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1.
Harmful Algae ; 135: 102633, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38830715

RESUMO

Nitrogen-fixing cyanobacteria not only cause severe blooms but also play an important role in the nitrogen input processes of lakes. The production of extracellular polymeric substances (EPS) and the ability to fix nitrogen from the atmosphere provide nitrogen-fixing cyanobacteria with a competitive advantage over other organisms. Temperature and nitrogen availability are key environmental factors in regulating the growth of cyanobacteria. In this study, Dolichospermum (formerly known as Anabaena) was cultivated at three different temperatures (10 °C, 20 °C, and 30 °C) to examine the impact of temperature and nitrogen availability on nitrogen fixation capacity and the release of EPS. Initially, confocal laser scanning microscopy (CLSM) and the quantification of heterocysts at different temperatures revealed that lower temperatures (10 °C) hindered the differentiation of heterocysts under nitrogen-deprived conditions. Additionally, while heterocysts inhibited the photosynthetic activity of Dolichospermum, the secretion of EPS was notably affected by nitrogen limitation, particularly at 30 °C. Finally, real-time quantitative polymerase chain reaction (qPCR) was used to measure the expression of nitrogen-utilizing genes (ntcA and nifH) and EPS synthesis-related genes (wzb and wzc). The results indicated that under nitrogen-deprived conditions, the expression of each gene was upregulated, and there was a significant correlation between the upregulation of nitrogen-utilizing and EPS synthesis genes (P < 0.05). Our findings suggested that Dolichospermum responded to temperature variation by affecting the formation of heterocysts, impacting its potential nitrogen fixation capacity. Furthermore, the quantity of EPS released was more influenced by nitrogen availability than temperature. This research enhances our comprehension of interconnections between nitrogen deprivation and EPS production under the different temperatures.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Fixação de Nitrogênio , Nitrogênio , Temperatura , Nitrogênio/metabolismo , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Anabaena/metabolismo , Anabaena/fisiologia , Anabaena/genética
2.
Environ Pollut ; 336: 122425, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37604393

RESUMO

The antibiotic pollution emerged in different environments has raised a great concern. Adsorption is an effective method to solve the problem. However, conventional adsorbents are not always efficient for antibiotic removal with interferences. Therefore, in this study, molecularly imprinted polymer (EMIP) with selective adsorption ability was prepared to remove a typical antibiotic-erythromycin (ERY) at environmentally relevant concentration. The specific surface area of EMIP was 265.62 m2/g with large pore volume, small pore size and hydrophobic surface. The adsorption capacity of EMIP was increased from 211.08 to 4015.51 µg/g when the concentration of ERY was increased from 5.00 to 100.00 µg/L. The isothermal adsorption process was fitted well with the Langmuir model. The adsorption kinetic could be well described by the pseudo-second-order model. With co-existing of interferences, the imprinting factor for ERY was 2.57, which demonstrated EMIP had good adsorption selectivity. After five consecutive adsorption-desorption experiments, the adsorption capacity of EMIP was still over 80%. The results of molecular dynamic simulation showed the adsorption energy between ERY and EMIP was high, which was favorable for ERY adsorption removal. Hopefully, the results of this study could provide new insights for trace antibiotic removal by molecular imprinting polymers in different aqueous environments.

3.
Sci Total Environ ; 889: 164277, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37211116

RESUMO

Cyanobacteria and their toxins widely exist in freshwater ecosystems. Microcystis aeruginosa is among dominant bloom-forming cyanobacteria. Water temperature is a key factor influencing the life cycle of M. aeruginosa. We simulated elevated temperature (4-35 °C) experiment and cultured M. aeruginosa during the overwintering, recruitment and rapid growth phases. The results showed that M. aeruginosa recovered growth after overwintering at 4-8 °C and recruited at 16 °C. The total extracellular polymeric substance (TEPS) concentration increased rapidly at 15 °C. The actual quantum yield of photosystem II (Fv'/Fm') peaked at 20 °C during the rapid growth phase, and the optimum temperature of M. aeruginosa growth was 20-25 °C. Additionally, TEPS and microcystins (MCs) secretion peaked at 20-25 °C. The cell density accumulated rapidly from 26 °C to 35 °C. Furthermore, enzymes of RuBisCO and FBA related to photosynthetic activity were confirmed to contribute to the metabolism, as well as mcyB gene was affected by elevated temperature. Our results provide insights of the physiological effects and metabolic activity during annual cycle of M. aeruginosa. And it is predicted that global warming may promote the earlier recruitment of M. aeruginosa, extend the optimum growth period, enhance the toxicity, and finally intensify M. aeruginosa blooms.


Assuntos
Microcystis , Temperatura , Cianobactérias , Ecossistema , Matriz Extracelular de Substâncias Poliméricas , Microcistinas/metabolismo , Microcystis/fisiologia
4.
J Environ Manage ; 336: 117661, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36913857

RESUMO

Extracellular polymeric substances (EPS) of activated sludge are a mixture of high molecular weight polymers secreted by microorganisms, which have the double structure of tightly-bound EPS (TB-EPS) in inner layer and loosely-bound EPS (LB-EPS) in outer layer. The characteristic of LB- and TB-EPS were different, which would affect their adsorption of antibiotics. However, the adsorption process of antibiotics on LB- and TB-EPS was still unclear yet. Therefore, in this work, the roles of LB-EPS and TB-EPS in adsorption of a typical antibiotic-trimethoprim (TMP) at environmentally relevant concentration (25.0 µg/L) were investigated. The results showed the content of TB-EPS was higher than that of LB-EPS, which was 17.08 and 10.36 mg/g VSS, respectively. The adsorption capacity of raw, LB-EPS extracted and both LB- and TB-EPS extracted activated sludges for TMP were 5.31, 4.65 and 9.51 µg/g VSS, respectively, which indicated LB-EPS had positive effect on TMP removal, while TB-EPS had negative effect. The adsorption process can be well described by a pseudo-second-order kinetic model (R2 > 0.980). The ratio of different functional groups was calculated and the CO and C-O bond might be responsible for the adsorption capacity difference between LB- and TB-EPS. The fluorescence quenching results indicated that tryptophan protein-like substances in LB-EPS provided more binding sites (n = 0.36) than that of tryptophan amino acid in TB-EPS (n = 0.1). Furthermore, the extend DLVO results also demonstrated that LB-EPS promoted the adsorption of TMP, while TB-EPS inhibited the process. We hope the results of this study were helpful for understanding the fate of antibiotics in wastewater treatment systems.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Esgotos , Esgotos/química , Matriz Extracelular de Substâncias Poliméricas/química , Trimetoprima/análise , Adsorção , Triptofano/análise , Antibacterianos/análise
5.
Arch Microbiol ; 204(8): 453, 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35786781

RESUMO

Soil microorganisms play a vital role in biogeochemical processes and nutrient turnover in agricultural ecosystems. However, the information on how the structure and co-occurrence patterns of microbial communities response to the change of planting methods is still limited. In this study, a total of 34 soil samples were collected from 17 different fields of 2 planting types (wheat and orchards) along the Taige Canal in Yangtze River Delta. The structure of bacterial and fungal communities in soil were determined by 16S rRNA gene and ITS gene, respectively. The dominated bacteria were Proteobacteria, Acidobacteriota, Actinobacteriota, Chloroflexi, Bacteroidota, and Firmicutes. The relative abundances of Actinobacteriota and Firmicutes were higher in the orchards, while Chloroflexi and Nitrospirota were more abundant in wheat fields. Ascomycota, Mortierellomycota, and Basidiomycota were the predominant fungus in both soil types. Diversity of bacterial and fungal communities were greater in the wheat fields than in orchards. Statistical analyses showed that pH was the main factor shaping the community structure, and parameters of water content (WC), total organic carbon (TOC) and total nitrogen (TN) had great influences on community structure. Moreover, high co-occurrence patterns of bacterial and fungal were confirmed in both wheat fields and orchards. Network analyses showed that both wheat fields and orchards occurred modular structure, including nodes of Acidobacteriota, Chloroflexi, Gemmatimonadota, Nitrospirota and Ascomycota. In summary, our work showed the co-occurrence network and the convergence/divergence of microbial community structure in wheat fields and orchards, giving a comprehensive understanding of the microbe-microbe interaction during planting methods' changes.


Assuntos
Microbiota , Triticum , Acidobacteria , Bactérias/genética , Firmicutes , Frutas , Fungos/genética , RNA Ribossômico 16S/genética , Solo
6.
Chemosphere ; 307(Pt 1): 135697, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35843429

RESUMO

Microplastics (MPs) can act as vectors for various contaminants in the aquatic environment. Although some research has investigated the adsorption characteristics and influencing factors of metals/organic molecules on MPs, the effects of dissolved organic matter (DOM) (which are ubiquitous active species in ecosystems) on metal oxyanions such as Cr(VI) capture by MPs are largely unknown. This study explored the adsorption behaviors and mechanisms of Cr(VI) oxyanions onto polystyrene (PS) MPs using batch adsorption experiments and multiple spectroscopic methods. The effects of representative DOM components (i.e., humic acid (HA), fulvic acid (FA) and tannic acid (TA)) on Cr(VI) capture by PS were particularly studied. Results revealed a significantly enhanced adsorption of Cr(VI) on PS in the presence of TA. The Cr(VI) adsorption capacity was increased from 2876 µg g-1 to 4259 µg g-1 and 5135 µg g-1 when the TA concentrations raised from 0 to 10 and 20 mg L-1, respectively. Combined microscopic and spectroscopic investigations revealed that Cr(VI) was reduced to Cr(III) by TA and formed stable Cr(OH)3 colloids on PS surfaces. Contrarily, HA and FA inhibited Cr(VI) adsorption onto PS, especially at pH > 2.0 and higher DOM concentrations, due to site competition and electrostatic repulsion. Increase in pH was found to reduce zeta potentials of MPs, resulting in inhibited Cr(VI) adsorption. The adsorbed Cr(VI) declined with increasing ionic strength, implying that outer-sphere surface complexation affected the adsorption process in the presence of DOM. These new findings improved our fundamental understanding of the fate of Cr(VI) and MPs in DOM-rich environmental matrices.


Assuntos
Microplásticos , Poluentes Químicos da Água , Adsorção , Benzopiranos , Cromo , Coloides , Ecossistema , Substâncias Húmicas/análise , Plásticos , Poliestirenos , Taninos/química , Poluentes Químicos da Água/análise
7.
J Environ Manage ; 306: 114502, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35033891

RESUMO

Adsorption is the primary mechanism of antibiotic removal in wastewater treatment plants, wherein the extracellular polymeric substances (EPS) of the activated sludge play an important role. Due to their complex characteristics, the effect of EPS components on antibiotic adsorption is unknown. Therefore, in this study, the role of main components of EPS in antibiotic adsorption was explored using enzymatic treatment. The results revealed that proteinase K and α-amylase can efficiently hydrolyse the proteins and polysaccharides of EPS. The protein content of EPS reduced from 31.25 mg/g VSS to 21.53, 18.75, and 10.76 mg/g VSS, after treatment with proteinase K, α-amylase and their combination, respectively; the polysaccharides content also observed a similar decrease from 15.20 mg/g VSS to 8.22, 7.83, and 6.03 mg/g VSS, respectively. The humic substance in EPS was stable during enzymatic treatment. The equilibrium adsorption capacity of activated sludge treated by enzyme for trimethoprim (TMP)- a typical antibiotic, was significantly increased from 2.19 µg/g VSS to 4.68, 5.34, and 8.36 µg/g VSS after treatment with proteinase K, α-amylase and their mixture. The adsorption process was adequately described by pseudo-second-order kinetic model. A multivariable linear regression model was subsequently used to quantify the adsorption capacity of activated sludge for TMP considering the concentration of EPS components. The modelling and validated results showed that the model could satisfactorily predict the TMP adsorption capacity. The results of this study can provide new insights into the role of EPS on antibiotic transformation in biological wastewater treatment systems.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Purificação da Água , Adsorção , Esgotos , Trimetoprima
8.
Bioresour Technol ; 342: 126012, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34571328

RESUMO

Nitrous oxide (N2O), as a powerful greenhouse gas, has drawn increasing attention in recent years and different strategies for N2O reduction were explored. In this study, a novel strategy for valuable polyhydroxyalkanoates (PHA) production coupling with N2O reduction by mixed microbial cultures (MMC) using different substrates was evaluated. Results revealed that N2O was an effective electron acceptor for PHA production. The highest PHA yield (0.35 Cmmol PHA/Cmmol S) and PHA synthesis rate (227.47 mg PHA/L/h) were obtained with acetic acid as substrate. Low temperature (15℃) and pH of 8.0 were beneficial for PHA accumulation. Results of the thermogravimetric analysis showed that PHA produced with N2O as electron acceptor has better thermal stability (melting temperature of 99.4℃ and loss 5% weight temperature of 211.4℃). Our work opens up new avenues for simultaneously N2O reduction and valuable bioplastic production, which is conducive to resource recovery and climate protection.


Assuntos
Poli-Hidroxialcanoatos , Ácido Acético , Reatores Biológicos , Estudos de Viabilidade , Óxido Nitroso
9.
Chemosphere ; 285: 131411, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34246936

RESUMO

Dissolved organic matter (DOM) is one of the most significant parameters to affect the remediation efficiency of Pb(II) by apatites. Numerous studies chose humic substances as a surrogate of DOM to investigate its influence on Pb(II) immobilization. However, the effect of low-molecular-weight organic acids such as oxalic acid (OA), which is ubiquitous in the environment and a primary component of DOM, in immobilizing Pb(II) was still not fully understood. Herein, humic acid (HA) and OA were examined to distinguish their influence on Pb(II) immobilization by a green synthesized nanocrystalline hydroxyapatite (nHAP). Various parameters were considered to evaluate the removal performance of nHAP towards Pb(II) as affected by HA/OA. Results indicated that Pb(II) immobilization was significantly promoted in the coexistence of OA owing to the precipitation of hydroxypyromorphite (HPY) as well as PbC2O4, but was independent on the addition sequence and slightly hindered by HA, disclosing that Pb(II) preferred to bind directly with nHAP instead of via HA. Characterization of the Pb(II) loaded solids by multiple technologies revealed that HPY was the predominant precipitate both in the absence and presence of HA, while the formation of PbC2O4 was preferred over that of HPY in the existence of OA. X-ray photoelectron spectroscopy indicated that PbC2O4 was the prevalent solid phase with the ratio of 62.97% after Pb(II) immobilization by nHAP in the presence of OA. These findings implied that the transformation efficiency of Pb(II) to HPY by apatites can be overestimated in the presence of OA due to the precipitation of PbC2O4.


Assuntos
Substâncias Húmicas , Poluentes do Solo , Durapatita , Chumbo , Ácido Oxálico , Poluentes do Solo/análise
10.
Chemosphere ; 274: 129798, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33540314

RESUMO

The extracellular polymeric substances (EPS) of activated sludge are a mixture of high molecular weight polymers secreted by microorganisms, which are mainly composed of proteins, polysaccharides and humic substances. It is widely accepted that EPS have a good adsorption ability for pollutants with different functional groups. However, recent studies showed the EPS had an inhibitory effect on pollutant sorption, which is contradictory to previous viewpoint. Therefore, in this study, three types of activated sludge with different EPS contents and compositions were used to investigate the role of EPS in an antibiotic-trimethoprim (TMP) sorption process at environmentally relevant concentration. The in situ experiments results showed the adsorption capacity of activated sludge for TMP were increased from 2.98, 5.37 and 28.33 µg/g VSS to 7.87, 12.93 and 150.24 µg/g VSS in nitrifying activated sludge, wastewater treatment plant activated sludge and anaerobic ammonia-oxidized activated sludge, respectively after EPS extracted. The adsorption process can be well described by the pseudo-second-order kinetic model. Results of zeta potential, contact angles and infrared spectrum showed TMP replacing proteins embedded into the cell membrane enhancing the TMP adsorption capacity of activated sludge after EPS extraction. Our results demonstrated that less proteins in EPS of activated sludge is more beneficial for TMP adsorption removal.


Assuntos
Esgotos , Purificação da Água , Adsorção , Matriz Extracelular de Substâncias Poliméricas , Trimetoprima
11.
Int J Biochem Cell Biol ; 125: 105795, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32580015

RESUMO

Lysyl oxidase-like 2 (LOXL2) is a member of the lysyl oxidase (LOX) family that contributes to tumor cell metastasis. Our previous data identified two splice variants of LOXL2 (i.e., LOXL2 Δ72 and Δ13) in esophageal squamous cell carcinoma (ESCC) cells that increased cell invasiveness and migration but had lower LOX activities than wild-type LOXL2 (LOXL2 WT). We generated a series of LOXL2 deletion mutants with different deleted biochemical domains and examined the relationship between the cell migration abilities and catalytic activities, as well as subcellular locations, of these deletion mutants compared with LOXL2 WT in ESCC cells to explore the mechanism of LOXL2-driven ESCC cell migration. Our results indicated that the deletion mutants of LOXL2 had impaired deamination enzymatic activity; LOXL2 ΔSRCR4, which lacks the fourth scavenger receptor cysteine-rich (SRCR) domain, had lower enzymatic activity; and LOXL2 Y689F had no catalytic activity compared with LOXL2 WT. However these two mutants stimulated greater cellular migration than LOXL2 WT. Furthermore, the degree of cell migration promoted by LOXL2 ΔLO (in which the LOX-like domain was deleted) was higher than that of LOXL2 WT, and LOXL2 ΔSRCR3, which does not have the third SRCR domain, had lower LOX activity and cellular migration ability than LOXL2 WT. These results suggested that LOXL2 promotes ESCC cell migration independent of catalytic activity.


Assuntos
Processamento Alternativo , Movimento Celular/genética , Neoplasias Esofágicas/enzimologia , Carcinoma de Células Escamosas do Esôfago/enzimologia , Proteína-Lisina 6-Oxidase/metabolismo , Catálise , Linhagem Celular Tumoral , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/metabolismo , Carcinoma de Células Escamosas do Esôfago/patologia , Humanos , Domínios Proteicos/genética , Proteína-Lisina 6-Oxidase/genética , Deleção de Sequência
12.
DNA Cell Biol ; 39(7): 1228-1242, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32429692

RESUMO

Heat shock protein (HSP) is a family of highly conserved protein, which exists widely in various organisms and has a variety of important physiological functions. Currently, there is no systematic analysis of HSPs in human glioma. The aim of this study was to investigate the characteristics of HSPs through constructing protein-protein interaction network (PPIN) considering the expression level of HSPs in glioma. After the identification of the differentially expressed HSPs in glioma tissues, a specific PPIN was constructed and found that there were many interactions between the differentially expressed HSPs in glioma. Subcellular localization analysis shows that HSPs and their interacting proteins distribute from the cell membrane to the nucleus in a multilayer structure. By functional enrichment analysis, gene ontology analysis, and Kyoto Encyclopedia of Genes and Genomes pathway analysis, the potential function of HSPs and two meaningful enrichment pathways was revealed. In addition, nine HSPs (DNAJA4, DNAJC6, DNAJC12, HSPA6, HSP90B1, DNAJB1, DNAJB6, DNAJC10, and SERPINH1) are prognostic markers for human brain glioma. These analyses provide a full view of HSPs about their expression, biological process, as well as clinical significance in glioma.


Assuntos
Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Glioma/genética , Proteínas de Choque Térmico/genética , Biomarcadores Tumorais/genética , Biologia Computacional , Glioma/diagnóstico , Glioma/metabolismo , Glioma/patologia , Proteínas de Choque Térmico/metabolismo , Humanos , Espaço Intracelular/metabolismo , Prognóstico , Mapas de Interação de Proteínas
13.
Water Res ; 174: 115604, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32088388

RESUMO

Microorganism-derived dissolved organic nitrogen (mDON) represents a significant and inevitable portion of dissolved organic nitrogen (DON) in the wastewater biotreatment processes. In the existing method, mDON concentrations are indirectly measured by the values of DON concentrations from the reactors with DON-free influent. However, this becomes problematic when influent contains DON. Especially when the real wastewater is involved, the paucity of the direct methods to quantitatively measure mDON is a major barrier to further research. This limitation is due to the difficulty of segregating mDON from the other nitrogenous organics, e.g., influent DON. In this study, we propose the ASM-mDON model based on ASM #1, which incorporates the production and consumption of mDON in the activated sludge processes to predict the mDON concentrations. In four independent lab-scale tests, our model was established and calibrated to obtain the accurate values of mDON (R2 = 0.929, p < 0.05), and the validity and applicability of the model were successfully examined by comparing the simulated and measured data. Moreover, the universality of the ASM-mDON model was further confirmed by simulating mDON production in a full-scale wastewater treatment plant. A reasonable prediction of mDON formation was shown in a full-scale test (1.98 ± 0.71 mg/L in June and 1.51 ± 0.54 mg/L in July) and is indirectly supported by an algal bioassay (p < 0.05, t-test). This study provides a useful approach to the efficient and accurate evaluation of mDON formation, which will improve current strategies designed to minimize the effluent mDON in wastewater bioprocesses.


Assuntos
Nitrogênio , Esgotos , Eliminação de Resíduos Líquidos , Águas Residuárias
14.
J Hazard Mater ; 384: 121311, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31585278

RESUMO

Metabolic uncouplers are widely used for reducing excess sludge in biological wastewater treatment systems. However, the formation of microbial products, such as extracellular polymeric substances, polyhydroxyalkanoate and soluble microbial products by activated sludge in the presence of metabolic uncouplers remains unrevealed. In this study, the impacts of a metabolic uncoupler o-chlorophenol (oCP) on the reduction of activated sludge yield and formation of microbial products in laboratory-scale sequencing batch reactors (SBRs) were evaluated for a long-term operation. The results show the average reduction of sludge yield in the four reactors was 17.40%, 25.80%, 33.02% and 39.50%, respectively, when dosing 5, 10, 15, and 20 mg/L oCP. The oCP addition slightly reduced the pollutant removal efficiency and decreased the formation of soluble microbial products in the SBRs, but stimulated the productions of extracellular polymeric substances and polyhydroxyalkanoate in activated sludge. Furthermore, the significant reduction of electronic transport system activity occurred after the oCP addition. Microbial community analysis of the activated sludge indicates dosing oCP resulted in a decrease of sludge richness and diversity in the SBRs. Hopefully, this study would provide useful information for reducing sludge yield in biological wastewater treatment systems and behaviors of activated sludge in the presence of uncouplers.


Assuntos
Clorofenóis/farmacologia , Esgotos/microbiologia , Desacopladores/farmacologia , Águas Residuárias/microbiologia , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , DNA Bacteriano/biossíntese , DNA Bacteriano/genética , Polímeros/química , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/química
15.
Environ Sci Pollut Res Int ; 27(2): 2319-2327, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31776910

RESUMO

Ammonia (NH3) volatilization from paddy soils is a main source of atmospheric NH3 and the magnitude is affected by many factors. Because of the complex field condition, it is difficult to identify the relative importance of individual factor on NH3 volatilization process in different locations and at different times. In this study, the grey relational entropy method was used to evaluate the relative impact of four main factors (i.e., nitrogen fertilizer application rate, NH4-N concentration, pH, and temperature of the floodwater) on NH3 volatilization loss from three different field experiments. The results demonstrated that floodwater NH4-N concentration was the most important factor governing NH3 volatilization process. Floodwater pH was the second most important factor, followed by temperature of the floodwater and nitrogen fertilizer application rate. We further validated the grey relational entropy method with NH3 volatilization loss data from other published study and confirmed the order of importance for the four factors. We hope the findings of this study will be helpful for guiding design to reduce paddy soil NH3 emission.


Assuntos
Amônia/química , Oryza , Solo , Amônia/metabolismo , Entropia , Fertilizantes/análise , Nitrogênio/metabolismo , Oryza/química , Solo/química , Volatilização
16.
Bioresour Technol ; 292: 121978, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31415988

RESUMO

This study aimed to explore the production of polyhydroxyalkanoates (PHA) and selection of PHA-accumulating microorganisms in bioreactors fed with rice winery wastewater at various organic loading rates (OLRs). The substrate utilization, sludge properties, PHA synthesis and microbial community structure of three sequencing batch reactors were monitored. The results show the highest PHA yield (0.23 g/g) was achieved in one of the three reactors with an OLR of 2.4 g COD/L/d, in which Zoogloea was the most dominant PHA-accumulating microorganism. To quantify the PHA production and track the population changing profiles of the PHA-accumulating microorganisms in the long-term reactor operation, the Activated Sludge Model No. 3 was modified with two different heterotrophic microorganisms responding differently with the same substrate. The modeling results indicate that a moderate OLR (>2.4 gCOD/L/d) was beneficial for PHA production. The results are useful for understanding the PHA production from industrial wastewaters and selection of PHA-accumulating microorganisms.


Assuntos
Oryza , Poli-Hidroxialcanoatos , Reatores Biológicos , Esgotos , Águas Residuárias
17.
Amino Acids ; 51(5): 813-828, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30900087

RESUMO

Lysyl oxidase-like 4 (LOXL4), a member of the LOX family proteins, catalyzes oxidative deamination of lysine residues in collagen and elastin, which are responsible for maintaining extracellular matrix homeostasis. In this study, the mRNA expression of LOXL4 in seven esophageal squamous cell carcinoma (ESCC) cell lines and 15 ESCC pairs of clinical samples were examined. Furthermore, LOXL4 protein levels in the ESCC cell lines were determined using western blotting. With the use of immunofluorescence, LOXL4 was observed to be localized primarily in the cytoplasm, but was also present in the nucleus. In addition, the results indicated that the upregulated expression of LOXL4 was associated with poor survival in patients with ESCC even following curative resection (P = 0.010). Similar Kaplan-Meier estimator curves for proteins that interact with LOXL4, SUV39H1 (P = 0.014) and COL2A1 (P = 0.011), were plotted. The analyses based on the protein-protein interaction network depicted the expression of LOXL4 and its associated proteins as well as their functions, suggesting that LOXL4 and its associated proteins may serve a significant role in the development and progression of ESCC. In conclusion, the results of the present study suggest that LOXL4 is a potential biomarker for patients with ESCC, as well as SUV39H1 and COL2A1, and high expression levels of these genes are associated with poor prognosis in patients with ESCC.


Assuntos
Aminoácido Oxirredutases/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Neoplasias Esofágicas/metabolismo , Regulação Neoplásica da Expressão Gênica , Aminoácido Oxirredutases/genética , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Mapas de Interação de Proteínas , Proteína-Lisina 6-Oxidase , Taxa de Sobrevida , Células Tumorais Cultivadas
18.
J Phys Condens Matter ; 30(46): 465701, 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30265248

RESUMO

A theoretical model is proposed to analyze the inter-valley electron transferring between direct Γ and indirect L valleys, which sheds light on the electron conduction dynamics in (0 0 1) tensile strained Ge. Inter-valley scattering is included to calculate average scattering time between Γ and L valleys based on a time-dependent Hamiltonian describing the electron-phonon interaction. Numerical results indicate that enhanced indirect-to-direct inter-valley scattering and reduced direct-to-indirect inter-valley scattering are reliable by introducing tensile strain in Ge material. The population ratio of electrons in Γ and L valleys in strained Ge will increase one to two orders of magnitude compared to the model without the inter-valley scattering. The results offer fundamental understanding of phonon engineering for further improvement of performance in strained germanium light sources.

19.
Environ Sci Pollut Res Int ; 25(23): 22810-22817, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29855881

RESUMO

Reversed A2O process (anoxic-anaerobic-aerobic) and conventional A2O process (anaerobic-anoxic-aerobic) are widely used in many wastewater treatment plants (WWTPs) in Asia. However, at present, there are still no consistent results to figure out which process has better total phosphorous (TP) removal performance and the mechanism for this difference was not clear yet. In this study, the treatment performances of both processes were compared in the same full-scale WWTP and the TP removal dynamics was analyzed by a modeling method. The treatment performance of full-scale WWTP showed the TP removal efficiency of the reversed A2O process was more efficient than in the conventional A2O process. The modeling results further reveal that the TP removal depends highly on the concentration and composition of influent COD. It had more efficient TP removal than the conventional A2O process only under conditions of sufficient influent COD and high fermentation products content. This study may lay a foundation for appropriate selection and optimization of treatment processes to suit practical wastewater properties.


Assuntos
Modelos Teóricos , Fósforo/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Fermentação , Fósforo/análise , Eliminação de Resíduos Líquidos/instrumentação , Águas Residuárias/química
20.
Amino Acids ; 50(6): 685-697, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29700654

RESUMO

Heat-shock proteins (HSPs), one of the evolutionarily conserved protein families, are widely found in various organisms, and play important physiological functions. Nevertheless, HSPs have not been systematically analyzed in esophageal squamous cell carcinoma (ESCC). In this study, we applied the protein-protein interaction (PPI) network methodology to explore the characteristics of HSPs, and integrate their expression in ESCC. First, differentially expressed HSPs in ESCC were identified from our previous RNA-seq data. By constructing a specific PPI network, we found differentially expressed HSPs interacted with hundreds of neighboring proteins. Subcellular localization analyses demonstrated that HSPs and their interacting proteins distributed in multiple layers, from membrane to nucleus. Functional enrichment annotation analyses revealed known and potential functions for HSPs. KEGG pathway analyses identified four significant enrichment pathways. Moreover, three HSPs (DNAJC5B, HSPA1B, and HSPH1) could serve as promising targets for prognostic prediction in ESCC, suggesting these HSPs might play a significant role in the development of ESCC. These multiple bioinformatics analyses have provided a comprehensive view of the roles of heat-shock proteins in esophageal squamous cell carcinoma.


Assuntos
Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/metabolismo , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Proteínas de Neoplasias/metabolismo , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/patologia , Feminino , Humanos , Masculino
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