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1.
Bioresour Technol ; 300: 122705, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31926472

RESUMO

Adsorption is an efficient and low-cost technology used to purify volatile organic compounds (VOCs). In the current study, novel microbial adsorbents were synthesized using cells of lyophilized fungi (Ophiostoma stenoceras LLC) or bacteria (Pseudomonas veronii ZW) that were modified by aminomethylation. Based on the adsorption performance and structural characterization results, the modified fungal biosorbent was the best. Its maximum adsorption capacities for ethyl acetate, α-pinene, and n-hexane were 620, 454, and 374 mg·g-1, respectively, which were much higher than those of other synthesized biosorbents. The specific surface area of the fungal biosorbent was 20 m2·g-1, and most of the components were hydrocarbon compounds and polysaccharides. The VOC adsorption process on these synthesized biosorbents was in accordance with the Langmuir isothermal model and the pseudo-first-order kinetic model, thereby suggesting that physical adsorption was the dominant mechanism. The fungal biosorbent could be used for five consecutive VOC sorption-desorption cycles without any obvious decrease in adsorption capacity.


Assuntos
Compostos Orgânicos Voláteis , Poluentes Químicos da Água , Adsorção , Biomassa , Fungos , Concentração de Íons de Hidrogênio , Cinética
2.
Int Immunopharmacol ; 77: 105948, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31629216

RESUMO

OBJECTIVE: The role of iNKT cells was investigated in chronic adipose tissue inflammation in obese mice after administration of α-GalCer in different pathways. METHODS: C57BL/6J mice were fed high-fat diet (HFD) for 12 weeks to establish the obese mouse model. The pathology of adipose tissue was observed by H&E staining. The rates of iNKT cells, macrophages and cell subsets in adipose tissue were detected by FCM. Cytokine levels in serum and adipose tissue lymphocyte-stimulated supernatants were assessed with the CBA kit. The expression levels of related transcription factor in adipose tissue were detected by Western blot. RESULTS: The proportions of iNKT cells, iNKT10 cells and M2 macrophages were decreased, while those of iNKT1 and M1 macrophages were increased in adipose tissue of HFD-fed mice. The expression levels of the related transcriptional proteins E4BP4 and Arg-1 were decreased while iNOS expression was increased in adipose tissue. Administration of α-GalCer by subcutaneous injection resulted in increased rates of iNKT10 cells and M2 macrophages, and decreased amounts of M1 macrophages in adipose tissue of HFD-fed mice. The expression of E4BP4 and Arg-1 were up-regulated, but iNOS was down-regulated. Meanwhile, infiltration of inflammatory cells into adipose tissue was further reduced. CONCLUSION: The imbalance between the proportions of iNKT1 and iNKT10 cells may be involved in the development of chronic inflammation in obese adipose tissue. Administration of α-GalCer by subcutaneous injection in HFD-fed mice activates adipose tissue iNKT10 cells, which promote M2 macrophage polarization and improve chronic inflammation in obese adipose tissue.

3.
Sci Total Environ ; 692: 940-951, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539998

RESUMO

A novel array double dielectric barrier discharge (ADDBD) combined with a TiO2/Al2O3-Co3O4/AC (TiCo) catalyst was applied to remove toluene. The effects of catalyst setting distance, catalyst combination mode, and process factors (including specific input energy, initial toluene concentration, and relative humidity) were investigated in terms of the toluene degradation efficiency (ηtoluene) and the selectivity of CO2 (SCO2). When the specific input energy was 65 J·L-1, the initial toluene concentration was 100 mg·m-3, and the relative humidity was 30%, the highest ηtoluene of 72% and SCO2 of 44% could be achieved with TiO2/Al2O3 10 cm and Co3O4/AC 20 cm downstream of the ADDBD. Based on the determination of active substances (e.g., O3, OH) and the catalyst activation mode, a synergistic effect of active substances and photon between the ADDBD and the TiCo catalyst was proposed for the removal of toluene. Finally, the biodegradability and toxicity of the outlet gas were evaluated, and the results showed that the outlet gas was more convenient for subsequent biopurification and less toxic to the surroundings after the treatment by the ADDBD combined with the TiCo catalyst.

4.
Immunogenetics ; 71(7): 489-499, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31297569

RESUMO

Epigenetic modifications have been shown to be important for immune cell differentiation by regulating gene transcription. However, the role and mechanism of histone methylation in the development and differentiation of iNKT cells in rheumatoid arthritis (RA) mice have yet to be deciphered. The DBA/1 mouse RA model was established by using a modified GPI mixed peptide. We demonstrated that total peripheral blood, thymus, and spleen iNKT cells in RA mice decreased significantly, while iNKT1 in the thymus and spleen was increased significantly. PLZF protein and PLZF mRNA levels were significantly decreased in thymus DP T cells, while T-bet protein and mRNA were significantly increased in thymus iNKT cells. We found a marked accumulation in H3K27me3 around the promoter regions of the signature gene Zbtb16 in RA mice thymus DP T cells, and an accumulation of H3K4me3 around the promoters of the Tbx21 gene in iNKT cells. The expression levels of UTX in the thymus of RA mice were significantly reduced. The changes in the above indicators were particularly significant in the progressive phase of inflammation (11 days after modeling) and the peak phase of inflammation (14 days after modeling) in RA mice. Developmental and differentiation defects of iNKT cells in RA mice were associated with abnormal methylation levels (H3K27me3 and H3K4me3) in the promoters of key genes Zbtb16 (encoding PLZF) and Tbx21 (encoding T-bet). Decreased UTX of thymus histone demethylase levels resulted in the accumulation of H3K27me3 modification.


Assuntos
Artrite Reumatoide/patologia , Lisina/metabolismo , Células T Matadoras Naturais/patologia , Regiões Promotoras Genéticas , Timo/fisiologia , Animais , Artrite Experimental/patologia , Diferenciação Celular , Epigênese Genética , Regulação da Expressão Gênica , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Metilação , Camundongos Endogâmicos DBA , Proteína com Dedos de Zinco da Leucemia Promielocítica/genética , Proteína com Dedos de Zinco da Leucemia Promielocítica/metabolismo , Baço/patologia , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo
5.
Int Immunopharmacol ; 74: 105727, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31284229

RESUMO

The existence of association between the subpopulation of iNKT cells with different functions and nonalcoholic fatty liver disease has not been confirmed. To investigative the role of iNKT cells in the pathogenesis of nonalcoholic fatty liver disease, we established a non-alcoholic fatty liver model by feeding C57BL/6J mice for 12 weeks with a high-fat diet and injecting α-GalCer through different routes to activate hepatic iNKT cells. The liver of the mice fed a high-fat diet (HFD) had severe hepatic steatosis appearance, elevated pro-inflammatory cytokines and reduced anti-inflammatory cytokines in the liver, and high serum levels of TC, LDL, HDL, and ALT. Our results showed that the percentage of iNKT cells in the liver of the HFD-fed mice was lower than that of the control mice. The expression levels of the related transcription factor of T-bet increased but that of GATA-3 decreased in the HFD-fed mice. The administration of α-GalCer by intraperitoneal injection resulted in increasing of hepatic iNKT and iNKT2 cells but decreasing of hepatic iNKT1 cells, and the expression of GATA-3 and anti-inflammatory cytokine (IL-4) was increased in the liver, and hepatic steatosis was ameliorated in the HFD-fed mice. The administration of α-GalCer by subcutaneous injection resulted in a decrease in hepatic iNKT and iNKT2 and an augmentation of hepatic iNKT1 cells. However, hepatic steatosis was not significantly improved. We concluded that the intraperitoneal injection with α-GalCer effectively improved hepatic steatosis, according to increasing the number of hepatic iNKT2 cells. The precise mechanism requires further exploration.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31083278

RESUMO

In this study, a water-silicone oil biphasic system was developed to enhance the biodegradation of monochlorobenzene (CB) by Delftia tsuruhatensis LW26. Compared to the single phase, the biphasic system with a suitable silicone oil fraction (v/v) of 20% allowed a 2.5-fold increase in the maximum tolerated CB concentration. The CB inhibition on D. tsuruhatensis LW26 was reduced in the presence of silicone oil, and the electron transport system activity was maintained at high levels even under high CB stress. Adhesion of cells to the water-oil interface at the water side was observed using confocal laser scanning microscopy. Nearly 75% of cells accumulated on the interface, implying that another interfacial substrate uptake pathway prevailed besides that initiated by cells in the aqueous phase. The 8-fold increase in cell surface hydrophobicity upon the addition of 20% (v/v) silicone oil showed that silicone oil modified the surface characteristics of D. tsuruhatensis LW26. The protein/polysaccharide ratio of extracellular polymeric substances (EPS) from D. tsuruhatensis LW26 presented a 3-fold enhancement. These results suggested that silicone oil induced the increase in the protein content of EPS and rendered cells hydrophobic. The resulting hydrophobic cells could adhere on the water-oil interface, improving the mass transfer by direct CB uptake from silicone oil.


Assuntos
Clorobenzenos/metabolismo , Delftia/metabolismo , Óleos de Silicone/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Água/análise , Biodegradação Ambiental
7.
J Hazard Mater ; 366: 16-26, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30500694

RESUMO

The type of packing material for biofiltration has a great impact on microbial growth and pollutant removal. This study evaluated the feasibility of a nutritional slow-release packing material with functional microorganisms (NSRP-FM) in a biofilter for the removal of gaseous n-butyl acetate. Through the emulsification-cross linked process and microbial immobilization, an innovative packing material was obtained, with a specific surface area of 2.45 m2 g-1 and a bulk density of 40.75 kg m-3. The cumulative release rates of total phosphorus and total nitrogen were 90.6% and 75.6%, respectively, as measured while continuously spraying deionized water. To evaluate the performance of biofiltration, NSRP-FM was compared with the commercial polyurethane foam (PU-foam), in two identical biotrickling filters (BTFs). The BTF packed with the prepared NSRP-FM maintained a consistent removal efficiency (over 95%) without nutrients addition and pH adjustment. The other BTF had poor removal performance, and the removal efficiency declined to 65% when there was no pH adjustment. Energy dispersive X-ray spectroscopy (EDS) analysis of NSRP-FM showed that inorganic elements were released during the operation of BTF. The abundance of functional microorganisms suggested that the prepared NSRP-FM provided a better environment for microbial growth, despite changes in the operating conditions.


Assuntos
Acetatos/metabolismo , Poluentes Atmosféricos/metabolismo , Aspergillus fumigatus/metabolismo , Poliuretanos , Ralstonia pickettii/metabolismo , Biodegradação Ambiental , Filtração/métodos
8.
J Sci Food Agric ; 99(1): 39-46, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29786860

RESUMO

BACKGROUND: Atmospheric cold plasma (ACP) has emerged as a potential alternative to traditional methods for non-thermal food decontamination. However, few data are available about ACP treatment for seafood. In this study, dielectric barrier discharge (DBD) was applied to generate CP, and the aim of the study was to investigate the effectiveness of DBD-ACP on improving the quality of chub mackerel on the basis of chemical, microbial and sensory characteristics. RESULTS: The effect of DBD-ACP on the quality of chub mackerel (Scomber japonicus) during storage was examined. Results revealed that the optimal voltage level and exposure time of this treatment were 60 kV and 60 s respectively, and such conditions exhibited excellent inactivation efficacy and weak influence on proximate chemical compositions. Variations in total viable count (TVC), sensory scores and total volatile basic nitrogen (TVB-N) indicated that ACP treatment extended the shelf life of chub mackerel to 14 days, whereas samples without this treatment exceeded the limits of the three parameters after 6 days. The slow development rates of peroxide value (PV) and thiobarbituric acid (TBA) value implied that lipid oxidation was also effectively retarded by ACP exposure. Scanning electron microscopy confirmed that CP could effectively delay the degradation of myofibrillar proteins and enhance the stability of tissue structures. CONCLUSION: The excellent antimicrobial efficacy of ACP treatment makes it a potential and promising alternative to other seafood preservation technology. This is the first report on the application of ACP to seafood, which is essential to perishable food storage. © 2018 Society of Chemical Industry.


Assuntos
Conservação de Alimentos/métodos , Perciformes , Gases em Plasma/química , Alimentos Marinhos/análise , Alimentos Marinhos/efeitos da radiação , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/efeitos da radiação , Humanos , Lipídeos/química , Oxirredução , Perciformes/microbiologia , Alimentos Marinhos/microbiologia , Paladar , Tiobarbitúricos/análise
9.
Sci Total Environ ; 650(Pt 2): 2095-2106, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30290351

RESUMO

The first step of microbial biodegradation is the adsorption of pollutants on the microorganisms' surface, which is determined by the microorganism type and pollutant hydrophobicity. One fungus Ophiostoma stenoceras LLC and one bacterium Pseudomonas veronii ZW were chosen for the investigation of cell surface hydrophobicity and adsorption abilities to various organic compounds. Results showed that the fungus could better capture and adsorb organic compounds in liquid and gas phases, and the adsorption was a physical monolayer adsorption process. Much smaller partition coefficient for gas-fungus suggested that direct gaseous adsorption was preferred. The XPS (X-ray photoelectron spectroscopy) characterization further confirmed that several functional groups changed after the adsorption of compounds. The time taken for complete degradation of hexane, tetrahydrofuran and chlorobenzene was shorter with the addition of O. stenoceras LLC. Such findings are useful in exploring the special cell surface of fungus in adsorption and bioenhancement for organic treatment of organic contaminants using bacteria.


Assuntos
Poluentes Atmosféricos/metabolismo , Recuperação e Remediação Ambiental/métodos , Ophiostoma/metabolismo , Compostos Orgânicos/metabolismo , Pseudomonas/metabolismo , Poluentes Químicos da Água/metabolismo , Adsorção , Biodegradação Ambiental , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia Fotoeletrônica , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Eliminação de Resíduos Líquidos/métodos
10.
Int Immunopharmacol ; 67: 427-440, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30586666

RESUMO

BACKGROUND: The therapeutic effect of adoptive infusion of specific thymus-derived invariant natural killer T (iNKT) cells in a mouse model of rheumatoid arthritis (RA) was observed, and the mechanism of cellular immunotherapy was preliminarily explored. METHODS: Thymus-derived iNKT cells were infused to RA model mice, with α-GalCer as a positive control. Then, ankle swelling was examined, as well as inflammatory cell infiltration to the joint tissue (hematoxylin-eosin [H&E] staining). Flow cytometry (FCM) was used to assess iNKT cell and helper T lymphocyte (Th) subsets. Serum cytokine levels were determined with cytometric bead array (CBA), with protein expression levels of related transcription factors assessed by Western blot. RESULTS: The joint swelling in RA model animals were significantly improved in the cell therapy and α-GalCer positive control groups (P < 0.05). In addition, iNKT frequencies in peripheral blood, the thymus and spleen were increased significantly (P < 0.05). Meanwhile, iNKT1 subset frequencies in the thymus and spleen were decreased, as well as splenic Th1 and Th17 cell subset rates, and serum TNF-α, IFN-γ and IL-6 levels. The rates of iNKT2 and Th2 subsets as well as IL-4 and IL-10 levels were increased (P < 0.05). Thymus GATA-3 and splenic PLZF protein levels were increased (P < 0.05). CONCLUSIONS: Adoptive infusion of thymus-derived iNKT cells exerts therapeutic effects in RA mice by increasing iNKT frequency, altering the proportions of iNKT cell subsets, correcting Th cell subset imbalance and reducing the amounts of inflammatory cytokines.


Assuntos
Artrite Reumatoide/terapia , Imunoterapia Adotiva , Células T Matadoras Naturais , Timo/citologia , Animais , Artrite Reumatoide/induzido quimicamente , Masculino , Camundongos , Células T Matadoras Naturais/classificação , Peptídeos/toxicidade , Distribuição Aleatória , Baço/citologia
11.
Carbohydr Polym ; 199: 516-525, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30143158

RESUMO

Ultraviolet (UV) shielding, superhydrophobic and antimicrobial cotton fabrics were fabricated using functional coatings combined with advantages of polyvinylsilsesquioxane and ZnO nanoparticles by solution immersion. The influence of composite coatings on surface morphology, water-repellence, UV shielding property, mechanical property, thermal degradation behavior and antibacterial property of the cotton fabrics was investigated respectively. It is evidently found that the cotton fabrics functionalized by composite coatings exhibited excellent UV shielding, durable superhydrophobic and antimicrobial properties as compared to the reference materials. Most notably, the mechanical properties of cotton fabrics was significantly improved by surface treatment of the composite coatings without compromising their thermal stability as compared to the pristine cotton fabric. This strategy for fabricating UV shielding and superhydrophobic cotton fabrics will guide for developing advanced functional textile in the future work, which will likely be found in many applications such as advanced protective textiles, oil/water separation, water-proof, antibacterial and self-cleaning fields.

12.
Huan Jing Ke Xue ; 39(2): 633-639, 2018 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964825

RESUMO

The performance and microbial communities of methyl tert-butyl ether (MTBE) treatment using a biotrickling filter (BTF) that was inoculated with activated sewage sludge were investigated. The BTF successfully started up within 23 days when the inlet concentration of MTBE was 100 mg·m-3 and empty bed retention time was 60 s, with 70% removal efficiency (RE). Under steady-state conditions, an elimination capacity (EC) and a mineralization ratio of 13.47 g·(m3·h)-1 and 68% were achieved, respectively. The ECmax was 21.03 g·(m3·h)-1 according to the Haldane model, and a KS of 0.16 g·m-3 and KI of 0.99 g·m-3 were obtained. High-throughput sequencing was used to identify the community structure of the mixed microbial consortium in the BTF. The results indicated that Methylibium sp. (11.33%) and Blastocatella sp. (9.95%) were the dominant bacteria.


Assuntos
Reatores Biológicos/microbiologia , Filtração , Gases/análise , Éteres Metílicos/análise , Consórcios Microbianos , Bactérias/classificação , Biodegradação Ambiental , Esgotos
13.
Int J Syst Evol Microbiol ; 68(8): 2627-2632, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29957173

RESUMO

A yellowish-pigmented bacterial strain, designated as MQ-18T, was isolated from a sample of activated sludge collected from a pharmaceutical factory in Zhejiang, China. The strain was characterized through a polyphasic taxonomy approach. 16S rRNA gene sequence analysis demonstrated that strain MQ-18T showed high similarities to Piscinibacter defluvii SH-1T (99.7 %) and Piscinibacter aquaticus IMCC1728T (98.4 %), thereby suggesting that it belongs to the genus Piscinibacter. The DNA-DNA relatedness values of this strain to strains SH-1T and IMCC1728T were only 35.4 and 33.3 %, respectively. Cells of MQ-18T were Gram-negative, aerobic, motile, rod-shaped and non-spore forming. This strain exhibited growth at 25-37 °C (optimum: 30 °C) in the presence of 0-3.0 % (w/v) NaCl (optimum, 0 % NaCl) and at pH 5.0-8.0 (pH 7.0). The predominant fatty acids were C12 : 0 (5.5 %), C16 : 0 (33.7 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 38.5 %), and summed feature 4 (anteiso-C17 : 1 B and/or iso C17 : 1 I; 11.6 %). The main quinone type was ubiquinone-8, and the major polyamines were cadaverine and putrescine. The major polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 70.1 mol%. On the basis of its phylogenetic, phenotypic and physiological characteristics, strain MQ-18T is considered to represent a novel species of the genus Piscinibacter, for which the name Piscinibacter caeni sp. nov. is proposed. The type strain is MQ-18T (CCTCC AB 2017223T=JCM 32138T).


Assuntos
Burkholderiales/classificação , Filogenia , Esgotos/microbiologia , Bactérias/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Burkholderiales/genética , Burkholderiales/isolamento & purificação , Cadaverina/química , China , DNA Bacteriano/genética , Indústria Farmacêutica , Ácidos Graxos/química , Resíduos Industriais , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Pigmentação , Putrescina/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
14.
Int J Biol Macromol ; 108: 383-390, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29225174

RESUMO

Hydrogels composed of natural materials exhibit great application potential in artificial scaffolds for cartilage repair as they can resemble the extracellular matrices of cartilage tissues comprised of various glycosaminoglycan and collagen. Herein, the natural polymers with vinyl groups, i.e. maleilated chitosan (MCS) and methacrylated silk fibroin (MSF) micro/nanoparticles, were firstly synthesized. The chemical structures of MCS and MSF micro/nanoparticles were investigated using Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Then MCS/MSF micro/nanocomposite hydrogels were prepared by the photocrosslinking of MCS and MSF micro/nanoparticles in aqueous solutions in the presence of the photoinitiator Darocur 2959 under UV light irradiation. A series of properties of the MCS/MSF micro/nanocomposite hydrogels including rheological property, equilibrium swelling, sol content, compressive modulus, and morphology were examined. The results showed that these behaviors could be tunable via the control of MSF content. When the MSF content was 0.1%, the hydrogel had the compressive modulus of 0.32±0.07MPa, which was in the range of that of articular cartilage. The in vitro cytotoxic evaluation and cell culture of the micro/nanocomposite hydrogels in combination with mouse articular chondrocytes were also investigated. The results demonstrated that the micro/nanocomposite hydrogels with TGF-ß1 was biocompatible to mouse articular chondrocytes and could support cells attachment well, indicating their potential as tissue engineering scaffolds for cartilage repair.


Assuntos
Quitosana/química , Fibroínas/química , Hidrogéis/química , Nanocompostos/química , Engenharia Tecidual , Tecidos Suporte/química , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Cartilagem Articular , Sobrevivência Celular , Condrócitos , Colágeno , Matriz Extracelular , Hidrogéis/síntese química , Espectroscopia de Ressonância Magnética , Teste de Materiais , Fenômenos Mecânicos , Camundongos , Processos Fotoquímicos , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier
15.
J Hazard Mater ; 342: 589-596, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28892796

RESUMO

Volatile organic sulfide compounds (VOSCs) are usually resistant to biodegradation, thereby limiting the performance of traditional biotechnology dealing with waste gas containing such pollutants especially in mixture. In this study, a solid composite microbial inoculant (SCMI) was prepared to remove dimethyl sulfide (DMS) and propanethiol (PT). Given that the DMS degradation activity of Alcaligenes sp. SY1 is inducible and the PT-degradation activity of Pseudomonas putida S-1 is constitutive, different strategies are designed for cell cultivation to obtain high VOSC removal rates of SCMI. Compared with the microbial suspension, the prepared SCMI exhibited better storage stability at 4 and 25°C. Inoculation of the SCMI in biotrickling filters (BTFs) could effectively shorten the start-up period and enhance the removal performance. Microbial analysis by Illumina MiSeq indicated that Alcaligenes sp. SY1 and P. putida S-1 might be dominant and persistent among the microbial communities of the BTF during the operation.


Assuntos
Alcaligenes/metabolismo , Sulfeto de Hidrogênio/química , Pseudomonas putida/metabolismo , Compostos de Sulfidrila/química , Sulfetos/química , Compostos Orgânicos Voláteis/química , Inoculantes Agrícolas , Biodegradação Ambiental , Filtração , Pseudomonas putida/química
16.
Int J Biol Macromol ; 106: 227-233, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28780418

RESUMO

Photocrosslinkable water-soluble maleilated chitosan and methacrylated poly (vinyl alcohol) were synthesized and therefore maleilated chitosan/methacrylated poly (vinyl alcohol) (MCS/MPVA) hydrogels were prepared under UV radiation. Series of properties of the hydrogels including rheological property, swelling behavior, morphology and mechanical test were investigated. The main results showed that the MCS/MPVA hydrogels had fast gel-forming rate (complete transformation to gel within 150s), improved compressive strength at 0.169±0.011MPa and rapid absorbent capacity. These behaviors could be tunable via the control of weight ratio of MCS to MPVA. The indirect cytotoxicity assessments demonstrated the photocrosslinked hydrogels was compatible to mouse fibroblasts (L929 cells), indicating their potential as tissue engineering scaffolds.


Assuntos
Quitosana/análogos & derivados , Hidrogéis/química , Maleatos/química , Metacrilatos/química , Álcool de Polivinil/química , Engenharia Tecidual , Animais , Linhagem Celular , Quitosana/farmacologia , Quitosana/efeitos da radiação , Força Compressiva , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Hidrogéis/farmacologia , Hidrogéis/efeitos da radiação , Teste de Materiais , Camundongos , Transição de Fase , Processos Fotoquímicos , Polimerização , Álcool de Polivinil/farmacologia , Álcool de Polivinil/efeitos da radiação , Reologia , Solubilidade , Tecidos Suporte , Raios Ultravioleta , Água/química
17.
Mar Drugs ; 15(6)2017 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-28561771

RESUMO

The presence of nicotine and nicotinic acid (NA) in the marine environment has caused great harm to human health and the natural environment. Therefore, there is an urgent need to use efficient and economical methods to remove such pollutants from the environment. In this study, a nicotine and NA-degrading bacterium-strain JQ581-was isolated from sediment from the East China Sea and identified as a member of Pseudomonas putida based on morphology, physio-biochemical characteristics, and 16S rDNA gene analysis. The relationship between growth and nicotine/NA degradation suggested that strain JQ581 was a good candidate for applications in the bioaugmentation treatment of nicotine/NA contamination. The degradation intermediates of nicotine are pseudooxynicotine (PN) and 3-succinoyl-pyridine (SP) based on UV, high performance liquid chromatography, and liquid chromatography-mass spectrometry analyses. However, 6-hydroxy-3-succinoyl-pyridine (HSP) was not detected. NA degradation intermediates were identified as 6-hydroxynicotinic acid (6HNA). The whole genome of strain JQ581 was sequenced and analyzed. Genome sequence analysis revealed that strain JQ581 contained the gene clusters for nicotine and NA degradation. This is the first report where a marine-derived Pseudomonas strain had the ability to degrade nicotine and NA simultaneously.


Assuntos
Organismos Aquáticos/genética , Niacina/metabolismo , Nicotina/metabolismo , Pseudomonas putida/genética , Organismos Aquáticos/metabolismo , Biodegradação Ambiental , Butanonas/metabolismo , China , DNA Bacteriano/genética , DNA Ribossômico/genética , Nicotina/análogos & derivados , Ácidos Nicotínicos/metabolismo , Filogenia , Pseudomonas putida/metabolismo , Piridinas/metabolismo , Análise de Sequência de DNA , Microbiologia do Solo , Succinatos/metabolismo
18.
Appl Microbiol Biotechnol ; 101(9): 3829-3837, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28091789

RESUMO

Bioremediation usually exhibits low removal efficiency toward hexane because of poor water solubility, which limits the mass transfer rate between the substrate and microorganism. This work aimed to enhance the hexane degradation rate by increasing cell surface hydrophobicity (CSH) of the degrader, Pseudomonas mendocina NX-1. The CSH of P. mendocina NX-1 was manipulated by treatment with starch and chitosan solution of varied concentrations, reaching a maximum hydrophobicity of 52%. The biodegradation of hexane conformed to the Haldane inhibition model, and the maximum degradation rate (ν max) of the cells with 52% CSH was 0.72 mg (mg cell)-1·h-1 in comparison with 0.47 mg (mg cell)-1·h-1 for cells with 15% CSH. The production of CO2 by high CSH cells was threefold higher than that by cells at 15% CSH within 30 h, and the cumulative rates of O2 consumption were 0.16 and 0.05 mL/h, respectively. High CSH was related to low negative charge carried by the cell surface and probably reduced the repulsive electrostatic interactions between hexane and microorganisms. The FT-IR spectra of cell envelopes demonstrated that the methyl chain was inversely proportional to increasing CSH values, but proteins exhibited a positive effect to CSH enhancement. The ratio of extracellular proteins and polysaccharides increased from 0.87 to 3.78 when the cells were treated with starch and chitosan, indicating their possible roles in increased CSH.


Assuntos
Quitosana/metabolismo , Hexanos/metabolismo , Pseudomonas mendocina/química , Pseudomonas mendocina/metabolismo , Amido/metabolismo , Propriedades de Superfície , Biotransformação , Dióxido de Carbono/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Oxigênio/metabolismo , Pseudomonas mendocina/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Huan Jing Ke Xue ; 38(2): 802-808, 2017 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964540

RESUMO

A bacterium strain LW26 which could utilize chlorobenzene (CB) as sole carbon and energy source was isolated from a biotrickling filter reactor treating CB-contaminated off-gas. Based on its morphological and physiological characteristics, as well as the analysis of 16S rRNA gene sequence and Biolog test, the strain LW26 was identified as Delftia tsuruhatensis. To our best knowledge, it is the first time that the strain Delftia tsuruhatensis was applied for CB purification. In this study, the effects of temperature, pH, initial CB concentration and Cl- concentration on the biodegradation were investigated. The results showed that the optimal temperature and pH for CB biodegradation were 25℃ and 7.0,respectively; the maximum CB tolerated concentration for LW26 was as high as 500 mg·L-1; when the concentration of Cl- was above 0.14 mol·L-1, the CB degradation was significantly restrained. The degrading process of the strain LW26 followed the Haldane kinetic model and the maximum specific growth rate and the maximum specific degradation rate were 0.42 h-1 and 2.53 h-1, respectively.GC-MS analysis of the metabolites revealed that CB was firstly converted to o-chlorophenol by strain LW26. Combined with the activity of catechol dioxygenase, it can be speculated that CB was finally mineralized to CO2, or converted to cell biomass after processes of ortho cleavage,dechlorination and oxidation.


Assuntos
Biodegradação Ambiental , Clorobenzenos/metabolismo , Delftia/classificação , Delftia/isolamento & purificação , Delftia/metabolismo , RNA Ribossômico 16S
20.
Huan Jing Ke Xue ; 38(3): 918-923, 2017 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965561

RESUMO

The biodegradation of gas-phase mixtrue of dimethyl sulfide (DMS) and 1-propanethiol (PT) was examined in a biotrickling filter (BTF), inoculated with a microbial consortium composed of activated sewage sludge, and pure strains of Alcaligenes sp. SY1 and Pseudomonas putida. S-1. BTF could be successfully started up within only 11 days when the inlet concentrations of DMS and PT were both 50 mg·m-3 and EBRT was 30 s, with 90% removal efficiency (RE) of DMS and 100% RE of PT. In the steady state, the maximum elimination capacities of DMS and PT were 8.7 g·(m3·h)-1 and 12.4 g·(m3·h)-1, respectively. The presence of PT with a concentration up to 51 mg·m-3 showed an antagonistic removal pattern for DMS, but the opposite did not occur. Meanwhile, the BTF showed high efficiency in the biodegradation of H2S. When the concentration of H2S was as high as 230 mg·m-3, the RE of H2S could reach 98%. However, H2S showed a declining effect on the removal of DMS when the concentration exceeded 115 mg·m-3.


Assuntos
Reatores Biológicos/microbiologia , Filtração , Odorantes , Esgotos/microbiologia , Enxofre/isolamento & purificação , Alcaligenes , Sulfeto de Hidrogênio/isolamento & purificação , Pseudomonas putida
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