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1.
Gut Microbes ; 16(1): 2356642, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38769708

RESUMO

Adherent-invasive Escherichia coli (AIEC) strain LF82, isolated from patients with Crohn's disease, invades gut epithelial cells, and replicates in macrophages contributing to chronic inflammation. In this study, we found that RstAB contributing to the colonization of LF82 in a mouse model of chronic colitis by promoting bacterial replication in macrophages. By comparing the transcriptomes of rstAB mutant- and wild-type when infected macrophages, 83 significant differentially expressed genes in LF82 were identified. And we identified two possible RstA target genes (csgD and asr) among the differentially expressed genes. The electrophoretic mobility shift assay and quantitative real-time PCR confirmed that RstA binds to the promoters of csgD and asr and activates their expression. csgD deletion attenuated LF82 intracellular biofilm formation, and asr deletion reduced acid tolerance compared with the wild-type. Acidic pH was shown by quantitative real-time PCR to be the signal sensed by RstAB to activate the expression of csgD and asr. We uncovered a signal transduction pathway whereby LF82, in response to the acidic environment within macrophages, activates transcription of the csgD to promote biofilm formation, and activates transcription of the asr to promote acid tolerance, promoting its replication within macrophages and colonization of the intestine. This finding deepens our understanding of the LF82 replication regulation mechanism in macrophages and offers new perspectives for further studies on AIEC virulence mechanisms.


Assuntos
Aderência Bacteriana , Biofilmes , Infecções por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli , Regulação Bacteriana da Expressão Gênica , Macrófagos , Macrófagos/microbiologia , Animais , Camundongos , Escherichia coli/genética , Escherichia coli/patogenicidade , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Biofilmes/crescimento & desenvolvimento , Infecções por Escherichia coli/microbiologia , Humanos , Concentração de Íons de Hidrogênio , Virulência , Colite/microbiologia , Doença de Crohn/microbiologia , Modelos Animais de Doenças , Transdução de Sinais , Ácidos/metabolismo
2.
Planta ; 259(6): 145, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38709313

RESUMO

MAIN CONCLUSION: Soil acidity in Ethiopian highlands impacts barley production, affecting root system architecture. Study on 300 accessions showed significant trait variability, with potential for breeding enhancement. Soil acidity poses a significant challenge to crop production in the highland regions of Ethiopia, particularly impacting barley, a crucial staple crop. This acidity serves as a key stressor affecting the root system architecture (RSA) of this crop. Hence, the objective of this study was to assess the RSA traits variability under acidic soil conditions using 300 barley accessions in a greenhouse experiment. The analysis of variance indicated substantial variations among the accessions across all traits studied. The phenotypic coefficient of variation ranged from 24.4% for shoot dry weight to 11.1% for root length, while the genotypic coefficient variation varied between 18.83 and 9.2% for shoot dry weight and root length, respectively. The broad-sense heritability ranged from 36.7% for leaf area to 69.9% for root length, highlighting considerable heritability among multiple traits. The genetic advances as a percent of the mean ranged from 13.63 to 29.9%, suggesting potential for enhancement of these traits through breeding efforts. Principal component analysis and cluster analysis grouped the genotypes into two major clusters, each containing varying numbers of genotypes with contrasting traits. This diverse group presents an opportunity to access a wide range of potential parent candidates to enhance genetic variablity in breeding programs. The Pearson correlation analysis revealed significant negative associations between root angle (RA) and other RSA traits. This helps indirect selection of accessions for further improvement in soil acidity. In conclusion, this study offers valuable insights into the RSA characteristics of barley in acidic soil conditions, aiding in the development of breeding strategies to enhance crop productivity in acidic soil environments.


Assuntos
Genótipo , Hordeum , Raízes de Plantas , Plântula , Solo , Hordeum/genética , Hordeum/fisiologia , Hordeum/crescimento & desenvolvimento , Hordeum/anatomia & histologia , Solo/química , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Plântula/anatomia & histologia , Fenótipo , Concentração de Íons de Hidrogênio , Melhoramento Vegetal , Etiópia , Variação Genética , Análise de Componente Principal , Ácidos/metabolismo
3.
J Agric Food Chem ; 72(20): 11652-11662, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38738910

RESUMO

Pectin lyases (PNLs) can enhance juice clarity and flavor by degrading pectin in highly esterified fruits, but their inadequate acid resistance leads to rapid activity loss in juice. This study aimed to improve the acid resistance of Aspergillus niger PNL pelA through surface charge design. A modification platform was established by fusing pelA with a protein tag and expressing the fusion enzyme in Escherichia coli. Four single-point mutants were identified to increase the surface charge using computational tools. Moreover, the combined mutant M6 (S514D/S538E) exhibited 99.8% residual activity at pH 3.0. The M6 gene was then integrated into the A. niger genome using a multigene integration system to obtain the recombinant PNL AM6. Notably, AM6 improved the light transmittance of orange juice to 45.3%, which was 8.39 times higher than that of pelA. In conclusion, AM6 demonstrated the best-reported acid resistance, making it a promising candidate for industrial juice clarification.


Assuntos
Aspergillus niger , Sucos de Frutas e Vegetais , Proteínas Fúngicas , Polissacarídeo-Liases , Aspergillus niger/enzimologia , Aspergillus niger/genética , Sucos de Frutas e Vegetais/análise , Polissacarídeo-Liases/genética , Polissacarídeo-Liases/metabolismo , Polissacarídeo-Liases/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/química , Concentração de Íons de Hidrogênio , Manipulação de Alimentos , Ácidos/química , Ácidos/metabolismo , Ácidos/farmacologia , Citrus sinensis/química , Pectinas/química , Pectinas/metabolismo , Estabilidade Enzimática
4.
J Agric Food Chem ; 72(15): 8749-8759, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38579123

RESUMO

The precise impact of species and strain diversity on fungal-bacterial interactions and the overall community functioning has remained unclear. First, our study revealed how Debaryomyces hansenii influences diverse bacteria to accumulate key metabolites in a simulated fermented food system. For flavor, D. hansenii promoted the accumulation of branched-chain esters in Staphylococcus xylosus by promoting growth and facilitating the precursor branched-chain acids transformations but hindered the accumulation of Staphylococcus equorum. Furthermore, fungal-bacterial interactions displayed diversity among S. equorum strains. For bioactive compounds, species and strain diversity of lactic acid bacteria (LAB) also influences the production of indole derivatives. Then, we investigated specific metabolic exchanges under reciprocal interaction. Amino acids, rather than vitamins, were identified as the primary drivers of the bacterial growth promotion. Moreover, precursor transformations by D. hansenii played a significant role in branched-chain esters production. Finally, a synthetic community capable of producing high concentrations of branched-chain esters and indole derivatives was successfully constructed. These results provide valuable insights into understanding and designing synthetic communities for fermented sausages.


Assuntos
Produtos da Carne , Simbiose , Ésteres , Fermentação , Ácidos , Produtos da Carne/análise , Indóis
5.
PLoS One ; 19(4): e0298266, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38573921

RESUMO

A mechanical device inspired by the pistol shrimp snapper claw was developed. This technology features a claw characterized by a periodic opening/closing motion, at a controlled frequency, capable of producing oscillating flows at transitional Reynolds numbers. An innovative method was also proposed for determining the corrosion rate of carbon steel samples under oscillating acidic streams (aqueous solution of HCl). By employing very-thin carbon steel specimens (25 µm thickness), with one side coated with Zn and not exposed to the stream, it became possible to electrochemically sense the Zn surface once the steel sample was perforated, thus providing the average dissolution rate into the most relevant pit on the steel surface. Furthermore, a laser light positioned beneath the metallic sample, along with a camera programmed to periodically capture images of the steel surface, facilitated the accurate counting of the number of newly formed pits. The system consisting of the thin steel sample and the Zn coating can be seen as a type of corrosion sensor. Furthermore, the proposed laser illumination method allows corroborating the electrochemical detection of pits and also establishing their location. The techniques crafted in this study pave the way for developing alternative corrosion sensors that boast appealing attributes: affordability, compactness, and acceptable accuracy to detect in time and space localized damage.


Assuntos
Carbono , Aço , Carbono/química , Aço/química , Corrosão , Rios , Ácidos/química
6.
Microb Cell Fact ; 23(1): 101, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38566056

RESUMO

BACKGROUND: Short-chain fatty acids (SCFAs) are cost-effective carbon sources for an affordable production of lipids. Hexanoic acid, the acid with the longest carbon chain in the SCFAs pool, is produced in anaerobic fermentation of organic residues and its use is very challenging, even inhibiting oleaginous yeasts growth. RESULTS: In this investigation, an adaptive laboratory evolution (ALE) was performed to improve Yarrowia lipolytica ACA DC 50109 tolerance to high hexanoic acid concentrations. Following ALE, the transcriptomic analysis revealed several genetic adaptations that improved the assimilation of this carbon source in the evolved strain compared to the wild type (WT). Indeed, the evolved strain presented a high expression of the up-regulated gene YALI0 E16016g, which codes for FAT1 and is related to lipid droplets formation and responsible for mobilizing long-chain acids within the cell. Strikingly, acetic acid and other carbohydrate transporters were over-expressed in the WT strain. CONCLUSIONS: A more tolerant yeast strain able to attain higher lipid content under the presence of high concentrations of hexanoic acid has been obtained. Results provided novel information regarding the assimilation of hexanoic acid in yeasts.


Assuntos
Yarrowia , Fermentação , Yarrowia/metabolismo , Caproatos/metabolismo , Ácidos Graxos Voláteis/metabolismo , Ácidos Graxos/metabolismo , Ácidos/metabolismo , Perfilação da Expressão Gênica , Carbono/metabolismo
7.
Sci Rep ; 14(1): 7663, 2024 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561404

RESUMO

Heavy metal contamination is an urgent ecological governance problem in mining areas. In order to seek for a green and environmentally friendly reagent with better plant restoration effect to solve the problem of low efficiency in plant restoration in heavy metal pollution soil. In this study, we evaluated the effects of three biodegradable chelating agents, namely citric acid (CA), fulvic acid (FA) and polyaspartic acid (PASP), on the physicochemical properties of copper tailings, growth of ryegrass (Lolium perenne L.) and heavy metal accumulation therein. The results showed that the chelating agent application improved the physicochemical properties of copper tailings, increased the biomass of ryegrass and enriched more Cu and Cd in copper tailings. In the control group, the main existing forms of Cu and Cd were oxidizable state, followed by residual, weak acid soluble and reducible states. After the CA, FA or PASP application, Cu and Cd were converted from the residual and oxidizable states to the reducible and weak acid soluble states, whose bioavailability in copper tailings were thus enhanced. Besides, the chelating agent incorporation improved the Cu and Cd extraction efficiencies of ryegrass from copper tailings, as manifested by increased root and stem contents of Cu and Cd by 30.29-103.42%, 11.43-74.29%, 2.98-110.98% and 11.11-111.11%, respectively, in comparison with the control group. In the presence of multiple heavy metals, CA, FA or PASP showed selectivity regarding the ryegrass extraction of heavy metals from copper tailings. PCA analysis revealed that the CA-4 and PASP-7 treatment had great remediation potentials against Cu and Cd in copper tailings, respectively, as manifested by increases in Cu and Cd contents in ryegrass by 90.98% and 74.29% compared to the CK group.


Assuntos
Lolium , Metais Pesados , Poluentes do Solo , Cobre/metabolismo , Cádmio/metabolismo , Quelantes/farmacologia , Biodegradação Ambiental , Poluentes do Solo/metabolismo , Metais Pesados/análise , Ácidos/metabolismo , Solo/química
8.
J Hazard Mater ; 470: 134221, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38615651

RESUMO

Constructed wetlands (CWs) are a promising approach for treating acid mine drainage (AMD). However, the extreme acidity and high loads of heavy metals in AMD can easily lead to the collapse of CWs without proper pre-treatment. Therefore, it is considered essential to maintain efficient and stable performance for AMD treatment in CWs. In this study, pre-prepared attapulgite-soda residue (ASR) composites were used to improve the substrate of CWs. Compared with CWs filled with gravel (CWs-G), the removal efficiencies of sulfate and Fe, Mn, Cu, Zn Cd and Pb in CWs filled with ASR composites (CWs-ASR) were increased by 30% and 10-70%, respectively. These metals were mainly retained in the substrate in stable forms, such as carbonate-, Fe/Mn (oxide)hydroxide-, and sulfide-bound forms. Additionally, higher levels of photosynthetic pigments and antioxidant enzyme activities in plants, along with a richer microbial community, were observed in CWs-ASR than in CWs-G. The application of ASR composites alleviated the adverse effects of AMD stresses on wetland plants and microorganisms. In return, the increased bacteria abundance, particularly SRB genera (e.g., Thermodesulfovibrionia and Desulfobacca), promoted the formation of metal sulfides, enabling the saturated ASR adsorbed with metals to regenerate and continuously capture heavy metals. The synergistic adsorption of ASR composites and microbial sulfate reduction maintained the stable and efficient operation of CWs. This study contributes to the resource utilization of industrial alkaline by-products and promotes the breakthrough of new techniques for low-cost and passive treatment systems such as CWs.


Assuntos
Compostos de Magnésio , Metais Pesados , Mineração , Compostos de Silício , Sulfatos , Poluentes Químicos da Água , Áreas Alagadas , Sulfatos/química , Metais Pesados/química , Adsorção , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo , Compostos de Silício/química , Compostos de Magnésio/química , Ácidos/química , Oxirredução , Biodegradação Ambiental , Concentração de Íons de Hidrogênio
9.
Food Microbiol ; 121: 104498, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38637069

RESUMO

Organic acids are widely used in foodstuffs to inhibit pathogen and spoiler growth. In this study, six organic acids (acetic, lactic, propionic, phenyllactic, caprylic, and lauric acid) and monolaurin were selected based on their physicochemical properties: their molecular structure (carbon chain length), their lipophilicity (logP), and their ability to dissociate in a liquid environment (pKa). The relation between these physicochemical properties and the inhibitory efficacy against B. weihenstephanensis KBAB4 growth was evaluated. After assessing the active form of these compounds against the strain (undissociated, dissociated or both forms), their MIC values were estimated in nutrient broth at pH 6.0 and 5.5 using two models (Lambert & Pearson, 2000; Luong, 1985). The use of two models highlighted the mode of action of an antibacterial compound in its environment, thanks to the additional estimation of the curve shape α or the Non-Inhibitory Concentration (NIC). The undissociated form of the tested acids is responsible for growth inhibition, except for lauric acid and monolaurin. Moreover, long-carbon chain acids have lower estimated MICs, compared to short-chain acids. Thus, the inhibitory efficacy of organic acids is strongly related to their carbon chain length and lipophilicity. Lipophilicity is the main mechanism of action of a membrane-active compound, it can be favored by long chain structure or high pKa in an acid environment like food.


Assuntos
Bacillus , Lauratos , Monoglicerídeos , Monoglicerídeos/farmacologia , Monoglicerídeos/química , Ácidos , Ácidos Láuricos/farmacologia , Carbono
10.
PLoS One ; 19(4): e0301923, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38652724

RESUMO

The chemical and pore structures of coal play a crucial role in determining the content of free gas in coal reservoirs. This study focuses on investigating the impact of acidification transformation on the micro-physical and chemical structure characteristics of coal samples collected from Wenjiaba No. 1 Mine in Guizhou. The research involves a semi-quantitative analysis of the chemical structure parameters and crystal structure of coal samples before and after acidification using Fourier Transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) experiments. Additionally, the evolution characteristics of the pore structure are characterized through high-pressure mercury injection (HP-MIP), low-temperature nitrogen adsorption (LT-N2A), and scanning electron microscopy (SEM). The experimental findings reveal that the acid solution modifies the structural features of coal samples, weakening certain vibrational structures and altering the chemical composition. Specifically, the asymmetric vibration structure of aliphatic CH2, the asymmetric vibration of aliphatic CH3, and the symmetric vibration of CH2 are affected. This leads to a decrease in the contents of -OH and -NH functional groups while increasing aromatic structures. The crystal structure of coal samples primarily dissolves transversely after acidification, affecting intergranular spacing and average height. Acid treatment corrodes mineral particles within coal sample cracks, augmenting porosity, average pore diameter, and the ratio of macro-pores to transitional pores. Moreover, acidification increases fracture width and texture, enhancing the connectivity of the fracture structure in coal samples. These findings provide theoretical insights for optimizing coalbed methane (CBM) extraction and gas control strategies.


Assuntos
Carvão Mineral , Difração de Raios X , Carvão Mineral/análise , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Ácidos/química , Microscopia Eletrônica de Varredura , Minas de Carvão
11.
Bioresour Technol ; 400: 130702, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38615968

RESUMO

The bioconversion of lignocellulosic biomass into novel bioproducts is crucial for sustainable biorefineries, providing an integrated solution for circular economy objectives. The current study investigated a novel microwave-assisted acidic deep eutectic solvent (DES) pretreatment of waste cocoa pod husk (CPH) biomass to extract xylooligosaccharides (XOS). The sequential DES (choline chloride/citric acid, molar ratio 1:1) and microwave (450W) pretreatment of CPH biomass was effective in 67.3% xylan removal with a 52% XOS yield from total xylan. Among different XOS of varying degrees of polymerization, a higher xylobiose content corresponding to 69.3% of the total XOS (68.22 mg/g CPH) from liquid fraction was observed. Enzymatic hydrolysis of residual xylan from pretreated CPH biomass with low commercial xylanase (10 IU/g) concentration yielded 24.2% XOS. The MW-ChCl/citric acid synergistic pretreatment approach holds great promise for developing a cost-effective and environmentally friendly method contributing to the sustainable production of XOS from agricultural waste streams.


Assuntos
Biomassa , Cacau , Solventes Eutéticos Profundos , Glucuronatos , Micro-Ondas , Oligossacarídeos , Oligossacarídeos/química , Cacau/química , Cacau/metabolismo , Hidrólise , Solventes Eutéticos Profundos/química , Xilanos , Biotecnologia/métodos , Ácidos/química , Solventes/química
12.
Int J Biol Macromol ; 267(Pt 2): 131462, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38614163

RESUMO

The rapid development of the industry has led to the destruction of the earth's ozone layer, resulting in an increasingly serious problem of excessive ultraviolet radiation. Exploring effective measures to address these problems has become a hot topic. Lignin shows promise in the design and preparation of anti-ultraviolet products due to its inherent properties. However, it is important to investigate way to enhance the reactivity of lignin and determine its application form in related products. In this study, phenolic reactions with tea polyphenols were conducted through acid-catalyzed conversion, utilizing organic solvent lignin as the primary material. The phenolic hydroxyl content of the original lignin increased significantly by 218.8 %, resulting in notable improvements in UV resistance and oxidation resistance for phenolic lignin. Additionally, micro-nanocapsule emulsions were formed using phenolic lignin particles as surfactants through ultrasonic cavitation with small-molecule sunscreens. A bio-based sunscreen was prepared with phenolated lignin micro-nanocapsules as the active ingredient, achieving an SPF 100.2 and demonstrating excellent stability. The sunscreen also exhibited strong antioxidant properties and impermeability, ensuring user safety. This research offers a current solution for improving the application of lignin in sunscreens while also broadening the potential uses of plant-based materials in advanced functional products.


Assuntos
Lignina , Oxirredução , Polifenóis , Protetores Solares , Chá , Raios Ultravioleta , Lignina/química , Polifenóis/química , Catálise , Chá/química , Protetores Solares/química , Protetores Solares/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Ácidos/química
13.
J Agric Food Chem ; 72(18): 10487-10496, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38683727

RESUMO

The current study aimed to improve the acid resistance and thermostability of Bacillus velezensis α-amylase through site-directed mutagenesis, with a specific focus on its applicability to the feed industry. Four mutation sites, P546E, H572D, A614E, and K622E, were designed in the C domain of α-amylase, and three mutants, Mut1 (E), Mut2 (ED), and Mut3 (EDEE), were produced. The results showed that the specific activity of Mut3 was 50 U/mg higher than the original α-amylase (Ori) after incubation at 40 °C for 4 h. Compared to Ori, the acid resistance of Mut3 showed a twofold increase in specific activity at pH 2.0. Moreover, the results of preliminary feed hydrolysis were compared between Ori and Mut3 by designing three factors, three levels of orthogonal experiment for enzymatic hydrolysis time, feed quantity, and amount of amylase. It was observed that the enzymatic hydrolysis time and feed quantity showed an extremely significant difference (p < 0.01) in Mut3 compared to Ori. However, the amount of enzyme showed significant (p < 0.05) improvement in the enzymatic hydrolysis in Mut3 as compared to Ori. The study identified Mut3 as a promising candidate for the application of α-amylase in the feed industry.


Assuntos
Bacillus , Proteínas de Bactérias , Estabilidade Enzimática , Mutagênese Sítio-Dirigida , alfa-Amilases , Bacillus/enzimologia , Bacillus/genética , Bacillus/química , alfa-Amilases/genética , alfa-Amilases/química , alfa-Amilases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Concentração de Íons de Hidrogênio , Hidrólise , Ração Animal/análise , Cinética , Temperatura Alta , Ácidos/metabolismo , Ácidos/química , Ácidos/farmacologia , Temperatura
14.
Sci Rep ; 14(1): 5739, 2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459152

RESUMO

Gold (Au), as one of the most precious metal resources that is used for both industrial products and private ornaments, is a global investment target, and mining companies are making huge investments to discover new Au deposits. Here, we report in situ Au adsorption in an acidic hot spring by a unique adsorption sheet made from blue-green algae with a high preferential adsorption ability for Au. The results of in situ Au adsorption experiments conducted for various reaction times ranging from 0.2 h to 7 months showed that a maximum Au concentration of 30 ppm was adsorbed onto the blue-green algal sheet after a reaction time of 7 months. The Au concentration in the hot spring water was below the detection limit (< 1 ppt); therefore, Au was enriched by preferential adsorption onto the blue-green algal sheet by a factor of more than ~ 3 × 107. Thus, our gold recovery method has a high potential to recover Au even from an Au-poor solution such as hot spring water or mine wastewater with a low impact on the environment.


Assuntos
Ouro , Fontes Termais , Adsorção , Ácidos , Água
15.
Environ Microbiol ; 26(3): e16602, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38454738

RESUMO

Terrestrial geothermal ecosystems are hostile habitats, characterized by large emissions of environmentally relevant gases such as CO2 , CH4 , H2 S and H2 . These conditions provide a niche for chemolithoautotrophic microorganisms. Methanotrophs of the phylum Verrucomicrobia, which inhabit these ecosystems, can utilize these gases and grow at pH levels below 1 and temperatures up to 65°C. In contrast, methanotrophs of the phylum Proteobacteria are primarily found in various moderate environments. Previously, novel verrucomicrobial methanotrophs were detected and isolated from the geothermal soil of the Favara Grande on the island of Pantelleria, Italy. The detection of pmoA genes, specific for verrucomicrobial and proteobacterial methanotrophs in this environment, and the partially overlapping pH and temperature growth ranges of these isolates suggest that these distinct phylogenetic groups could coexist in the environment. In this report, we present the isolation and characterization of a thermophilic and acid-tolerant gammaproteobacterial methanotroph (family Methylococcaceae) from the Favara Grande. This isolate grows at pH values ranging from 3.5 to 7.0 and temperatures from 35°C to 55°C, and diazotrophic growth was demonstrated. Its genome contains genes encoding particulate and soluble methane monooxygenases, XoxF- and MxaFI-type methanol dehydrogenases, and all enzymes of the Calvin cycle. For this novel genus and species, we propose the name 'Candidatus Methylocalor cossyra' CH1.


Assuntos
Ecossistema , Solo , Filogenia , Ácidos , Proteobactérias , Gases , Metano , Microbiologia do Solo
16.
Int J Mol Sci ; 25(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38473990

RESUMO

Insulin tightly regulates glucose levels within a narrow range through its action on muscle, adipose tissue and the liver. The activation of insulin receptors activates multiple intracellular pathways with different functions. Another tightly regulated complex system in the body is acid-base balance. Metabolic acidosis, defined as a blood pH < 7.35 and serum bicarbonate < 22 mmol/L, has clear pathophysiologic consequences including an effect on insulin action. With the ongoing intake of typical acid-producing Western diets and the age-related decline in renal function, there is an increase in acid levels within the range considered to be normal. This modest increase in acidosis is referred to as "acid stress" and it may have some pathophysiological consequences. In this article, we discuss the effects of acid stress on insulin actions in different tissues.


Assuntos
Acidose , Insulina , Humanos , Insulina/metabolismo , Acidose/metabolismo , Equilíbrio Ácido-Base , Transdução de Sinais , Ácidos
17.
Chemosphere ; 355: 141759, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38531500

RESUMO

The presence and fate of pharmaceutically active compounds (PhACs) in agricultural fields are rarely investigated. The present study highlights that root-derived low-molecular-weight organic acids (LMWOAs) affect the mobility of PhACs in cultivated humic Arenosol. Sorption experiments are conducted using three PhACs characterised by different physicochemical properties: carbamazepine (CBZ), 17α-ethinylestradiol (EE2), and diclofenac-sodium (DFC). The results suggest that the adsorption of EE2 is more intense than the other two PhACs, whereas DFC and CBZ are primarily dominated by desorption. LMWOAs mainly provide additional low-energy adsorption sites for the PhACs, and slight pH changes do not significantly affect the sorption mechanism. During competitive adsorption, the high-energy sites of the adsorbents are initially occupied by EE2 owing to its high adsorption energy (∼15 kJ/mol). The new low-energy binding sites enhance the adsorption of DFC (from 8.5 % to 72.0 %) and CBZ (from 31.0 % to 70.0 %) during multicomponent adsorption. LMWOAs not only affect adsorption by modifying the pH but also provide additional binding sites that allow the PhACs to remain in the root environment for a longer period. As the concentration of LMWOAs temporarily changes, so does the availability of PhACs in the root zone. Environmental changes in the humic horizon enhance the mobility of the adsorbed PhACs, which renders them continuously available for uptake by plants, thus increasing the possibility of PhACs entering the human food chain.


Assuntos
Areia , Poluentes Químicos da Água , Humanos , Compostos Orgânicos , Ácidos , Adsorção , Poluentes Químicos da Água/análise
18.
Int J Biol Macromol ; 264(Pt 2): 130769, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38467215

RESUMO

Two novel chitosan derivatives (water soluble and acid soluble) modified with thiocarbohydrazide were produced by a quick and easy technique using formaldehyde as links. The novel compounds were synthesized and then characterized by thermogravimetric analysis, elemental analysis, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. Their surface morphologies were examined using scanning electron microscopy. These chitosan derivatives could produce pH-dependent gels. The behavior of mild steel in 5 % acetic acid, including both inhibitors at various concentrations, was investigated using gravimetric and electrochemical experiments. According to the early findings, both compounds (TCFACN and TCFWCN) functioned as mixed-type metal corrosion inhibitors. Both inhibitors showed their best corrosion inhibition efficiency at 80 mg L-1. TCFACN and TCFWCN, showed approximately 92 % and 94 % corrosion inhibition, respectively, at an optimal concentration of 80 mg L-1, according to electrochemical analysis. In the corrosion test, the water contact angle of the polished MS sample at 87.90 °C was reduced to 51 °C. The water contact angles for MS inhibited by TCFACN and TCFWCN in the same electrolyte were greater, measuring 78.10 °C and 93.10 °C, respectively. The theoretical results also support the experimental findings.


Assuntos
Quitosana , Quitosana/química , Corrosão , Adsorção , Ácidos , Aço/química , Água
19.
Food Chem ; 447: 138968, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38489877

RESUMO

Given the severe problem of Baijiu authenticity, it is essential to discriminate Baijiu from different origins quickly and effectively. As organic acids (OAs) are the most dominant taste-imparting substances in Baijiu, we proposed a simple, fast, and effective OAs-targeted colorimetric sensor array based on the colorimetric reaction of 4-aminophenol (AP)/4-amino-3-chlorophenol (ACP) under oxidation of Cu(NO3)2 for the rapid discrimination of origins of Baijiu with three main aroma types. Hydrogen ions ionized from OAs induced the protonation of the amino group, which blocked the colorimetric reaction, and the different levels of OAs in Baijiu enabled the array to discriminate different origins of Baijiu. The array was implemented to analyze 10 simple OAs and 16 mixed OAs and further for the discrimination of 42 Baijius with an accuracy of 98%. This method provided an efficient research strategy for a basis for rapid quality analysis of Baijiu.


Assuntos
Clorofenóis , Odorantes , Compostos Orgânicos Voláteis , Odorantes/análise , Colorimetria , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos Voláteis/análise , Ácidos/análise
20.
Bioresour Technol ; 399: 130557, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38460561

RESUMO

A novel cascade pyrolysis upgrading process for acid hydrolysis lignin (AHL), consisting of pyrolysis, catalytic upgrading of pyrolysis vapors, and pyrolysis char, was developed to improve the yield of value-added products (monophenolic chemicals and carbon materials). Pyrolysis of AHL at 450 °C and subsequent catalytic upgrading of pyrolysis vapors over Ni/H-ZSM-5 boosted the concentration of monophenolic chemicals in pyrolysis liquids by 58%. The carbon material prepared from pyrolysis char using KOH as activating agent exhibited a large specific surface area of 2902.5 m2/g and a large total pore volume of 1.45 cm3/g, thus affording good adsorption capacity for methylene blue (824.87 mg/g) and iodine (2333.17 mg/g). Moreover, the cascade pyrolysis upgrading of AHL achieved a yield of 68.52% desired products, which was much higher than the reported results (single production of monophenols and pyrolysis char). In summary, this work provides a potential reference for efficient utilization of lignin in large-scale applications.


Assuntos
Carbono , Lignina , Pirólise , Adsorção , Hidrólise , Gases , Ácidos
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