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1.
Int J Food Microbiol ; 337: 108951, 2021 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-33202299

RESUMO

Pit mud microbiota plays a key role in flavour production for Chinese strong-aroma type liquor. However, the pit mud microbiota cannot be cultured in laboratory. In this study, an oligotrophic medium with acetate as carbon source was used to enrich pit mud microbiota. The 16S rRNA gene amplicon sequencing was applied to examine the microbial dynamics of the enrichment consortia. Both methanogens and bacteria were simultaneously enriched. Euryarchaeota, Bacteroidetes and Firmicutes were the top 3 enriched phyla, and 31 genera were successfully enriched. More specifically, 11 genera (65%) out of the 17 dominant genera in pit mud were successfully enriched, including Petrimonas, Proteiniphilum, Anaerocella, Hydrogenispora, Methanosarcina, Fermentimonas, LNR_A2-18, Sedimentibacter, Lutispora, Syntrophomonas and Aminobacterium. Furthermore, 20 rare genera in the analyzed pit mud samples were also enriched. Aceticlastic Methanosaeta and Methanosarcina were found to be dominant methanogens in the enrichment consortia. Metagenomic sequencing was then applied to the enriched microbial consortia to explore the metabolic potentials of pit mud microbes. Aceticlastic methanogenesis pathway of Methanosaeta was reconstructed. Furthermore, 26 high-quality metagenome-assembled genomes (MAGs) were obtained based on the metagenomic binning analysis. Moreover, nutrients in pit mud were found to be crucial to sustain the methanogenesis of the enriched microbial consortia. These results suggested that the enrichment approach by using oligotrophic culturing can effectively cultivate the pit mud microbiota. Combined with metagenomics, the oligotrophic culturing will be greatly helpful to decipher the community composition and metabolic potentials of pit mud microbiota.


Assuntos
Bebidas Alcoólicas/microbiologia , Microbiota , Acetatos/análise , Acetatos/metabolismo , Archaea/classificação , Archaea/genética , Archaea/isolamento & purificação , Archaea/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , China , Meios de Cultura/química , Fermentação , Humanos , Microbiota/genética , RNA Ribossômico 16S/genética
2.
Nat Commun ; 11(1): 6191, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33273474

RESUMO

In plants, light-dependent activation of de novo fatty acid synthesis (FAS) is partially mediated by acetyl-CoA carboxylase (ACCase), the first committed step for this pathway. However, it is not fully understood how plants control light-dependent FAS regulation to meet the cellular demand for acyl chains. We report here the identification of a gene family encoding for three small plastidial proteins of the envelope membrane that interact with the α-carboxyltransferase (α-CT) subunit of ACCase and participate in an original mechanism restraining FAS in the light. Light enhances the interaction between carboxyltransferase interactors (CTIs) and α-CT, which in turn attenuates carbon flux into FAS. Knockouts for CTI exhibit higher rates of FAS and marked increase in absolute triacylglycerol levels in leaves, more than 4-fold higher than in wild-type plants. Furthermore, WRINKLED1, a master transcriptional regulator of FAS, positively regulates CTI1 expression by direct binding to its promoter. This study reveals that in addition to light-dependent activation, "envelope docking" of ACCase permits fine-tuning of fatty acid supply during the plant life cycle.


Assuntos
Acetil-CoA Carboxilase/metabolismo , Arabidopsis/metabolismo , Ácidos Graxos/biossíntese , Membranas Intracelulares/metabolismo , Acetatos/metabolismo , Acetil-CoA Carboxilase/química , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Radioisótopos de Carbono , Regulação da Expressão Gênica no Desenvolvimento , Luz , Simulação de Acoplamento Molecular , Plastídeos/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Domínios Proteicos , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Protoplastos/metabolismo
3.
Science ; 370(6521): 1230-1234, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33273103

RESUMO

Microorganisms in marine subsurface sediments substantially contribute to global biomass. Sediments warmer than 40°C account for roughly half the marine sediment volume, but the processes mediated by microbial populations in these hard-to-access environments are poorly understood. We investigated microbial life in up to 1.2-kilometer-deep and up to 120°C hot sediments in the Nankai Trough subduction zone. Above 45°C, concentrations of vegetative cells drop two orders of magnitude and endospores become more than 6000 times more abundant than vegetative cells. Methane is biologically produced and oxidized until sediments reach 80° to 85°C. In 100° to 120°C sediments, isotopic evidence and increased cell concentrations demonstrate the activity of acetate-degrading hyperthermophiles. Above 45°C, populated zones alternate with zones up to 192 meters thick where microbes were undetectable.


Assuntos
Bactérias Formadoras de Endosporo/crescimento & desenvolvimento , Sedimentos Geológicos/microbiologia , Temperatura Alta , Acetatos/metabolismo , Bactérias Formadoras de Endosporo/metabolismo , Sedimentos Geológicos/química , Metano/metabolismo
4.
PLoS Biol ; 18(11): e3000981, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33253182

RESUMO

The metabolite acetyl-coenzyme A (acetyl-CoA) serves as an essential element for a wide range of cellular functions including adenosine triphosphate (ATP) production, lipid synthesis, and protein acetylation. Intracellular acetyl-CoA concentrations are associated with nutrient availability, but the mechanisms by which a cell responds to fluctuations in acetyl-CoA levels remain elusive. Here, we generate a cell system to selectively manipulate the nucleo-cytoplasmic levels of acetyl-CoA using clustered regularly interspaced short palindromic repeat (CRISPR)-mediated gene editing and acetate supplementation of the culture media. Using this system and quantitative omics analyses, we demonstrate that acetyl-CoA depletion alters the integrity of the nucleolus, impairing ribosomal RNA synthesis and evoking the ribosomal protein-dependent activation of p53. This nucleolar remodeling appears to be mediated through the class IIa histone deacetylases (HDACs). Our findings highlight acetylation-mediated control of the nucleolus as an important hub linking acetyl-CoA fluctuations to cellular stress responses.


Assuntos
Acetilcoenzima A/biossíntese , Nucléolo Celular/metabolismo , ATP Citrato (pro-S)-Liase/deficiência , ATP Citrato (pro-S)-Liase/genética , ATP Citrato (pro-S)-Liase/metabolismo , Acetatos/metabolismo , Acetilação , Linhagem Celular , Nucléolo Celular/ultraestrutura , Expressão Gênica , Técnicas de Inativação de Genes , Células HCT116 , Histona Desacetilases/metabolismo , Humanos , Modelos Biológicos , Proteínas Nucleares/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Ribossômicas/metabolismo , Proteína Supressora de Tumor p53/metabolismo
5.
Sci Rep ; 10(1): 16314, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004914

RESUMO

Lachancea kluyveri, a weak Crabtree positive yeast, has been extensively studied for its unique URC pyrimidine catabolism pathway. It produces more biomass than Saccharomyces cerevisiae due to the underlying weak Crabtree effect and resorts to fermentation only in oxygen limiting conditions that renders it as a suitable industrial host. The yeast also produces ethyl acetate as a major overflow metabolite in aerobic conditions. Here, we report the first genome-scale metabolic model, iPN730, of L. kluyveri comprising of 1235 reactions, 1179 metabolites, and 730 genes distributed in 8 compartments. The in silico viability in different media conditions and the growth characteristics in various carbon sources show good agreement with experimental data. Dynamic flux balance analysis describes the growth dynamics, substrate utilization and product formation kinetics in various oxygen-limited conditions. We have also demonstrated the effect of switching carbon sources on the production of ethyl acetate under varying oxygen uptake rates. A phenotypic phase plane analysis described the energetic cost penalty of ethyl acetate and ethanol production on the specific growth rate of L. kluyveri. We generated the context specific models of L. kluyveri growing on uracil or ammonium salts as the sole nitrogen source. Differential flux calculated using flux variability analysis helped us in highlighting pathways like purine, histidine, riboflavin and pyrimidine metabolism associated with uracil degradation. The genome-scale metabolic construction of L. kluyveri will provide a better understanding of metabolism behind ethyl acetate production as well as uracil catabolism (pyrimidine degradation) pathway. iPN730 is an addition to genome-scale metabolic models of non-conventional yeasts that will facilitate system-wide omics analysis to understand fungal metabolic diversity.


Assuntos
Genoma Fúngico/genética , Saccharomycetales/genética , Acetatos/metabolismo , Simulação por Computador , Metabolismo Energético , Etanol/metabolismo , Genes Fúngicos/genética , Redes e Vias Metabólicas/genética , Modelos Biológicos , Saccharomycetales/crescimento & desenvolvimento , Saccharomycetales/metabolismo
6.
Science ; 370(6514): 364-368, 2020 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-33060364

RESUMO

The heart consumes circulating nutrients to fuel lifelong contraction, but a comprehensive mapping of human cardiac fuel use is lacking. We used metabolomics on blood from artery, coronary sinus, and femoral vein in 110 patients with or without heart failure to quantify the uptake and release of 277 metabolites, including all major nutrients, by the human heart and leg. The heart primarily consumed fatty acids and, unexpectedly, little glucose; secreted glutamine and other nitrogen-rich amino acids, indicating active protein breakdown, at a rate ~10 times that of the leg; and released intermediates of the tricarboxylic acid cycle, balancing anaplerosis from amino acid breakdown. Both heart and leg consumed ketones, glutamate, and acetate in direct proportionality to circulating levels, indicating that availability is a key driver for consumption of these substrates. The failing heart consumed more ketones and lactate and had higher rates of proteolysis. These data provide a comprehensive and quantitative picture of human cardiac fuel use.


Assuntos
Ácidos Graxos/metabolismo , Insuficiência Cardíaca/metabolismo , Miocárdio/metabolismo , Acetatos/metabolismo , Idoso , Glicemia/metabolismo , Ciclo do Ácido Cítrico , Feminino , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Cetonas/metabolismo , Perna (Membro)/irrigação sanguínea , Masculino , Metabolômica , Pessoa de Meia-Idade , Contração Miocárdica , Proteólise
7.
Int J Food Microbiol ; 333: 108796, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32771820

RESUMO

The objective of this study was to investigate the role of yeasts in the wet fermentation of coffee beans and their contribution to coffee quality using a novel approach. Natamycin (300 ppm) was added to the fermentation mass to suppress yeast growth and their metabolic activities, and the resultant microbial ecology, bean chemistry and sensory quality were analyzed and compared to non-treated spontaneous fermentation we reported previously. The yeast community was dominated by Hanseniaspora uvarum and Pichia kudriavzevii and grew to a maximum population of about 5.5 log CFU/g in the absence of Natamycin, while when Natamycin was added yeasts were suppressed. The major bacterial species in both the spontaneous and yeast-suppressed fermentations included the lactic acid bacteria Leuconostoc mesenteroides and Lactococcus lactis, the acetic acid bacteria Gluconobacter cerinus and Acetobacter persici and the Enterobacteriaceae Enterobacter, Citrobacter and Erwinia. For both fermentations, the mucilage layers were completely degraded by the end of the process and the absence of yeast activities had no significant impact on mucilage degradation. During fermentation, reducing sugars were consumed while lactic acid was accumulated inside the beans, and its concentration was significantly higher in the spontaneous fermentation (3 times) than that where yeasts were suppressed by Natamycin. Glycerol was detected with a concentration of 0.08% in the absence of Natamycin and was not identified when Natamycin was added. Green beans fermented with yeast growth contained a higher amount of isoamyl alcohol (21 times), ethanol (3.7 times), acetaldehyde (8 times), and ethyl acetate (25 times) compared to beans fermented in the absence of yeast activities, which remained higher in the former after roasting. Beans fermented without yeast activities had a mild fruity aroma, and lower sensory scores of fragrances (7.0), flavor (6.5), acidity (6.3), body (7.0) and overall score (6.5) compared to the former. These findings demonstrated the crucial roles of yeasts in wet fermentation of coffee beans and for producing high quality coffee.


Assuntos
Bactérias/metabolismo , Café/metabolismo , Fermentação/fisiologia , Hanseniaspora/metabolismo , Pichia/metabolismo , Leveduras/metabolismo , Acetaldeído/metabolismo , Acetatos/metabolismo , Ácido Acético/metabolismo , Anti-Infecciosos/farmacologia , Bactérias/classificação , Reatores Biológicos/microbiologia , Café/microbiologia , Etanol/metabolismo , Ácido Láctico/metabolismo , Natamicina/farmacologia , Odorantes/análise , Pentanóis/metabolismo , Paladar
8.
Ecotoxicol Environ Saf ; 206: 111140, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32858325

RESUMO

Although the toxicity of triclocarban at molecular level has been investigated, the metabolic networks involved in regulating the stress processes are not clear. Whether the cells would maintain specific phenotypic characteristics after triclocarban stress is also needed to be clarified. In this study, Escherichia coli was selected as a model to elucidate the cellular metabolism response associated with triclocarban stress and the recovery metabolic network of the triclocarban-treated cells using the proteomics and metabolomics approaches. Results showed that triclocarban caused systematic metabolic remodeling. The adaptive pathways, glyoxylate shunt and acetate-switch were activated. These arrangements allowed cells to use more acetyl-CoA and to reduce carbon atom loss. The upregulation of NH3-dependent NAD+ synthetase complemented the NAD+ consumption by catabolism, maintaining the redox balance. The synthesis of 1-deoxy-D-xylulose-5-phosphate was suppressed, which would affect the accumulation of end products of its downstream pathway of isoprenoid synthesis. After recovery culture for 12 h, the state of cells returned to stability and the main impacts on metabolic network triggered by triclocarban have disappeared. However, drug resistance caused by long-term exposure to environmentally relevant concentration of triclocarban is still worthy of attention. The present study revealed the molecular events under triclocarban stress and clarified how triclocarban influence the metabolic networks.


Assuntos
Anti-Infecciosos Locais/toxicidade , Carbanilidas/toxicidade , Escherichia coli/fisiologia , Redes e Vias Metabólicas , Acetatos/metabolismo , Carbono/metabolismo , Glioxilatos , Metabolômica , Proteômica
9.
Nat Commun ; 11(1): 3941, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32770005

RESUMO

Anaerobic oxidation of methane (AOM) mediated by anaerobic methanotrophic archaea (ANME) is the primary process that provides energy to cold seep ecosystems by converting methane into inorganic carbon. Notably, cold seep ecosystems are dominated by highly divergent heterotrophic microorganisms. The role of the AOM process in supporting heterotrophic population remains unknown. We investigate the acetogenic capacity of ANME-2a in a simulated cold seep ecosystem using high-pressure biotechnology, where both AOM activity and acetate production are detected. The production of acetate from methane is confirmed by isotope-labeling experiments. A complete archaeal acetogenesis pathway is identified in the ANME-2a genome, and apparent acetogenic activity of the key enzymes ADP-forming acetate-CoA ligase and acetyl-CoA synthetase is demonstrated. Here, we propose a modified model of carbon cycling in cold seeps: during AOM process, methane can be converted into organic carbon, such as acetate, which further fuels the heterotrophic community in the ecosystem.


Assuntos
Acetatos/metabolismo , Archaea/enzimologia , Proteínas de Bactérias/metabolismo , Coenzima A Ligases/metabolismo , Metano/metabolismo , Anaerobiose , Archaea/genética , Proteínas de Bactérias/genética , Ciclo do Carbono/fisiologia , Coenzima A Ligases/genética , Genoma Arqueal , Sedimentos Geológicos/microbiologia , Redes e Vias Metabólicas/genética , Oxirredução , Água do Mar/microbiologia
10.
Biochim Biophys Acta Bioenerg ; 1861(11): 148283, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32763239

RESUMO

Acetate:succinate CoA transferase (ASCT) is a mitochondrial enzyme that catalyzes the production of acetate and succinyl-CoA, which is coupled to ATP production with succinyl-CoA synthetase (SCS) in a process called the ASCT/SCS cycle. This cycle has been studied in Trypanosoma brucei (T. brucei), a pathogen of African sleeping sickness, and is involved in (i) ATP and (ii) acetate production and proceeds independent of oxygen and an electrochemical gradient. Interestingly, knockout of ASCT in procyclic form (PCF) of T. brucei cause oligomycin A-hypersensitivity phenotype indicating that ASCT/SCS cycle complements the deficiency of ATP synthase activity. In bloodstream form (BSF) of T. brucei, ATP synthase works in reverse to maintain the electrochemical gradient by hydrolyzing ATP. However, no information has been available on the source of ATP, although ASCT/SCS cycle could be a potential candidate. Regarding mitochondrial acetate production, which is essential for fatty acid biosynthesis and growth of T. brucei, ASCT or acetyl-CoA hydrolase (ACH) are known to be its source. Despite the importance of this cycle, direct evidence of its function is lacking, and there are no comprehensive biochemical or structural biology studies reported so far. Here, we show that in vitro-reconstituted ASCT/SCS cycle is highly specific towards acetyl-CoA and has a higher kcat than that of yeast and bacterial ATP synthases. Our results provide the first biochemical basis for (i) rescue of ATP synthase-deficient phenotype by ASCT/SCS cycle in PCF and (ii) a potential source of ATP for the reverse reaction of ATP synthase in BSF.


Assuntos
Acetatos/metabolismo , Trifosfato de Adenosina/metabolismo , Coenzima A-Transferases/metabolismo , Mitocôndrias/metabolismo , Succinato-CoA Ligases/metabolismo , Trypanosoma brucei brucei/metabolismo , Acil Coenzima A/metabolismo , Coenzima A-Transferases/química , Coenzima A-Transferases/genética , Mutação , Fosforilação Oxidativa , Succinato-CoA Ligases/química , Succinato-CoA Ligases/genética , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/crescimento & desenvolvimento
11.
J Chem Ecol ; 46(7): 567-580, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32676764

RESUMO

Two odorant receptors (ORs), OnubOR3 and OnubOR6, in the sex pheromone communication systems of E- and Z-strain European corn borers, Ostrinia nubilalis, were broadly receptive to analogs of their pheromone components. In addition to responding to their natural 14-carbon pheromone components, (Z)-11- and (E)-11-tetradecenyl acetates (Z11- and E11-14:OAc), these pheromone ORs responded to the longer-chain compounds, (Z)-11- and (E)-11-hexadecenyl acetate (Z11- and E11-16:OAc). Z11-16:OAc is a pheromone gland constituent of E-strain O. nubilalis females in Europe but has not previously been shown to have behavioral activity to males. Here, we demonstrate that Z11-16:OAc evokes high levels of upwind flight and source location in E-strain males when substituted for Z11-14:OAc (minor component) in the E-strain blend. Since Z11-16:OAc is found in the gland and has behavioral activity when Z11-14:OAc is missing, then it should be classified as a cryptic, redundant minor pheromone component in E-strain O. nubilalis. The opposite geometric isomer, E11-16:OAc, also functions in Z-strain O. nubilalis, substituting behaviorally for the E11-14:OAc minor component, but has not been found in Z-strain female glands. Single-sensillum recordings showed that sensory neurons of E- and Z-strain male antennae expressing OnubOR3 and OnubOR6 produced responses to these hexadecenyl acetates similar to those evoked by the natural (tetradecenyl acetate) pheromone components. We postulate that the wide responsiveness of these two ORs to the 16-carbon acetates could be a preadaptation for O. nubilalis to use these compounds as minor components in lieu of the respective 14-carbon acetates. Alternatively, the responsiveness of OnubOR3 to E11-16:OAc and OnubOR6 to Z11-16:OAc could represent a vestigial state of these receptors, with the 16-carbon acetates having previously acted as functional minor components in an ancestral blend.


Assuntos
Quimiotaxia , Mariposas/fisiologia , Receptores Odorantes/fisiologia , Atrativos Sexuais/fisiologia , Acetatos/metabolismo , Animais , Ácidos Graxos Monoinsaturados/metabolismo , Masculino , Especificidade da Espécie
12.
Sci Rep ; 10(1): 11845, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678209

RESUMO

Human milk oligosaccharides (HMOs) are a mixture of structurally diverse carbohydrates that contribute to shape a healthy gut microbiota composition. The great diversity of the HMOs structures does not allow the attribution of specific prebiotic characteristics to single milk oligosaccharides. We analyze here the utilization of four disaccharides, lacto-N-biose (LNB), galacto-N-biose (GNB), fucosyl-α1,3-GlcNAc (3FN) and fucosyl-α1,6-GlcNAc (6FN), that form part of HMOs and glycoprotein structures, by the infant fecal microbiota. LNB significantly increased the total levels of bifidobacteria and the species Bifidobacterium breve and Bifidobacterium bifidum. The Lactobacillus genus levels were increased by 3FN fermentation and B. breve by GNB and 3FN. There was a significant reduction of Blautia coccoides group with LNB and 3FN. In addition, 6FN significantly reduced the levels of Enterobacteriaceae family members. Significantly higher concentrations of lactate, formate and acetate were produced in cultures containing either LNB or GNB in comparison with control cultures. Additionally, after fermentation of the oligosaccharides by the fecal microbiota, several Bifidobacterium strains were isolated and identified. The results presented here indicated that each, LNB, GNB and 3FN disaccharide, might have a specific beneficial effect in the infant gut microbiota and they are potential prebiotics for application in infant foods.


Assuntos
Acetilglucosamina/análogos & derivados , Acetilglucosamina/isolamento & purificação , Dissacaridases/isolamento & purificação , Dissacarídeos/isolamento & purificação , Leite Humano/química , Prebióticos/análise , Acetatos/metabolismo , Bifidobacterium bifidum/classificação , Bifidobacterium bifidum/genética , Bifidobacterium bifidum/isolamento & purificação , Bifidobacterium bifidum/metabolismo , Bifidobacterium breve/classificação , Bifidobacterium breve/genética , Bifidobacterium breve/isolamento & purificação , Bifidobacterium breve/metabolismo , Clostridiales/classificação , Clostridiales/genética , Clostridiales/isolamento & purificação , Clostridiales/metabolismo , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Enterobacteriaceae/metabolismo , Fezes/microbiologia , Formiatos/metabolismo , Microbioma Gastrointestinal/fisiologia , Humanos , Lactente , Ácido Láctico/metabolismo , Lactobacillus/classificação , Lactobacillus/genética , Lactobacillus/isolamento & purificação , Lactobacillus/metabolismo
13.
Int J Food Microbiol ; 333: 108792, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32707524

RESUMO

Gamma aminobutyric acid (GABA) is a non-protein amino acid that is widely distributed in nature and its physiological importance goes beyond its role as an inhibitory neurotransmitter of the central nervous system in mammals. Since microbial fermentation is one of the most promising methods to obtain GABA, the production of this metabolite by several strains of lactic acid bacteria isolated from quinoa and amaranth sourdoughs was investigated. Lactobacillus brevis CRL 2013 produced the highest GABA levels, reaching 265 mM when optimal culture conditions were set up. The fermentative profile showed that CRL 2013 was able to catabolize carbohydrates through the phosphoketolase pathway yielding variable amounts of lactic acid, acetate and ethanol, which depended on the type of carbon source available and the presence of external electron acceptors such as fructose. Enhanced growth parameters and low GABA synthesis were associated to pentose fermentation. This impairment on GABA production machinery was partially overpassed by the addition of ethanol to the culture media. These results support the potential use of L. brevis CRL 2013 as a starter culture for the manufacture of GABA-enriched functional foods and provide further insights to the understanding of the GAD system regulation in lactic acid bacteria.


Assuntos
Pão/microbiologia , Metabolismo dos Carboidratos/fisiologia , Fermentação/fisiologia , Lactobacillus brevis/metabolismo , Ácido gama-Aminobutírico/biossíntese , Acetatos/metabolismo , Amaranthus/microbiologia , Carboidratos , Chenopodium quinoa/microbiologia , Meios de Cultura/metabolismo , Etanol/metabolismo , Ácido Láctico/metabolismo
14.
PLoS One ; 15(7): e0235795, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645115

RESUMO

To investigate the growth, physiological changes and mechanism of drought resistance of Camellia oleifera GWu-2 under drought stress conditions, changes in the main growth and physiological indices of GWu-2 under different water gradients were studied. Factor analysis was used to study the differences between indicators under different water gradients, and correlation analysis was implemented to analyze the relationship between different factors. We observed that the growth state, enzyme secretion, stomatal morphology and leaf osmotic adjustment substances were significantly affected by drought stress. In particular, increases in leaf abscisic acid (ABA), indole acetic acid (IAA) and methyl jasmonate (MeJA) contents under drought stress were negatively correlated with the stomatal opening degree, and the ratio of ZR/GA3 was significantly correlated with the growth and physiological indicators of GWu-2, indicating that different hormones respond differently to drought stress and have different functions in the growth regulation and drought resistance of GWu-2. We concluded that the drought resistance mechanism of GWu-2 was controlled by maintaining root growth to obtain the necessary water, increasing the contents of osmotic substances of leaves to maintain water holding capacity, reducing the transpiration of water by increasing leaf ABA, IAA and MeJA content to close stomata and reducing the damage caused by drought by increasing the activity of superoxide dismutase (SOD).


Assuntos
Aclimatação , Camellia/fisiologia , Ácido Abscísico/metabolismo , Acetatos/metabolismo , Camellia/crescimento & desenvolvimento , Ciclopentanos/metabolismo , Secas , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Estômatos de Plantas/crescimento & desenvolvimento , Estômatos de Plantas/fisiologia , Estresse Fisiológico , Água/metabolismo
15.
Environ Sci Pollut Res Int ; 27(34): 43028-43043, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32725563

RESUMO

Current research was performed to explore the hepatoprotective potential of Moringa oleifera leaves extract on lead acetate-induced hepatic injury. Twenty-four male Wistar rats were divided equally into 4 groups. The first group was control, while the second, third, and fourth groups were given 200 mg/kg aqueous Moringa extract only, 100 mg/kg lead only, and 100 mg/kg lead plus 200 mg/kg aqueous Moringa leaves extract, respectively, via oral gavage for 4 weeks. Weight gain and feed efficiency ratio were recorded. Serum lipid profiles, liver enzyme activities, and proteins beside hepatic superoxide dismutase activity, reduced glutathione, tumor necrosis factor alpha (TNF-α), and deoxyribonucleic acid fragmentation were assessed. Liver histopathological examination and nuclear factor kappa B (NF-kB) immunohistochemistry were performed. Administration of lead lowered (P < 0.05) weight gain, feed efficiency ratio, and perturbed lipid profile than control. Lead increased liver enzyme activities and TNF-α, while reduced serum proteins and hepatic antioxidant markers compared to control. Lead aggravated hepatic DNA fragmentation beside the presence of histopathological lesions. Co-administration of aqueous Moringa extract with lead significantly alleviated lead-induced adverse effects. The administration of aqueous Moringa extract with its antioxidant significantly restored the lead perturbations through reduction of oxidative stress-induced DNA damage via amelioration of NF-kB and TNF-α which kept hepatocyte integrity and reduced serum hepatic enzyme activities.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Moringa oleifera , Acetatos/metabolismo , Animais , Antioxidantes/metabolismo , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Chumbo/metabolismo , Fígado/metabolismo , Masculino , Estresse Oxidativo , Extratos Vegetais/metabolismo , Folhas de Planta , Ratos , Ratos Wistar
16.
Nature ; 584(7821): 470-474, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32669712

RESUMO

The rate of cell growth is crucial for bacterial fitness and drives the allocation of bacterial resources, affecting, for example, the expression levels of proteins dedicated to metabolism and biosynthesis1,2. It is unclear, however, what ultimately determines growth rates in different environmental conditions. Moreover, increasing evidence suggests that other objectives are also important3-7, such as the rate of physiological adaptation to changing environments8,9. A common challenge for cells is that these objectives cannot be independently optimized, and maximizing one often reduces another. Many such trade-offs have indeed been hypothesized on the basis of qualitative correlative studies8-11. Here we report a trade-off between steady-state growth rate and physiological adaptability in Escherichia coli, observed when a growing culture is abruptly shifted from a preferred carbon source such as glucose to fermentation products such as acetate. These metabolic transitions, common for enteric bacteria, are often accompanied by multi-hour lags before growth resumes. Metabolomic analysis reveals that long lags result from the depletion of key metabolites that follows the sudden reversal in the central carbon flux owing to the imposed nutrient shifts. A model of sequential flux limitation not only explains the observed trade-off between growth and adaptability, but also allows quantitative predictions regarding the universal occurrence of such tradeoffs, based on the opposing enzyme requirements of glycolysis versus gluconeogenesis. We validate these predictions experimentally for many different nutrient shifts in E. coli, as well as for other respiro-fermentative microorganisms, including Bacillus subtilis and Saccharomyces cerevisiae.


Assuntos
Adaptação Fisiológica , Meio Ambiente , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Acetatos/metabolismo , Bacillus subtilis/citologia , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/metabolismo , Divisão Celular , Escherichia coli/enzimologia , Escherichia coli/genética , Fermentação , Gluconeogênese , Glucose/metabolismo , Glicólise , Metabolômica , Modelos Biológicos , Mutação , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo
17.
Mol Pharmacol ; 98(2): 120-129, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32499331

RESUMO

Alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases (ALDHs) are vital enzymes involved in the metabolism of a variety of alcohols. Differences in the expression and enzymatic activity of human ADHs and ALDHs correlate with individual variability in metabolizing alcohols and drugs and in the susceptibility to alcoholic liver disease. MicroRNAs (miRNAs) function as epigenetic modulators to regulate the expression of drug-metabolizing enzymes. To characterize miRNAs that target ADHs and ALDHs in human liver cells, we carried out a systematic bioinformatics analysis to analyze free energies of the interaction between miRNAs and their cognate sequences in ADH and ALDH transcripts and then calculated expression correlations between miRNAs and their targeting ADH and ALDH genes using a public data base. Candidate miRNAs were selected to evaluate bioinformatic predictions using a series of biochemical assays. Our results showed that 11 miRNAs have the potential to modulate the expression of two ADH and seven ALDH genes in the human liver. We found that hsa-miR-1301-3p suppressed the expression of ADH6, ALDH5A1, and ALDH8A1 in liver cells and blocked their induction by ethanol. In summary, our results revealed that hsa-miR-1301-3p plays an important role in ethanol metabolism by regulating ADH and ALDH gene expression. SIGNIFICANCE STATEMENT: Systematic bioinformatics analysis showed that 11 microRNAs might play regulatory roles in the expression of two alcohol dehydrogenase (ADH) and seven aldehyde dehydrogenase (ALDH) genes in the human liver. Experimental evidences proved that hsa-miR-1301-3p suppressed the expression of ADH6, ALDH5A1, and ALDH8A1 in liver cells and decreased their inducibility by ethanol.


Assuntos
Álcool Desidrogenase/genética , Aldeído Desidrogenase/genética , Fígado/metabolismo , MicroRNAs/genética , Succinato-Semialdeído Desidrogenase/genética , Acetaldeído/metabolismo , Acetatos/metabolismo , Linhagem Celular , Etanol/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Células Hep G2 , Humanos , Redes e Vias Metabólicas
18.
PLoS One ; 15(6): e0234077, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32559199

RESUMO

Geobacter spp. enrichment biofilms were cultivated in batch using one-chamber and two-chamber bioelectrochemical reactors. Time-resolved substrate quantification was performed to derive physiological parameters as well as incremental coulombic efficiency (i.e., coulombic efficiency during one batch cycle, here every 6h) during early stage biofilm development. The results of one-chamber reactors revealed an intermediate acetate increase putatively due to the presence of acetogens. Total coulombic efficiencies of two-chamber reactors were considerable lower (19.6±8.3% and 49.3±13.2% for 1st and 2nd batch cycle, respectively) compared to usually reported values of mature Geobacter spp. enrichment biofilms presumably reflecting energetic requirements for biomass production (i.e., cells and extracellular polymeric substances) during early stages of biofilm development. The incremental coulombic efficiency exhibits considerable changes during batch cycles indicating shifts between phases of maximizing metabolic rates and maximizing biomass yield. Analysis based on Michaelis-Menten kinetics yielded maximum substrate uptake rates (vmax,Ac, vmax,I) and half-saturation concentration coefficients (KM,Ac,KM,I) based on acetate uptake or current production, respectively. The latter is usually reported in literature but neglects energy demands for biofilm growth and maintenance as well as acetate and electron storage. From 1st to 2nd batch cycle, vmax,Ac and KM,Ac, decreased from 0.0042-0.0051 mmol Ac- h-1 cm-2 to 0.0031-0.0037 mmol Ac- h-1 cm-2 and 1.02-2.61 mM Ac- to 0.28-0.42 mM Ac-, respectively. Furthermore, differences between KM,Ac/KM,I and vmax,Ac/vmax,I were observed providing insights into the physiology of Geobacter spp. enrichment biofilms. Notably, KM,I considerably scattered while vmax,Ac/vmax,I and KM,Ac remained rather stable indicating that acetate transport within biofilm only marginally affects reaction rates. The observed data variation mandates the requirement of a more detailed analysis with an improved experimental system, e.g., using flow conditions and a comparison with Geobacter spp. pure cultures.


Assuntos
Biofilmes/crescimento & desenvolvimento , Geobacter/fisiologia , Acetatos/análise , Acetatos/metabolismo , Técnicas de Cultura Celular por Lotes , Biomassa , Cromatografia Líquida de Alta Pressão , Transporte de Elétrons , Geobacter/metabolismo , Cinética
19.
Ecotoxicol Environ Saf ; 201: 110735, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32480163

RESUMO

Methyl jasmonate (Me-JA) is a plant growth regulator known for modulating plant responses to various abiotic and biotic stresses. The unavoidable arsenic (As) contamination in rice (Oryza sativa) results in reduced crop yield and greater carcinogenic risk to humans. The present work examines the significance of Me-JA induced molecular signaling and tolerance towards arsenic toxicity in rice. The arsenite (AsIII; 25 µM) stress hampered the overall growth and development of the rice seedling. However, the co-application (25 µM AsIII+0.25 µM Me-JA) resulted in increased biomass, chlorophyll content, enhanced antioxidant enzyme activities as compared to AsIII treated plants. The co-application also demonstrated a marked decrease in malondialdehyde content, electrolyte leakage and accumulation of total AsIII content (root + shoot) as compared to AsIII treated plants. The co-application also modulated the expression of genes involved in downstream JA signaling pathway (OsCOI, OsJAZ3, OsMYC2), AsIII uptake (OsLsi1, OsLsi2, OsNIP1;1, OsNIP3;1), translocation (OsLsi6, and OsINT5) and detoxification (OsNRAMP1, OsPCS2, and OsABCC2) which revealed the probable adaptive response of the rice plant to cope up arsenic stress. Our findings reveal that Me-JA alleviates AsIII toxicity by modulating signaling components involved in As uptake, translocation, and detoxification and JA signaling in rice. This study augments our knowledge for the future use of Me-JA in improving tolerance against AsIII stress.


Assuntos
Acetatos/farmacologia , Arsênico/toxicidade , Ciclopentanos/farmacologia , Oryza/efeitos dos fármacos , Oxilipinas/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Acetatos/metabolismo , Arsênico/metabolismo , Arsenitos/metabolismo , Arsenitos/toxicidade , Transporte Biológico , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Humanos , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos
20.
Sci Rep ; 10(1): 10319, 2020 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-32587286

RESUMO

The plant hormones salicylic acid (SA) and jasmonic acid (JA) regulate defense mechanisms capable of overcoming different plant stress conditions and constitute distinct but interconnected signaling pathways. Interestingly, several other molecules are reported to trigger stress-specific defense responses to biotic and abiotic stresses. In this study, we investigated the effect of 14 elicitors against diverse but pivotal types of abiotic (drought) and biotic (the chewing insect Ascia monuste, the hemibiotrophic bacterium Pseudomonas syringae DC 3000 and the necrotrophic fungus Alternaria alternata) stresses on broccoli and Arabidopsis. Among the main findings, broccoli pre-treated with SA and chitosan showed the highest drought stress recovery in a dose-dependent manner. Several molecules led to increased drought tolerance over a period of three weeks. The enhanced drought tolerance after triggering the SA pathway was associated with stomata control. Moreover, methyl jasmonate (MeJA) reduced A. monuste insect development and plant damage, but unexpectedly, other elicitors increased both parameters. GUS reporter assays indicated expression of the SA-dependent PR1 gene in plants treated with nine elicitors, whereas the JA-dependent LOX2 gene was only expressed upon MeJA treatment. Overall, elicitors capable of tackling drought and biotrophic pathogens mainly triggered the SA pathway, but adversely also induced systemic susceptibility to chewing insects. These findings provide directions for potential future in-depth characterization and utilization of elicitors and induced resistance in plant protection.


Assuntos
Arabidopsis/imunologia , Brassica/imunologia , Resistência à Doença , Doenças das Plantas/imunologia , Acetatos/metabolismo , Alternaria/patogenicidade , Animais , Arabidopsis/microbiologia , Arabidopsis/parasitologia , Brassica/microbiologia , Brassica/parasitologia , Borboletas/patogenicidade , Ciclopentanos/metabolismo , Secas , Regulação da Expressão Gênica de Plantas/imunologia , Oxilipinas/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Proteínas de Plantas/metabolismo , Pseudomonas syringae/patogenicidade , Ácido Salicílico/metabolismo
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