Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Brief Bioinform ; 24(3)2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-36987778

RESUMEN

Alternative splicing (AS) is a key transcriptional regulation pathway. Recent studies have shown that AS events are associated with the occurrence of complex diseases. Various computational approaches have been developed for the detection of disease-associated AS events. In this review, we first describe the metrics used for quantitative characterization of AS events. Second, we review and discuss the three types of methods for detecting disease-associated splicing events, which are differential splicing analysis, aberrant splicing detection and splicing-related network analysis. Third, to further exploit the genetic mechanism of disease-associated AS events, we describe the methods for detecting genetic variants that potentially regulate splicing. For each type of methods, we conducted experimental comparison to illustrate their performance. Finally, we discuss the limitations of these methods and point out potential ways to address them. We anticipate that this review provides a systematic understanding of computational approaches for the analysis of disease-associated splicing.


Asunto(s)
Empalme Alternativo , Biología Computacional
2.
J Environ Manage ; 351: 119602, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38061093

RESUMEN

This paper provides a comprehensive overview of research works on in-situ thermal conductive heating (TCH), including heat transfer in soil, desorption behavior of pollutants, and mass transfer mechanism within the site. Each stage influences the effectiveness of subsequent stages. Comparison of simulation and experimental results demonstrates that heat transfer and temperature rise in soil are related to the hydrogeological conditions, wells layout and pollutants contents. Thermal desorption of pollutants from soil particles can be influenced by four aspects: energy input, pollutant properties, soil characteristics, and the binding state of pollutant in soil. The exponential decay kinetic model exhibits better applicability for fitting thermal desorption processes. After desorption, the pollutants migrate in soil driven by high temperature and extraction pressure, while hydrogeological conditions of the site determine the actual migration path and rate. Applying convection-dispersion model allows for quantitatively describing the complex migration behavior of pollutants in heterogeneous sites. Future research should focus more on the composite effects of multiple factors in TCH and develop multi-field coupling models through the combination of numerical simulation and in-situ experiments. Accurate characterization and prediction of entire TCH process can improve remediation efficiency, reduce energy costs, and achieve sustainable low-carbon remediation.


Asunto(s)
Contaminantes Ambientales , Restauración y Remediación Ambiental , Contaminantes del Suelo , Suelo/química , Calefacción , Contaminantes del Suelo/química
3.
J Environ Manage ; 361: 121169, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38815425

RESUMEN

Thermal desorption is a preferred technology for site remediation due to its various advantages. To ensure the effective removal of different pollutants in practical applications, it is necessary to understand the kinetic behaviors and removal mechanisms of pollutants in thermal desorption process. This paper explored the thermal desorption processes of five organic pollutants (nitrobenzene, naphthalene, n-dodecane, 1-nitronaphthalene, and phenanthrene) at 50-350 °C in two different subsoils with 6-18% moisture content. The results suggested that the thermal desorption process was well-fitted by the exponential decay model (R2 = 0.972-0.999) and could be divided into two distinct stages. The first stage was relatively fast and highly influenced by soil moisture, while the second stage showed a slower desorption rate due to the constraints imposed by the soil texture and structure. The influence of soil moisture on thermal desorption depended on the octanol/water partition coefficient (KOW) of pollutants. Pollutants with log KOW values lower than the critical value exhibited enhanced thermal desorption, while those with log KOW values higher than the critical value were inhibited. The critical value of log KOW might be between 3.33 and 4.46. Changes in soil texture and structure caused by heating promoted thermal desorption, especially for naphthalene, 1-nitronaphthalene and phenanthrene. The differences in texture and structure between the two soils diminished as the temperature increased. Finally, an extended kinetic model under changing temperature conditions was derived, and the simulation results for the two subsoils were very close to the actual thermogravimetric results, with the differences ranging from -1.28% to 0.94% and from -0.67% to 1.35%, respectively. These findings propose new insights into the influencing mechanisms of soil moisture and structure on the thermal desorption of organic pollutants. The extended kinetic model can provide reference for future kinetic research and guide practical site remediation.


Asunto(s)
Naftalenos , Contaminantes del Suelo , Suelo , Contaminantes del Suelo/química , Cinética , Suelo/química , Naftalenos/química , Fenantrenos/química , Restauración y Remediación Ambiental/métodos
4.
Prep Biochem Biotechnol ; : 1-10, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38349751

RESUMEN

Saccharomyces cerevisiae cannot assimilate xylose, second to glucose derived from lignocellulosic biomass. Here, the engineered S. cerevisiae strains INVSc-XI and INVSc-XI/XT were constructed using xylA and Xltr1p to co-utilize xylose and glucose, achieving economic viability and sustainable production of fuels. The xylose utilization rate of INVSc-XI/XT was 2.3-fold higher than that of INVSc-XI, indicating that overexpressing Xltr1p could further enhance xylose utilization. In mixed sugar media, a small amount of glucose enhanced the consumption of xylose by INVSc-XI/XT. Transcriptome analysis showed that glucose increased the upregulation of acetate of coenzyme A synthetase (ACS), alcohol dehydrogenase (ADH), and transketolase (TKL) gene expression in INVSc-XI/XT, further promoting xylose utilization and ethanol yield. The highest ethanol titer of 2.91 g/L with a yield of 0.29 g/g at 96 h by INVSc-XI/XT was 56.9% and 63.0% of the theoretical ethanol yield from glucose and xylose, respectively. These results showed overexpression of xylA and Xltr1p is a promising strategy for improving xylose and glucose conversion to ethanol. Although the ability of strain INVSc-XI/XT to produce ethanol was not very satisfactory, glucose was discovered to influence xylose utilization in strain INVSc-XI/XT. Altering the glucose concentration is a promising strategy to improve the xylose and glucose co-utilization.


INVSc-XI and INVSc-XI/XT strains were newly constructed to utilize xylose and glucose.XylA, in combination with xylose transporter Xltr1p, enhances xylose consumption.A small amount of glucose enhanced xylose utilization in INVSc-XI/XT strain.The expression of ACS, ADH, and TKL genes is upregulated in the media containing mixed sugars.The highest ethanol yield of 0.29 g/g was produced in a 2-L scale-up fermenter.

5.
Ecotoxicol Environ Saf ; 256: 114856, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37015188

RESUMEN

Coexisting multi-pollutants like sulfonamides (SAs) and chlorophenols (CPs) in the ecological environment pose a potential risk to living organisms. The development of a strategy for the effective removal of multiple pollutants has become an urgent need. Herein, we systematically investigated the potential of immobilized bacterial laccase to remove chlorophenols (CPs), sulfonamides (SAs), and their mixtures. Laccase from Bacillus pumilus ZB1 was efficiently immobilized on chitin and its thermal stability, pH stability, and affinity to substrates were improved. Reusability assessment showed the immobilized laccase retained 75.5% of its initial activity after five cycles. The removal efficiency of CPs and SAs by immobilized laccase was significantly improved compared with that of free laccase. In particular, the removal of 2,4-dichlorophenol and 2,4,6-trichlorophenol reached 96.9% and 89.3% respectively within 8 h. The immobilized laccase could remove 63.70% of 2,4-dichlorophenol after four cycles. The degradation pathways of 2,4-dichlorophenol and sulfamethazine were proposed via LC/MS analysis. When the co-pollutants containing 2,4,6-trichlorophenol and sulfamethoxazole, immobilized laccase showed 100% removal of 2,4,6-trichlorophenol and 38.71% removal of sulfamethoxazole simultaneously. Cytotoxicity and phytotoxicity tests indicated that immobilized laccase can alleviate the toxicity of co-pollutants. The results demonstrate that chitin-based laccase immobilization can be an effective strategy for the removal of SAs, CPs, and their co-pollutants.


Asunto(s)
Clorofenoles , Contaminantes Ambientales , Enzimas Inmovilizadas/metabolismo , Lacasa/metabolismo , Sulfonamidas , Quitina , Clorofenoles/química , Fenoles , Sulfanilamida , Sulfametoxazol
6.
Pediatr Surg Int ; 40(1): 26, 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-38133659

RESUMEN

PURPOSE: To investigate the correlation between postoperative feeding intolerance and defecation, with a view to carrying out prognostic assessment and timely intervention for the recovery of postoperative gastrointestinal function. METHODS: The 114 neonates with congenital intestinal atresia who underwent primary anastomosis admitted to Shenzhen Children's Hospital from January 2014 to December 2022 were studied, and the patients' basic information, intraoperative conditions, postoperative feeding and defecation, and hospitalization time were retrospectively analyzed. RESULTS: The risk factors for feeding intolerance after primary anastomosis for intestinal atresia are the gestational days, the time of the first postoperative defecations, the number of defecations on the previous day and the average number of defecations before feeding. CONCLUSION: The incidence of postoperative feeding intolerance is higher in preterm infants, and pediatricians can decide the timing of breastfeeding on the basis of the patients' defecation. The focus on accurate defecation may be more meaningful in determining and predicting postoperative feeding intolerance in the infants.


Asunto(s)
Enfermedades del Recién Nacido , Atresia Intestinal , Lactante , Niño , Femenino , Recién Nacido , Humanos , Recien Nacido Prematuro , Defecación , Atresia Intestinal/cirugía , Estudios Retrospectivos , Anastomosis Quirúrgica/efectos adversos
7.
Appl Microbiol Biotechnol ; 106(7): 2751-2761, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35278114

RESUMEN

Rhodococcus pyridinivorans B403 is a promising bacterium for degrading phenolic pollutants. In the application, the high-concentration substrate has a significant inhibitory effect on cell growth and phenol degradation, which makes adaptive evolution study of bacteria an important guarantee for further application. The present work found evolved R. pyridinivorans (X1 and X2) had enhanced tolerance to phenolic pollutants as compared to the ancestor strain: the minimum inhibitory concentrations (MIC) of phenol, m-cresol, and catechol increased from 1.2, 0.7, 0.8 g/L to 1.8, 1.0, 1.2 g/L of strain X1, and to 2.4, 1.2, 1.4 g/L of strain X2, respectively. Furthermore, compared to B403, X1, and X2 accumulated more biomass in 500-mg/L cresol medium and degraded phenols more efficiently. Correspondingly, genome sequencing revealed that the mutation sites in genes were annotated as encoding phosphotransferase, MFS transporter, AcrR regulator, and GlpD regulator in the adapted strains, which were closely associated with improved phenol tolerance and degradation. The conclusions provided theoretical basis for the phenol tolerance and degradation, which could promote construction of engineering bacteria for practical application. KEY POINTS: • Evolved strains were more resistant to phenols • Evolved strains degraded phenols more quickly • Genome sequencing elucidated mechanisms of enhanced phenol tolerance and degradation.


Asunto(s)
Contaminantes Ambientales , Rhodococcus , Biodegradación Ambiental , Contaminantes Ambientales/metabolismo , Genómica , Fenol/metabolismo , Fenoles/metabolismo , Rhodococcus/genética , Rhodococcus/metabolismo
8.
Ecotoxicol Environ Saf ; 238: 113577, 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35526458

RESUMEN

This study aimed to exploit the potential of Enterococcus faecalis R1107 in the bioremediation of azo dyes. The maximal decolorization of Congo Red (CR), Reactive Black 5 (RB5), and Direct Black 38 (DB38) were 90.17%, 96.82%, and 81.95%, respectively, with the bacterial treatment for 48 h. 65.57% of CR and 72.64% of RB5 could be decolorized by E. faecalis R1107 within 48 h when the concentration of azo dyes increased up to 1000 mg/L. FTIR analysis confirmed that E. faecalis R1107 could effectively break down the chemical structures of three azo dyes. E. faecalis R1107 alleviated the phytotoxicity of azo dyes and improved seed germination, which contributed to the increase in the lengths of roots, stems, and leaves of Vigna radiata seedlings. Transcriptomic analysis suggested that the gene regulatory networks in E. faecalis R1107 synergistically improved the degradation and detoxification of RB5, including the major metabolic pathways, the secondary metabolism, the transport system, the amino acid metabolic pathways, and the signal transduction systems. Simulated textile effluent (STE) was used to mimic real textile effluent to evaluate the bioremediation potential of E. faecalis R1107, and 72.79% STE can be decolorized after E. faecalis R1107 treatment for 48 h. In summary, our study demonstrated that E. faecalis R1107 might be well suitable for potential applications in the bioremediation of textile effluent.


Asunto(s)
Colorantes , Enterococcus faecalis , Compuestos Azo/metabolismo , Compuestos Azo/toxicidad , Biodegradación Ambiental , Colorantes/metabolismo , Rojo Congo , Enterococcus faecalis/metabolismo , Industria Textil , Textiles
9.
Ecotoxicol Environ Saf ; 226: 112823, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34597843

RESUMEN

To alleviate the risk of textile effluent, the development of highly effective bioremediation strategies for synthetic dye removal is needed. Herein, we aimed to assess whether intensified bioactivity of Bacillus pumilus ZB1 by oxidative stress could improve the removal of textile dyes. Methyl methanesulfonate (MMS) induced oxidative stress significantly promoted laccase expression of B. pumilus ZB1. Both the level of hydrogen dioxide and superoxide anion showed a significant positive correlation with laccase activity (RSQ = 0.963 and 0.916, respectively) along with the change of MMS concentration. The regulation of laccase expression was closely related to oxidative stress. The overexpressed laccase in the supernatant improved the decolorization of synthetic dyes (16.43% for Congo Red, 54.05% for Crystal Violet, and 41.61% for Reactive Blue 4). Laccase was subsequently expressed in E. coli. Investigation of the potential of bacterial laccase in dye remediation using Congo Red showed that an effective degradation of azo dye could be achieved with laccase treatment. Laccase remediation alleviated the cytotoxicity of Congo Red to human hepatocytes. In silico study identified eight amino acid residues of laccase involved in binding with Congo Red. Overall, regulation of oxidative stress towards bacterium can be used as a promising approach for the improvement of bacterial bioactivity in synthetic dye remediation.


Asunto(s)
Colorantes , Lacasa , Biodegradación Ambiental , Rojo Congo , Escherichia coli/metabolismo , Humanos , Lacasa/genética , Lacasa/metabolismo , Estrés Oxidativo
10.
J Environ Manage ; 285: 112063, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33588171

RESUMEN

The advanced oxidation process (AOP) based on activated Peroxymonosulfate (PMS) has been attracting many people in the field of soil and water remediation in many ways while ignoring the shortcomings. The high cost of activators, and energy input, as well as the expense to separate the catalyst and transition metal reducing agent from the treated soil, were some disadvantages of using activated PMS. Based on the above rationales of problems related to the use of activated PMS, this study aimed to study the performance of using unactivated peroxymonosulfate for the advanced oxidation process to remediate soil contaminated by trichloroethylene (TCE), and to evaluate the synergistic effect on selected soil properties after treatment. The results showed that within 45 min, a single injection of 5 mM PMS at its initial pH value can degrade 86.90% of the total TCE in the soil. However, when PMS was continuously injected, the removal rate was increased to 95.25%. The direct reaction of TCE and PMS was the main cause of degradation. PMS can degrade TCE in a wide pH range (pH 3-11), but the maximum degradation was at pH = 2.9 (the initial pH of PMS). After the treatment, the soil organic matter (SOM) was degraded significantly. In contrast, FTIR, SEM, and hydrometer tests conducted on the soil showed that the treatment had no significant effect on the functional groups and particle size distribution of the treated soil. The study on the effect of the treatment on the concentration of bioavailable heavy metals in the treated soil showed that only manganese and copper metals were significantly increased after the treatment. According to the results obtained in this study, it is more beneficial and feasible to use unactivated peroxymonosulfate in the advanced oxidation process when remediating soil contaminated by chlorinated organic matter.


Asunto(s)
Tricloroetileno , Contaminantes Químicos del Agua , Humanos , Oxidación-Reducción , Peróxidos , Suelo , Contaminantes Químicos del Agua/análisis
11.
Ecotoxicol Environ Saf ; 205: 111134, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32829208

RESUMEN

The recalcitrant azo dyes combined with heavy metals constitute a major challenge for the bioremediation of industrial effluents. This study aimed to investigate the effect and mechanism of action of a white-rot fungus Trametes hirsuta TH315 on the simultaneous removal of hexavalent chromium [Cr(VI)] and azo dye (Reactive Black 5, RB5). Here, this study discovered that toxic Cr(VI) (1 mM) greatly promoted RB5 decolorization (from 57.15% to 83.65%) by white-rot fungus Trametes hirsuta with high Cr(VI)-reducing ability (>96%), resulting in the simultaneous removal of co-contaminants. On the basis of transcriptomic and biochemical analysis, our study revealed that the oxidative stress in co-contaminants mainly caused by Cr(VI), and a number of dehydrogenases and oxidases showed up-regulation in response to Cr(VI) stress. It was noteworthy that the oxidative stress caused by Cr(VI) in co-contaminants can both significantly induce glutathione S-transferase and laccase expression. Glutathione S-transferase potentially involved in antioxidation against Cr(VI) stress. Laccase was found to play a key role in RB5 decolorization by T. hirsuta. These results suggested that the simultaneous removal of co-contaminants by T. hirsuta could be achieved with Cr(VI) exposure. Overall, the elucidation of the molecular basis in details will help to advance the general knowledge about the fungus by facing harsh environments, and put forward a further possible application of fungi on environmental remediation.


Asunto(s)
Biodegradación Ambiental , Cromo/toxicidad , Naftalenosulfonatos/química , Trametes/fisiología , Compuestos Azo/análisis , Restauración y Remediación Ambiental , Lacasa/metabolismo , Metales Pesados/análisis , Trametes/metabolismo
12.
Ecotoxicol Environ Saf ; 164: 398-408, 2018 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-30142606

RESUMEN

Fungi can use n-hexadecane (HXD) as a sole carbon source. But the mechanism of HXD degradation remains unclear. This work mainly aimed to study the degradation of HXD by Aspergillus sp. RFC-1 obtained from oil-contaminated soil. The HXD content, medium acidification and presence of hexadecanoic acid in the medium were determined by gas chromatography-mass spectrometry, and fungal growth was observed. Enzyme and gene expression assays suggested the involvement of an alkane hydroxylase, an alcohol dehydrogenase, and a P450 enzyme system in HXD degradation. A biosurfactant produced by the strain RFC-1 was also characterized. During 10 days of incubation, 86.3% of HXD was degraded by RFC-1. The highest activities of alkane hydroxylase (125.4 µmol mg-1 protein) and alcohol dehydrogenase (12.5 µmol mg-1 proteins) were recorded. The expression level of cytochrome P450 gene associated with oxidation was induced (from 0.94-fold to 5.45-fold) under the HXD condition by Real-time PCR analysis. In addition, HXD accumulated in inclusion bodies of RFC-1with the maximum of 5.1 g L-1. Results of blood agar plate and thin-layer chromatography analysis showed RFC-1 released high lipid and emulsification activity in the fungal culture. Induced cell surface hydrophobicity and reduced surface tension also indicated the RFC-1-mediated biosurfactant production, which facilitated the HXD degradation and supported the degradation process.


Asunto(s)
Alcanos/metabolismo , Aspergillus/metabolismo , Biodegradación Ambiental , Alcohol Deshidrogenasa/metabolismo , Citocromo P-450 CYP4A/metabolismo , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica de Rastreo , Espectroscopía Infrarroja por Transformada de Fourier , Tensoactivos/metabolismo
13.
J Proteomics ; 292: 105047, 2024 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-37981008

RESUMEN

The wide distribution of laccases in nature makes them involved in different biological processes. However, little information is known about how laccase participates in the defense machinery of bacteria against oxidative stress. The present study aimed to elucidate the oxidative stress response mechanism of Bacillus pumilus ZB1 and the functional role of bacterial laccase in stress defense. The oxidative stress caused by methyl methanesulfonate (MMS) significantly induced laccase activity and its transcript level. The morphological analysis revealed that the defense of B. pumilus ZB1 against oxidative stress was activated. Based on the proteomic study, 114 differentially expressed proteins (DEPs) were up-regulated and 79 DEPs were down-regulated. In COG analysis, 66.40% DEPs were classified into the category "Metabolism". We confirmed that laccase was up-regulated in response to MMS stress and its functional annotation was related to "Secondary metabolites biosynthesis, transport and catabolism". Based on protein-protein interaction prediction, two up-regulated DEPs (YcnJ and GabP) showed interaction with laccase and contributed to the formation of laccase stability and adaptability. The overexpressed laccase might improve the antioxidative property of B. pumilus ZB1. These findings provide an insight and the guidelines for better exploitation of bioremediation using bacterial laccase. SIGNIFICANCE: Bacillus pumilus is a gram-positive bacterium that has the potential for many applications, such as bioremediation. The expression of bacterial laccase is significantly influenced by oxidative stress, while the underlying mechanism of laccase overexpression in bacteria has not been fully studied. Elucidation of the biological process may benefit the bioremediation using bacteria in the future. In this study, the differentially expressed proteins were analyzed using a TMT-labeling proteomic approach when B. pumilus was treated with methyl methanesulfonate (MMS). Reactive oxygen species induced by MMS activated the secondary metabolites biosynthesis, transport, and catabolism in B. pumilus, including laccase overexpression. Moreover, the simultaneously up-regulated YcnJ and GabP may benefit the synthesis and the stability of laccase, then improve the antioxidative property of B. pumilus against environmental stress. Our findings advance the understanding of the adaptive mechanism of B. pumilus to environmental conditions.


Asunto(s)
Bacillus pumilus , Bacillus pumilus/metabolismo , Lacasa/metabolismo , Proteómica , Metilmetanosulfonato/metabolismo , Proteínas Bacterianas/metabolismo , Estrés Oxidativo
14.
Bioresour Technol ; 397: 130498, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38432542

RESUMEN

Bioaugmentation is an efficient method for improving the efficiency of coking wastewater removal. Nevertheless, how different immobilization approaches affect the efficiency of bioaugmentation remains unclear, as does the corresponding mechanism. With the assistance of immobilized bioaugmentation strain Rhodococcus biphenylivorans B403, the removal of synthetic coking wastewater was investigated (drying agent, alginate agent, and absorption agent). The reactor containing the absorption agent exhibited the highest average removal efficiency of phenol (99.74 %), chemical oxygen demand (93.09 %), and NH4+-N (98.18 %). Compared to other agents, the covered extracellular polymeric substance on the absorption agent surface enhanced electron transfer and quorum sensing, and the promoted quorum sensing benefited the activated sludge stability and microbial regulation. The phytotoxicity test revealed that the wastewater's toxicity was greatly decreased in the reactor with the absorption agent, especially under high phenol concentrations. These findings showed that the absorption agent was the most suitable for wastewater treatment bioaugmentation.


Asunto(s)
Carbón Orgánico , Coque , Rhodococcus , Aguas Residuales , Fenol , Amoníaco , Regulación hacia Arriba , Percepción de Quorum , Matriz Extracelular de Sustancias Poliméricas/química , Electrones , Fenoles , Aguas del Alcantarillado/química , Coque/análisis
15.
Environ Sci Pollut Res Int ; 31(23): 33752-33762, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38687450

RESUMEN

High concentration of phenol residues in soil are harmful to human health and ecological safety. However, limited information is available on the in-situ bioremediation of phenol-contaminated soil using biochar as a carrier for bacteria. In this study, bamboo -derived biochar was screened as a carrier to assemble microorganism-immobilized composite with Rhodococcus pyridinivorans B403. Then, SEM used to observe the micromorphology of composite and its bioactivity was detected in solution and soil. Finally, we investigated the effects of free B403 and biochar-immobilized B403 (BCJ) on phenol biodegradation in two types of soils and different initial phenol concentrations. Findings showed that bacterial cells were intensively distributed in/onto the carriers, showing high survival. Immobilisation increased the phenol degradation rate of strain B403 by 1.45 times (37.7 mg/(L·h)). The phenol removed by BCJ in soil was 81% higher than free B403 on the first day. Moreover, the removal of BCJ remained above 51% even at phenol concentration of 1,500 mg/kg, while it was only 15% for free B403. Compared with the other treatment groups, BCJ showed the best phenol removal effect in both tested soils. Our results indicate that the biochar-B403 composite has great potential in the remediation of high phenol-contaminated soil.


Asunto(s)
Biodegradación Ambiental , Carbón Orgánico , Rhodococcus , Contaminantes del Suelo , Suelo , Rhodococcus/metabolismo , Carbón Orgánico/química , Contaminantes del Suelo/metabolismo , Suelo/química , Fenol , Microbiología del Suelo
16.
Environ Sci Pollut Res Int ; 30(8): 20415-20430, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36255571

RESUMEN

Under the background of the deep convergence of China's digital services and manufacturing, it is of great significance to investigate the effects of the convergence of digital services and manufacturing on economic growth and carbon emissions reduction to the application of digital technology in the whole world. This paper constructs a simultaneous equation model and uses three-stage least squares to estimate the effect and mechanism of industrial convergence on economic growth and carbon emissions. The results show that (i) industrial convergence improves the change of total factor productivity (TFP) and the change of technical efficiency, and the reduction of carbon emissions is the main factor driving the growth of TFP and technical efficiency; (ii) industrial convergence and carbon emissions show a significant U-shaped relationship; (iii) the heterogeneity analysis shows that the convergence of capital-intensive, technology-intensive and labor-intensive manufacturing with digital services will help to improve the growth of TFP, it can inhibit carbon emissions first and then promote it. Therefore, the government should take targeted measures to promote industrial convergence of digital services and manufacturing according to the economic development and industry characteristics, so as to give full play to its positive role in economic growth and emissions reduction.


Asunto(s)
Carbono , Desarrollo Económico , Carbono/análisis , Dióxido de Carbono/análisis , Comercio , China
17.
J Vis Exp ; (196)2023 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-37427914

RESUMEN

The optokinetic reflex (OKR) is an essential innate eye movement that is triggered by the global motion of the visual environment and serves to stabilize retinal images. Due to its importance and robustness, the OKR has been used to study visual-motor learning and to evaluate the visual functions of mice with different genetic backgrounds, ages, and drug treatments. Here, we introduce a procedure for evaluating OKR responses of head-fixed mice with high accuracy. Head fixation can rule out the contribution of vestibular stimulation on eye movements, making it possible to measure eye movements triggered only by visual motion. The OKR is elicited by a virtual drum system, in which a vertical grating presented on three computer monitors drifts horizontally in an oscillatory manner or unidirectionally at a constant velocity. With this virtual reality system, we can systematically change visual parameters like spatial frequency, temporal/oscillation frequency, contrast, luminance, and the direction of gratings, and quantify tuning curves of visual feature selectivity. High-speed infrared video-oculography ensures accurate measurement of the trajectory of eye movements. The eyes of individual mice are calibrated to provide opportunities to compare the OKRs between animals of different ages, genders, and genetic backgrounds. The quantitative power of this technique allows it to detect changes in the OKR when this behavior plastically adapts due to aging, sensory experience, or motor learning; thus, it makes this technique a valuable addition to the repertoire of tools used to investigate the plasticity of ocular behaviors.


Asunto(s)
Reflejo Vestibuloocular , Reflejo , Femenino , Ratones , Masculino , Animales , Reflejo Vestibuloocular/fisiología , Visión Ocular , Nistagmo Optoquinético , Rotación , Cara , Estimulación Luminosa
18.
Biotechnol Biofuels Bioprod ; 16(1): 164, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37915106

RESUMEN

BACKGROUND: As a cost-effective and eco-friendly approach, biocatalysis has great potential for the transformation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA). However, the compatibility of each enzyme in the cascade reaction limits the transformation efficiency of HMF to FDCA. RESULTS: Coupled with an alcohol oxidase from Colletotrichum gloeosporioides (CglAlcOx), this study aims to study the potential of bacterial laccase from Bacillus pumilus (BpLac) in an enzymatic cascade for 2,5-furandicarboxylic acid (FDCA) biosynthesis from 5-hydroxymethylfurfural (HMF). BpLac showed 100% selectivity for HMF oxidation and generated 5-hydroxymethyl-2-furancarboxylic acid (HMFCA). CglAlcOx was capable of oxidizing HMFCA to 2-formyl-5-furancarboxylic acid (FFCA). Both BpLac and CglAlcOx could oxidize FFCA to FDCA. At the 5 mM scale, a complete transformation of HMF with a 97.5% yield of FDCA was achieved by coupling BpLac with CglAlcOx in the cascade reaction. The FDCA productivity in the reaction was 5.3 mg/L/h. Notably, BpLac could alleviate the inhibitory effect of FFCA on CglAlcOx activity and boost the transformation efficiency of HMF to FDCA. Moreover, the reaction was scaled up to 40 times the volume, and FDCA titer reached 2.6 mM with a yield of 58.77% at 168 h. CONCLUSIONS: This work provides a candidate and novel insight for better design of an enzymatic cascade in FDCA production.

19.
Nat Commun ; 14(1): 8467, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38123558

RESUMEN

Sensory cortices modulate innate behaviors through corticofugal projections targeting phylogenetically-old brainstem nuclei. However, the principles behind the functional connectivity of these projections remain poorly understood. Here, we show that in mice visual cortical neurons projecting to the optic-tract and dorsal-terminal nuclei (NOT-DTN) possess distinct response properties and anatomical connectivity, supporting the adaption of an essential innate eye movement, the optokinetic reflex (OKR). We find that these corticofugal neurons are enriched in specific visual areas, and they prefer temporo-nasal visual motion, matching the direction bias of downstream NOT-DTN neurons. Remarkably, continuous OKR stimulation selectively enhances the activity of these temporo-nasally biased cortical neurons, which can efficiently promote OKR plasticity. Lastly, we demonstrate that silencing downstream NOT-DTN neurons, which project specifically to the inferior olive-a key structure in oculomotor plasticity, impairs the cortical modulation of OKR and OKR plasticity. Our results unveil a direction-selective cortico-brainstem pathway that adaptively modulates innate behaviors.


Asunto(s)
Instinto , Vías Visuales , Animales , Ratones , Vías Visuales/fisiología , Movimientos Oculares , Reflejo/fisiología , Tronco Encefálico
20.
J Hazard Mater ; 443(Pt B): 130370, 2023 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-36444079

RESUMEN

Laccases are considered promising tools for removing synthetic dyes from textile and tannery effluents. However, the alkaline pH in the effluents causes laccase instability, inactivation, and difficulty in its bioremediation. Based on a Bacillus pumilus ZB1 (BpLac) derived alkaline stable laccase, this study aimed to elucidate its alkaline stable mechanism at molecular level using molecular dynamics simulation. The effects of metal ions, organic solvents, and inhibitors on BpLac activity were assessed. BpLac formed more salt bridges and negatively charged surface in alkaline environment. Thereafter, pH-induced conformation changes were analyzed using GROMACS at pH 5.0 and 10.0. Among the identified residues with high fluctuation, the distance between Pro359 and Thr414 was stable at pH 10.0 but highly variable at pH 5.0. DSSP analysis suggested that BpLac formed more ß-sheet and less coil at pH 10.0. Principal component analysis and free energy landscape indicated that irregular coils formed at pH 5.0 benefit for activity, while rigid α-helix and ß-sheet structures formed at pH 10.0 contributed to alkaline stability. Breaking the α-helix near T1 copper center would not reduce alkaline stability but could improve dye decolorization by BpLac. Overall, these findings would advance the potential application of bacterial laccase in alkaline effluent treatment.


Asunto(s)
Bacillus pumilus , Lacasa , Simulación de Dinámica Molecular , Colorantes , Textiles
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA