flooding period, the concentration of As(III) was significantly increased, and this elevated As(III) toxicity visibly inhibited the bacterial population, but the latter quickly adapted to As(III) toxicity. During the flooding period, some lysogenic phages re-infected new hosts after an early burst, while others persistently followed the productive cycle (i.e., lytic cycle). The unique phage-host interplay contributed to the rapid spread of arsM among soil microbiota, enabling the quick recovery of the bacterial community. Moreover, the higher abundance of arsM imparted a greater arsenic methylation capability to soil microbiota. Collectively, this study provides experimental evidence for lysogenic phages assisting their hosts in adapting to an extreme environment, which highlights the ecological perspectives on lysogenic phage-host mutualism.
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Arsênio , Bacteriófagos , Bacteriófagos/genética , Arsênio/toxicidade , Lisogenia , Bactérias/genética , SoloRESUMO
Insufficient absorption sites and low charge separation notably limit the activation of photocatalytic molecular oxygen. In this study, atomic-layer BiOBr (BiOBr-QDs)/ZnAl-LDH composites with a considerable number of edges were developed to address the above-mentioned problems. The result of this study indicated the spatial separation of atomic-layer BiOBr-QDs/ZnAl-LDH's conduction band maximum (CBM) and valence band minimum (VBM). As a result, holes were produced on the substrate surface based on irradiation, and electrons were generated at the sites of the edge, such that ultra-fast charge separation can be carried out. The edges exposed massive adsorption sites in terms of oxygen molecules. Thus, electrons at the sites of the edge led to the reduction of absorbed oxygen molecules, thus exhibiting stronger photocatalytic â¢O2- production. Furthermore, the result confirmed that the atomic layer BiOBr-QDs/ZnAl-LDH are promising in environmental catalytic degradation for its increased activity of â¢O2- production. In this study, a novel insight into advanced photocatalyst design based on edge unsaturated ligand engineering at an atomic level is provided.
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In wastewater treatment plants (WWTPs), the stable operation of biological wastewater treatment is strongly dependent on the stability of associated microbiota. Bacteriophages (phages), viruses that specifically infect bacteria and archaea, are highly abundant and diverse in WWTPs. Although phages do not have known metabolic functions for themselves, they can shape functional microbiota via various phage-host interactions to impact biological wastewater treatment. However, the developments of phage-host interaction in WWTPs and their impact on biological wastewater treatment are overlooked. Here, we review the current knowledge regarding the phage-host interactions in biological wastewater treatment, mainly focusing on the characteristics of different phage populations, the phage-driven changes in functional microbiota, and the potential driving factors of phage-host interactions. We also discuss the efforts required further to understand and manipulate the phage-host interactions in biological wastewater treatment. Overall, this review advocates more attention to the phage dynamics in WWTPs.
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Bacteriófagos , Microbiota , Águas Residuárias , Purificação da Água , Archaea , Bactérias , Bacteriófagos/fisiologia , Águas Residuárias/microbiologia , Águas Residuárias/virologiaRESUMO
BACKGROUND: Capsule of alkaloids from leaf of Alstonia scholaris (CALAS) is a new investigational botanical drug (No. 2011L01436) for respiratory disease. Clinical population pharmacokinetics (PK), metabolomics and therapeutic data are essential to guide dosing in patients. Previous research has demonstrated the potential therapeutic effect of CALAS on acute bronchitis. Further clinical trial data are needed to verify its clinical efficacy, pharmacokinetics behavior, and influence of dosage and other factors. PURPOSE: To verify the clinical efficacy and explore the potential biomarkers related to CALAS treatment for acute bronchitis. MATERIALS AND METHODS: Oral CALAS was assessed in a randomized, double-blind, placebo-controlled trial. Fifty-five eligible patients were randomly assigned to four cohorts to receive 20, 40 or 80 mg, of CALAS three times daily for seven days, or placebo. Each CALAS cohort included 15 subjects, and the placebo group included 10 subjects. A population PK model of CALAS was developed using plasma with four major alkaloid components. Metabolomics analysis was performed to identify biomarkers correlated with the therapeutic effect of CALAS, and efficacy and safety were assessed based on clinical symptoms and adverse events. RESULTS: The symptoms of acute bronchitis were alleviated by CALAS treatment without serious adverse events or clinically significant changes in vital signs, electrocardiography or upper abdominal Doppler ultrasonography. Moreover, one compartment model with first-order absorption showed that an increase in aspartate transaminase will reduce the clearance (CL) of scholaricine, and picrinine CL was inversely proportional to body mass index, while 19-epischolaricine and vallesamine CL increased with aging. The serum samples from acute bronchitis patients at different time points were analyzed using UPLC-QTOF in combination with the orthogonal projection to latent structures-discriminant analysis, which indicated higher levels of lysophosphatidylcholines, lysophosphatidylethanolamines and amino acids with CALAS treatment than with placebo. CONCLUSION: This is the first study to evaluate the clinical efficacy and explored the potential biomarkers related to CALAS therapeutic mechanism of acute bronchitis by means of clinical trial combined the metabolomics study. This exploratory study provides a basis for further research on clinical efficacy and optimal dosing regimens based on pharmacokinetics behavior. Additional acute bronchitis patients and CALAS PK samples collected in future studies may be used to improve model performance and maximize its clinical value.
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The method of continuous thermophilic composting (CTC) remarkably shortened the active composting cycle and enhanced the compost stability. Effects of CTC on the quantities of bacteria, with a comparison to the traditional composting (TC) method, were explored by plate count with incubation at 30, 40 and 50°C, respectively, and by quantitative PCR targeting the universal bacterial 16S rRNA genes and the Bacillus 16S rRNA genes. The comparison of cultivatable or uncultivatable bacterial numbers indicated that CTC might have increased the biomass of bacteria, especially Bacillus spp., during the composting. Denaturing gradient gel electrophoresis (DGGE) analysis was employed to investigate the effects of CTC on bacterial diversity, and a community dominated by fewer species was detected in a typical CTC run. The analysis of sequence and phylogeny based on DGGE indicated that the continuously high temperature had changed the structure of bacterial community and strengthened the mainstay role of the thermophilic and spore-forming Bacillus spp. in CTC run.
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Bacillus/crescimento & desenvolvimento , Temperatura Alta , Eliminação de Resíduos/métodos , Microbiologia do Solo , Solo , Bacillus/genética , Biomassa , Contagem de Colônia Microbiana , DNA Bacteriano/genética , Eletroforese em Gel de Gradiente Desnaturante , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
The enrichment of zinc oxide nanoparticles (ZnO NPs) in waste activated sludge (WAS) has raised concerns about their potential impact on anaerobic digestion of WAS. To date, there is no information regarding how to attenuate the negative effects of ZnO NPs on WAS anaerobic digestion. In this study, it was found that the appropriate amount of cationic polyacrylamide (cPAM) could mitigate the toxicity of ZnO NPs. During short-term exposure, the supplement of 4.0 mg cPAM/g TSS significantly restored biochemical methane potential from 28.6% inhibition to 9.3% inhibition compared with the control digester (P < 0.01). The spiked cPAM promoted the solubilization and acidification stages by weakening the contact between ZnO NPs and anaerobes in anaerobic digestion process, thus providing abundant substance for sequent bio-utilization. In the long-term semi-continues operated reactor, the continuous replacement of cPAM (at 4.0 mg/g TSS) significantly strengthened the recovery of VS destruction rate (20.3% to 26.4%, P < 0.01) and the daily yield of methane (93.5 mL/d to 124.2 mL/d, P < 0.01). Consistent with the restored performance, the application of cPAM increased the total microbial communities and the relative abundances of dominant acidogens and methanogens. Further explorations showed decreased toxicity of ZnO NPs primarily attributed to the decline of reactive oxygen species (ROS) induced by ZnO NPs.
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Nanopartículas , Óxido de Zinco , Resinas Acrílicas , Anaerobiose , Reatores Biológicos , Metano , Espécies Reativas de Oxigênio , Esgotos , Eliminação de Resíduos LíquidosRESUMO
Biochar was proved as an electron shuttle to facilitate extracellular electron transfer (EET) of electrochemically active bacteria (EAB); however, its underlying mechanism was not fully understood. In this study, we aimed to further explore how the regulation of surface functional groups of biochar would affect the microbial iron reduction process of Geobacter sulfurreducens as a typical EAB. Two modified biochars were achieved after HNO3 (NBC) and NaBH4 (RBC) pretreatments, and a control biochar was produced after deionized water (WBC) washing. Results showed that WBC and RBC significantly accelerated microbial iron reduction of G. sulfurreducens PCA, while had no effect in the final Fe (II) minerals (e.g., vivianite and green rust (CO32-)). Besides, Brunauer-Emmett-Teller (BET) surface area, electron spin resonance (ESR) and electrochemical measurements showed that larger surface area, lower redox potential, and more redox-active groups (e.g., aromatic structures and quinone/hydroquinone moieties) in RBC explained its better electron transfer performance comparing to WBC. Interestingly, NBC completely suppressed the Fe (III) reduction process, mainly due to the production of reactive oxygen species which inhibited the growth of G. sulfurreducens PCA. Overall, this work paves a feasible way to regulate the surface functional groups for biochar, and comprehensively revealed its effect on EET process of microorganisms.
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Geobacter , Carvão Vegetal , Transporte de Elétrons , Compostos Férricos , Ferro , OxirreduçãoRESUMO
When temperate phages and their hosts have a consistent interest, they are considered reciprocal. Based on the bacterium-phage collaboration, lysogenic phage treatment is a promising method to resist pollution through lysogenic phage reshaping indigenous microbial communities to maintain their ecological function under environmental stress. However, the potential factors affecting the establishment of bacterium-phage collaboration are still poorly understood. Here, lysogenic phages carrying arsenic biotransformation genes (ABGs) were induced from the enriched arsenic-resistant microorganisms (from arsenic-contaminated sites). The diversity analysis of viral arsC and arsM demonstrated that arsM tended to proliferate rapidly under high arsenic levels, and the transduction of arsM might be the key to lysogenic phages to help the hosts relieve the stress of high arsenic. Microcosm experiments confirmed that with the increase of the As(III) content (0% to 50%, of 200 mg/kg total arsenic) in the soil, inoculation of lysogenic phages with both arsC and arsM resulted in more transduction of arsM (0.06 ± 0.007 to 0.23 ± 0.024 per 16S rRNA) among soil microorganisms. In contrast, inoculation of lysogenic phages carrying the only arsC transduces more arsC (0.12 ± 0.037 to 0.315 ± 0.051 per 16S rRNA) compare with the control. This article confirmed that different arsenic species proportions and different viral gene compositions could change the abundance of ABGs in the soil microbe, which might provide basic knowledge for further understanding of arsenic pollution control mediated by lysogenic phage.
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Arsênio , Bacteriófagos , Bacteriófagos/genética , Biotransformação , Genes Virais , RNA Ribossômico 16S/genéticaRESUMO
In this work, the incorporation of Fe-bearing sludge-derived biochar greatly enhanced both biotic and abiotic reduction of nitrobenzene (NB) to aniline, which was attributed to the concomitant microbial dissimilatory iron reduction. Biogenic Fe(II) produced by Geobacter sulfurreducens dominated the anaerobic reduction of NB following the pseudo-first-order kinetic. Besides, the increase of pyrolysis temperature from 600 to 900 â to generate biochar resulted in an accelerated removal rate of NB in Geobacter-biochar combined system. The morphology and structural characterization of biochar with G. sulfurreducens confirmed the formation of conductive bacteria-biochar aggregates. Electrochemical measurements suggested the presence of graphitized domains and quinone-like moieties in biochar as redox-active centers, which might play an important role in accelerating electron transfer for microbial dissimilatory iron reduction and NB degradation. This study provides a feasible way of using Fe-bearing sludge as a valuable feedstock for biochar generation and its application with electrochemically active bacteria for the bioremediation of nitroaromatic compounds-polluted wastewater.
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Elétrons , Esgotos , Carvão Vegetal , Geobacter , NitrobenzenosRESUMO
The stable operation of the anaerobic digestion of waste activated sludge (WAS) is threatened by numerous emerging contaminants. Meanwhile, the extensive microplastic pollution increased the environmental exposure risk of plasticizer benzyl butyl phthalate (BBP), the BBP content has reached a substantial level in WAS. However, the effect of BBP on WAS anaerobic digestion is still unknown. Here we show that high-level BBP brings on anaerobic digestion upset. The presence of 10.0 mg/L BBP (in sludge with 17,640 ± 510 mg/L TSS) led to deferred cell lysis, which was confirmed by the results of continuous parallel factor analysis of dissolved organic matter and the liberation of lactate dehydrogenase. Further, the deferred cell rupture was confirmed associate with prophage activation during WAS anaerobic digestion. Besides solubilization, the hydrolysis, acetogenesis and methanogenesis were also affected by the addition of BBP. The long-term effects of BBP revealed that the dominant microbial structure in anaerobic digester was stable, but the abundance of many functional microorganisms was changed, including short chain fatty acid producers and consumers. This work highlights one of the susceptibility mechanisms for WAS anaerobic digestion processes and provides new perspectives for the comprehensive assessment of emerging contaminant's environmental risks.