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1.
J Nanosci Nanotechnol ; 20(10): 5997-6006, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32384944

RESUMO

Tumor-targeted drug delivery systems represent challenging and widely investigated strategies to enhance cancer chemotherapy. In this study, we introduce a novel high-hydrophilic mesoporous silica nanoparticle system with a pH-sensitive drug release. The resultant composite nanoparticles appear as spheres of uniform size (450±25 nm) with a porous structure, which enables a high drug-loading ratio. Through modification of chitosan and polyethylene glycol monomethyl ether, the modified mesoporous silica was non-toxic to normal cells, but effective at inducing tumor cell death. With regard to the characteristics of drug release, the modified mesoporous silica clearly displayed a pH-stimulated release of the model drug doxorubicin hydrochloride in an acidic phosphate buffer solution (pH 4.0 and 6.0). The release was much greater than that observed in neutral or alkaline phosphate buffer solutions (pH 7.3 and 8.0). Furthermore, the release behavior was in accordance with the Higuchi model, indicating that this modified mesoporous silica drug delivery system can exhibit controlled release. The above results imply that the modified mesoporous silica is an effective drug delivery system for cancer therapy.

2.
Plant Physiol Biochem ; 151: 34-46, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32193092

RESUMO

Tomato (Lycopersicon esculentum Mill [Solanum lycopersicum L.].) is an important food material and cash crop, as well as a model plant for genetic evolution and molecular biology research. However, as a cold-sensitive crop originating from the tropics, the growth and development of tomato is often affected by low temperature stress. Therefore, how processing tomatoes resist this type of stress has important theoretical and practical significance. In this study, the LeCOLD1 gene was cloned from processing tomato. Subcellular localization analysis showed that LeCOLD1 was located in the plasma membrane. Real-time quantitative PCR analysis showed that LeCOLD1 was highly expressed in roots. Drought, salt and low temperatures induced the expression of COLD1. Overexpression and RNA interference vectors of LeCOLD1 were constructed and were transformed into tomato by the Agrobacterium-mediated method, and then obtaining transgenic tomato plants. It was found that LeCOLD1 increased the height of processing tomato plants and increased the length of their roots. In addition, overexpression of LeCOLD1 significantly improved the cold resistance of the plants. Overexpressing LeCOLD1 in tomato plants reduced the damage to the cell membrane, accumulation of ROS and photoinhibition of PSII, and maintained the high activity of antioxidant enzymes and the content of osmotic regulators. Further analysis revealed that during low temperature stress, the cells maintained high levels of antioxidant enzyme activity by regulating the transcription of the genes encoding these enzymes. The results show that overexpressing LeCOLD1 in tomato increases the plants' resistance to low temperatures, and that reducing LeCOLD1 expression makes the plants more sensitive to low temperatures.

3.
Bioresour Technol ; 302: 122901, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32033842

RESUMO

The impact of lignin extracted from γ-valerolactone/water (GVL/H2O) pretreatment of corn stover on the enzymatic hydrolysis of cellulose was investigated. Two lignin samples were separated and named as GL25 and GL75 according to the amounts of sulfuric acid (25 mM and 75 mM) used in the GVL/H2O pretreatment. With the addition of 2 g/L of GL25 and GL75, the glucan conversion of enzymatic hydrolysis of Avicel improved markedly from 28.0% to 37.4% and 31.3%, respectively. Moreover, the improvement of glucan conversion increased when increasing the loadings of GL25 and GL75. A similar observation was made when GVL/H2O pretreated corn stover was the substrate. The results of the cellulase adsorption experiments showed that the GLs had a lower maximum cellulase adsorption capacity and binding strength compared to that of acid-insoluble lignin. Further structural characterization of the GLs revealed that they had a low zeta-potential and hydrophobicity, but a high Syringyl/Guaiacyl ratio.


Assuntos
Celulase , Lignina , Celulose , Hidrólise , Lactonas , Água , Zea mays
4.
Appl Microbiol Biotechnol ; 104(4): 1533-1543, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31894364

RESUMO

Marine microorganisms live in dramatically different environments and have attracted much attention for their structurally unique natural products with potential strong biological activity. Based on the one strain-many compounds (OSMAC) strategy and liquid chromatography mass spectrometry (LC-MS) methods, our continuing efforts on the investigation of novel active compounds from marine Verrucosispora sp. MS100137 has led to the identification of a new polycyclic metabolite, abyssomicin Y (1), together with six known abyssomicin and proximicin analogs (2-7). Abyssomicin Y is a type I abyssomicin with an epoxide group at C-8 and C-9. Compounds 1-3 showed potent inhibitory effects against the influenza A virus; their observed inhibition rates were 97.9%, 98.3%, and 95.9%, respectively, at a concentration of 10 µM, and they displayed lower cytotoxicity than 4. The structures were determined by different NMR techniques and HRMS experiments. This investigation revealed that OSMAC could serve as a useful method for enabling the activation of the silent genes in the microorganism and for the formation of previously unreported active secondary metabolites.

5.
Bioresour Technol ; 296: 122319, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31689612

RESUMO

A kind of reduced graphene oxide decorated with titanium-based (RGO/TiO2) composites are successfully synthesized and employed in this current study as a novel nonprecious metal catalyst for enhancing bioelectricity generation and cathodic oxygen reduction reaction (ORR) in single chamber microbial fuel cells (MFCs). Compared with commercial Pt/C, RGO/TiO2 shows obviously enhanced oxygen reduction reaction activity due to the appropriately-permeated, large electrochemical active area, enough exposure of electrocatalytic active sites of RGO/TiO2. The air-cathode MFC with RGO/TiO2-1 cathode achieves 1786.7 mW m-3 of power density, 86.7% ±â€¯1.2% of COD removal and 31.6% ±â€¯1.1% of CE, which are higher than commercial Pt/C. Moreover, RGO/TiO2-1 cathode exhibits high-effective electrocatalytic activity, and the power density of RGO/TiO2-1 can keep a stable level and only has a minor decline (5.35%) during 30-cycles operation. These results indicate that RGO/TiO2-1 is a potential cathode catalyst, markedly enhancing cathode ORR, wastewater treatment efficiency, and bioelectricity generation of MFC.


Assuntos
Oxigênio , Titânio , Eletrodos , Características da Família , Grafite
6.
Ecotoxicol Environ Saf ; 183: 109576, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31509928

RESUMO

Formaldehyde (FA), a ubiquitous indoor environmental pollutant, has been classified as a carcinogen. There are many studies showed that low levels of FA could promote cell proliferation, however, little is known about the signal pathways. To determine the potential molecular mechanisms, human chronic myeloid leukemia cells (K562 cells) and human bronchial epithelial cells (16HBE cells) were exposed to different concentrations of FA. The data showed that FA at 0-125 µM or 0-60 µM promoted the proliferation of K562 cells or 16HBE cells respectively, indicating that FA did have the Hormesis effect. FA at 75 µM (K562 cells) and 40 µM (16HBE cells) significantly promoted cell proliferation, increased intracellular reactive oxygen species (ROS) levels, and decreased glutathione (GSH) content. At the same time, FA treatment induced a marked increase in the key molecules of cell division like CyclinD-cdk4 and E2F1. In addition, pyruvate kinase isozyme M2 (PKM2), glucose, glucose transporter 1 (GLUT1), lactic acid and lactate dehydrogenase A (LDHA) content in the Warburg effect were increased. Administering Vitamin E (VE), significantly disrupted cell division and disturbed the Warburg effect, effectively indicating the decrease of cell activity. Conclusively, these findings suggested that low concentrations of FA could promote cell proliferation by accelerating cell division process or enhancing the Warburg effect to embody the Hormesis effect.


Assuntos
Divisão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Formaldeído/toxicidade , Hormese/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Glucose/metabolismo , Humanos , Células K562 , Piruvato Quinase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
7.
Bioresour Technol ; 294: 122130, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31526933

RESUMO

A novel sulfide-based denitrification and Anammox process was established for simultaneous removal of nitrogen and sulfide in a UBF reactor. The effects of the N/S ratio on reactor performance were investigated under five N/S molar ratios (4.56, 2.38, 0.96, 0.73, and 0.51). The best total nitrogen removal efficiency was 82.8% at a N/S ratio of 2.38. When the N/S ratio exceeded 0.96, Anammox contributed to more than 90% of the N loss. Sulfide was completely removed during the full operational period and S0 accumulation occurred when N/S ratio was less than 1. Thiobacillus (6.1%) and Candidatus Kuenenia (18.8%) were the main functional microorganisms when nitrate was in excess on day 12. As nitrate became limited on day 50, Thiobacillus (21.0%), Sulfurimonas (3.9%), and Candidatus Kuenenia (19.7%) became dominated. In this study, Candidatus Kuenenia was not inhibited by the sulfide.


Assuntos
Microbiota , Thiobacillus , Reatores Biológicos , Desnitrificação , Nitrogênio , Oxirredução , Sulfetos
8.
Huan Jing Ke Xue ; 40(3): 1405-1411, 2019 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-31087991

RESUMO

Two different mixed sludges (aerobic nitrifying sludge and ANAMMOX-denitrification sludge:R1, and anaerobic digestion flocculent sludge and ANAMMOX-denitrification sludge:R2), were used as inocula in two UBF reactors to enrich Anammox bacteria. Both kinds of mixed sludge set up the Anammox process successfully. It took 36 days for R1, while R2 required 53 days. Nitrogen removal rates of R1 and R2 were high during the whole operation. During the stable operation stage, the removal rates of NH4+-N, NO2--N, and TN were about 99.92%, 96.64%, and 81.87% for R1; and 97.54%, 94.91%, and 80.98% for R2. Illumina High-throughput Sequencing revealed Candidatus Kuenenia was in the top six taxa in the two reactors with 3.22% relative abundance in R1 and 2.35% in R2 after the successful start-up. Simulation results indicated that the Modified Stover-Kincannon model and the second-order model were appropriate models. It was deduced that the N-removal potential of R1 was a little greater than that of R2 after comparing the projected maximum substrate removal rate Umax of the two reactors.

9.
Bioresour Technol ; 278: 440-443, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30737065

RESUMO

The impact of γ-valerolactone/water (GVL/H2O) pretreatment coupled with alkaline post-incubation on the digestibility of cellulose substrates was investigated. When Avicel was pretreated by GVL/H2O with H2SO4 as catalyst, the glucan conversion decreased from 27% (untreated Avicel) to 16% due to the esterification of cellulose after pretreatment. After incubation of GVL/H2O pretreated Avicel with 1% NaOH at 50 °C for 1 h, the glucan conversion enhanced to 20%. When corn stover (CS) pretreated by GVL/H2O with 25 mM H2SO4 was used as substrate, alkaline post-incubation removed 72% and 50% of the hemicellulose and lignin, respectively, and increased the glucan conversion by 1.9-fold consequently. Moreover, higher cellulases adsorption capacity, affinity and binding strength on GVL/H2O pretreated CS was achieved after alkaline post-incubation. These results indicated that the improved digestibility of GVL/H2O pretreated lignocellulose by alkaline post-incubation was attributed to the depletion of ester groups on cellulose and removal of hemicellulose and lignin.


Assuntos
Celulose/metabolismo , Lactonas/química , Adsorção , Álcalis , Celulases/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Água/química , Zea mays/metabolismo
10.
Bioresour Technol ; 267: 793-796, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30017365

RESUMO

This work focuses to investigate the impact of lignin content on chemical compositions, crystallinity, surface characterizations, cellulase adsorption profiles and hydrolysability of Hybrid Pennisetum (HP) after alkaline sulfite pretreatment (ASP). For the HP with lower lignin content, the increase of the cellulose content by ASP was more obvious than raw HP. ASP decreased total lignin content and surface lignin content of HP substrates. HP with lower lignin content (e.g., ∼15%) is suitable for ASP, because a pretty perfect glucose yield (91%) was obtained using a low dosage of enzyme loadings (5 FPU of cellulases/g dry matter). The study provides a potential strategy to efficiently produce platform sugars from HP with reduced lignin content, indicating the importance of reduction HP lignin content properly by breeding or transgenesis programs. The work could also help elucidate the mechanism of alkaline sulfite pretreatment for efficient production of fermentable sugars from lignocelluloses.


Assuntos
Lignina/química , Pennisetum/química , Celulase , Celulose , Hidrólise , Melhoramento Vegetal , Açúcares , Sulfitos
11.
Bioresour Technol ; 261: 223-231, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29669312

RESUMO

In this work, a simplified and cost-effective chlorite pretreatment method to improve the hydrolysabiliy of biomass was developed. Compared to common used sodium chlorite-acetic acid (SCA) pretreatment (18.1%), sodium chlorite (SC) pretreatment resulted in less xylan loss (7.8%), thus led more carbohydrates retention. Moreover, the Chinese silvergrass pretreated by SC for 2 h achieved higher glucose yield (70.5%) than the substrate pretreated by SCA under the same pretreatment conditions did (58.7%), after 48 h enzymatic hydrolysis by cellulase. By synergistic action of cellulase and xylanase, the glucose yield of SC pretreated (12 h) samples reached to 93.5% with 808.7 mg/g DM total reducing sugars yields. In addition, without the usage of acetic acid could decrease the process cost and result in less inhibitor generation in pretreatment process.


Assuntos
Metabolismo dos Carboidratos , Cloretos/química , Carboidratos , Celulase , Hidrólise , Poaceae
12.
Environ Sci Pollut Res Int ; 24(28): 22371-22381, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28801857

RESUMO

The performance of biogas generation and sludge degradation was studied under different zero-valent iron/activated carbon (ZVI/AC) ratios in detail in mesophilic anaerobic digestion of sludge. A good enhancement of methane production was obtained at the 10:1 ZVI/AC ratio, and the cumulative methane production was 132.1 mL/g VS, 37.6% higher than the blank. The methane content at the 10:1 ZVI/AC ratio reached 68.8%, which was higher than the blank (55.2%) and the sludge-added AC alone (59.6%). For sludge degradation, the removal efficiencies of total chemical oxygen demand (TCOD), proteins, and polysaccharides were all the highest at the 10:1 ZVI/AC ratio. The concentration of available phosphorus (AP) decreased after anaerobic digestion process. On the other hand, the concentrations of available nitrogen (AN) and available potassium (AK) increased after the anaerobic digestion process and showed a gradually decreasing trend with increasing ZVI/AC ratio. The concentrations of AN and AK were 2303.1-4200.3 and 274.7-388.3 mg/kg, showing a potential for land utilization.


Assuntos
Biocombustíveis/análise , Reatores Biológicos/microbiologia , Carvão Vegetal/química , Ferro/química , Metano/análise , Esgotos , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Análise da Demanda Biológica de Oxigênio , Modelos Teóricos , Esgotos/química , Esgotos/microbiologia
13.
Bioresour Technol ; 244(Pt 1): 33-39, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28777988

RESUMO

The effect of glucose on nitrogen removal and microbial communities in the anammox-denitrification systems was investigated. The optimal nitrogen removal could be achieved when the influent glucose concentration was 56.4mgL-1. The influent nitrite to ammonium ratio of 0.95-1.40 would not obviously affect the nitrogen removal due to the coexistence of anammox, denitrification and partial denitrification. The anammox activity was deteriorated with increasing glucose concentration. When the influent glucose concentration was increased to 374.9mgL-1, the average ammonium removal efficiency decreased from 97% to around 10% and anammox activity was seriously inhibited. The anammox activity quickly recovered with decreasing influent glucose and increasing influent nitrite. High-throughput sequencing analysis suggested that the predominant genus changed from Candidatus Kuenenia to Diaphorobacter with the addition of glucose and then changed to Hydrogenophaga with the decrease of glucose. It indicated that organics concentration had an effect on the microbial communities.


Assuntos
Reatores Biológicos , Desnitrificação , Compostos de Amônio , Glucose , Nitrogênio
14.
Bioresour Technol ; 239: 422-429, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28535492

RESUMO

Two up-flow blanket filter (UBF) reactors were employed to treat synthetic wastewater with different substrate concentrations and nitrogen load rates (NLR) for 178days. During days 0-60, higher influent NLR of R2 (0.21-0.58kg·m3·d) slowed down the formation of anammox sludge compared with the lower NLR of R1 (0.18-0.31kg·m3·d). Difference in sludge color and nitrogen conversion rate indicated greater anammox activity of R2 than R1. During days 61-178, R1 and R2 achieved the maximum nitrogen removal rates (NRR) of 1.213 and 1.684kg/(m3·d) under the NLRs of 1.924 and 2.502kg/(m3·d), respectively. Furthermore, high-throughput sequencing showed that R2 (43.5%) had a higher proportion of anammox bacteria than R1 (37.8%) and less species. These results showed that after going through a higher NLR acclimation process during start-up period, stronger resistant capability against high impact nitrogen load and greater anammox activity were obtained by R2.


Assuntos
Reatores Biológicos , Águas Residuárias , Bactérias , Desnitrificação , Nitrogênio , Esgotos
15.
Sci Rep ; 7: 43691, 2017 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-28252002

RESUMO

Post-translational modifications of viral proteins play important roles in regulating viral replication. Here we demonstrated that the PB2 of influenza A virus (IAV) can be modified by NEDD8. We revealed that E3 ligase HDM2 can promote PB2 NEDDylation. Overexpression of either NEDD8 or HDM2 can inhibit IAV replication, while knockdown of HDM2 has the opposite effect. Then we identified residue K699 in PB2 as the major NEDDylation site. We found that NEDDylation deficient PB2 mutant (PB2 K699R) has a longer half-life than wild-type PB2, indicating that NEDDylation of PB2 reduces its stability. We generated an IAV mutant in which PB2 was mutated to PB2 K699R (WSN-PB2 K699R) and examined the replication of WSN and WSN-PB2 K699R viruses in both MDCK and A549 cells and found that the replication of WSN-PB2 K699R was more efficient than wild-type WSN. In addition, we observed that overexpression of NEDD8 significantly inhibited the replication of WSN, but not WSN-PB2 K699R. The infection assay in mice showed that WSN-PB2 K699R exhibited enhanced virulence in mice compared to WSN, suggesting that NEDDylation of PB2 reduced IAV replication in vivo. In conclusion, we demonstrated that NEDDylation of PB2 by HDM2 negatively regulates IAV infection.


Assuntos
Vírus da Influenza A/fisiologia , Proteínas Virais/metabolismo , Replicação Viral , Animais , Linhagem Celular , Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/genética , Influenza Humana/metabolismo , Influenza Humana/virologia , Proteína NEDD8/genética , Proteína NEDD8/metabolismo , Ligação Proteica , Processamento de Proteína Pós-Traducional , Estabilidade Proteica , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Recombinação Genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Virais/genética , Virulência/genética
16.
Huan Jing Ke Xue ; 38(4): 1544-1550, 2017 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965158

RESUMO

The volume loading of upflow blanket filter increased from 0.52 kg·(m3·d)-1to 2.75 kg·(m3·d)-1 by improving the influent NH4+-N and NO2--N concentrations. The removal efficiency of NH4+-N, NO2--N and TN increased from 76.18%, 53.47%, 55.66% to 94.04%, 86.97%, 82.96% respectively. Meanwhile, the microbial community of UBF ANAMMOX reactor was analyzed by Illumina high-throughput sequencing during the initial and later operational process. The results indicated that the denitrifying bacteria coexisted in the reactor. The percentages of Planctomycetes, Proteobacteria and Nitrospirae in the sludge were 27.9%-39.9%, 1.1%-26.4% and 0.035%-0.188%, respectively. The proportions of Planctomycetes and Proteobacteria increased from 1.1%, 27.9% in the enrichment stage to 26.4%, 39.9% in the stable operation stage respectively. In addition, Planctomycetes increased significantly. The proportion of Brocadiacea reached 24.57%. Therefore, Brocadiacea became the dominant bacteria in the phylum Planctomycete, which contained Candidatus brocadia. The alpha diversity index and relative abundance of clustering figure indicated that the diversity of microbial community decreased gradually and the structure of microbial community changed obviously.


Assuntos
Reatores Biológicos/microbiologia , Desnitrificação , Nitrogênio/isolamento & purificação , Esgotos/microbiologia , Amônia , Bactérias/classificação , Oxirredução
17.
Sheng Wu Gong Cheng Xue Bao ; 32(1): 105-13, 2016 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-27363203

RESUMO

Influenza A virus is an enveloped virus that belongs to the Orthomyxoviridae family. It has 8 negative RNA segments that encode 16 viral proteins. The viral polymerase consists of 3 proteins (PB 1, PB2 and PA) which plays an important role in the transcription and replication of the influenza A virus. Polymerase basic protein 1 (PB 1) is a critical member of viral polymerase complex. In order to further study the function of PB1, we need to prepare the PB1 antibody with good quality. Therefore, we amplified PB1 conserved region (nt1648-2265) by PCR and cloned it into pET-30a vector, and transformed into Escherichia coli BL2 1. The expression of His tagged PB 1 protein was induced by IPTG, and His-PB 1 proteins were purified by Ni-NTA resin. For preparation of PB 1 protein antiserum, rabbits were immunized with His-PB 1 fusion protein 3 times. Then the titer of PB 1 polyclonal antibody was measured by indirect ELISA. The antibody was purified by membrane affinity purification and subjected to immunoblotting analysis. Data showed that PB1 antibody can recognize PB 1 protein from WSN virus infected or pCMV FLAG-PB 1 transfected cells. Meanwhile, PB 1 antibody can also recognize specifically other subtype strains of influenza A virus such as H9N2 and H3N2. PB 1 polyclonal antibody we generated will be a useful tool to study the biological function of PB1.


Assuntos
Anticorpos Antivirais/biossíntese , Proteínas Virais/imunologia , Animais , Clonagem Molecular , Ensaio de Imunoadsorção Enzimática , Escherichia coli/metabolismo , Vetores Genéticos , Vírus da Influenza A Subtipo H3N2 , Vírus da Influenza A Subtipo H9N2 , Plasmídeos , Coelhos
18.
J Gen Virol ; 97(1): 27-38, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26498766

RESUMO

In order to explore the roles of microRNA(s) [miRNA(s)] in the influenza A virus life cycle, we compared the miRNA profiles of 293T and HeLa cell lines, as influenza A virus can replicate efficiently in 293T cells but only poorly in HeLa cells. We analysed differentially expressed miRNAs and identified five, including miR-33a, that could disturb influenza A virus replication significantly. Using TargetScan analysis, we found that ARCN1 could be a potential target of miR-33a. To confirm whether miR-33a could truly target ARCN1, we generated a luciferase reporter for the ARCN1 3' untranslated region (UTR) and performed a luciferase assay. The data indicated that miR-33a could suppress the luciferase activity of the reporter for the ARCN1 3' UTR but not a reporter in which the predicted miR-33a targeting sites on ARCN1 3' UTR were mutated. We performed immunoblotting to confirm that miR-33a could downregulate the protein level of ARCN1. Consistently, the level of ARCN1 protein in HeLa cells was significantly lower than that in 293T cells. We also demonstrated that ectopic expression of ARCN1 could partially rescue the inhibitory effect of miR-33a on virus replication. Furthermore, we demonstrated that miR-33a could impede virus replication at the stage of virus internalization, which was similar to the pattern for knockdown of ARCN1, indicating that miR-33a inhibits influenza virus infection by suppressing ARCN1 expression. In addition, we found that miR-33a could also weaken the viral ribonucleoprotein activity in an ARCN1-independent manner. In conclusion, we found that miR-33a is a novel inhibitory factor for influenza A virus replication.


Assuntos
Proteína Coatomer/antagonistas & inibidores , Interações Hospedeiro-Patógeno , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologia , MicroRNAs/metabolismo , Ribonucleoproteínas/antagonistas & inibidores , Internalização do Vírus , Fusão Gênica Artificial , Linhagem Celular , Perfilação da Expressão Gênica , Genes Reporter , Humanos , Immunoblotting , Luciferases/análise , Luciferases/genética
19.
Bioresour Technol ; 159: 404-11, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24681301

RESUMO

Long-term performance of a two-stage partial nitritation (PN)-anaerobic ammonium oxidation (ANAMMOX) process treating mature landfill leachate was investigated. Stable partial nitritation performance was achieved in a sequencing batch reactor (SBR) using endpoint pH control, providing an effluent with a ratio of NO2(-)-N/NH4(+)-N at 1.23 ± 0.23. High rate nitrogen removal over 4 kg N/m(3)/d was observed in the ANAMMOX reactor in the first three months. However, during long-term operation, the ANAMMOX reactor can only stably operate under nitrogen load of 1 kg N/m(3)/d, with 85 ± 1% of nitrogen removal. The ammonium oxidizing bacteria (AOB) in the PN-SBR were mainly affiliated to Nitrosomonas sp. IWT514, Nitrosomonas eutropha and Nitrosomonas eutropha, the anaerobic ammonium oxidizing bacteria (AnAOB) in the ANAMMOX reactor were mainly affiliated to Kuenenia stuttgartiensis.


Assuntos
Compostos de Amônio/metabolismo , Bactérias/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Ar , Anaerobiose , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Concentração de Íons de Hidrogênio , Nitrificação , Nitrogênio/isolamento & purificação , Oxirredução , Filogenia , Temperatura
20.
Huan Jing Ke Xue ; 29(6): 1638-43, 2008 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-18763515

RESUMO

The microbial community structure and biodiversity in the ANAMMOX system were studied by applying the methods of microtechnic, separation and purification technology of microorganisms, and molecular biotechnology. The ANAMMOX microbial population in an upflow anaerobic sludge blanket (UASB) bioreactor and a UASB-biofilm bioreactor was successfully enriched in the laboratory with inorganic and dark condition. The removal efficiencies of NH4+-N and NO2(-)-N in UASB reactor were 99.99% and 99.9% respectively. For the UASB- biofilm, they were 99.3% and 97.4% respectively in an optimal condition in which the temperature was 30-34 degrees C and the pH was 7-8. In traditional methods of identifying microorganism, the population of bacteria, actinomycete and fungi were researched and the species in the two reactors were basically identical. Most of the microorganisms were anaerobic and anoxic bacteria. The size of the preponderant bacteria was (0.6-0.8) microm x (0.9-1.2) microm from the scanning electron micrographs of sludge cultivated in the two reactors, and the shape was oval. The rate of this preponderant bacteria was above 90%. The result of the denaturing gradient gel electrophoresis(DGGE) and 16S rDNA digested reveals that there was one predominant species and the biodiversity was not high.


Assuntos
Bactérias Anaeróbias/metabolismo , Reatores Biológicos/microbiologia , Compostos de Amônio Quaternário/metabolismo , Eliminação de Resíduos Líquidos/métodos , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/fisiologia , Biofilmes , Ecossistema , Variação Genética , Microscopia Eletrônica de Varredura , Oxirredução , Dinâmica Populacional , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/isolamento & purificação , RNA Ribossômico 16S/genética , Eliminação de Resíduos Líquidos/instrumentação
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