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1.
Bioresour Technol ; 302: 122892, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32028149

RESUMO

The impact of algal biochar addition on mesophilic and thermophilic anaerobic co-digestion of algal biomass and food waste was investigated with a focus on semi-continuous operations and functional microbial communities. Under batch co-digestion, the highest co-digestion synergy was observed for a mixture of 25% food waste and 75% algal biomass. During semi-continuous co-digestion of 25% food waste-75% algal biomass mixture, biochar amended digesters exhibited a 12-54% increase in average methane yield (275.8-394.6 mL/gVS) compared to the controls. Elevated temperature induced narrow distributions of volatile fatty acids (VFAs) by inhibiting the production of branched VFAs. Genus Proteiniphilum was selectively enriched by 3.2 folds in mesophilic digesters with biochar amendment while genus Defluviitoga was selectively enriched in thermophilic digesters due to elevated temperature. Methanogenic communities were significantly different in mesophilic and thermophilic digesters. Biochar amendment contributed to shifts in the predominant methanogens leading to a more balanced state of two methanogenic pathways.


Assuntos
Microbiota , Eliminação de Resíduos , Anaerobiose , Biomassa , Reatores Biológicos , Carvão Vegetal , Alimentos , Metano , Esgotos , Temperatura Ambiente
2.
Sci Total Environ ; 715: 136789, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32006778

RESUMO

The increasing world population necessitates the production of larger amounts of food in a safe and environmentally sustainable manner, while concomitantly managing an increasing amount of food waste similarly. These needs can theoretically be met by the recycling of the nutrients in food waste via anaerobic digestion, which also produces renewable energy. This hypothesis is proven by the growing of a commonly consumed leafy vegetable, xiao bai cai (Brassica rapa), by the addition of food waste anaerobic digestate in place of commercial fertilizer. Different concentrations of the digestate were tested, as well as different heat treatments to simulate hygienization, and the results for most part (aerial fresh weight, dry weight, chlorophyll content) are not significantly different from growth utilizing commercial inorganic 15:15:15 NPK fertilizer. Microbial analysis of the growth media was also carried out to explicate digestate effects and to show that some common foodborne disease pathogens were not detected.

3.
Environ Technol ; 41(5): 617-626, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30074855

RESUMO

The microalgae Chlorella vulgaris ATCC 13482 was used in the present study for municipal wastewater treatment. Batch experiments were performed in bubble column photobioreactors of 7 L working volume maintained at 25 ± 2°C and 14 h/10 h of photo and dark cycle. The treatment process was enhanced by using CO2-augmented air (5% CO2 v/v) supply into the microalgal culture in comparison to the use of normal air (0.03% CO2 v/v). For a period of 7 days, C. vulgaris effected maximum removals of 74.4% soluble fraction of chemical oxygen demand, 72% ammonia (NH4-N), 60% nitrate (NO3-N) and 81.93% orthophosphate (PO4-P) with use of normal air, whereas 84.6% sCOD, 88% NH4-N, 72% NO3-N and 92.8% PO4-P removals, respectively, with use of 5% CO2/air supply. Using kinetic study data, the specific rates of ammonia and phosphate uptake (qammonia and qphosphate) by C. vulgaris at 5% CO2/air supply were found to be 2.41 and 0.85 d-1, respectively. Using the algal remediation technology, nitrogen-phosphorus-potassium recovery from sewage treatment plant of 37.5 million litres per day wastewater influent capacity was calculated to be ∼298.5, 55.4 and 83.7 kg d-1, respectively.


Assuntos
Chlorella vulgaris , Microalgas , Biomassa , Dióxido de Carbono , Nitrogênio , Nutrientes , Fotobiorreatores , Águas Residuárias
4.
Bioresour Technol ; 294: 122177, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31563113

RESUMO

The relationship between mixing time and methane production was investigated by anaerobically co-digesting food waste (FW) and chicken manure (CM) at four different organic loading rates. The mixing pattern and turbulence intensity obtained from CFD were adopted to evaluate the mixing performance in digesters with different viscosities. The simulated mixing time from CFD was selected as a reference for the first time to analyze the methane yield. The results showed that if the digester was well mixed under intermittent mixing mode with relatively short mixing time, then extending mixing time or changing intermittent mixing to continuous mixing would have no substantial effects on methane production. By contrast, continuously mixed digesters performed better when the intermittent mixing modes cannot make the digester get to a high degree of uniformity. Hence, the simulated mixing time from CFD can be used as a reference to determine the experimental mixing time in different cases.


Assuntos
Esterco , Eliminação de Resíduos , Anaerobiose , Animais , Reatores Biológicos , Galinhas , Alimentos , Metano
5.
Bioresour Technol ; 288: 121597, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31176202

RESUMO

To find the optimal operation parameters and provide an explanation of methanogenic pathway for methane production in mesophilic (35 °C) and thermophilic (55 °C) anaerobic digestion (MAD, TAD) of soybean curd residue (SCR), MAD and MAD were contrastively investigated for 95 days. The maximum available OLR was identified as 3.3 gVS/L for both MAD and TAD. Compared to MAD, TAD exhibited a 20% higher average methane yield (0.591 L/gVS) and a 7.5% higher volatile solids removal efficiency (74.1 ±â€¯10.4%). Bacterial phyla Bacteroidetes, Firmicutes and Proteobacteria dominated in MAD digesters while genus Defluviitoga was selectively enriched in TAD digesters due to higher temperature and organic loading pressure. Principal coordinates analysis of methanogen community showed that both temperature and OLR were crucial environmental variables shifting the taxonomic patterns of the methanogens. The enriched methanogen genus Methanothermobacter (93%) with a hydrogenotrophic methanogenic pathway had a close correlation with the TAD performance.


Assuntos
Reatores Biológicos , Soja , Anaerobiose , Metano , Esgotos , Temperatura Ambiente
6.
Langmuir ; 35(22): 7285-7293, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31082261

RESUMO

The biomimetic membrane technology may unlock unprecedented membrane separation capabilities to solve the increasing need for clean water. Despite the efforts in exploring numerous membrane preparation methods, the membrane performance achieved to date is still far from the theoretical predictions. To overcome this bottleneck, a deeper understanding of the role of the channels or vesicles immobilized on the membrane would be required. In this work, we seek to quantify the amount of vesicles immobilized per unit area of membrane and correlate it with the membrane performance. The results show that, although the vesicles successfully immobilized onto the membrane increase with an increasing vesicle concentration, less than 4% of the vesicles loaded onto the membrane successfully remains on the membrane after interfacial polymerization. Furthermore, an increase in the amount of vesicles remaining on the membrane may not always result in improvement in membrane performance. To the best of our knowledge, this is the first time that a study has been performed to determine an accurate relationship between the vesicles immobilized and the biomimetic membrane performance.

7.
Anal Chim Acta ; 1066: 121-130, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31027526

RESUMO

A visual, rapid, and sensitive method for the detection of two algal metabolites, geosmin (GSM) and 2-methylisoborneol (2-MIB) using a competitive displacement technique based on molecular imprinted polymers (MIPs) and fluorescent tags was developed. In this method, fluorescent tags that bind to synthetic receptor sites of MIPs were designed and synthesised. In the presence of target analytes (geosmin and 2-methylisoborneol respectively), the tags are displaced leading to fluorescence signals. The MIPs were derived from the polymerisation of functional monomers and crosslinkers in the presence of suitable templates. Good to high binding capacities and selectivities were obtained with the MIPs. The displacement of fluorescent-tagged substrates from the respective MIPs by the target analytes enabled the quantitative detection of geosmin at concentrations as low as 0.38 µM (69 µg L-1), while the LOD for 2-methylisoborneol is 0.29 µM (48 µg L-1) without any cross-reactivity, non-specific (false-positive) binding, and matrix complications. Qualitative detection of geosmin and 2-methylisoborneol is also possible via visualisation of fluorescence using a hand held UV lamp, with LOD for geosmin and 2-methylisoborneol at 0.44 µM (80 µg L-1) and 0.35 µM (60 µg L-1), respectively. The sensitivity of the system can be improved with a pre-concentration step using the respective MIPs as a sorbent.


Assuntos
/análise , Clorófitas/química , Fluorescência , Impressão Molecular , Naftóis/análise , Polímeros/química , /metabolismo , Clorófitas/metabolismo , Cinética , Estrutura Molecular , Naftóis/metabolismo , Tamanho da Partícula , Polímeros/síntese química , Propriedades de Superfície
8.
Bioresour Technol ; 285: 121333, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31004947

RESUMO

A three-stage anaerobic digester setup was configured and evaluated for enhanced methane production during co-digestion of food waste and waste activated sludge and the corresponding bacterial and methanogen communities were characterized. Results showed that the average methane yield (0.496 L/gVS) in the three-stage digester was 13-52% higher than that of one- and two-stage digesters. Compared to controls, an increase of 12-47% in volatile solids reduction was achieved in the three-stage digester (69.3 ±â€¯6.7%). Bacterial phyla Proteobacteria, Firmicutes and Bacteroidetes dominated in one-, two- and three-stage digester while genera Pseudomonas, Tissierella, and Petrimonas were selectively enriched in the three-stage digester due to functional segregation. Taxonomic analysis identified 8 dominant methanogen genera, of which Methanosarcina, Methanosaeta, Methanobacterium and Methanolinea collectively accounted for 80%. With increasing OLR and digester stage number, the dominant methanogenic pathway shifted from hydrogenotrophic pattern to acetoclastic pattern and reached a final synergy of these two.


Assuntos
Archaea , Esgotos , Anaerobiose , Bactérias , Reatores Biológicos , Metano
9.
Chemosphere ; 215: 893-903, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30408885

RESUMO

A sequencing batch bioreactor (SBR) treating municipal wastewater was photosynthetically aerated using microalgae cultivated in a photobioreactor (PBR). Symbiotic interactions and CO2/O2 exchange were established between activated sludge in the SBR and microalgae in the PBR through hydrophobic hollow fiber membranes. Photosynthetic aeration enhanced COD removal in the SBR from 52.2% (without external aeration) to 90.3%, whereas N-NH4+ and P-PO43- removal increased by 63.5% and 90.4%, respectively. The SBR performance under photosynthetic aeration was comparable to that under mechanical aeration. However, no nitrification was observed in the SBR, indicating oxygen limitation and poor growth condition for nitrifiers. In the PBR, there was a rapid increase in biomass concentration and it stabilized at 3.0 g/L after 22 days of operation. High nitrogen demand in the PBR indicated the steady flow of inorganic carbon from the SBR through the membranes. Prolonged oxygen limitation and massive sludge attachment on the membranes resulted in low suspended sludge concentration in the SBR. Microbial community analysis indicated gradual enrichment of facultative and strictly anaerobic microorganisms in the SBR. These results highlight the potential of microalgae in lowering the cost of wastewater aeration and underline the challenges in sustaining symbiotic gas exchange during long-term.


Assuntos
Microbiota/fisiologia , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Fotossíntese , Águas Residuárias/análise
10.
Waste Manag ; 79: 607-614, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30343793

RESUMO

A common challenge for the anaerobic digestion (AD) of food waste (FW) is the contamination by disposable plastic materials and utensils. The objective of this batch study was to investigate the effects of disposable plastic materials - polystyrene (PS), polypropylene (PP), high density polyethylene (HDPE) and wooden chopsticks (WC) on the AD of FW. Results showed that methane production from the AD of FW was inhibited to different extents when different materials were present in FW. PS and PP were found to reduce methane production from food waste more than HDPE and WC. The reduction in methane production was hypothesized to be due to the production of toxic plastic by-products or due to reduced contact between microbes and FW. Pyrosequencing and Field Emission Scanning Electron Microscope (FESEM) results indicated that the reduction in methane production was more likely due to the interference of good contact necessary between microbes and FW for biodegradation, and that the biological processes of AD were not affected by the contamination of plastics. Greater reductions in methane yields were also observed when the surface areas of the disposable materials were increased. Studying the effects of disposable materials on the AD of FW would provide plant operators with more information that could optimise the process of resource recovery from food waste.


Assuntos
Reatores Biológicos , Plásticos , Anaerobiose , Alimentos , Metano
11.
Biomaterials ; 180: 163-172, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30053657

RESUMO

Intra-tumoral injection of radiopharmaceuticals such as yttrium-90 (90Y) or phosphorus-32 (32P) is an important route for brachytherapy in unresectable solid tumors such as locally advanced hepatocellular carcinoma. However, the injected radiopharmaceuticals can potentially leak out from the tumor site due to high intra-tumoral pressure. In this study, we demonstrated the use of thermogelling copolymers that can be injected into tumor and subsequently solidify as hydrogels within the tumor that can potentially overcome the above problem. To this end, a series of thermogelling polyurethane copolymers with varying compositions were designed and synthesized from Pluronic F127, poly(3-hydroxylbutyrate), and poly(propylene glycol), which were characterized in terms of their molecular structures, compositions, phase diagrams, rheological properties, and injectability and body temperature stability in vitro and in vivo. The analyses of our data elucidated the injectability of the copolymer solutions at low temperatures, and the stability of the hydrogels at the body temperature. This provided the basis on which we could identify one copolymer with balanced composition as the most suitable candidate for intra-tumoral injection and for prevention of the leakage. Finally, the injectability and in vivo stability of the copolymer solution and hydrogel loaded with 90Y were further demonstrated in a mouse tumor model, and the in vivo biodistribution of 90Y showed that the radionuclide could be retained at the tumor site, indicating that the 90Y-loaded copolymer has a great potential for tumor radio-brachytherapy.


Assuntos
Braquiterapia/métodos , Polímeros/química , Radioisótopos de Ítrio/química , Animais , Camundongos , Poloxâmero/química , Poliésteres/química , Polietilenoglicóis/química
12.
Nat Commun ; 9(1): 917, 2018 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-29500445

RESUMO

Polymyxins remain the last line treatment for multidrug-resistant (MDR) infections. As polymyxins resistance emerges, there is an urgent need to develop effective antimicrobial agents capable of mitigating MDR. Here, we report biodegradable guanidinium-functionalized polycarbonates with a distinctive mechanism that does not induce drug resistance. Unlike conventional antibiotics, repeated use of the polymers does not lead to drug resistance. Transcriptomic analysis of bacteria further supports development of resistance to antibiotics but not to the macromolecules after 30 treatments. Importantly, high in vivo treatment efficacy of the macromolecules is achieved in MDR A. baumannii-, E. coli-, K. pneumoniae-, methicillin-resistant S. aureus-, cecal ligation and puncture-induced polymicrobial peritonitis, and P. aeruginosa lung infection mouse models while remaining non-toxic (e.g., therapeutic index-ED50/LD50: 1473 for A. baumannii infection). These biodegradable synthetic macromolecules have been demonstrated to have broad spectrum in vivo antimicrobial activity, and have excellent potential as systemic antimicrobials against MDR infections.


Assuntos
Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Farmacorresistência Bacteriana Múltipla , Substâncias Macromoleculares/uso terapêutico , Animais , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Ceco/cirurgia , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Feminino , Hemólise/efeitos dos fármacos , Cinética , Ligadura , Substâncias Macromoleculares/farmacocinética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Polímeros/síntese química , Polímeros/química , Polímeros/farmacocinética , Polímeros/uso terapêutico , Punções , Análise de Sequência de RNA , Distribuição Tecidual/efeitos dos fármacos
13.
Waste Manag ; 71: 334-341, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29037880

RESUMO

This study characterised and compared the microbial communities of anaerobic digestion (AD) sludge using three different methods - (1) Clone library; (2) Pyrosequencing; and (3) Terminal restriction fragment length polymorphism (T-RFLP). Although high-throughput sequencing techniques are becoming increasingly popular and affordable, the reliance of such techniques for frequent monitoring of microbial communities may be a financial burden for some. Furthermore, the depth of microbial analysis revealed by high-throughput sequencing may not be required for monitoring purposes. This study aims to develop a rapid, reliable and economical approach for the monitoring of microbial communities in AD sludge. A combined approach where genetic information of sequences from clone library was used to assign phylogeny to T-RFs determined experimentally was developed in this study. In order to assess the effectiveness of the combined approach, microbial communities determined by the combined approach was compared to that characterised by pyrosequencing. Results showed that both pyrosequencing and clone library methods determined the dominant bacteria phyla to be Proteobacteria, Firmicutes, Bacteroidetes, and Thermotogae. Both methods also found that sludge A and B were predominantly dominated by acetogenic methanogens followed by hydrogenotrophic methanogens. The number of OTUs detected by T-RFLP was significantly lesser than that detected by the clone library. In this study, T-RFLP analysis identified majority of the dominant species of the archaeal consortia. However, many of the more highly diverse bacteria consortia were missed. Nevertheless, the combined approach developed in this study where clone sequences from the clone library were used to assign phylogeny to T-RFs determined experimentally managed to accurately predict the same dominant microbial groups for both sludge A and sludge B, as compared to the pyrosequencing results. Results showed that the combined approach of clone library and T-RFLP accurately predicted the dominant microbial groups and thus is a reliable and more economical way to monitor the evolution of microbial systems in AD sludge.


Assuntos
RNA Ribossômico 16S , Esgotos/microbiologia , Archaea , Bactérias , Biocombustíveis , Reatores Biológicos , Filogenia
14.
Environ Sci Pollut Res Int ; 25(21): 20399-20406, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28656576

RESUMO

The pure cultures of microalgae Chlorella vulgaris ATCC 13482 and Scenedesmus obliquus FACHB 417 were grown in municipal wastewater in 7-L airlift bubble column photobioreactor supplied with 5% CO2/air (v/v). Batch experiments were conducted at 25 °C with 14-h light/10-h dark cycle for a period of 10 days. The CO2 capture efficiencies for both the microalgae were monitored in terms of their respective biomass productivities, carbon contents, and CO2 consumption rates. In the present study, the initial concentration of ammonia (43.7 mg L-1) was decreased to 2.9 and 3.7 mg L-1 by C. vulgaris and S. obliquus, respectively. And, the initial concentration of phosphate (18.5 mg L-1) was decreased to 1.1 and 1.6 mg L-1 by C. vulgaris and S. obliquus, respectively. CO2 biofixation rates by C. vulgaris and S. obliquus, cultivated in municipal wastewater, were calculated to be 140.91 and 129.82 mg L-1 day-1, respectively. The findings from the present study highlight the use of microalgae for wastewater treatment along with CO2 uptake and biomass utilization for pilot scale production of biodiesel, biogas, feed supplements for animals, etc., thus minimizing the production costs.


Assuntos
Dióxido de Carbono/metabolismo , Chlorella vulgaris , Scenedesmus , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias , Poluentes Químicos da Água , Purificação da Água/métodos , Amônia/metabolismo , Biodegradação Ambiental , Biocombustíveis , Biomassa , Carbono/metabolismo , Chlorella vulgaris/crescimento & desenvolvimento , Chlorella vulgaris/metabolismo , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Fosfatos/metabolismo , Fotobiorreatores , Scenedesmus/crescimento & desenvolvimento , Scenedesmus/metabolismo , Águas Residuárias/análise , Água/química
15.
Bioresour Technol ; 249: 729-736, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29096147

RESUMO

The effects of activated carbon (AC) on methane production and the fate of antibiotic resistance genes (ARGs) were evaluated through comparing the anaerobic digestion performance and transformation of ARGs among anaerobic mono-digestion of food waste, co-digestion of food waste and chicken manure, and co-digestion of food waste and waste activated sludge. Results showed that adding AC in anaerobic digesters improved methane yield by at least double through the enrichment of bacteria and archaea. Conventional digestion process showed ability in removing certain types of ARGs, such as tetA, tetX, sul1, sul2, cmlA, floR, and intl1. Supplementing AC in anaerobic digester enhanced the removal of most of the ARGs in mono-digestion of food waste. The effects tended to be minimal in co-digestion of co-substrates such as chicken manure and waste activated sludge, both of which contain a certain amount of antibiotics.


Assuntos
Integrons , Metano , Resíduos Sólidos , Anaerobiose , Antibacterianos , Reatores Biológicos , Esgotos
16.
Sci Rep ; 7(1): 11565, 2017 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-28912594

RESUMO

Aquaporin incorporated biomimetic membranes are anticipated to offer unprecedented desalination capabilities. However, the lack of accurate methods to quantify the reconstituted aquaporin presents a huge hurdle in investigating aquaporin performance and optimizing membrane fabrication. Herein, we present three quantification methods to determine the Aquaporin-Z reconstituted into E. coli lipid vesicles: 1) nanogold labeling with transmission electron microscopy (TEM) visualization, 2) nickel labeling with inductively coupled plasma-mass spectrometry (ICP-MS) and 3) gel electrophoresis. The TEM method serves as a quick way to determine if aquaporin has been reconstituted, but is not quantitative. The numerical results from quantitative methods, ICP-MS and gel electrophoresis, correlate closely, showing that 60 ± 20% vs 66 ± 4% of Aquaporin-Z added is successfully reconstituted into vesicles respectively. These methods allow more accurate determination of Aquaporin-Z reconstituted and loss during reconstitution, with relatively commonly available equipment and without complex sample handling, or lengthy data analysis. These would allow them to be widely applicable to scientific studies of protein function in the biomimetic environment and engineering studies on biomimetic membrane fabrication.


Assuntos
Aquaporinas/metabolismo , Biomimética , Membrana Celular/metabolismo , Aquaporinas/química , Biomimética/métodos , Ouro/química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Permeabilidade , Ultracentrifugação
17.
Bioresour Technol ; 245(Pt A): 1148-1154, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28869126

RESUMO

In this study, a multifarious microbial mix from different sources is acclimatized over a period of three months to digesting cowgrass, and the changes in the community structure are examined with both a traditional denaturing gradient gel electrophoresis method as well as a next generation sequencing MiSeq method. It is shown that the much more in depth analysis by Illumina gives more information about the relative abundance and thus putative importance of the role of various microbes, in particular the bacterium Mesotoga infera and the archaeon Methanosaeta concilii.


Assuntos
Anaerobiose , Reatores Biológicos , Eletroforese em Gel de Gradiente Desnaturante , Sequenciamento de Nucleotídeos em Larga Escala , Aclimatação , Animais , Esterco
18.
Sci Rep ; 7(1): 11293, 2017 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-28900280

RESUMO

Powdered activated carbon (AC) is commonly used as an effective additive to enhance anaerobic digestion (AD), but little is known about how the metabolic pathways resulting from adding AC change the microbial association network and enhance food waste treatment. In this work, the use of AC in an anaerobic digestion system for food waste was explored. Using bioinformatics analysis, taxonomic trees and the KEGG pathway analysis, changes in microbial network and biometabolic pathways were tracked. The overall effect of these changes were used to explain and validate improved digestion performance. The results showed that AC accelerated the decomposition of edible oil in food waste, enhancing the conversion of food waste to methane with the optimized dosage of 12 g AC per reactor. Specifically, when AC was added, the proponoate metabolic pathway that converts propanoic acid to acetic acid became more prominent, as measured by 16S rRNA in the microbial community. The other two metabolic pathways, Lipid Metabolism and Methane Metabolism, were also enhanced. Bioinformatics analysis revealed that AC promoted the proliferation of syntrophic microorganisms such as Methanosaeta and Geobacter, forming a highly intensive syntrophic microbial network.


Assuntos
Anaerobiose , Metabolismo Energético , Metagenoma , Metagenômica , Microbiota , Biologia Computacional/métodos , Fermentação , Alimentos , Redes e Vias Metabólicas , Metagenômica/métodos , Metano/biossíntese , Eliminação de Resíduos Líquidos
19.
Macromol Biosci ; 17(9)2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28683186

RESUMO

The progression of cancer is often accompanied by changes in the mechanical properties of an extracellular matrix. However, limited efforts have been made to reproduce these biological events in vitro. To this end, this study demonstrates that matrix remodeling caused by matrix metalloproteinase (MMP)-1 regulates phenotypic activities and modulates radiosensitivity of cancer cells exclusively in a 3D matrix. In this study, hepatocarcinoma cells are cultured in a collagen-based gel tailored to present an elastic modulus of ≈4.0 kPa. The subsequent exposure of the gel to MMP-1 decreases the elastic modulus from 4.0 to 0.5 kPa. In response to MMP-1, liver cancer cells undergo active proliferation, downregulation of E-cadherin, and the loss of detoxification capacity. The resulting spheroids are more sensitive to radiation than the spheroids cultured in the stiffer gel not exposed to MMP-1. Overall, this study serves to better understand and control the effects of MMP-induced matrix remodeling.


Assuntos
Carcinoma Hepatocelular/radioterapia , Matriz Extracelular/metabolismo , Neoplasias Hepáticas/radioterapia , Metaloproteinase 1 da Matriz/metabolismo , Tolerância a Radiação , Antígenos CD , Caderinas/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/fisiopatologia , Proliferação de Células , Módulo de Elasticidade , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/fisiopatologia
20.
J Colloid Interface Sci ; 501: 282-293, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28460221

RESUMO

A single-step fabrication method, coaxial electrohydrodynamic atomization (CEHDA), was developed to synthesize drug-loaded microbubbles (MBs) for combination treatment of ischemic stroke. The bioactivity of therapeutic agent (tPA, tissue plasminogen activator) after preparation was evaluated, showing that CEHDA could be very promising method for producing MBs with therapeutic functions. The bubble performance and tPA release profiles were also examined by exposing the bubbles to 2MHz ultrasound of various intensities. The results showed that the mean diameter of tPA-loaded MBs was found to fluctuate about its original diameter when exposed to ultrasound and higher intensity ultrasound was more effective in triggering the burst of CEHDA MBs. High ultrasound-triggered bubble disintegration effectiveness in a short period (first 5min) fits well with the requirement of short ultrasound exposure time for human brain. Moreover, a numerical model was also applied to investigate the stability of the fabricated MBs in the bloodstream. It was found that MB dissolution time increased with initial radius, decreased with initial surface tension and increased with initial shell resistance but it was barely affected by the average excessive bloodstream pressure.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Microbolhas , Fosfolipídeos/química , Ativador de Plasminogênio Tecidual/administração & dosagem , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/terapia , Liberação Controlada de Fármacos , Desenho de Equipamento , Humanos , Modelos Moleculares , Ativador de Plasminogênio Tecidual/química , Ultrassonografia Doppler Transcraniana/instrumentação
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