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1.
Biochim Biophys Acta Proteins Proteom ; 1870(1): 140733, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34662731

RESUMO

Substrate competition for human acetylcholinesterase (AChE) and human butyrylcholinesterase (BChE) was studies under steady-state conditions using wide range of substrate concentrations. Competing couples of substates were acetyl-(thio)esters. Phenyl acetate (PhA) was the reporter substrate and competitor were either acetylcholine (ACh) or acetylthiocholine (ATC). The common point between investigated substrates is that the acyl moiety is acetate, i.e. same deacylation rate constant for reporter and competitor substrate. Steady-state kinetics of cholinesterase-catalyzed hydrolysis of PhA in the presence of ACh or ATC revealed 3 phases of inhibition as concentration of competitor increased: a) competitive inhibition, b) partially mixed inhibition, c) partially uncompetitive inhibition for AChE and partially uncompetitive activation for BChE. This sequence reflects binding of competitor in the active centrer at low concentration and on the peripheral anionic site (PAS) at high concentration. In particular, it showed that binding of a competing ligand on PAS may affect the catalytic behavior of AChE and BChE in an opposite way, i.e. inhibition of AChE and activation of BChE, regardless the nature of the reporter substrate. For both enzymes, progress curves for hydrolysis of PhA at very low concentration (≪Km) in the presence of increasing concentration of ATC showed that: a) the competing substrate and the reporter substrate are hydrolyzed at the same time, b) complete hydrolysis of PhA cannot be reached above 1 mM competing substrate. This likely results from accumulation of hydrolysis products (P) of competing substrate and/or accumulation of acetylated enzyme·P complex that inhibit hydrolysis of the reporter substrate.


Assuntos
Colinesterases/química , Acetatos/metabolismo , Acetilcolina/metabolismo , Sítios de Ligação , Colinesterases/metabolismo , Humanos , Cinética , Simulação de Acoplamento Molecular , Fenóis/metabolismo , Ligação Proteica , Especificidade por Substrato
2.
J Toxicol Environ Health A ; 85(1): 29-42, 2022 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-34445936

RESUMO

The aim of this study was to investigate changes in the intracellular metabolism resulting from cisplatin (CDDP)-induced nephrotoxicity in normal kidney tubular epithelial NRK-52E cells. Cytotoxicity, cell cycle analysis, and apoptotic cell death were all evaluated in NRK-52E cells treated with CDDP. Subsequently, proton nuclear magnetic resonance (1H-NMR) spectroscopy was used to investigate cellular metabolic profiles. CDDP-induced nephrotoxicity was determined in vivo model. Cytotoxicity in the NRK-52E cells significantly rose following treatment with CDDP and these increases were found to be concentration-dependent. Both p53 and Bax protein expression was increased in CDDP-treated NRK-52E cells, correlating with enhanced cellular apoptosis. In addition, a number of metabolites were altered in both media and cell lysates in these cells. In cell lysates, citrate, creatinine, and acetate levels were dramatically reduced following treatment with 20 µM CDDP concentrations, while glutamate level was elevated. Lactate and acetate levels were significantly increased in culture media but citrate concentrations were reduced following high 20 µM CDDP concentrations incubation. In addition, excretion of clusterin, calbindin, neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), selenium binding protein 1 (SBP1), and pyruvate kinase M2 (PKM2) into the culture media was significantly increased in CDDP-treated cells while expression of acetyl CoA synthetase 1 (AceCS1) was markedly reduced in these cells. These findings suggest that acetate-dependent metabolic pathway may be a reliable and useful biomarker for detecting CDDP-induced nephrotoxicity. Taken together, data demonstrate that the discovery of novel biomarkers by metabolite profiling in target cells may contribute to the detection of nephrotoxicity and new drug development.


Assuntos
Injúria Renal Aguda/metabolismo , Cisplatino/toxicidade , Acetatos/metabolismo , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/patologia , Animais , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Metabolômica , Modelos Biológicos , Ratos
3.
Biomolecules ; 11(12)2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34944553

RESUMO

Integrases of different retroviruses assemble as functional complexes with varying multimers of the protein. Retroviral integrases require a divalent metal cation to perform one-step transesterification catalysis. Tetrameric prototype foamy virus (PFV) intasomes assembled from purified integrase and viral DNA oligonucleotides were characterized for their activity in the presence of different cations. While most retroviral integrases are inactive in calcium, PFV intasomes appear to be uniquely capable of catalysis in calcium. The PFV intasomes also contrast with other retroviral integrases by displaying an inverse correlation of activity with increasing manganese beginning at relatively low concentrations. The intasomes were found to be significantly more active in the presence of chloride co-ions compared to acetate. While HIV-1 integrase appears to commit to a target DNA within 20 s, PFV intasomes do not commit to target DNA during their reaction lifetime. Together, these data highlight the unique biochemical activities of PFV integrase compared to other retroviral integrases.


Assuntos
DNA/metabolismo , Integrases/química , Integrases/metabolismo , Spumavirus/enzimologia , Acetatos/metabolismo , Sítios de Ligação , Cloretos/metabolismo , Esterificação , Manganês/metabolismo , Oligonucleotídeos , Spumavirus/química , Proteínas Virais/química , Proteínas Virais/metabolismo
4.
Int J Mol Sci ; 22(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34638573

RESUMO

13-lipoxygenases (13-LOX) catalyze the dioxygenation of various polyunsaturated fatty acids (PUFAs), of which α-linolenic acid (LeA) is converted to 13-S-hydroperoxyoctadeca-9, 11, 15-trienoic acid (13-HPOT), the precursor for the prostaglandin-like plant hormones cis-(+)-12-oxophytodienoic acid (12-OPDA) and methyl jasmonate (MJ). This study aimed for characterizing the four annotated A. thaliana 13-LOX enzymes (LOX2, LOX3, LOX4, and LOX6) focusing on synthesis of 12-OPDA and 4Z,7Z,10Z)-12-[[-(1S,5S)-4-oxo-5-(2Z)-pent-2-en-1yl] cyclopent-2-en-1yl] dodeca-4,7,10-trienoic acid (OCPD). In addition, we performed interaction studies of 13-LOXs with ions and molecules to advance our understanding of 13-LOX. Cell imaging indicated plastid targeting of fluorescent proteins fused to 13-LOXs-N-terminal extensions, supporting the prediction of 13-LOX localization to plastids. The apparent maximal velocity (Vmax app) values for LOX-catalyzed LeA oxidation were highest for LOX4 (128 nmol·s-1·mg protein-1), with a Km value of 5.8 µM. A. thaliana 13-LOXs, in cascade with 12-OPDA pathway enzymes, synthesized 12-OPDA and OCPD from LeA and docosahexaenoic acid, previously shown only for LOX6. The activities of the four isoforms were differently affected by physiologically relevant chemicals, such as Mg2+, Ca2+, Cu2+ and Cd2+, and by 12-OPDA and MJ. As demonstrated for LOX4, 12-OPDA inhibited enzymatic LeA hydroperoxidation, with half-maximal enzyme inhibition at 48 µM. Biochemical interactions, such as the sensitivity of LOX toward thiol-reactive agents belonging to cyclopentenone prostaglandins, are suggested to occur in human LOX homologs. Furthermore, we conclude that 13-LOXs are isoforms with rather specific functional and regulatory enzymatic features.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Lipoxigenase/metabolismo , Acetatos/metabolismo , Sequência de Aminoácidos , Ciclopentanos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Ácidos Linoleicos/metabolismo , Oxilipinas/metabolismo
5.
BMC Plant Biol ; 21(1): 450, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615468

RESUMO

BACKGROUND: Methyl jasmonate (MeJA), which has been identified as a lipid-derived stress hormone, mediates plant resistance to biotic/abiotic stress. Understanding MeJA-induced plant defense provides insight into how they responding to environmental stimuli. RESULT: In this work, the dynamic network analysis method was used to quantitatively identify the tipping point of growth-to-defense transition and detect the associated genes. As a result, 146 genes were detected as dynamic network biomarker (DNB) members and the critical defense transition was identified based on dense time-series RNA-seq data of MeJA-treated Arabidopsis thaliana. The GO functional analysis showed that these DNB genes were significantly enriched in defense terms. The network analysis between DNB genes and differentially expressed genes showed that the hub genes including SYP121, SYP122, WRKY33 and MPK11 play a vital role in plant growth-to-defense transition. CONCLUSIONS: Based on the dynamic network analysis of MeJA-induced plant resistance, we provide an important guideline for understanding the growth-to-defense transition of plants' response to environment stimuli. This study also provides a database with the key genes of plant defense induced by MeJA.


Assuntos
Acetatos/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Estudo de Associação Genômica Ampla
6.
Biochemistry ; 60(37): 2773-2780, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34469142

RESUMO

The prevailing opinion is that prefibrillar ß-amyloid (Aß) species, rather than end-stage amyloid fibrils, cause neuronal dysfunction in Alzheimer's disease, although the mechanisms behind Aß neurotoxicity remain to be elucidated. Luminescent conjugated oligothiophenes (LCOs) exhibit spectral properties upon binding to amyloid proteins and have previously been reported to change the toxicity of Aß1-42 and prion protein. In a previous study, we showed that an LCO, pentamer formyl thiophene acetic acid (p-FTAA), changed the toxicity of Aß1-42. Here we investigated whether an LCO, heptamer formyl thiophene acetic acid (h-FTAA), could change the toxicity of Aß1-42 by comparing its behavior with that of p-FTAA. Moreover, we investigated the effects on toxicity when Aß with the Arctic mutation (AßArc) was aggregated with both LCOs. Cell viability assays on SH-SY5Y neuroblastoma cells demonstrated that h-FTAA has a stronger impact on Aß1-42 toxicity than does p-FTAA. Interestingly, h-FTAA, but not p-FTAA, rescued the AßArc-mediated toxicity. Aggregation kinetics and binding assay experiments with Aß1-42 and AßArc when aggregated with both LCOs showed that h-FTAA and p-FTAA either interact with different species or affect the aggregation in different ways. In conclusion, h-FTAA protects against Aß1-42 and AßArc toxicity, thus showing h-FTAA to be a useful tool for improving our understanding of the process of Aß aggregation linked to cytotoxicity.


Assuntos
Acetatos/química , Precursor de Proteína beta-Amiloide/metabolismo , Tiofenos/química , Acetatos/metabolismo , Amiloide/química , Peptídeos beta-Amiloides/química , Precursor de Proteína beta-Amiloide/fisiologia , Precursor de Proteína beta-Amiloide/toxicidade , Proteínas Amiloidogênicas/química , Corantes Fluorescentes/química , Humanos , Cinética , Luminescência , Fragmentos de Peptídeos/metabolismo , Agregados Proteicos/efeitos dos fármacos , Agregados Proteicos/fisiologia , Coloração e Rotulagem/métodos , Tiofenos/metabolismo
7.
Molecules ; 26(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34500623

RESUMO

Lignans are the main secondary metabolites synthetized by Linum species as plant defense molecules. They are also valuable for human health, in particular, for their potent antiviral and antineoplastic properties. In this study, the adventitious root cultures of three Linum species (L. flavum, L. mucronatum and L. dolomiticum) were developed to produce aryltetralin lignans. The effect of two elicitors, methyl jasmonate and coronatine, on aryltetralin lignans production was also evaluated. The adventitious root cultures from L. dolomiticum were obtained and analyzed for the first time and resulted as the best producer for all the aryltetralins highlighted in this system: Podophyllotoxin, 6-methoxypodophyllotoxin and 6-methoxypodophyllotoxin-7-O-ß-glucoside, the last showing a productivity of 92.6 mg/g DW. The two elicitors differently affected the production of the 6-methoxypodophyllotoxin and 6-methoxypodophyllotoxin-7-O-ß-glucoside.


Assuntos
Linho/metabolismo , Lignanas/biossíntese , Raízes de Plantas/metabolismo , Acetatos/metabolismo , Aminoácidos/biossíntese , Ciclopentanos/metabolismo , Indenos , Oxilipinas/metabolismo , Podofilotoxina/análogos & derivados , Podofilotoxina/biossíntese
8.
Molecules ; 26(18)2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34577094

RESUMO

Among rare earth elements, cerium has the unique ability of regulating the growth of plant cells and the biosynthesis of metabolites at different stages of plant development. The signal pathways of Ce3+-mediated ginsenosides biosynthesis in ginseng hairy roots were investigated. At a low concentration, Ce3+ improved the elongation and biomass of hairy roots. The Ce3+-induced accumulation of ginsenosides showed a high correlation with the reactive oxygen species (ROS), as well as the biosynthesis of endogenous methyl jasmonate (MeJA) and ginsenoside key enzyme genes (PgSS, PgSE and PgDDS). At a Ce3+ concentration of 20 mg L-1, the total ginsenoside content was 1.7-fold, and the total ginsenosides yield was 2.7-fold that of the control. Malondialdehyde (MDA) content and the ROS production rate were significantly higher than those of the control. The activity of superoxide dismutase (SOD) was significantly activated within the Ce3+ concentration range of 10 to 30 mg L-1. The activity of catalase (CAT) and peroxidase (POD) strengthened with the increasing concentration of Ce3+ in the range of 20-40 mg L-1. The Ce3+ exposure induced transient production of superoxide anion (O2•-) and hydrogen peroxide (H2O2). Together with the increase in the intracellular MeJA level and enzyme activity for lipoxygenase (LOX), there was an increase in the gene expression level of MeJA biosynthesis including PgLOX, PgAOS and PgJMT. Our results also revealed that Ce3+ did not directly influence PgSS, PgSE and PgDDS activity. We speculated that Ce3+-induced ROS production could enhance the accumulation of ginsenosides in ginseng hairy roots via the direct stimulation of enzyme genes for MeJA biosynthesis. This study demonstrates a potential approach for understanding and improving ginsenoside biosynthesis that is regulated by Ce3+-mediated signal transduction.


Assuntos
Acetatos/metabolismo , Cério/farmacologia , Ciclopentanos/metabolismo , Ginsenosídeos/biossíntese , Oxilipinas/metabolismo , Panax/química , Panax/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Ginsenosídeos/análise , Panax/efeitos dos fármacos , Panax/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
Nat Commun ; 12(1): 4798, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376656

RESUMO

We describe the anaerobic conversion of inositol stereoisomers to propionate and acetate by the abundant intestinal genus Anaerostipes. A inositol pathway was elucidated by nuclear magnetic resonance using [13C]-inositols, mass spectrometry and proteogenomic analyses in A. rhamnosivorans, identifying 3-oxoacid CoA transferase as a key enzyme involved in both 3-oxopropionyl-CoA and propionate formation. This pathway also allowed conversion of phytate-derived inositol into propionate as shown with [13C]-phytate in fecal samples amended with A. rhamnosivorans. Metabolic and (meta)genomic analyses explained the adaptation of Anaerostipes spp. to inositol-containing substrates and identified a propionate-production gene cluster to be inversely associated with metabolic biomarkers in (pre)diabetes cohorts. Co-administration of myo-inositol with live A. rhamnosivorans in western-diet fed mice reduced fasting-glucose levels comparing to heat-killed A. rhamnosivorans after 6-weeks treatment. Altogether, these data suggest a potential beneficial role for intestinal Anaerostipes spp. in promoting host health.


Assuntos
Acetatos/metabolismo , Clostridiales/metabolismo , Inositol/metabolismo , Intestinos/química , Propionatos/metabolismo , Animais , Clostridiales/classificação , Clostridiales/fisiologia , Dieta , Fezes/microbiologia , Interações entre Hospedeiro e Microrganismos , Humanos , Intestinos/microbiologia , Espectroscopia de Ressonância Magnética/métodos , Masculino , Camundongos Endogâmicos C57BL , Ácido Fítico/metabolismo , Espectrometria de Massas em Tandem/métodos
10.
Vet Microbiol ; 261: 109187, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34399296

RESUMO

Chicken colibacillosis is caused by avian pathogenic Escherichia coli (APEC), and results in huge economic losses to the poultry industry. With the investigation of the gut-lung axis, more studies have demonstrated the important role of gut microbiota in lung inflammation. The precise role of the gut microbiota in chickens-associated colibacillosis, however, is unknown. Thus, this study assessed the function of the gut microbiota in the chicken defense against APEC infection. Chicken gut microbiota was depleted by drinking water with a mixture of antibiotics (Abx), and subsequently, a model of colibacillosis was established by the intranasal perfusion of APEC. The results showed that gut microbiota protects the chicken challenge by APEC from aggravated lung histopathologic injury, up-regulated pro-inflammatory cytokine production, and increased bacterial load in lung tissues compared with controls. In addition, the air-blood barrier permeability was significantly increased in gut microbiota-depleted chickens compared to the control chickens after challenge with APEC. Furthermore, feeding acetate significantly inhibited the lung inflammatory response and the reduced air-blood permeability induced by APEC infection. The expression of free fatty acid receptor 2 (FFAR2), a receptor for acetate, was also increased in the lung after treatment with acetate. In conclusion, depletion of the gut microbiota resulted in increased susceptibility of chickens to APEC challenge, and gut microbiota derived acetate acted as a protective mediator during the APEC challenge. Novel therapeutic targets that focus on the gut microbiota may be effective in controlling colibacillosis in poultry.


Assuntos
Acetatos/metabolismo , Antibiose/fisiologia , Infecções por Escherichia coli/veterinária , Microbioma Gastrointestinal/fisiologia , Doenças das Aves Domésticas/microbiologia , Animais , Galinhas , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle
11.
Commun Biol ; 4(1): 928, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34330996

RESUMO

Bacterial sepsis is a major cause of mortality resulting from inadequate immune responses to systemic infection. Effective immunomodulatory approaches are urgently needed but it has remained elusive, which targets might be suitable for intervention. Increased expression of the G-protein-coupled receptor GPR43, which is known to govern intestinal responses to acetate, has been associated with sepsis patient survival but the mechanisms behind this observation have remained unclear. We show that elevated serum acetate concentrations prime neutrophils in a GPR43-dependent fashion, leading to enhanced neutrophil chemotaxis, oxidative burst, cytokine release and upregulation of phagocytic receptors. Consequently, acetate priming improved the capacity of human neutrophils to eliminate methicillin-resistant Staphylococcus aureus. Acetate administration increased mouse serum acetate concentrations and primed neutrophils. Notably, it rescued wild-type mice from severe S. aureus sepsis and reduced bacterial numbers in peripheral organs by several magnitudes. Acetate treatment improved the sepsis course even when applied several hours after onset of the infection, which recommends GPR43 as a potential target for sepsis therapy. Our study indicates that the severity of sepsis depends on transient neutrophil priming by appropriate blood acetate concentrations. Therapeutic interventions based on GPR43 stimulation could become valuable strategies for reducing sepsis-associated morbidity and mortality.


Assuntos
Acetatos/metabolismo , Staphylococcus aureus Resistente à Meticilina/fisiologia , Neutrófilos/imunologia , Receptores Acoplados a Proteínas G/genética , Sepse/imunologia , Infecções Estafilocócicas/imunologia , Receptores Acoplados a Proteínas G/imunologia , Sepse/genética , Infecções Estafilocócicas/genética
12.
Nat Commun ; 12(1): 4368, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272383

RESUMO

Bioproduction of renewable chemicals is considered as an urgent solution for fossil energy crisis. However, despite tremendous efforts, it is still challenging to generate microbial strains that can produce target biochemical to high levels. Here, we report an example of biosynthesis of high-value and easy-recoverable derivatives built upon natural microbial pathways, leading to improvement in bioproduction efficiency. By leveraging pathways in solventogenic clostridia for co-producing acyl-CoAs, acids and alcohols as precursors, through rational screening for host strains and enzymes, systematic metabolic engineering-including elimination of putative prophages, we develop strains that can produce 20.3 g/L butyl acetate and 1.6 g/L butyl butyrate. Techno-economic analysis results suggest the economic competitiveness of our developed bioprocess. Our principles of selecting the most appropriate host for specific bioproduction and engineering microbial chassis to produce high-value and easy-separable end products may be applicable to other bioprocesses.


Assuntos
Acetatos/metabolismo , Butiratos/química , Clostridium/metabolismo , Ácidos Graxos/metabolismo , Fermentação/genética , Engenharia Metabólica/métodos , Acetilcoenzima A/metabolismo , Biocombustíveis/microbiologia , Biomassa , Clostridium/enzimologia , Clostridium/genética , Ésteres/metabolismo , Redes e Vias Metabólicas/genética , NAD/metabolismo , Proteínas/genética , Proteínas/metabolismo , Proteínas Recombinantes
13.
Molecules ; 26(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34299465

RESUMO

Lytic transglycosylases such as Slt35 from E. coli are enzymes involved in bacterial cell wall remodelling and recycling, which represent potential targets for novel antibacterial agents. Here, we investigated a series of known glycosidase inhibitors for their ability to inhibit Slt35. While glycosidase inhibitors such as 1-deoxynojirimycin, castanospermine, thiamet G and miglitol had no effect, the phenothiazinium dye thionine acetate was found to be a weak inhibitor. IC50 values and binding constants for thionine acetate were similar for Slt35 and the hen egg white lysozyme. Molecular docking simulations suggest that thionine binds to the active site of both Slt35 and lysozyme, although it does not make direct interactions with the side-chain of the catalytic Asp and Glu residues as might be expected based on other inhibitors. Thionine acetate also increased the potency of the beta-lactam antibiotic ampicillin against a laboratory strain of E. coli.


Assuntos
Glicosiltransferases/metabolismo , Fenotiazinas/farmacologia , Acetatos/metabolismo , Sequência de Aminoácidos/genética , Proteínas de Bactérias/química , Sítios de Ligação/genética , Domínio Catalítico/genética , Parede Celular/metabolismo , Cristalografia por Raios X/métodos , Escherichia coli/metabolismo , Proteínas de Escherichia coli/efeitos dos fármacos , Proteínas de Escherichia coli/metabolismo , Glicosiltransferases/antagonistas & inibidores , Glicosiltransferases/efeitos dos fármacos , Modelos Moleculares , Simulação de Acoplamento Molecular , Muramidase/antagonistas & inibidores , Muramidase/metabolismo , Peptidoglicano/metabolismo , Fenotiazinas/metabolismo , Conformação Proteica/efeitos dos fármacos
14.
NPJ Biofilms Microbiomes ; 7(1): 47, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-34059681

RESUMO

Maintaining functional stability of microbial electrolysis cell (MEC) treating wastewater depends on maintaining functional redundancy of efficient electroactive bacteria (EAB) on the anode biofilm. Therefore, investigating whether efficient EAB competing for the same resources (electron donor and acceptor) co-exist at the anode biofilm is key for the successful application of MEC for wastewater treatment. Here, we compare the electrochemical and kinetic properties of two efficient acetoclastic EAB, Geobacter sulfurreducens (GS) and Desulfuromonas acetexigens (DA), grown as monoculture in MECs fed with acetate. Additionally, we monitor the evolution of DA and GS in co-culture MECs fed with acetate or domestic wastewater using fluorescent in situ hybridization. The apparent Monod kinetic parameters reveal that DA possesses higher jmax (10.7 ± 0.4 A/m2) and lower KS, app (2 ± 0.15 mM) compared to GS biofilms (jmax: 9.6 ± 0.2 A/m2 and KS, app: 2.9 ± 0.2 mM). Further, more donor electrons are diverted to the anode for respiration in DA compared to GS. In acetate-fed co-culture MECs, DA (98% abundance) outcompete GS for anode-dependent growth. In contrast, both EAB co-exist (DA: 55 ± 2%; GS: 24 ± 1.1%) in wastewater-fed co-culture MECs despite the advantage of DA over GS based on kinetic parameters alone. The co-existence of efficient acetoclastic EAB with high current density in MECs fed with wastewater is significant in the context of functional redundancy to maintain stable performance. Our findings also provide insight to future studies on bioaugmentation of wastewater-fed MECs with efficient EAB to enhance performance.


Assuntos
Acetatos/metabolismo , Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Fenômenos Eletrofisiológicos , Bactérias/crescimento & desenvolvimento , Bactérias/ultraestrutura , Águas Residuárias/microbiologia , Microbiologia da Água
15.
Benef Microbes ; 12(3): 267-281, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34109894

RESUMO

Regulation on gut microbiota and short-chain fatty acids (SCFAs) are believed to be a pathway to suppress the development of metabolic syndrome. In this study, three Lactobacillus strains derived from the human gut were investigated for their effects on alleviation of metabolic disorders. These strains were individually administered to metabolic disorder rats induced by high-fat-high-sucrose (HFHS) diet. Each strain exhibited its own characteristics in attenuating the impaired glucose-insulin homeostasis, hepatic oxidative damage and steatosis. Correlation analysis between SCFAs and host metabolic parameters suggested that Lactobacillus protective effects on metabolic disorders are partly mediated by recovery of SCFAs production, especially the faecal acetic acid. Correspondingly, it indicated that probiotics restore the gut microbiota dysbiosis in different extent, thereby protect against metabolic disorders in a manner that is associated with microbiota, but not totally reverse the changed composition of microbiota to the normal state. Thus, Lactobacillus strains partly protect against diet-induced metabolic syndrome by microbiota modulation and acetate elevation.


Assuntos
Ácidos Graxos Voláteis/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Lactobacillus/fisiologia , Doenças Metabólicas/terapia , Probióticos/uso terapêutico , Acetatos/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Fezes/química , Fezes/microbiologia , Microbioma Gastrointestinal/genética , Humanos , Lactobacillus/isolamento & purificação , Metabolismo dos Lipídeos/efeitos dos fármacos , Doenças Metabólicas/etiologia , Doenças Metabólicas/metabolismo , Doenças Metabólicas/microbiologia , Estresse Oxidativo/efeitos dos fármacos , Probióticos/farmacologia , Ratos
16.
Nat Metab ; 3(6): 859-875, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34140692

RESUMO

Global histone acetylation varies with changes in the nutrient and cell cycle phases; however, the mechanisms connecting these variations are not fully understood. Herein, we report that nutrient-related and cell-cycle-regulated nuclear acetate regulates global histone acetylation. Histone deacetylation-generated acetate accumulates in the nucleus and induces histone hyperacetylation. The nuclear acetate levels were controlled by glycolytic enzyme triosephosphate isomerase 1 (TPI1). Cyclin-dependent kinase 2 (CDK2), which is phosphorylated and activated by nutrient-activated mTORC1, phosphorylates TPI1 Ser 117 and promotes nuclear translocation of TPI1, decreases nuclear dihydroxyacetone phosphate (DHAP) and induces nuclear acetate accumulation because DHAP scavenges acetate via the formation of 1-acetyl-DHAP. CDK2 accumulates in the cytosol during the late G1/S phases. Inactivation or blockade of nuclear translocation of TPI1 abrogates nutrient-dependent and cell-cycle-dependent global histone acetylation, chromatin condensation, gene transcription and DNA replication. These results identify the mechanism of maintaining global histone acetylation by nutrient and cell cycle signals.


Assuntos
Ciclo Celular/fisiologia , Núcleo Celular/metabolismo , Fosfato de Di-Hidroxiacetona/metabolismo , Histonas/metabolismo , Nutrientes/metabolismo , Transdução de Sinais , Acetatos/metabolismo , Acetilação , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Replicação do DNA , Humanos , Fosforilação , Transcrição Genética
17.
Plant Sci ; 309: 110952, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34134848

RESUMO

Linalool is an aromatic monoterpene produced in the Chinese medicinal plant Dendrobium officinale, but little information is available on the regulation of linalool biosynthesis. Here, a novel basic helix-loop-helix (bHLH) transcription factor, DobHLH4 from D. officinale, was identified and functionally characterized. The expression profile of DobHLH4 was positively correlated with that of DoTPS10 (R2 = 0.985, p < 0.01), which encodes linalool synthase that is responsible for linalool production, during floral development. DobHLH4 was highly expressed in petals, and was significantly induced by methyl jasmonate. Analysis of subcellular localization showed that DobHLH4 was located in the nucleus. Yeast one-hybrid and dual-luciferase assays indicated that DobHLH4 bound directly to the DoTPS10 promoter harboring the G-box element, and up-regulated DoTPS10 expression. A yeast two-hybrid screen confirmed that DobHLH4 physically interacted with DoJAZ1, suggesting that DobHLH4 might function in the jasmonic acid-mediated accumulation of linalool. Furthermore, transient overexpression of DobHLH4 in D. officinale petals significantly increased linalool production by triggering linalool biosynthetic pathway genes, especially DoTPS10. We suggest a hypothetical model that depicts how jasmonic acid signaling may regulate DoTPS10 by interacting with DobHLH4 and DoJAZ1. In doing so, the formation of linalool is controlled. Our results indicate that DobHLH4 is a positive regulator of linalool biosynthesis and may be a promising target for in vitro-based metabolic engineering to produce linalool.


Assuntos
Acetatos/metabolismo , Monoterpenos Acíclicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Ciclopentanos/metabolismo , Dendrobium/genética , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Vias Biossintéticas , Dendrobium/química , Dendrobium/metabolismo , Flores/química , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Óleos Voláteis/metabolismo , Óleos Vegetais/metabolismo , Proteínas de Plantas/genética
18.
Gene ; 795: 145781, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34153410

RESUMO

The Bifidobacterium longum 51A strain of isolated from feces of a healthy child, has demonstrated probiotic properties by in vivo and in vitro studies, which may be assigned to its production of metabolites such as acetate. Thus, through the study of comparative genomics, the present work sought to identify unique genes that might be related to the production of acetate. To perform the study, the DNA strain was sequenced using Illumina HiSeq technology, followed by assembly and manual curation of coding sequences. Comparative analysis was performed including 19 complete B. longum genomes available in Genbank/NCBI. In the phylogenetic analysis, the CECT 7210 and 157F strains of B. longum subsp. infantis aggregated within the subsp. longum cluster, suggesting that their taxonomic classification should be reviewed. The strain 51A of B. longum has 26 unique genes, six of which are possibly related to carbohydrate metabolism and acetate production. The phosphoketolase pathway from B. longum 51A showed a difference in acetyl-phosphate production. This result seems to corroborate the analysis of their unique genes, whose presence suggests the strain may use different sources of carbohydrates that allow a greater production of acetate and consequently offer benefits to the host health.


Assuntos
Acetatos/metabolismo , Bifidobacterium longum/genética , Bifidobacterium longum/metabolismo , Metabolismo dos Carboidratos/genética , Genes Bacterianos , Probióticos/metabolismo , Sequência de Bases , Bifidobacterium longum/classificação , Criança , Simulação por Computador , Fezes/microbiologia , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Filogenia , Análise de Sequência de DNA
19.
World J Microbiol Biotechnol ; 37(7): 125, 2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34173085

RESUMO

Ethyl-acetate is important for the flavor and aroma of the alcoholic beverages, therefore, there have been extensive efforts toward increasing its production by engineering yeast strains. In this study, we reported a new approach to breed non-genetic modified producing yeast strain with higher ethyl-acetate production for beer brewing. First, we demonstrated the positive effect of higher acetic acid concentration on inducing the expression of acetyl-CoA synthetase (ACS). Then, we applied adaptive laboratory evolution method to evolve strain with higher expression level of ACS. As a result, we obtained several evolved strains with increased ACS expression level as well as ethyl-acetate production. In 3 L scale fermentation, the optimal strain EA60 synthesized more ethyl-acetate than M14 at the same time point. At the end of fermentation, the ethyl-acetate production in EA60 was 21.4% higher than M14, while the other flavor components except for acetic acid were changed in a moderate degree, indicating this strain had a bright prospect in industrial application. Moreover, this study also indicated that ACS1 played a more important role in increasing the acetic acid tolerance of yeast, while ACS2 contributed to the synthesis of cytosol acetyl-CoA, thereby facilitating the production of ethyl-acetate during fermentation.


Assuntos
Acetatos/metabolismo , Ácido Acético/metabolismo , Bebidas Alcoólicas/microbiologia , Coenzima A Ligases/metabolismo , Saccharomyces/metabolismo , Adaptação Biológica , Cerveja/microbiologia , Evolução Molecular Direcionada/métodos , Fermentação , Aromatizantes/metabolismo , Microbiologia Industrial/métodos , Laboratórios , Engenharia Metabólica , RNA Fúngico , Reação em Cadeia da Polimerase em Tempo Real , Saccharomyces/genética
20.
FEBS Lett ; 595(15): 2047-2056, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34125966

RESUMO

Acetate overflow refers to the metabolism by which a large part of carbon incorporated as glucose into Escherichia coli cells is catabolized and excreted as acetate into the medium. We previously found that mutants for the acetate overflow pathway enzymes phosphoacetyltransferase (Pta) and acetate kinase (AckA) showed significant diauxic growth after glucose depletion in E. coli. Here, we analyzed the underlying mechanism in the pta mutant. Proteomic and other analyses revealed an increase in pyruvate dehydrogenase complex subunits and a decrease in glyoxylate shunt enzymes, which resulted from pyruvate accumulation. Since restoration of these enzyme levels by overexpressing PdhR (pyruvate-sensing transcription factor) or deleting iclR (gene encoding a pyruvate- and glyoxylate-sensing transcription factor) alleviated the growth lag of the pta mutant after glucose depletion, these changes were considered as the reason for the phenotype. Given the evidence for decreased coenzyme A (HS-CoA) levels in the pta mutant, the growth inhibition after glucose depletion was partly explained by limited availability of HS-CoA in the cell. The findings provide insights into the role of acetate overflow in metabolic regulation, which may be useful for biotechnological applications.


Assuntos
Acetatos/metabolismo , Escherichia coli/metabolismo , Glucose/metabolismo , Escherichia coli/crescimento & desenvolvimento , Proteômica
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