Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.500
Filtrar
1.
Int J Biol Macromol ; 229: 413-421, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36587644

RESUMO

Fucoidan is a highly sulfated polysaccharide with a wide range of bioactivities, including anti-pathogenic activity. However, the relationship between structure and activity of fucoidan in inhibiting pathogen infections remains unclear. Here, different-molecular-weight fucoidans were prepared by photocatalytic degradation followed by membrane ultrafiltration, and their chemical structures and anti-pathogenic microbiota activity were compared. Results showed that photocatalytic degradation could effectively degrade fucoidan while its structure block and sulfate groups were not destroyed obviously. Fucoidan (90.8 kDa) of 5 mg/mL could inhibit the growth of S. aureus, S. typhimurium and E. coli, but its degradation products, Dfuc1 (19.2 kDa) and Dfuc2 (5.5 kDa), demonstrated lower inhibitory effect. In addition, compared to Dfuc1 and Dfuc2, fucoidan showed stronger capability to prevent the adhesion of S. aureus, L. monocytogenes, V. parahaemolyticus and S. typhimurium to HT-29 cells. Moreover, the inhibitory effect against SARS-CoV-2 and the binding activity to S protein were also positively correlated to molecular weight. These results indicate that natural fucoidan with higher molecular weight are more effective to inhibit these pathogenic bacteria and SARS-CoV-2, providing a better understanding of the relationship between structure and activity of fucoidan against pathogenic microbiota.


Assuntos
COVID-19 , Laminaria , Humanos , Laminaria/química , SARS-CoV-2 , Peso Molecular , Escherichia coli , Staphylococcus aureus , Polissacarídeos/química , Bactérias , Sulfatos/metabolismo
2.
J Agric Food Chem ; 71(2): 1100-1112, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36604158

RESUMO

Glucoraphanin, rich in broccoli seed extract (BSE), is generally inert but can be biotransformed into active sulforaphane by gut bacteria. This study aimed to screen probiotics with glucoraphanin-metabolizing ability and explore the effect of a combination of strain and BSE on colitis induced by dextran sulfate sodium (DSS) in mice. Bifidobacterium longum CCFM1206 was isolated from healthy adult feces. Ultra-high-performance liquid chromatography Q Exactive mass spectrometry analysis revealed the presence of sulforaphane, sulforaphane-l-cysteine, and erucin in the BSE supernatant fermented by B. longum CCFM1206 in vitro. Combined and individual interventions of BSE and B. longum CCFM1206 were applied to explore the effects on DSS-induced colitis. The results suggested that the combination of B. longum CCFM1206 and BSE could ameliorate colitis symptoms, relieve colonic inflammatory reactions and oxidative stress, and protect the intestinal barrier in DSS-induced mice. In comparison to the BSE intervention alone, the combined intervention of B. longum CCFM1206 and BSE promoted the generation of sulforaphane and sulforaphane-N-acetylcysteine in mice colon from 220.88 ± 19.81 to 333.99 ± 36.46 nmol/g and from 232.04 ± 26.48 to 297.50 ± 40.08 nmol/g dry weight feces, respectively. According to quantitative reverse transcription polymerase chain reaction and immunohistochemical analysis, B. longum CCFM1206 and BSE effectively activated the transcription and expression of genes related to the Nrf2 signaling pathway. These results were intended to elucidate that probiotics could elevate the bioactivity of dietary phytochemicals in vivo, and the combination had potential for therapeutic treatment of colitis.


Assuntos
Bifidobacterium longum , Colite , Camundongos , Animais , Bifidobacterium longum/metabolismo , Dextranos/metabolismo , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/microbiologia , Colo/metabolismo , Biotransformação , Sulfatos/metabolismo , Sódio/metabolismo , Sulfato de Dextrana/metabolismo , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL
3.
J Clin Invest ; 133(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36719378

RESUMO

Sulfate plays a pivotal role in numerous physiological processes in the human body, including bone and cartilage health. A role of the anion transporter SLC26A1 (Sat1) for sulfate reabsorption in the kidney is supported by the observation of hyposulfatemia and hypersulfaturia in Slc26a1-knockout mice. The impact of SLC26A1 on sulfate homeostasis in humans remains to be defined. By combining clinical genetics, functional expression assays, and population exome analysis, we identify SLC26A1 as a sulfate transporter in humans and experimentally validate several loss-of-function alleles. Whole-exome sequencing from a patient presenting with painful perichondritis, hyposulfatemia, and renal sulfate wasting revealed a homozygous mutation in SLC26A1, which has not been previously described to the best of our knowledge. Whole-exome data analysis of more than 5,000 individuals confirmed that rare, putatively damaging SCL26A1 variants were significantly associated with lower plasma sulfate at the population level. Functional expression assays confirmed a substantial reduction in sulfate transport for the SLC26A1 mutation of our patient, which we consider to be novel, as well as for the additional variants detected in the population study. In conclusion, combined evidence from 3 complementary approaches supports SLC26A1 activity as a major determinant of sulfate homeostasis in humans. In view of recent evidence linking sulfate homeostasis with back pain and intervertebral disc disorder, our study identifies SLC26A1 as a potential target for modulation of musculoskeletal health.


Assuntos
Proteínas de Transporte de Ânions , Sulfatos , Animais , Camundongos , Humanos , Proteínas de Transporte de Ânions/genética , Proteínas de Transporte de Ânions/metabolismo , Transportadores de Sulfato/genética , Transportadores de Sulfato/metabolismo , Transporte de Íons , Sulfatos/metabolismo , Homeostase , Camundongos Knockout , Antiporters/genética
4.
Biochem Biophys Res Commun ; 643: 105-110, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36592583

RESUMO

The 3'-phosphoadenosine-5'-phosphosulfate (PAPS) molecule is essential during enzyme-catalyzed sulfation reactions as a sulfate donor and is an intermediate in the reduction of sulfate to sulfite in the sulfur assimilation pathway. PAPS is produced through a two-step reaction involving ATP sulfurylase and adenosine 5'-phosphosulfate (APS) kinase enzymes/domains. However, archaeal APS kinases have not yet been characterized and their mechanism of action remains unclear. Here, we first structurally characterized APS kinase from the hyperthermophilic archaeon Archaeoglobus fulgidus, (AfAPSK). We demonstrated the PAPS production activity of AfAPSK at the optimal growth temperature (83 °C). Furthermore, we determined the two crystal structures of AfAPSK: ADP complex and ATP analog adenylyl-imidodiphosphate (AMP-PNP)/Mg2+/APS complex. Structural and complementary mutational analyses revealed the catalytic and substrate recognition mechanisms of AfAPSK. This study also hints at the molecular basis behind the thermal stability of AfAPSK.


Assuntos
Archaeoglobus fulgidus , Fosfotransferases (Aceptor do Grupo Álcool) , Archaeoglobus fulgidus/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Sulfato Adenililtransferase/química , Adenosina Fosfossulfato/química , Adenosina Fosfossulfato/metabolismo , Fosfoadenosina Fosfossulfato , Sulfatos/metabolismo , Trifosfato de Adenosina/metabolismo
5.
Methods Mol Biol ; 2557: 709-720, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36512246

RESUMO

Subcellular fractionation is an introductory step in a variety of experimental approaches designed to study intracellular components, like membranes and organelle systems. Subcellular fractions enriched in membranes of the Golgi apparatus of mammalian cells have been isolated to address localization and activity of proteins, including enzymes, to study intracellular membrane transport mechanisms, and to reconstitute in vitro cellular processes associated with the Golgi apparatus. Here, I describe methods to purify Golgi membranes by subcellular fractionation, to assay nucleotide sulfate (PAPS) uptake into Golgi vesicles, and to measure sulfate incorporation into in vitro synthesized glycosaminoglycans.


Assuntos
Fosfoadenosina Fosfossulfato , Proteoglicanas , Animais , Fosfoadenosina Fosfossulfato/metabolismo , Proteoglicanas/metabolismo , Complexo de Golgi/metabolismo , Glicosaminoglicanos/metabolismo , Sulfatos/metabolismo , Mamíferos/metabolismo
6.
New Phytol ; 237(1): 78-87, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36226797

RESUMO

Sulfur (S) is an essential macronutrient for plants and a signaling molecule in abiotic stress responses. It is known that S availability modulates root system architecture; however, the underlying molecular mechanisms are largely unknown. We previously reported an Arabidopsis gain-of-function mutant sulfate utilization efficiency4 (sue4) that could tolerate S deficiency during germination and early seedling growth with faster primary root elongation. Here, we report that SUE4, a novel plasma membrane-localized protein, interacts with the polar auxin transporter PIN1, resulting in reduced PIN1 protein levels and thus decreasing auxin transport to the root tips, which promotes primary root elongation. Moreover, SUE4 is induced by sulfate deficiency, consistent with its role in root elongation. Further analyses showed that the SUE4-PIN1 interaction decreased PIN1 levels, possibly through 26 S proteasome-mediated degradation. Taken together, our finding of SUE4-mediated root elongation is consistent with root adaptation to highly mobile sulfate in soil, thus revealing a novel component in the adaptive response of roots to S deficiency.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Proteínas de Membrana/metabolismo , Raízes de Plantas/metabolismo , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Transporte Biológico , Enxofre/metabolismo , Sulfatos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo
7.
Biomed Pharmacother ; 157: 114078, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36481402

RESUMO

Luteolin and naringenin are flavonoids found in various foods/beverages and present in certain dietary supplements. After a high intake of these flavonoids, their sulfate and glucuronide conjugates reach micromolar concentrations in the bloodstream. Some pharmacokinetic interactions of luteolin and naringenin have been investigated in previous studies; however, only limited data are available in regard to their metabolites. In this study, we aimed to investigate the interactions of the sulfate and glucuronic acid conjugates of luteolin and naringenin with human serum albumin, cytochrome P450 (CYP2C9, 2C19, and 3A4) enzymes, and organic anion transporting polypeptide (OATP1B1 and OATP2B1) transporters. Our main findings are as follows: (1) Sulfate conjugates formed more stable complexes with albumin than the parent flavonoids. (2) Luteolin and naringenin conjugates showed no or only weak inhibitory action on the CYP enzymes examined. (3) Certain conjugates of luteolin and naringenin are potent inhibitors of OATP1B1 and/or OATP2B1 enzymes. (4) Conjugated metabolites of luteolin and naringenin may play an important role in the pharmacokinetic interactions of these flavonoids.


Assuntos
Citocromo P-450 CYP3A , Transportadores de Ânions Orgânicos , Humanos , Citocromo P-450 CYP3A/metabolismo , Glucuronídeos , Luteolina/farmacologia , Albumina Sérica Humana/metabolismo , Sulfatos/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Flavonoides/farmacologia , Citocromo P-450 CYP2C9/metabolismo , Citocromo P-450 CYP2C19/metabolismo
8.
Int J Mol Sci ; 23(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36499496

RESUMO

Phenolic acids are known flavonoid metabolites, which typically undergo bioconjugation during phase II of biotransformation, forming sulfates, along with other conjugates. Sulfated derivatives of phenolic acids can be synthesized by two approaches: chemoenzymatically by 3'-phosphoadenosine-5'-phosphosulfate (PAPS)-dependent sulfotransferases or PAPS-independent aryl sulfotransferases such as those from Desulfitobacterium hafniense, or chemically using SO3 complexes. Both approaches were tested with six selected phenolic acids (2-hydroxyphenylacetic acid (2-HPA), 3-hydroxyphenylacetic acid (3-HPA), 4-hydroxyphenylacetic acid (4-HPA), 3,4-dihydroxyphenylacetic acid (DHPA), 3-(4-hydroxyphenyl)propionic acid (4-HPP), and 3,4-dihydroxyphenylpropionic acid (DHPP)) to create a library of sulfated metabolites of phenolic acids. The sulfates of 3-HPA, 4-HPA, 4-HPP, DHPA, and DHPP were all obtained by the methods of chemical synthesis. In contrast, the enzymatic sulfation of monohydroxyphenolic acids failed probably due to enzyme inhibition, whereas the same reaction was successful for dihydroxyphenolic acids (DHPA and DHPP). Special attention was also paid to the counterions of the sulfates, a topic often poorly reported in synthetic works. The products obtained will serve as authentic analytical standards in metabolic studies and to determine their biological activity.


Assuntos
Fosfoadenosina Fosfossulfato , Sulfotransferases , Fosfoadenosina Fosfossulfato/química , Fosfoadenosina Fosfossulfato/metabolismo , Sulfotransferases/metabolismo , Sulfatos/metabolismo , Hidroxibenzoatos
9.
Molecules ; 27(23)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36500233

RESUMO

M10, a novel myricetin derivative, is an anti-inflammatory agent designed for treatment of colitis. Here, we aim to investigate its pharmacokinetic behavior and tissue distribution in a mouse model with colitis. Pharmacokinetics and tissue distribution of M10 and its metabolite myricetin were compared in normal mice and in dextran-sodium-sulfate (DSS)-induced colitis mice. The role of fecal microbiota was also analyzed during metabolism of M10 in vitro. After oral administration, M10 was very low in the plasma of both normal and diseased mice. However, both M10 and myricetin were mainly distributed in the gastrointestinal tract, including the stomach, colon and small intestine, in physiological and pathological conditions. Significantly, M10 and myricetin were found in higher levels in gastrointestinal tracts with inflamed tissues than in normal tissues of mice. An in vitro assay revealed that 80% of M10 was metabolized to myricetin via fecal microbiota. After oral administration, M10 was not absorbed into circulation but mainly distributed in the inflamed submucosal tissues of colitic mice, where it was metabolized into myricetin to prevent colitis development.


Assuntos
Colite Ulcerativa , Colite , Camundongos , Animais , Sulfato de Dextrana/efeitos adversos , Colite Ulcerativa/induzido quimicamente , Distribuição Tecidual , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/metabolismo , Colo/metabolismo , Modelos Animais de Doenças , Sulfatos/metabolismo , Sódio/metabolismo , Camundongos Endogâmicos C57BL
10.
Trop Anim Health Prod ; 55(1): 3, 2022 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-36496527

RESUMO

A competitive relationship exists between sulphate-reducing bacteria and methanogens in the anaerobic environment including rumen for hydrogen where sulphate is not limiting growth and consequently inhibit enteric methane emission as thermodynamically energetic sulphate reduction (∆Go = - 21.1 kJ/mole of H2) is more favourable than methanogenesis (∆Go = - 16.9 kJ/mole H2). To validate this hypothesis, a study was designed to investigate the effect of supplementation of sulphate-reducing bacteria (SRB) identified as Streptococcus caviae RM296 as microbial feed additives alone or along with sulphur (as sodium sulphate) on methane production, live weight gain, feed intake, nutrient digestibility and energy metabolism in goats. The experiment was conducted on growing kids (n = 36, 5-6 months of age) with average body weight of 10.08 ± 0.21 kg, divided into six groups (n = 6). The duration of the feeding trial was of 150 days. The six treatments were control fed a basal diet (T1), SRB 0.5 ml/kg BW (T2), sulphur (as sodium sulphate) 0.095% of DMI (total sulphur level in the diet 1.5 times the requirement) (T3), sulphur (as sodium sulphate) 0.095% of DMI + SRB 0.5 ml/kg BW (T4), sulphur (as sodium sulphate) 0.19% of DMI (total sulphur level in the diet 2 times the requirement) (T5) and sulphur (as sodium sulphate) 0.19% of DMI + SRB 0.5 ml/kg BW (T6). Duration of study was 150 days and goats were fed as per ICAR (2013) feeding standard. Methane (CH4) production (l/kg DMI) was reduced by 11.8% (P = 0.052) in T6 where sulphur (0.19% DMI) was supplemented along with SRB4 (at the rate 0.5 ml/kg BW) as compared to T1 (un-supplemented group). However, the dry matter intake (DM), total weight gain (TG), average daily gain (ADG), feed conversion ratio (FCR), excretion of purine derivatives (allantoin, uric acid, xanthine and hypoxanthine) and digestibility of organic matter (OM), dry matter (DM), ether extract (EE), crude protein (CP), acid detergent fibre (ADF) and neutral detergent fibre (NDF) were similar (P > 0.05) among all the groups. The experimental data revealed that feeding of SRB as a microbial feed additive along with sulphur (as sodium sulphate) is capable of reducing enteric CH4 emission without any adverse effect on rumen fermentation and digestibility of the nutrients.


Assuntos
Cabras , Metano , Animais , Metano/metabolismo , Cabras/metabolismo , Digestão , Ração Animal/análise , Rúmen/metabolismo , Sulfatos/metabolismo , Sulfatos/farmacologia , Dieta/veterinária , Fermentação , Suplementos Nutricionais , Aumento de Peso , Enxofre , Bactérias/metabolismo
11.
BMC Plant Biol ; 22(1): 491, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36253724

RESUMO

BACKGROUND: ATP sulfurylase (ATPS) is a crucial enzyme for the selenate assimilation pathway in plants. RESULTS: In this study, genome-wide and comparative analyses of ATPS in Cardamine hupingshanensis, including sequence and structural analyses, were performed. The expression of ChATPS gene family members in C. hupingshanensis under selenium (Se) stress was also investigated, and our results suggest that ChATPS1-2 play key roles in the response to Se stress. Nine ATPS genes were found from C. hupingshanensis, which share highly conserved sequences with ATPS from Arabidopsis thaliana. In addition, we performed molecular docking of ATP sulfurylase in complex with compounds ATP, selenate, selenite, sulfate, and sulfite. ChAPS3-1 was found to have stronger binding energies with all compounds tested. Among these complexes, amino acid residues Arg, Gly, Ser, Glu, and Asn were commonly present. CONCLUSION: Our study reveals the molecular mechanism of C. hupingshanensis ATP sulfurylase interacting with selenate, which is essential for understanding selenium assimilation. This information will guide further studies on the function of the ChATPS gene family in the selenium stress response and lay the foundation for the selenium metabolic pathway in higher plants.


Assuntos
Arabidopsis , Cardamine , Selênio , Trifosfato de Adenosina , Aminoácidos/metabolismo , Arabidopsis/metabolismo , Cardamine/metabolismo , Simulação de Acoplamento Molecular , Ácido Selênico , Ácido Selenioso/metabolismo , Selênio/metabolismo , Sulfato Adenililtransferase/química , Sulfato Adenililtransferase/genética , Sulfato Adenililtransferase/metabolismo , Sulfatos/metabolismo , Sulfitos/metabolismo
12.
Chemosphere ; 309(Pt 1): 136640, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36181841

RESUMO

Chlorinated ethenes (CEs) are common and persistent contaminants of soil and groundwater. Their degradation is mostly driven by a process of bacterial reductive dechlorination (also called organohalide respiration) in anaerobic conditions. This study summarizes the outcomes of the long-term in-situ application of glycerol for the enhanced reductive dechlorination of CEs on a highly contaminated site. Glycerol injection resulted in an almost immediate increase in the abundance of fermentative Firmicutes, which produce essential sources of carbon (acetate) and electrons (H2) for organohalide-respiring bacteria (OHRB) and change groundwater conditions to be suitable for OHRB growth. The decreased redox potential of groundwater promoted also the proliferation of sulfate-reducing bacteria, which compete for electron donors with OHRB but at the same time support their growth by producing essential corrinoids and acetate. A considerable increase in the abundance of OHRB Dehalococcoides, concurrently with vinyl chloride (VC) reductase gene levels, was revealed by real time polymerase chain reaction (qPCR) method. Consistent with the shifts in bacterial populations, the concentrations of pollutants tetrachloroethylene and trichloroethylene decreased during the monitoring period, with rising levels of cis-1,2-dichloroethylene, VC, and most importantly, the final CE degradation products: ethene and ethane. Our study implies the importance of syntrophic bacterial interactions for successful and complete CE degradation and evaluates glycerol as convenient substrate to enhance reductive dechlorination and as an effective source of electrons for OHRB.


Assuntos
Chloroflexi , Corrinoides , Microbiota , Tetracloroetileno , Tricloroetileno , Cloreto de Vinil , Poluentes Químicos da Água , Tetracloroetileno/metabolismo , Tricloroetileno/metabolismo , Glicerol/metabolismo , Biodegradação Ambiental , Poluentes Químicos da Água/metabolismo , Bactérias/genética , Bactérias/metabolismo , Solo , Carbono/metabolismo , Oxirredutases/metabolismo , Sulfatos/metabolismo , Chloroflexi/metabolismo
13.
Front Cell Infect Microbiol ; 12: 639624, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36237423

RESUMO

Peritoneal dialysis (PD) is a renal replacement therapy for end-stage renal disease. Gut microbiota-derived uremic solutes, indoxyl sulfate (IS), p-cresyl sulfate (PCS), and trimethylamine-N-oxide (TMAO) accumulate in PD patients. The objective was to explore the gut microbiota and their influence on uremic toxins in PD patients and healthy controls (HC). Fecal samples were collected from PD patients (n = 105) and HC (n = 102). 16S rRNA gene regions were sequenced for gut microbiota analysis. IS, PCS, and TMAO levels were measured using HPLC-MS. PD patients exhibited lower alpha diversity and altered gut microbiota composition compared to HC. At the genus level, PD patients showed increased abundance of opportunistic pathogenic bacteria, and decreased abundance of beneficial bacteria. Three Operational Taxonomic Units discriminated PD patients from HC. Phenylalanine metabolism increased in PD, whereas tryptophan metabolism was unaltered. Low serum PCS did not necessarily mean healthier due to the loss of alpha diversity, increased Proteobacteria and opportunistic pathogenic bacteria. High serum PCS was mainly caused by elevated p-cresol-producing bacteria, enriched amino acid related enzymes, and enhanced sulfur metabolism, rather than declined residual renal function. In patients with different urine volumes, the gut microbiota alpha diversity and composition were unaltered, but serum IS and TMAO were significantly elevated in anuric patients. In conclusion, the gut microbiota abundance, composition, and function were altered in PD patients, which increased the PCS levels. We provided a better understanding of the microbiota-metabolite-kidney axis in PD patients. Targeting certain bacteria could decrease the PCS levels, whereas preserving the residual renal function could reduce the IS and TMAO levels.


Assuntos
Microbioma Gastrointestinal , Diálise Peritoneal , Bactérias/genética , Bactérias/metabolismo , Humanos , Indicã/metabolismo , Metilaminas , Óxidos/metabolismo , Fenilalanina/metabolismo , RNA Ribossômico 16S/genética , Sulfatos/metabolismo , Enxofre/metabolismo , Triptofano/metabolismo
14.
Water Res ; 226: 119227, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36240714

RESUMO

Dissimilatory sulfate reduction-based processes have long been a viable option for treating acidic metal-laden wastewater (AMW). Such processes can be optimized through enhancing sulfidogenic activity and the microbial consortia's resilience against a harsh environment. This study investigated how granular and flocculent sulfate-reducing bacteria (SRB) sludge respond to AMW as well as the mechanisms through which they adapt to the wastewater, with particular focuses on the stability of the sulfidogenic activities, metal removal, and the bacteria's resistance over the long-term: the flocculent SRB lost more than 50% of their treatment capacity after 35 days of treating AMW with the presence of Cd2+, Cu2+, Zn2+, and Ni2+ at 30 mg/L each, under pH = 4.5. In contrast, the granular SRB maintained its metal removal rate at 91% throughout the 161-day trial. Despite the SRB abundance remaining at approximate 40%, organics-partial oxidizing genera (Desulfobulbus and Desulfobacter) began to dominate due to their kinetic advantage. The extracellular glycosyl compositions were revealed to be critical for the stability of the granular structure and microbial activity as the extracellular proteins disintegrated irreversible. Usage the molecular dynamic simulation, the mobility of the metal ions in the SRB granular system was suppressed by the presence of a more diverse glycosyl composition compared with the flocculent system (10-50% diffusion coefficients differences). All of the identified glycosyls (especially xylose and rhamnose) exhibited strong interactions with Cu2+ (-470 kJ mol-1), while the maximum binding strength of Cd2+ to glycosyls was greater than -40 kJ mol-1, suggesting a low Cd2+complexation efficiency. The findings of this study shed light on the defensive mechanisms of SRB granules against multi-metal stress, and provide clues for efficient AMW treatment.


Assuntos
Desulfovibrio , Esgotos , Esgotos/microbiologia , Sulfatos/metabolismo , Reatores Biológicos , Cádmio , Desulfovibrio/metabolismo
15.
Methods Enzymol ; 676: 197-209, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36280350

RESUMO

Sulfur metabolism provides a number of compounds that are essential for plant survival and fitness and that affect the yield and quality of crops. Sulfur metabolism is a dynamic process, responding to a number of external cues. Because of this dynamics and rapid turnover, steady-state levels of sulfur-containing compounds do not always fully reflect plant responses to such cues. Therefore, measurements of the flux through sulfate assimilation may give a more precise estimate of the effects of environmental stimuli or metabolic disturbances on sulfur metabolism. The flux can be determined after feeding plants with sulfate labelled with an isotopic tracer. Here we describe a protocol for using [35S]sulfate to measure flux through sulfate assimilation in Arabidopsis. The protocol can be adapted for any plant species and growth conditions, and does not require any special equipment beyond a standard high performance liquid chromatograph. We hope that the protocol will support our colleagues in a more frequent use of flux measurements to answer new biological questions in plant sulfur metabolism.


Assuntos
Arabidopsis , Sulfatos , Sulfatos/metabolismo , Enxofre/metabolismo , Arabidopsis/metabolismo , Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
16.
Nat Commun ; 13(1): 6208, 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36266333

RESUMO

Outer hair cell elecromotility, driven by prestin, is essential for mammalian cochlear amplification. Here, we report the cryo-EM structures of thermostabilized prestin (PresTS), complexed with chloride, sulfate, or salicylate at 3.52-3.63 Å resolutions. The central positively-charged cavity allows flexible binding of various anion species, which likely accounts for the known distinct modulations of nonlinear capacitance (NLC) by different anions. Comparisons of these PresTS structures with recent prestin structures suggest rigid-body movement between the core and gate domains, and provide mechanistic insights into prestin inhibition by salicylate. Mutations at the dimeric interface severely diminished NLC, suggesting that stabilization of the gate domain facilitates core domain movement, thereby contributing to the expression of NLC. These findings advance our understanding of the molecular mechanism underlying mammalian cochlear amplification.


Assuntos
Proteínas de Transporte de Ânions , Cloretos , Animais , Proteínas de Transporte de Ânions/metabolismo , Cloretos/metabolismo , Microscopia Crioeletrônica , Células Ciliadas Auditivas Externas/metabolismo , Ânions/metabolismo , Salicilatos , Sulfatos/metabolismo , Mamíferos/metabolismo
17.
FEMS Microbiol Ecol ; 98(11)2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36259757

RESUMO

The coupled application of biological sulphate reduction (BSR) and partial sulphide oxidation to treat sulphate-rich wastewater is an effective strategy to mitigate pollution and recover elemental sulphur for repurposing. The recent development of the hybrid linear flow channel reactor (LFCR) achieves simultaneous BSR and partial sulphide oxidation with biosulphur recovery via a floating sulphur biofilm (FSB). Here, we explore the microbial community zoning and dynamics facilitating the process. A total of three continuous LFCRs were used to evaluate the effect of reactor zones, hydraulic residence time (HRT), carbon source, namely lactate and acetate, as well as reactor geometry and scale on process performance and microbial community dynamics. Community composition of sessile and planktonic microbial consortia were resolved at a 5- and 2-day HRT through 16S rRNA amplicon sequencing. Preferential attachment and prevalence of specific phylotypes within the sessile and planktonic communities revealed clear adaptation of key microorganisms to different microenvironments. Key microbial taxa affiliated with sulphate reduction and sulphide oxidation as well as those implicated in fermentation and syntrophic metabolism, fluctuated in response to changes in HRT and process performance. Through understanding the relationship between microbial community dynamics and process performance, this research will inform better process design and optimization of the hybrid LFCR.


Assuntos
Microbiota , Sulfatos , Sulfatos/metabolismo , Reatores Biológicos , RNA Ribossômico 16S/genética , Oxirredução , Enxofre/metabolismo , Sulfetos/metabolismo
18.
J Environ Manage ; 323: 116368, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36261973

RESUMO

The sulfate-reducing mediate microbial fuel cell (MFC) shows advantages in treating recalcitrant flowback water (FW) from shale gas extraction, but the stability under fluctuant concentrations of sulfate in FW remains unknown. Herein, we investigated the impact of fluctuant sulfate concentrations on the performance of FW treatment in MFCs. Sulfate concentration showed a significant role in the MFC treating FW, with a COD removal of 69.8 ± 9.7% and a peak power density of 2164 ± 396 mW/m3 under 247.5 mg/L sulfate, but only 39.1% and 1216 mW/m3 under 50 mg/L sulfate. The fluctuation of sulfate in a short time allowed to a stable performance, but a longtime intermittent decrease of feeding sulfate concentration significantly inhibited power generation to no more than 512 mW/m3. The sulfur cycling between sulfate and sulfide existed in the system, but the cycling rate became much lower after the longtime intermittent decrease, with resulting to the decreased power generation. Abundant sulfur-oxidizing bacteria (SOB) of Desulfuromonadaceae and Helicobacteraceae in the MFC stably feeding with 247.5 mg/L sulfate supported a high sulfur cycling rate. With the cooperation of abundant sulfate-reducing bacteria (SRB) of Desulfovibrionaceae (capable of producing electricity) on the anode and Desulfobacteraceae in anolyte, this sulfur cycling endowed the MFC with high sulfate tolerance and critically contributed to recalcitrant organics removal and power generation. However, much less SOB of Helicobacteraceae and Campylobacteraceae on the anode with high S0 accumulation on the surface after the longtime intermittent decrease of sulfate likely led to the low sulfur cycling rate. With also less SRB of Marinilabiaceae (capable of producing electricity) and Synergistaceae in the system, this low sulfur cycling rate thus hampered power generation. This research provides an important reference for the bioelectrochemical treatment of wastewater containing recalcitrant organics and sulfate.


Assuntos
Fontes de Energia Bioelétrica , Desulfovibrio , Purificação da Água , Fontes de Energia Bioelétrica/microbiologia , Gás Natural , Enxofre/metabolismo , Sulfatos/metabolismo , Desulfovibrio/metabolismo , Bactérias/metabolismo , Sulfetos/metabolismo
19.
Nat Commun ; 13(1): 6115, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36253480

RESUMO

Anaerobic microorganisms are thought to play a critical role in regulating the flux of short-chain gaseous alkanes (SCGAs; including ethane, propane and butane) from terrestrial and aquatic ecosystems to the atmosphere. Sulfate has been confirmed to act as electron acceptor supporting microbial anaerobic oxidation of SCGAs, yet several other energetically more favourable acceptors co-exist with these gases in anaerobic environments. Here, we show that a bioreactor seeded with biomass from a wastewater treatment facility can perform anaerobic propane oxidation coupled to nitrate reduction to dinitrogen gas and ammonium. The bioreactor was operated for more than 1000 days, and we used 13C- and 15N-labelling experiments, metagenomic, metatranscriptomic, metaproteomic and metabolite analyses to characterize the microbial community and the metabolic processes. The data collectively suggest that a species representing a novel order within the bacterial class Symbiobacteriia is responsible for the observed nitrate-dependent propane oxidation. The closed genome of this organism, which we designate as 'Candidatus Alkanivorans nitratireducens', encodes pathways for oxidation of propane to CO2 via fumarate addition, and for nitrate reduction, with all the key genes expressed during nitrate-dependent propane oxidation. Our results suggest that nitrate is a relevant electron sink for SCGA oxidation in anaerobic environments, constituting a new microbially-mediated link between the carbon and nitrogen cycles.


Assuntos
Compostos de Amônio , Nitratos , Alcanos/metabolismo , Anaerobiose , Butanos , Carbono , Dióxido de Carbono , Ecossistema , Etano/metabolismo , Fumaratos , Metano/metabolismo , Nitratos/metabolismo , Oxirredução , Propano/metabolismo , Sulfatos/metabolismo
20.
Nat Commun ; 13(1): 6460, 2022 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-36309497

RESUMO

Transmembrane ion transport is a key process in living cells. Active transport of ions is carried out by various ion transporters including microbial rhodopsins (MRs). MRs perform diverse functions such as active and passive ion transport, photo-sensing, and others. In particular, MRs can pump various monovalent ions like Na+, K+, Cl-, I-, NO3-. The only characterized MR proposed to pump sulfate in addition to halides belongs to the cyanobacterium Synechocystis sp. PCC 7509 and is named Synechocystis halorhodopsin (SyHR). The structural study of SyHR may help to understand what makes an MR pump divalent ions. Here we present the crystal structure of SyHR in the ground state, the structure of its sulfate-bound form as well as two photoreaction intermediates, the K and O states. These data reveal the molecular origin of the unique properties of the protein (exceptionally strong chloride binding and proposed pumping of divalent anions) and sheds light on the mechanism of anion release and uptake in cyanobacterial halorhodopsins. The unique properties of SyHR highlight its potential as an optogenetics tool and may help engineer different types of anion pumps with applications in optogenetics.


Assuntos
Proteínas de Transporte de Ânions , Synechocystis , Halorrodopsinas/metabolismo , Rodopsinas Microbianas/metabolismo , Synechocystis/metabolismo , Ânions/metabolismo , Sulfatos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...