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1.
Bioresour Technol ; 310: 123450, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32388352

RESUMO

Enhancing anaerobic digestion performance is highly desired for its large-scale application. In the present work, magnetic fields (0-30 mT) and Ti-sphere core-shell structured additives (Ti-1 and Ti-2) are simultaneously introduced in anaerobic mono-digestion and co-digestions. Compared with the control group, the Ti-sphere core-shell structured additives increase the biogas yield by 27.12%-65.53% for mono-digestion and 8.47%-35.89% for co-digestion systems under the optimized magnetic field intensity (5 mT), respectively. Meanwhile, the degradation rate of total chemical oxygen demand is 54.68%-69.14% for anaerobic mono-digestion and 53.03%-78.25% for anaerobic co-digestion with Ti-sphere core-shell structured additives, respectively. The digestate with Ti-sphere core-shell structured additives exhibits the remarkable stability (45.24%-53.17%) and fertility (4.85%-4.97%). This work clarifies the effect of magnetic field in AD system, and proposes a possible mechanism for understanding the enhanced methanogenesis pathways induced by Ti-sphere core-shell structured additives.

2.
Bioresour Technol ; 307: 123204, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32224426

RESUMO

The performance of anaerobic digestion (AD) can be improved by the addition of accelerants. Three types of biomass-derived carbon-based composites (Co/C, CoO/C, and Co3O4/C) were used as accelerants to investigate the effect on AD systems in this work. These accelerants significantly improved the cumulative biogas yield (576-585 mL/g VS), and the total chemical oxygen demand degradation rate (68.48-71.11%) compared to the reference group (435.8 mL/g VS, 50.74%). The digestates with accelerants exhibited exceptional stability (59.24-63.67%) and superior fertilizer utilization (3.50-4.55%). In addition, first-principle density functional theory (DFT) calculations were conducted to provide the theoretical basis for the direct interspecies electron transfer (DIET), and a general strategy was proposed to help understand the enhanced methanogenesis pathway induced by the biomass-derived carbon-based composites. These important findings provide a novel avenue for the development of composite accelerants for AD systems.


Assuntos
Biocombustíveis , Fertilizantes , Anaerobiose , Biomassa , Reatores Biológicos , Carbono , Teoria da Densidade Funcional , Esterco , Metano
3.
Bioresour Technol ; 309: 123325, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32330801

RESUMO

This work investigated the effects of integration of floc, aggregate and carrier (IFAC) on anammox biofilm quality and development mechanisms. The IFAC system harvested high-quality anammox biofilm with a reduction of 60% in the formation period, an increment of 282.14%~397.26% in mechanical stability, an enhancement of 10.18 ~ 21.56% in ecological stability and an improvement of 9.44%~46.18% in abundance of the phylum Planctomycetes. Aggregates enabled carriers to accumulate initial biomass efficiently and equipped biofilm with additional joint forces. Floc promoted accumulation of terminal biomass, enhanced ecological stability by improving community diversity and raised abundance of the phylum Planctomycetes by assisting anammox consortium settlement. A model of the development procedure of high-quality anammox biofilm was established and a strategy for pre-designing the IFAC system to reap high-quality biofilm was proposed. We expect our findings to provide theoretical guidance for designs and applications of anammox process with excellent stability.

4.
J Hazard Mater ; 386: 121796, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901546

RESUMO

Biological acidification plays a crucial role in biological removal of organic compounds during petrochemical wastewater treatment. Trichloroacetaldehyde is a typical organic pollutant in petrochemical wastewater, however, no studies have been conducted on its effect on biological acidification. In this study, batch bioassays of volatile fatty acids were conducted to explore the inhibitory effect of trichloroacetaldehyde on biological acidification, the variations of key enzymes and extracellular polymeric substances under trichloroacetaldehyde shock, and the mechanism of trichloroacetaldehyde removal. The results of these bioassays indicated that trichloroacetaldehyde inhibited the acid yield at higher concentrations (EC50 112.20 mg/L), and butyric fermentation was predominant. Moreover, the contents of extracellular polymeric substances and several key acidifying enzymes greatly decreased when the trichloroacetaldehyde concentration exceeded 100 mg/L, which was due to the toxicity that trichloroacetaldehyde poses to the microbes involved in biological acidification. The trichloroacetaldehyde mechanism was as follows: first, trichloroacetaldehyde was adsorbed by extracellular polymeric substances and anaerobic granular sludge, and then transformed into trichloroethanol, trichloroethane, dichloroacetaldehyde, and dichloroethanol under the combined action of the aldehyde reductase and reductive dehalogenases secreted from the microbial consortium. The ability of biological acidification to remove trichloroacetaldehyde was limited; therefore, trichloroacetaldehyde should be pretreated before it enters biological treatment systems.

5.
Arch Microbiol ; 202(1): 31-41, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31456050

RESUMO

Anaerobic digestion, a recently hot technology to produce biogases especially methane generation for biofuel from wastewater, is considered an effective explanation for energy crisis and global pollution threat. A complex microbiome population is present in sludge, which plays an important role in the digestion of complex polymer into simple monomers. 16S rRNA approaches simply are not enough for amplification due to the involvement of extreme complex population. However, Illumina sequencing is a recent powerful technology to reveal the entire microbiome structure and methane generation pathways in anaerobic digestion. Metagenomic sequencing was tested to reveal the microbial structure of a digested sludge from a local wastewater treatment plant in Beijing. The Illumina HiSeq program was used to extract about 5 GB of data for metagenomic analysis. The classification investigation revealed about 97.64% dominancy of bacteria while 1.78% were detected to be archaea using MG-RAST server. The most abundant bacterial communities were reported to be Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. Furthermore, the important microbiome involved in methane generation was revealed. The dominant methanogens were detected (Methanosaeta and Methanosarcina), with affiliation of dominant genes involved in acetoclastic methanogenesis in a digesting sludge. The metagenomic analysis showed that microbial structure and methane generation pathways were successfully dissected in an anaerobic digester.


Assuntos
Biocombustíveis/microbiologia , Genoma Microbiano/genética , Metagenoma/genética , Metano/metabolismo , Esgotos/microbiologia , Anaerobiose , Archaea/genética , Bactérias/genética , Sequenciamento de Nucleotídeos em Larga Escala , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
6.
Bioresour Technol ; 299: 122598, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31869628

RESUMO

The H2-assisted biogas upgrading approach has recently attracted much interest as a low-cost and environmentally friendly alternative to commonly used ex-situ/ physiochemical biogas upgrading techniques. However, most studies conducted to date have been limited to anaerobic solid-waste treatment characterized by flocculant sludge and low organic loading rates (OLR). In an attempt to expand its application to high-rate anaerobic wastewater treatment, an innovative two-stage up-flow anaerobic sludge blanket reactor system was employed using anaerobic granular sludge. We found that the CH4 content of product gas was consistently >90% and that H2 and CO2 concentrations stayed below 5%, even when OLR was increased from 1 to 5 g L-1 d-1 and H2 feeding rates were increased from 0.13 to 0.63 g L-1 d-1. We were also able to show that CO (5-10%) in H2-rich syngas didn't inhibit methanogenesis or had significant impact on microbial community structure, suggesting that H2-assisted biogas upgrading with H2-rich syngas is feasible.


Assuntos
Biocombustíveis , Águas Residuárias , Anaerobiose , Reatores Biológicos , Metano , Esgotos , Eliminação de Resíduos Líquidos
7.
Arch Microbiol ; 202(4): 825-833, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31848653

RESUMO

Continuous observation of wastewater treatment plants is very crucial to keep them safe for proper use and protection from pathogenic contamination. Illumina sequencing technology was used for microbiome structuring from various samples taken from different portions of the wastewater treatment plant, including influent, activated, return sludge and effluent, where different microbial compositions were found. The effluent section was found to have pathogenic microbes such as viruses, Alpha- and deltaproteobacteria, Actinobacteria, Bacteroidetes, clostridia, and bacilli in various concentrations. The presence of viruses, Mycobacterium sp., Mycobacterium fortuitum, bacteroidia, and bacilli was investigated. The species Mycobacterium was found to be higher in quantity in the effluent section. Viruses, including hepatitis A and E, were detected in higher quantity in the effluent part of the sludge in comparison with the influent part of the plant. Our discovery reveals the significance and observation of wastewater treatment plants for the existence of water-borne pathogens in the effluent, principally due to the effect on humans while reusing the water.


Assuntos
Fenômenos Fisiológicos Bacterianos , Metagenoma , Microbiota , Fenômenos Fisiológicos Virais , Águas Residuárias/microbiologia , Bactérias/classificação , Bactérias/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Esgotos/microbiologia , Vírus/classificação , Vírus/genética
8.
Huan Jing Ke Xue ; 40(7): 3126-3134, 2019 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854710

RESUMO

Application of microalgae in wastewater treatment is regarded as a potential green technology. However, its engineering application has been largely hindered because of the difficulty of biomass separation and harvesting. This study aimed to identify the key parameters influencing the process of microalgae immobilization. To do this, the study focused on immobilization technology and Scenedesmus obliquus, and employed the response surface methodology (RSM) and the Box-Behnken design (BBD). In an evaluation of the performance of microalgae beads, the fixing agent concentration, the cross-linking agent concentration, and the cross-linking time were selected as the independent variables, and the mechanical strength, the mass transfer rate, and the growth rate of immobilized microalgae beads were the response values. The optimal conditions and the uptake potential of the microalgae beads with respect to ammonia nitrogen (NH4+-N) were further explored and analyzed. The results showed that the optimal parameters for the preparation of immobilized microalgae beads were 5%, 2%, and 16 h, and the maximum removal capacity was obtained using mixotrophic cultivation with an embedding density of 1×106 cells·mL-1 and an organic matter concentration of 300 mg·L-1. In addition, the removal capacity of immobilized microalgae with respect to high concentrations of NH4+-N was significantly higher than for free-living microalgae. When the initial concentrations of NH4+-N were approximately 50 and 70 mg·L-1, NH4+-N was removed by the immobilized microalgae (after a 5-day mixotrophic cultivation) at a rate of (96.6±0.1)% and (65.2±4.5)%, respectively. With an initial NH4+-N concentration of 30 mg·L-1, the dominance of free-living microalgae was clear, with a removal rate of (97.8±0.6)% after a 3-day cultivation. However, under heterotrophic cultivation, the removal rate of NH4+-N by immobilized microalgae was generally low and gradually decreased with increasing concentrations. When the initial concentration was approximately 30 mg·L-1, the removal rate was only (49.0±3.1)%. This study provides new prospects for sustainable urban wastewater treatment, a new approach for resource recycling, and a strong theoretical foundation for the popularization and application of microalgae in wastewater treatment.


Assuntos
Amônia/isolamento & purificação , Microalgas/metabolismo , Nitrogênio/isolamento & purificação , Águas Residuárias , Purificação da Água/métodos , Biomassa , Células Imobilizadas/metabolismo
9.
BMC Ophthalmol ; 19(1): 225, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31726999

RESUMO

BACKGROUND: Measurement of intraocular pressure (IOP) is essential for glaucoma patients. Many factors such as central corneal thickness (CCT) can affect the accuracy of IOP measurement. The purpose of this study was to evaluate the agreement of IOP measured by non-contact tonometer (NCT), iCare pro rebound tonometer (iCare), and Goldmann applanation tonometer (GAT) in different IOP group. METHODS: This was a Hospital-based cross-sectional study. Two hundred subjects were enrolled in this study. All subjects underwent IOP measurement using an NCT-iCare-GAT sequence. Bland-Altman, Pearson correlation and intraclass correlation analysis were performed using SPSS 17.0 software. The influence of CCT on each IOP measurement methods was evaluated by linear regression analysis. RESULTS: The mean difference (Δ) of NCT-GAT did not differ from (Δ) iCare-GAT in IOP < 10 and 10-21 mmHg group. However, (Δ) NCT-GAT was significantly higher than (Δ) iCare-GAT in IOP 22-30 and > 30 mmHg group (P < 0.05). Bland-Altman analysis showed significant agreement between the three devices (P < 0.01). IOP measurements of the three methods were significantly correlated with CCT (P < 0.01). CONCLUSIONS: ICare pro shows a higher agreement with GAT over a wide range of IOP compared with NCT. The consistency between the three tonometers was similar in a low and normal IOP range. However, NCT shows a greater overestimate of IOP in moderate and higher IOP group. The variability of IOP measurement affected by CCT is NCT > iCare pro > GAT.

10.
Circulation ; 140(23): 1881-1891, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31564137

RESUMO

BACKGROUND: The COAPT trial (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) demonstrated that edge-to-edge transcatheter mitral valve repair (TMVr) with the MitraClip resulted in reduced mortality and heart failure hospitalizations and improved quality of life compared with maximally tolerated guideline-directed medical therapy (GDMT) in patients with heart failure and 3 to 4+ secondary mitral regurgitation. Whether TMVr is cost-effective compared with GDMT in this population is unknown. METHODS: We used data from the COAPT trial to perform a formal patient-level economic analysis of TMVr+GDMT versus GDMT alone for patients with heart failure and 3 to 4+ secondary mitral regurgitation from the perspective of the US healthcare system. Costs for the index TMVr hospitalization were assessed using a combination of resource-based accounting and hospital billing data (when available). Follow-up medical care costs were estimated on the basis of medical resource use collected during the COAPT trial. Health utilities were estimated for all patients at baseline and 1, 6, 12, and 24 months with the Short Form Six-Dimension Health Survey. RESULTS: Initial costs for the TMVr procedure and index hospitalization were $35 755 and $48 198, respectively. Although follow-up costs were significantly lower with TMVr compared with GDMT ($26 654 versus $38 345; P=0.018), cumulative 2-year costs remained higher with TMVr because of the upfront cost of the index procedure ($73 416 versus $38 345; P<0.001). When in-trial survival, health utilities, and costs were modeled over a lifetime horizon, TMVr was projected to increase life expectancy by 1.13 years and quality-adjusted life-years by 0.82 years at a cost of $45 648, yielding a lifetime incremental cost-effectiveness ratio of $40 361 per life-year gained and $55 600 per quality-adjusted life-year gained. CONCLUSIONS: For symptomatic patients with heart failure and 3 to 4+ secondary mitral regurgitation, TMVr increases life expectancy and quality-adjusted life expectancy compared with GDMT at an incremental cost per quality-adjusted life-year gained that represents acceptable economic value according to current US thresholds. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01626079.

11.
J Am Coll Cardiol ; 74(23): 2833-2842, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31577923

RESUMO

BACKGROUND: In patients with severe aortic stenosis (AS) at low surgical risk, treatment with transcatheter aortic valve replacement (TAVR) results in lower rates of death, stroke, and rehospitalization at 1 year compared with surgical aortic valve replacement; however, the effect of treatment strategy on health status is unknown. OBJECTIVES: This study sought to compare health status outcomes of TAVR versus surgery in low-risk patients with severe AS. METHODS: Between March 2016 and October 2017, 1,000 low-risk patients with AS were randomized to transfemoral TAVR using a balloon-expandable valve or surgery in the PARTNER 3 (Placement of Aortic Transcatheter Valves) trial. Health status was assessed at baseline and 1, 6, and 12 months using the KCCQ (Kansas City Cardiomyopathy Questionnaire), SF-36 (Short Form-36 Health Survey), and EQ-5D (EuroQoL). The primary endpoint was change in KCCQ-OS (KCCQ Overall Summary) score over time. Longitudinal growth curve modeling was used to compare changes in health status between treatment groups over time. RESULTS: At 1 month, TAVR was associated with better health status than surgery (mean difference in KCCQ-OS 16.0 points; p < 0.001). At 6 and 12 months, health status remained better with TAVR, although the effect was reduced (mean difference in KCCQ-OS 2.6 and 1.8 points respectively; p < 0.04 for both). The proportion of patients with an excellent outcome (alive with KCCQ-OS ≥75 and no significant decline from baseline) was greater with TAVR than surgery at 6 months (90.3% vs. 85.3%; p = 0.03) and 12 months (87.3% vs. 82.8%; p = 0.07). CONCLUSIONS: Among low-risk patients with severe AS, TAVR was associated with meaningful early and late health status benefits compared with surgery.

12.
J Environ Sci (China) ; 85: 177-188, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471025

RESUMO

The effect of preparation parameters on the performance of zeolite for ammonium (20-300 mg N/L) adsorption from simulated wastewater is reported. It was found that the ratios of Na2O/SiO2 and Si/Al had a more important influence than crystallization time on zeolite adsorption properties. Relatively low Na2O/SiO2 ratios were beneficial for fabrication of zeolites with high proportions of micropore area and volume, which led to the surface adsorption mechanism being dominated by surface free energy and pore effects. However, with decreasing Si/Al ratios, the effect of ion-exchange was more prominent due to the high negative surface potential of zeolite. In addition, the concentration of weak acid sites on the zeolites was increased with lower ratios of Na2O/SiO2 and Si/Al, which may promote ammonium removal. Therefore, the most effective zeolite for ammonium removal, which was fabricated at Na2O/SiO2 = 1.375, Si/Al = 4 and crystallization time of 48 hr, exhibited the cooperative effects of adsorption, ion-exchange and a large amount of weak acid sites. The maximum ammonium adsorption capacity (35.06 ±â€¯0.98 mg/g) and the removal efficiency (94.44% ±â€¯4.00%) were obtained at the dosage of 4.0 g/L zeolite NaX at ammonium concentrations of 300 mg N/L and 20 mg N/L, respectively. The Freundlich isotherm and pseudo-first-order kinetics models provided excellent fitting for the ammonium adsorption process. In addition, zeolite NaX showed about 1.23-3.2 times the ammonium adsorption capacity of clinoptilolite. The stable and efficient reusability of zeolite NaX after five regeneration cycles demonstrated that this adsorbent has considerable potential for practical industrial applications.


Assuntos
Compostos de Amônio/química , Modelos Químicos , Zeolitas/química , Adsorção
13.
Bioresour Technol ; 289: 121685, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31323715

RESUMO

In this study, immobilized Scenedesmus obliquus (S. obliquus) was proposed to simultaneously alleviate the carbon dioxide (CO2) and ammonium (NH4+-N). Two trophic modes of autotrophy and mixotrophy were conducted by batch experiments with a period of 5 days. The results shown that NH4+-N could be removed more efficiently if algal cells were immobilized, and the trophic mode change had no significant effect on immobilized S. obliquus to NH4+-N removal under 5% CO2 sparging. Specifically, immobilized S. obliquus could remove NH4+-N completely at initial concentrations of 30 and 50 mg/L and reached about 80% removal rate of NH4+-N at the concentration of 70 mg/L under both trophic modes. The protein synthesis was its main removal mechanism and the dominant amino acid components including glutamic acid (Glu), cystine (Cys), arginine (Arg), methionine (Met) and lysine (Lys) were sensitive to NH4+-N assimilation.


Assuntos
Compostos de Amônio/metabolismo , Dióxido de Carbono/metabolismo , Proteínas de Plantas/biossíntese , Scenedesmus/metabolismo , Ciclo do Carbono
14.
Clin Lab ; 65(7)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31307160

RESUMO

BACKGROUND: Reticulocyte count (RET) has been used for many years to estimate the erythropoietic activity of the bone marrow. Fully automated methods not only provide enhanced precision and accuracy, but also enable reliable measurements of mRNA content and cellular indices. However, problems still exist, such as interference. The aim of the present study was to investigate the interferents of Sysmex XN 9000 reticulocyte analysis and ensure the accuracy of the results. METHODS: We collected a total of 510 specimens from normal control patients and patients with various diseases including anemias, leukemias, infectious diseases, immune diseases, kidney disease, etc. Correlation of the agreement for reticulocytes between the new methylene blue (NMB) visual microscopy method and automated reticulocyte counting was evaluated by paired sample method according to the CLSI-ICSH document H44-A2-Methods for Reticulocyte Count. Blood smear microscopic examination was carried out on the disturbed samples, and the interferents were analyzed with the medical history, flagging algorithms, the warning information, and the microscopic examination. RESULTS: A total of 44 (8.6%) cases exhibited interference. The main interferents of spuriously high reticulocyte count were caused by parasites, such as malaria, as well as suspicious autofluorescence due to drugs, while the main interferents of spuriously low reticulocyte count were caused by RBC fragments. CONCLUSIONS: Detection of potential interferences may be accomplished through alarm information and flagging algorithms incorporated into the instrument and by examination of a blood film to ensure absence of relevant interferences.


Assuntos
Automação Laboratorial/instrumentação , Contagem de Células Sanguíneas/instrumentação , Contagem de Reticulócitos/instrumentação , Reticulócitos/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/sangue , Automação Laboratorial/métodos , Contagem de Células Sanguíneas/métodos , Criança , Feminino , Humanos , Leucemia/sangue , Malária/sangue , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Contagem de Reticulócitos/métodos , Reticulócitos/citologia , Adulto Jovem
15.
J Environ Sci (China) ; 84: 144-154, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31284906

RESUMO

A systemic strategy was proposed to improve aerobic granular sludge (AGS) stability and nitrogen (N) removal efficiency by optimizing feeding mode and substrate aiming at complicated wastewater characteristics. Key functional groups at the genus level identified by high-throughput sequencing were evaluated as well. The results showed that anaerobic feeding mode and acetate promoted the compact AGS formation with excellent total nitrogen (TN) removal efficiency (averaging 91.7% ±â€¯4.1%) at various dissolved oxygen conditions. While the aerobic feeding mode led to a loose AGS structure with a vulnerable anaerobic core and poor TN removal efficiency (averaging 58.8% ±â€¯7.4%). Simultaneous nitrification and denitrification process played the dominant role in N removal in compact AGS over the alternating nitrification and denitrification process. High-concentration glucose undermined feast-famine condition with filamentous bacteria growth out of granule and decreased TN removal efficiency to 67.3% ±â€¯15.2%. Lower food to microorganism ratio may result in a lower N removal rate attributed to the sharply increased biomass concentration fed by glucose. Ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying bacteria, and denitrifying phosphorus accumulation organisms enriched during AGS granulation also contributed to the efficient N removal. The proposed strategy provided insights into the relationship between various factors and stable AGS formation, and systemic operation methods for various complicated wastewater treatment.


Assuntos
Reatores Biológicos/microbiologia , Nitrogênio/isolamento & purificação , Acetatos , Biomassa , Glucose , Microbiota , Tamanho da Partícula , Esgotos
16.
Arch Microbiol ; 201(9): 1163-1171, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31172250

RESUMO

Organic acid production including lactate and acetate is an economically attractive technology that has gained momentum worldwide over the past years. These series of action need to be performed by an esoteric and complex microbial community, in which different members have distinct roles in the establishment of a collective organization. In this study, we analyzed the bioma from bioreactors with various pH conditions of 4.0, 5.0 and 6.0 (R1, R2 and R3), respectively, involved in acidogenic digestion for stable production of various organic acids by means of high-throughput Illumina sequencing, disclosing thousands of genes and extracting more than 53 microbial genomes. At pH 5.0, the hydrolysis reaction was enhanced and thus the lactic acid fermentation was stably improved to 45.96 mm/L and acetic acid to 73.77 mm/L. R2 was found with the most suitable pH condition for stable organic acids production as Lactobacilli and Bifidobacteria were the major members. Both the members have the key roles in heterofermentation and produce higher transcripts of key encoding enzymes involved in the dominant heterofermentation pathways.


Assuntos
Acetatos/metabolismo , Bifidobacterium/genética , Reatores Biológicos/microbiologia , Ácido Láctico/metabolismo , Lactobacillus/genética , Microbiota/genética , Bifidobacterium/classificação , Bifidobacterium/metabolismo , Metabolismo dos Carboidratos , Fermentação/genética , Sequenciamento de Nucleotídeos em Larga Escala , Concentração de Íons de Hidrogênio , Hidrólise , Lactobacillus/classificação , Lactobacillus/metabolismo , Metagenômica
17.
Invest Ophthalmol Vis Sci ; 60(4): 1105-1121, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30901387

RESUMO

Purpose: To confirm the association of all reported common polymorphisms with POAG. Methods: We searched in PubMed and Web of Science (up to January 10, 2018) for genetic studies of POAG. All case control studies investigating the association between single-nucleotide polymorphisms (SNPs) and POAG risk were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by fixed- or random-effect model. Results: This meta-analysis included 108 case control studies involving 35,389 POAG patients and 51,742 controls. The pooled results showed a significant association between 20 SNPs in 12 genes (148Asp/Glu in APE1 gene; rs449647 in APOE gene; rs1052990 and rs4236601 in CAV1/CAV2 gene; rs1799750 in MMP gene; c.603T3A (Met98Lys) in OPTN gene; rs7081455 in PLXDC2 gene; rs1279683 in SLC23A2 gene; 372 T/C in TIMP1 gene; rs1927911, rs2149356, rs4986791, rs7037117, and rs10759930 in TLR4 gene; rs4656461 in TMCO1 gene; 399Arg/Gln in XRCC1 gene; and rs540782, rs547984, and rs693421 in ZP4 gene) with POAG. Conclusions: Based on the current meta-analysis, we indicate 20 SNPs in 12 genes (APE1, APOE, CAV1/CAV2, MMP, OPTN, PLXDC2, SLC23A2, TIMP1, TLR4, TMCO1, XRCC1, ZP4) as predictive risk factors for POAG. More studies with large sample sizes and various ethnicities are warranted in the future to provide more powerful evidence.


Assuntos
Predisposição Genética para Doença , Glaucoma de Ângulo Aberto/genética , Polimorfismo de Nucleotídeo Único , Estudos de Casos e Controles , Bases de Dados Factuais , Proteínas do Olho/genética , Humanos , Íntrons/genética , Fatores de Risco
18.
Bioresour Technol ; 283: 184-190, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30904698

RESUMO

In this study, the immobilization with sodium alginate (SA) for cultivating microalgae in entrapped matrix gel beads was conducted for separating it from water. Batch experiments with a period of 5 days were carried out for free and immobilized Scenedesmus obliquus simultaneously under two trophic modes, to compare the removal performances of different initial ammonium (NH4+-N) concentrations. In both free and immobilized form, the positive C-dependent effect in mixotrophy and the negative N-dependent effect in heterotrophy were observed. And the performances of immobilized form were all superior to that of free form, which showed greater tolerance to high concentration, maximally representing 96.6 ±â€¯0.1% removal in 50 mg/L of NH4+-N in mixotrophy. Assimilation of NH4+-N was the main removal pathway resulting the protein synthesis with the dominant component including glutamic acid (Glu), cystine (Cys), arginine (Arg) and proline (Pro). The results demonstrated a systematic understanding for NH4+-N removal in microalgae-based system.


Assuntos
Compostos de Amônio/metabolismo , Scenedesmus/metabolismo , Águas Residuárias/química , Microalgas/metabolismo
19.
Bioresour Technol ; 282: 353-360, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30878887

RESUMO

Anaerobic digestion could treat organic wastes and recovery energy. Dry anaerobic digestion had advantages of low heating energy, small digester and less digestate, but its methane production was poor. In this study, an enhanced dry anaerobic digestion of swine manure (thermal treatment + dry anaerobic digestion) was proposed, and its feasibility was investigated via semi-continuous experiment. Results showed that methane production rates were 314.6, 416.0, 298.0 and 69.9 mL CH4/g VS at solid retention time (SRT) of 41 d, 35 d, 29 d and 23 d. Volatile solids (VS) removal rate and methane production rate could reached 71.4% and 416.0 mL CH4/g VS respectively at SRT of 35 d. Methane production rate of the enhanced dry anaerobic digestion was 390% higher than that of dry anaerobic digestion. Microbial study indicated that hydrogenotrophic methanogens predominated with the abundance of 90.2%, while acetoclastic methanogens were not detected. This process was feasible, and was of great practical importance.


Assuntos
Esterco , Microbiota , Anaerobiose , Animais , Esterco/microbiologia , Metano/biossíntese , Suínos
20.
J Environ Manage ; 235: 169-177, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30682669

RESUMO

Compared to traditional anaerobic digestion (AD), high solid anaerobic digestion (HSAD) had the advantages of small digester, low heating energy and less digestate. However, the methane production was poor. In our previous study, thermal treatment (70 ±â€¯1 °C, 3 days) without any dilution could satisfactorily enhance the methane production rate of HSAD by up to 39.5%. However, effects of solid content on HSAD after thermal treatment were not yet studied. In this study, HSAD was conducted at 11.7-17.6% solid content, and the control experiment was conducted at low solid content (4.4% solid content). Results showed that HSAD's methane production rate was the highest at 11.7% solid content (158 mL CH4/g VS), and could reach up to 89.2% of that at 4.4% solid content. The utilization of organics was revealed by kinetics analysis that the readily biodegradable organics could be utilized at increasing solid content with decreasing hydrolysis rate. Furthermore, it was notable that methylotrophic methanogens predominated in HSAD with the abundance of 82.6%. This was quite unique from the general belief that AD system was usually dominated by acetoclastic or hydrogenotrophic methanogenic pathways. In this study, the microbial community structure of HSAD after thermal treatment was firstly studied, its unique specific methanogenic pathways was firstly revealed.


Assuntos
Esterco , Microbiota , Anaerobiose , Animais , Reatores Biológicos , Cinética , Metano , Suínos
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