Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 619
Filtrar
1.
J Environ Manage ; 370: 122397, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39278019

RESUMEN

UV/sulfite-based advanced reduction processes (ARP) have attracted increasing attention due to their high capability for removing a wide range of pollutants. Therefore, developing UV/sulfite ARP systems with assisted Artificial Intelligence (AI) models is considered an efficient strategy for sustainable pollutant removal. The present study delves into modeling and optimizing photodegradation of tetracycline (TC) antibiotics under UV/sulfite/рhenol reԁuсtion рroсess (UV/SPAP) using integrаteԁ Artifiсiаl Neurаl Networks (ANN), Suррort Veсtor Regression (SVR), аnԁ Genetiс Algorithm (GA). The сonсentrаtions of рhenol (X1) аnԁ sulfite (X2), рH (X3), reасtion time (X4), аnԁ TC сonсentrаtion (X5) in our exрerimentаl setuр were varied, аnԁ use the generаteԁ ԁаtа to trаin AI moԁels. The findings revealed that the AI-optimized performance is very effective in predicting and optimizing the removal of TC, thereby providing a sustainable water treatment approach. In general, SVR performed better based on scaling coefficients and ANN using different criteria indicated that X4 and X5 parameters were statistically significant. Oрtimаl rаnges for X1, X2, X3, X4, аnԁ X5 аre ԁetermineԁ to be 6.34, 3, 8.45, 80.13, аnԁ 1, resрeсtively. This аррroасh highlights the imрortаnсe of integrаting AI аnԁ ARP for sustаinаble environmentаl mаnаgement.

2.
Sci Total Environ ; 951: 175796, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-39187080

RESUMEN

The present study investigated the photo-reduction of perfluorooctane sulfonate (PFOS) and its alternatives, focusing on decomposition mechanisms, active species involvement, the influence of background water constituents, and kinetic model development. The decomposition and defluorination rates followed the order of PFOS > PFHxS > 6:2 FTSA > PFBS, with shorter chains and CH2 linkers enhancing the resistance of PFOS alternatives against the attack of hydrated electrons (eaq-). Two primary pathways were identified during the photodegradation of PFAS: (i) H/F exchange at CF bonds with the lowest bond dissociation energies (BDEs) and (ii) functional group cleavage followed by short-chain PFCAs formation, with OH playing a crucial role in transforming intermediates. Adding iodide and elevated temperatures demonstrated a synergistic effect on PFBS decomposition and defluorination, with high temperatures promoting functional group cleavage as the preferred defluorination pathway. The study examined the impact of background water constituents in different aqueous environments, from surface waters to wastewater streams and ion-exchange brine concentrates. Chloride exhibited a concentration-based dual impact on the UV/VUV/sulfite process: promotive effects at low dosages (1-10 mM) by acting as a secondary eaq- mediator, and adverse effects at high dosages (20-500 mM) due to the scavenging effect of generated chlorine radicals (Cl). High ionic strength adversely affected eaq- quantum efficiency. Additionally, bicarbonate and natural organic matter (NOM) had opposing effects on PFOS photo-reduction, primarily through eaq- scavenging and pH alteration. Kinetic modeling revealed reaction rate constants of the studied PFAS with eaq- ranging from 1.8 × 106 to 1.3 × 109 M-1 s-1, corroborating the concentration profiles of active species and highlighting the reductive nature of sulfite-mediated processes.

3.
Environ Sci Technol ; 58(36): 16225-16235, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39189336

RESUMEN

In this study, we proposed a moderate oxidation strategy for accelerating the oxidative dissolution of zerovalent iron (ZVI) using sulfite (S(IV)), thereby improving the removal of As(V) and As(III). Results revealed that, in the presence of 2.0 mM S(IV), both As(V) and As(III) were selectively converted into scorodite at pH0 3.0-7.0, while As(III) oxidation and As(V) immobilization were impressed over pH0 8.0-10.0. Batch experiments, radical quenching experiments, and electron spin resonance (ESR) measurements demonstrated that ZVI initially boosted S(IV) activation to generate SO4•-, •OH, and protons, and in turn, ZVI was further oxidized more intensely by these radicals than by oxygen. Concurrently, substantial protons derived from S(IV) oxidation neutralized hydroxyls produced by ZVI oxidation, maintaining an acidic environment conducive to the generation of scorodite rather than iron (hydr)oxides. Characterizations of X-ray diffraction (XRD), Raman, attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), X-ray absorption fine structure (XAFS), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM) confirmed that scorodite was formed in situ and then exfoliated from the surface of ZVI, and approximately 75% of ZVI could still be recovered, which contributed to efficient As removal in successive runs and real As-polluted wastewater. The application of S(IV) achieved a balance among ZVI reactivity improvement, As(V)/As(III) removal, and raw material consumption, making it a promising approach for addressing arsenic contamination in wastewater treatment.


Asunto(s)
Hierro , Oxidación-Reducción , Sulfitos , Hierro/química , Sulfitos/química , Arseniatos/química , Arsenitos/química , Contaminantes Químicos del Agua/química
4.
ISME J ; 18(1)2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-39206688

RESUMEN

Microorganisms play vital roles in sulfur cycling through the oxidation of elemental sulfur and reduction of sulfite. These metabolisms are catalyzed by dissimilatory sulfite reductases (Dsr) functioning in either the reductive or reverse, oxidative direction. Dsr-mediated sulfite reduction is an ancient metabolism proposed to have fueled energy metabolism in some of Earth's earliest microorganisms, whereas sulfur oxidation is believed to have evolved later in association with the widespread availability of oxygen on Earth. Organisms are generally believed to carry out either the reductive or oxidative pathway, yet organisms from diverse phyla have been discovered with gene combinations that implicate them in both pathways. A comprehensive investigation into the metabolisms of these phyla regarding Dsr is currently lacking. Here, we selected one of these phyla, the metabolically versatile candidate phylum SAR324, to study the ecology and evolution of Dsr-mediated metabolism. We confirmed that diverse SAR324 encode genes associated with reductive Dsr, oxidative Dsr, or both. Comparative analyses with other Dsr-encoding bacterial and archaeal phyla revealed that organisms encoding both reductive and oxidative Dsr proteins are constrained to a few phyla. Further, DsrAB sequences from genomes belonging to these phyla are phylogenetically positioned at the interface between well-defined oxidative and reductive bacterial clades. The phylogenetic context and dsr gene content in these organisms points to an evolutionary transition event that ultimately gave way to oxidative Dsr-mediated metabolism. Together, this research suggests that SAR324 and other phyla with mixed dsr gene content are associated with the evolution and origins of Dsr-mediated sulfur oxidation.


Asunto(s)
Archaea , Bacterias , Oxidación-Reducción , Filogenia , Azufre , Azufre/metabolismo , Archaea/genética , Archaea/metabolismo , Bacterias/genética , Bacterias/metabolismo , Bacterias/clasificación , Evolución Molecular , Hidrogenosulfito Reductasa/genética , Hidrogenosulfito Reductasa/metabolismo
5.
Pest Manag Sci ; 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39101333

RESUMEN

BACKGROUND: Vitellogenin (Vg), known as the yolk protein precursor for oocyte development in female insects, can be secreted to plant host from salivary glands of hemipterans, including rice leafhopper Recilia dorsalis. The aim of this study was to investigate the function of salivary-secreted Vg of R. dorsalis (RdVg) in rice host. We propose that RdVg possibly regulates the rice defense against insects, benefiting R. dorsalis feeding. RESULTS: RdVg was released into rice phloem along with saliva during R. dorsalis feeding. Knocking down RdVg increased the level of H2O2 and improved H2O2 metabolism in rice plants, making it difficult for R. dorsalis to feed. The transient expression or overexpression of the lipoprotein N-terminal domain of RdVg (RdVg2) significantly reduced hydrogen peroxide (H2O2) metabolism in plants. This suggests that salivary-secreted RdVg acts as an effector suppressing the H2O2 burst in rice plants, and RdVg2 is the key domain. RdVg2 could interact with rice sulfite oxidase (OsSO), which catalyzes the oxidation of SO3 2- and produces H2O2. Exposure of rice plants to R. dorsalis, overexpression of RdVg2 or knocking out OsSO reduced OsSO accumulation and SO3 2- oxidation, benefiting R. dorsalis feeding. However overexpression of OsSO increased SO3 2- oxidation and H2O2 metabolism, inhibiting R. dorsalis feeding. CONCLUSION: RdVg inhibits H2O2 generation via suppressing OsSO accumulation, ultimately benefiting R. dorsalis feeding. These findings identify RdVg as an effector that suppresses plant defense to insects, and provide insights into the function of salivary-secreted Vg in other Hemiptera insects. © 2024 Society of Chemical Industry.

6.
Mol Genet Metab ; 143(1-2): 108563, 2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-39168057

RESUMEN

Molybdenum cofactor deficiency type A has successfully been treated in a small number of children with daily intravenous administration of cyclic pyranopterin monophosphate. Pharmacodynamic data for this novel treatment have not been published and alternative dosing intervals have not been explored. We monitored pharmacodynamic biomarkers of sulfite oxidase and xanthine oxidoreductase activity in three patients with MoCD-A for a period of 2 to 9 months after discontinuation of cPMP substitution. We found that the clinical and metabolic effects were sustained for longer than expected, over 7 days at least. Our data implicate a biological half-life of the molybdenum cofactor dependent enzyme activities of approximately 3 days and suggest the possibility that less frequent than once daily dosing intervals could be a safe alternative to current practice.

7.
Heliyon ; 10(15): e34789, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39144967

RESUMEN

Sulfite oxidation is critical for the stable operation of desulfurization process and the treatment & recovery of desulfurization by-products. The Fe and Co oxides modified super hydrophobic layer was prepared on tubular ceramic membranes using hydrothermal synthesis and surface modifications to realize the combination of the membrane catalysis and membrane aeration. These two oxides were approximately two-layer distributed on the membrane surface, among which the Fe2O3 located in the bottom layer and the Co3O4 located in the upper layer. The catalytic rate of the bifunctional membrane was about 5.8 times than that of the original ceramic membrane, which was decreased with the increasing of Fe/Co ratio and declined after an initial rise with the increase of urea and cetyltrimethylammonium bromide. The conjoint effect of Fe and Co could improve the catalytic performance and reduce the dissolution loss of catalyzer. The oxidation rate tended to be constant after a 15 % decrease in 7 times experiments.

8.
Environ Pollut ; 361: 124847, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39216671

RESUMEN

A combined sorption/desorption and UV/sulfite degradation process was investigated for achieving efficient elimination of PFAS from water. Two gel-type resins, Purolite A532E and A600, and one macroporous resin, Purolite A860, were firstly tested for the sorption of individual PFPrA, PFHxA, PFOA, PFOS, and GenX at different concentrations. Sorption data and density functional theory (DFT) calculations revealed that electrostatic interactions predominated for short-chain PFAS sorption and hydrophobic interactions played a more significant role for long-chain PFAS than for short-chain PFAS. A600 and A860 were selected for desorption tests with 0.025% NaOH, 5% NaCl, and 5% NH4Cl solution with or without 20% ethanol (EtOH) due to their high sorption capacity for all target PFAS. The mixture of 5% NH4Cl and 20% EtOH as the desorption solution typically showed the highest desorption efficiency. PFOS was the most resistant for desorption but its desorption could be enhanced by stronger mixing conditions (in 5% NaCl + 20% EtOH). Direct degradation of studied PFAS in the desorption solution (0.025% NaOH, 5% NaCl, and 5% NH4Cl) by UV/sulfite achieved 97.6-100% degradation and 46.6-86.1% defluorination. EtOH hindered degradation and thus should be separated from the water before UV/sulfite degradation.

9.
Methods Mol Biol ; 2827: 109-143, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38985266

RESUMEN

Plant growth regulators are routinely added to in vitro culture media to foster the growth and differentiation of the cells, tissues, and organs. However, while the literature on usage of the more common auxins, cytokinins, gibberellins, abscisic acid, and ethylene is vast, other compounds that also have shown a growth-regulating activity have not been studied as frequently. Such substances are also capable of modulating the responses of plant cells and tissues in vitro by regulating their growth, differentiation, and regeneration competence, but also by enhancing their responses toward biotic and abiotic stress agents and improving the production of secondary metabolites of interest. This chapter will discuss the in vitro effects of several of such less frequently added plant growth regulators, including brassinosteroids (BRS), strigolactones (SLs), phytosulfokines (PSKs), methyl jasmonate, salicylic acid (SA), sodium nitroprusside (SNP), hydrogen sulfite, various plant growth retardants and inhibitors (e.g., ancymidol, uniconazole, flurprimidol, paclobutrazol), and polyamines.


Asunto(s)
Reguladores del Crecimiento de las Plantas , Reguladores del Crecimiento de las Plantas/farmacología , Reguladores del Crecimiento de las Plantas/metabolismo , Técnicas de Cultivo de Tejidos/métodos , Brasinoesteroides/farmacología , Brasinoesteroides/metabolismo , Desarrollo de la Planta/efectos de los fármacos , Plantas/metabolismo , Plantas/efectos de los fármacos , Lactonas/farmacología , Lactonas/metabolismo , Oxilipinas/farmacología , Oxilipinas/metabolismo , Ciclopentanos/farmacología , Ciclopentanos/metabolismo , Ácido Salicílico/farmacología , Ácido Salicílico/metabolismo , Acetatos/farmacología , Acetatos/metabolismo
10.
Biomolecules ; 14(7)2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39062583

RESUMEN

Molybdenum (Mo) is an essential element for human life, acting as a cofactor in various enzymes crucial for metabolic homeostasis. This review provides a comprehensive insight into the latest advances in research on molybdenum-containing enzymes and their clinical significance. One of these enzymes is xanthine oxidase (XO), which plays a pivotal role in purine catabolism, generating reactive oxygen species (ROS) capable of inducing oxidative stress and subsequent organ dysfunction. Elevated XO activity is associated with liver pathologies such as non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC). Aldehyde oxidases (AOs) are also molybdenum-containing enzymes that, similar to XO, participate in drug metabolism, with notable roles in the oxidation of various substrates. However, beneath its apparent efficacy, AOs' inhibition may impact drug effectiveness and contribute to liver damage induced by hepatotoxins. Another notable molybdenum-enzyme is sulfite oxidase (SOX), which catalyzes the conversion of sulfite to sulfate, crucial for the degradation of sulfur-containing amino acids. Recent research highlights SOX's potential as a diagnostic marker for HCC, offering promising sensitivity and specificity in distinguishing cancerous lesions. The newest member of molybdenum-containing enzymes is mitochondrial amidoxime-reducing component (mARC), involved in drug metabolism and detoxification reactions. Emerging evidence suggests its involvement in liver pathologies such as HCC and NAFLD, indicating its potential as a therapeutic target. Overall, understanding the roles of molybdenum-containing enzymes in human physiology and disease pathology is essential for advancing diagnostic and therapeutic strategies for various health conditions, particularly those related to liver dysfunction. Further research into the molecular mechanisms underlying these enzymes' functions could lead to novel treatments and improved patient outcomes.


Asunto(s)
Aldehído Oxidasa , Molibdeno , Oxidación-Reducción , Sulfito-Oxidasa , Xantina Oxidasa , Humanos , Molibdeno/metabolismo , Xantina Oxidasa/metabolismo , Sulfito-Oxidasa/metabolismo , Aldehído Oxidasa/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/enzimología , Animales , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/enzimología , Especies Reactivas de Oxígeno/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Estrés Oxidativo
11.
Biofabrication ; 16(4)2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-38996414

RESUMEN

Riboflavin overproduction byCorynebacterium glutamicumwas achieved by screening synthetic operons, enabling fine-tuned expression of the riboflavin biosynthetic genesribGCAH.The synthetic operons were designed by means of predicted translational initiation rates of each open reading frame, with the best-performing selection enabling riboflavin overproduction without negatively affecting cell growth. Overexpression of the fructose-1,6-bisphosphatase (fbp) and 5-phosphoribosyl 1-pyrophosphate aminotransferase (purF) encoding genes was then done to redirect the metabolic flux towards the riboflavin precursors. The resulting strain produced 8.3 g l-1of riboflavin in glucose-based fed-batch fermentations, which is the highest reported riboflavin titer withC. glutamicum. Further genetic engineering enabled both xylose and mannitol utilization byC. glutamicum, and we demonstrated riboflavin overproduction with the xylose-rich feedstocks rice husk hydrolysate and spent sulfite liquor, and the mannitol-rich feedstock brown seaweed hydrolysate. Remarkably, rice husk hydrolysate provided 30% higher riboflavin yields compared to glucose in the bioreactors.


Asunto(s)
Corynebacterium glutamicum , Ingeniería Metabólica , Riboflavina , Riboflavina/biosíntesis , Riboflavina/química , Riboflavina/metabolismo , Corynebacterium glutamicum/metabolismo , Corynebacterium glutamicum/genética , Xilosa/metabolismo , Fermentación , Glucosa/metabolismo , Operón , Manitol/metabolismo , Manitol/química , Reactores Biológicos , Ingeniería Genética
12.
Talanta ; 279: 126605, 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39084038

RESUMEN

Intracellular lipid droplets (LDs) are important organelles regulating intracellular redox processes. Endogenous bisulfite/sulfite (HSO3-/SO32-) is one of the metabolites of thiol metabolism. The variation in HSO3-/SO32- content around LDs is closely related to cellular homeostasis. However, there is currently no effective method to visualize and quantify the dynamic changes in HSO3-/SO32- content around LDs. In this work, a fluorescent probe MC-BEN utilizing a triphenylamine basic framework was developed to selectively recognize HSO3-/SO32- via a nucleophilic addition reaction. The probe exhibits excellent anti-interference capability, short response time, outstanding photostability, and a low fluorescence detection limit (6.1 µM) for HSO3-/SO32- recognition. More interesting, there is a trend of accelerated contact between LDs and lysosomes after MC-BEN targeting LDs and reacting with endogenous/exogenous HSO3-/SO32-, which may provide new ideas for the study of intracellular lysosomal lipophagy.


Asunto(s)
Colorantes Fluorescentes , Gotas Lipídicas , Sulfitos , Sulfitos/química , Sulfitos/análisis , Colorantes Fluorescentes/química , Gotas Lipídicas/química , Humanos , Lisosomas/química , Lisosomas/metabolismo , Células HeLa , Imagen Óptica , Límite de Detección
13.
Environ Res ; 260: 119662, 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39043355

RESUMEN

Ultrafiltration (UF) is a highly efficient technique for algal-rich water purification, but it is heavily contaminated due to the complex water characteristics. To solve this problem, potassium permanganate (KMnO4) oxidation enhanced with sodium sulfite (Na2SO3) was proposed as a pretreatment means. The results showed that the end-normalized flux was elevated from 0.10 to 0.91, and the reversible fouling resistance was reduced by 99.95%. The membrane fouling mechanism also changed obviously, without the generation of cake filtration. Regarding the properties of algal-rich water, the zeta potential was decreased from -29.50 to -5.87 mV after KMnO4/Na2SO3 pretreatment, suggesting that the electrostatic repulsion was significantly reduced. Meanwhile, the fluorescent components in algal-rich water were significantly eliminated, and the removal of dissolved organic carbon was increased to 67.46%. In the KMnO4/Na2SO3 process, reactive manganese species (i.e., Mn(V), Mn(III) and MnO2) and reactive oxygen species (i.e., SO4•- and •OH) played major roles in purifying algal-rich water. Specifically, SO4•-, •OH, Mn(V) and Mn(III) could effectively oxidize algal pollutants. Simultaneously, the in-situ adsorption and coagulation of MnO2 could accelerate the formation of flocs by decreasing the electrostatic repulsion between cells, and protect the algal cells from being excessive oxidized. Overall, the KMnO4/Na2SO3 process showed significant potential for membrane fouling alleviation in purifying algal-rich water.


Asunto(s)
Permanganato de Potasio , Especies Reactivas de Oxígeno , Sulfitos , Purificación del Agua , Permanganato de Potasio/química , Purificación del Agua/métodos , Sulfitos/química , Especies Reactivas de Oxígeno/metabolismo , Membranas Artificiales , Manganeso/química , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Ultrafiltración/métodos , Oxidación-Reducción
14.
J Hazard Mater ; 476: 135144, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39018598

RESUMEN

Iron-based sulfite (S(IV)) activation has emerged as a novel strategy to generate sulfate radicals (SO4•-) for contaminants degradation. However, numerous studies focused on dissolved iron-induced homogeneous activation processes while the potential of structural Fe(III) remains unclear. In this study, five iron (hydr)oxide soil minerals (FeOx) including ferrihydrite, schwertmannite, lepidocrocite, goethite and hematite, were successfully employed as sources of structural Fe(III) for S(IV) activation. Results showed that the catalytical ability of structural Fe(III) primarily depended on the crystallinity of FeOx instead of their specific surface area and particle size, with ferrihydrite and schwertmannite being the most active. Furthermore, in-situ ATR-FTIR spectroscopy and 2D-COS analysis revealed that HSO3- was initially adsorbed on FeO6 octahedrons of FeOx via monodentate inner-sphere complexation, ultimately oxidized into SO42- which was then re-adsorbed via outer-sphere complexation. During this process, strong oxidizing SO4•- and •OH were formed for pollutants degradation, confirmed by radical quenching experiments and electron spin resonance. Moreover, FeOx/S(IV) system exhibited superior applicability with respect to recycling test, real waters and twenty-six pollutants degradation. Eventually, plausible degradation pathways of three typical pollutants were proposed. This study highlights the feasibility of structural Fe(III)-containing soil minerals for S(IV) activation in wastewater treatment.

15.
J Photochem Photobiol B ; 257: 112962, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38917720

RESUMEN

Pulsed light illumination stands out as a noteworthy technique for photosynthetic H2 production, playing a crucial role in eliminating O2 and activating hydrogenase enzymes. However, further improvements are essential to make H2 photoproduction suitable for future commercial applications. In our study, we observed a distinct enhancement in pulsed light-induced H2 photoproduction in the unicellular green alga Chlamydomonas reinhardtii when treated with the optimal concentration of the mild O2 scavenger Na2SO3. This improvement was a result of reduced O2 content, increased hydrogenase enzyme activity, and suppressed H2-uptake activity. Furthermore, our findings indicate that exposing Na2SO3-treated C. reinhardtii to optimal light waveform continues to significantly boost pulsed light-induced H2 photoproduction, attributed to the alleviation of impaired photosystem II activity. Altogether, the combined application of optimal sulfite concentration and light waveform effectively enhances pulsed light-induced photosynthetic H2 production in the green alga C. reinhardtii.


Asunto(s)
Chlamydomonas reinhardtii , Hidrógeno , Luz , Complejo de Proteína del Fotosistema II , Sulfitos , Sulfitos/metabolismo , Chlamydomonas reinhardtii/metabolismo , Chlamydomonas reinhardtii/efectos de la radiación , Chlamydomonas reinhardtii/efectos de los fármacos , Hidrógeno/metabolismo , Complejo de Proteína del Fotosistema II/metabolismo , Fotosíntesis/efectos de la radiación , Fotosíntesis/efectos de los fármacos , Oxígeno/metabolismo , Hidrogenasas/metabolismo
16.
Talanta ; 278: 126445, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38908139

RESUMEN

A near-infrared fluorescent "turn on" probe DTMI featuring simple skeleton was constructed easily. It undergoes a structure transformation from an A-π-A to a D-π-A framework towards SO32-. Besides, DTMI is capable of distinctive sensing sulfite with a fast response and a significant Stokes shift as well as with high sensitivity, excellent selectivity, long-term stability of fluorescence signals, and good anti-interference ability. The detection limit (LOD) of DTMI for sulfite within the linear concentration range of 0.5-10 µM is 27.39 nM. More importantly, DTMI has been favorably utilized for detecting sulfite in food samples such as red wine and vermicelli. Based on its low biotoxicity, DTMI has been successfully applied in imaging experiments involving HeLa cells, onion inner epidermal cells, and zebrafish. Therefore, the results show that the presented probe possesses potential sensing activity towards sulfite in complex biological system and food samples.


Asunto(s)
Colorantes Fluorescentes , Sulfitos , Pez Cebra , Sulfitos/análisis , Sulfitos/química , Humanos , Células HeLa , Colorantes Fluorescentes/química , Animales , Cebollas/química , Límite de Detección , Análisis de los Alimentos/métodos , Imagen Óptica/métodos , Vino/análisis , Espectrometría de Fluorescencia/métodos , Contaminación de Alimentos/análisis
17.
J Food Sci ; 89(8): 4839-4855, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38922905

RESUMEN

Mung bean sprouts are widely consumed as a seasonal fresh vegetable, renowned for their affordability and richness in antioxidants and bioactive compounds. This study employed ultra-high-performance liquid chromatogram-Q-Exactive HF mass spectrometry (UHPLC-QE-MS) and multivariate statistical analysis to comprehensively evaluate the chemical profile of mung bean sprouts following sulfite immersion. The findings revealed a significant alteration in the overall chemical composition of mung bean sprouts following sodium sulfite immersion. Eleven components, including four sulfur-containing compounds, were identified as characteristic markers distinguishing between non-immersed and sodium sulfite-immersed mung bean sprouts. Esterification and addition reactions were inferred to occur during sodium sulfite immersion, leading to the transformation of flavonoid and saponin sulfates. Commercial samples analysis indicated that sulfur-containing compounds were detectable in 9 of 11 commercial mung bean sprouts. Meanwhile, when sodium sulfite concentration exceeded 3.00 mg/mL and immersion time exceeded 360 min, the contents of total polyphenol and flavonoid were significantly reduced and the antioxidant activity was adversely influenced.


Asunto(s)
Antioxidantes , Flavonoides , Metabolómica , Sulfitos , Vigna , Sulfitos/farmacología , Antioxidantes/análisis , Vigna/química , Vigna/crecimiento & desarrollo , Flavonoides/análisis , Cromatografía Líquida de Alta Presión/métodos , Metabolómica/métodos , Polifenoles/análisis , Semillas/química , Espectrometría de Masas/métodos , Plantones/química , Plantones/crecimiento & desarrollo , Germinación
18.
bioRxiv ; 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38915618

RESUMEN

Escherichia coli NADPH-dependent assimilatory sulfite reductase is responsible for fixing sulfur for incorporation into sulfur-containing biomolecules. The oxidoreductase is composed of two subunits, an NADPH, FMN, and FAD-binding diflavin reductase and an iron siroheme and Fe4S4-containing oxidase. How they interact has been an unknown for over 50 years because the complex is highly flexible, thus has been intransigent for traditional X-ray or cryo-EM structural analysis. Using a combination of the chameleon plunging system with a fluorinated lipid we overcame the challenge of preserving the minimal dimer between the subunits for high-resolution cryo-EM analysis. Here, we report the first structure of the complex between the reductase and oxidase, revealing how they interact in a minimal interface. Further, we determined the structural elements that discriminate between the pairing of a siroheme-containing oxidase with a diflavin reductase or a ferredoxin partner to channel the six electrons that reduce sulfite to sulfide.

19.
bioRxiv ; 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38895255

RESUMEN

Domesticated strains of Saccharomyces cerevisiae have adapted to resist copper and sulfite, two chemical stressors commonly used in winemaking. S. paradoxus, has not adapted to these chemicals despite being consistently present in sympatry with S. cerevisiae in vineyards. This contrast represents a case of apparent evolutionary constraints favoring greater adaptive capacity in S. cerevisiae. In this study, we used a comparative mutagenesis approach to test whether S. paradoxus is mutationally constrained with respect to acquiring greater copper and sulfite resistance. For both species, we assayed the rate, effect size, and pleiotropic costs of resistance mutations and sequenced a subset of 150 mutants isolated from our screen. We found that the distributions of mutational effects displayed by the two species were very similar and poorly explained the natural pattern. We also found that chromosome VIII aneuploidy and loss of function mutations in PMA1 confer copper resistance in both species, whereas loss of function mutations in REG1 were only a viable route to copper resistance in S. cerevisiae. We also observed a single de novo duplication of the CUP1 gene in S. paradoxus but none in S. cerevisiae. For sulfite, loss of function mutations in RTS1 and KSP1 confer resistance in both species, but mutations in RTS1 have larger average effects in S. paradoxus. Our results show that even when the distributions of mutational effects are largely similar, species can differ in the adaptive paths available to them. They also demonstrate that assays of the distribution of mutational effects may lack predictive insight concerning adaptive outcomes.

20.
Foods ; 13(11)2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38890986

RESUMEN

Sulfites play imperative roles in food crops and food products, serving as sulfur nutrients for food crops and as food additives in various foods. It is necessary to develop an effective method for the on-site quantification of sulfites in food samples. Here, 7-(diethylamino) quinoline is used as a fluorescent group and electron donor, alongside the pyridinium salt group as an electron acceptor and the C=C bond as the sulfite-specific recognition group. We present a novel fluorescent sensor based on a mechanism that modulates the efficiency of intramolecular charge transfer (ICT), CY, for on-site quantitative measurement of sulfite in food. The fluorescent sensor itself exhibited fluorescence in the near-infrared light (NIR) region, effectively minimizing the interference of background fluorescence in food samples. Upon exposure to sulfite, the sensor CY displayed a ratiometric fluorescence response (I447/I692) with a high sensitivity (LOD = 0.061 µM), enabling accurate quantitative measurements in complex food environments. Moreover, sensor CY also displayed a colorimetric response to sulfite, making sensor CY measure sulfite in both fluorescence and colorimetric dual-signal modes. Sensor CY has been utilized for quantitatively measuring sulfite in red wine and sugar with recoveries between 99.65% and 101.90%, and the RSD was below 4.0%. The sulfite concentrations in live cells and zebrafish were also monitored via fluorescence imaging. Moreover, the sulfite assimilated by lettuce leaves was monitored, and the results demonstrated that excessive sulfite in leaf tissue could lead to leaf tissue damage. In addition, the sulfate-transformed sulfite in lettuce stem tissue was tracked, providing valuable insights for evaluating sulfur nutrients in food crops. More importantly, to accomplish the on-site quantitative measurement of sulfite in food samples, a portable sensing system was prepared. Sensor CY and the portable sensing system were successfully used for the on-site quantitative measurement of sulfite in food.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA