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1.
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
2.
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
3.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
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
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.
Environ Sci Pollut Res Int ; 31(16): 24163-24179, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38436860

RESUMO

Coastal sedimentary systems are affected by continental and marine metal pollutant inputs associated with different hydrodynamic characteristics and geochemical processes. These include the formation of acid-volatile sulfides (AVS) within sediments, which affects metal bioavailability and associated aquatic biota toxicity risks. Physicochemical changes in these environments in the face of extreme natural or man-made environmental influences can dramatically alter metal bioavailability and toxicity through metal binding and immobilization as insoluble sulfides. Surface sediments from Guanabara Bay, river mouths, and two mangrove areas were collected, and AVS and simultaneously extracted metals Cd, Cu, Fe, Mn, Ni, Pb, and Zn and ΣSEM were determined to assess sediment quality. A severe eutrophication history favored AVS concentrations exceeding or close to the sum-SEM concentrations, demonstrating that AVS play an important role in making trace metals unavailable for assimilation by living organisms, mitigating the risks of contamination for the local biota. This eutrophication-driven sulfide accumulation may attenuate the sediment toxicity in sites heavily polluted by metals, while some fewer eutrophic sites became more exposed to metals in excess to AVS.


Assuntos
Metais Pesados , Oligoelementos , Poluentes Químicos da Água , Ácidos , Baías , Monitoramento Ambiental , Sedimentos Geológicos/química , Metais/análise , Metais Pesados/análise , Sulfetos/química , Poluentes Químicos da Água/análise
13.
Food Res Int ; 182: 114187, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38519195

RESUMO

The flavor profiles of fresh and aged fermented peppers obtained from four varieties were thoroughly compared in this study. A total of 385 volatile compounds in fermented pepper samples were detected by flavoromics (two-dimensional gas chromatography-time-of-flight mass spectrometry). As fermentation progressed, both the number and the total concentration of volatile compounds changed, with esters, alcohols, acids, terpenoids, sulfur compounds, and funans increasing, whereas hydrocarbons and benzenes decreased. In contrast to the fresh fermented peppers, the aged fermented samples exhibited lower values of pH, total sugars, and capsaicinoids but higher contents of organic acids and free amino acids. Furthermore, the specific differences and characteristic aroma substances among aged fermented peppers were unveiled by multivariate statistical analysis. Overall, 64 volatiles were screened as differential compounds. In addition, Huanggongjiao samples possessed the most abundant differential volatiles and compounds with odor activity values > 1, which were flavored with fruity, floral, and slightly phenolic odors. Correlation analysis demonstrated that the levels of 23 key aroma compounds (e.g., ethyl 2-methylbutyrate, 1-butanol, and ethyl valerate) showed a significantly positive correlation with Asp, Glu and 5 organic acids. By contrast, there is a negative association between the pH value and total sugar. Overall, aging contributed significantly to the flavor attributes of fermented peppers.


Assuntos
Frutas , Piper nigrum , Frutas/química , Odorantes/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Álcoois/análise , Fermentação , Ácidos/análise
14.
J Agric Food Chem ; 72(12): 6593-6600, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38502529

RESUMO

Furpenthiazinate is a yellow pigment formed by the Maillard reaction between cysteine and furfural under strongly acidic conditions. Here, we describe the conditions and mechanism of pigment formation in a model system and in an acid hydrolyzate of food and analyze its biological properties. A reaction solution containing 32 mM cysteine and 128 mM furfural or 64 mM cysteine and 256 mM furfural in the presence of 2-6 M hydrochloric acid that was heated to 110 °C for 1-2 h yielded approximately 3 mM furpenthiazinate. Nuclear magnetic resonance analysis of furpenthiazinate prepared using 1-13C or 5-13C d-ribose suggests that it was formed through the condensation of cysteine and two C5 chains derived from pentose with the dehydration and elimination of formic acid. Furpenthiazinate was detected in mieki, a seasoning, and some acid hydrolyzates of food, and it did not show antibacterial or mutagenic activity.


Assuntos
Furaldeído , Reação de Maillard , Tiazinas , Cisteína , Furanos , Ácidos
15.
Appl Environ Microbiol ; 90(4): e0150023, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38456674

RESUMO

Plasmalogen is a specific glycerophospholipid present in both animal and bacterial organisms. It plays a crucial function in eukaryotic cellular processes and is closely related to several human diseases, including neurological disorders and cancers. Nonetheless, the precise biological role of plasmalogen in bacteria is not well understood. In this study, we identified SMU_438c as the enzyme responsible for plasmalogen production in Streptococcus mutans under anaerobic conditions. The heterologous expression of SMU_438c in a plasmalogen-negative strain, Streptococcus sanguinis, resulted in the production of plasmalogen, indicating that this enzyme is sufficient for plasmalogen production. Additionally, the plasmalogen-deficient S. mutans exhibited significantly lower acid tolerance and diminished its colonization in Drosophila flies compared to the wild-type strain and complemented strain. In summary, our data suggest that plasmalogen plays a vital role in bacterial stress tolerance and in vivo colonization. IMPORTANCE: This study sheds light on the biological role of plasmalogen, a specific glycerophospholipid, in bacteria, particularly in Streptococcus mutans. Plasmalogens are known for their significant roles in eukaryotic cells and have been linked to human diseases like neurological disorders and cancers. The enzyme SMU_438c, identified as essential for plasmalogen production under anaerobic conditions, was crucial for acid tolerance and in vivo colonization in Drosophila by S. mutans, underscoring its importance in bacterial stress response and colonization. These findings bridge the knowledge gap in bacterial physiology, highlighting plasmalogen's role in microbial survival and offering potential insights into microbial pathogenesis and host-microbe interactions.


Assuntos
Neoplasias , Doenças do Sistema Nervoso , Humanos , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Plasmalogênios/metabolismo , Streptococcus mutans/metabolismo , Ácidos/metabolismo , Drosophila , Biofilmes
16.
J Bacteriol ; 206(4): e0006924, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38488356

RESUMO

Bacteria are capable of withstanding large changes in osmolality and cytoplasmic pH, unlike eukaryotes that tightly regulate their pH and cellular composition. Previous studies on the bacterial acid stress response described a rapid, brief acidification, followed by immediate recovery. More recent experiments with better pH probes have imaged single living cells, and we now appreciate that following acid stress, bacteria maintain an acidic cytoplasm for as long as the stress remains. This acidification enables pathogens to sense a host environment and turn on their virulence programs, for example, enabling survival and replication within acidic vacuoles. Single-cell analysis identified an intracellular pH threshold of ~6.5. Acid stress reduces the internal pH below this threshold, triggering the assembly of a type III secretion system in Salmonella and the secretion of virulence factors in the host. These pathways are significant because preventing intracellular acidification of Salmonella renders it avirulent, suggesting that acid stress pathways represent a potential therapeutic target. Although we refer to the acid stress response as singular, it is actually a complex response that involves numerous two-component signaling systems, several amino acid decarboxylation systems, as well as cellular buffering systems and electron transport chain components, among others. In a recent paper in the Journal of Bacteriology, M. G. Gorelik, H. Yakhnin, A. Pannuri, A. C. Walker, C. Pourciau, D. Czyz, T. Romeo, and P. Babitzke (J Bacteriol 206:e00354-23, 2024, https://doi.org/10.1128/jb.00354-23) describe a new connection linking the carbon storage regulator CsrA to the acid stress response, highlighting new additional layers of complexity.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/metabolismo , Cebolas/metabolismo , Proteínas de Bactérias/metabolismo , Citoplasma/metabolismo , Vacúolos/metabolismo , Salmonella/metabolismo , Ácidos/metabolismo , Proteínas Repressoras/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Escherichia coli/metabolismo
17.
J Agric Food Chem ; 72(11): 5555-5573, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38442481

RESUMO

Mid-to-long-chain dicarboxylic acids (DCAi, i ≥ 6) are organic compounds in which two carboxylic acid functional groups are present at the terminal position of the carbon chain. These acids find important applications as structural components and intermediates across various industrial sectors, including organic compound synthesis, food production, pharmaceutical development, and agricultural manufacturing. However, conventional petroleum-based DCA production methods cause environmental pollution, making sustainable development challenging. Hence, the demand for eco-friendly processes and renewable raw materials for DCA production is rising. Owing to advances in systems metabolic engineering, new tools from systems biology, synthetic biology, and evolutionary engineering can now be used for the sustainable production of energy-dense biofuels. Here, we explore systems metabolic engineering strategies for DCA synthesis in various chassis via the conversion of different raw materials into mid-to-long-chain DCAs. Subsequently, we discuss the future challenges in this field and propose synthetic biology approaches for the efficient production and successful commercialization of these acids.


Assuntos
Ácidos Dicarboxílicos , Engenharia Metabólica , Ácidos Dicarboxílicos/metabolismo , Ácidos , Biocombustíveis , Compostos Orgânicos
18.
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
19.
Environ Sci Pollut Res Int ; 31(17): 25287-25298, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38468001

RESUMO

Ionizing irradiation, as a new pretreatment method for the anaerobic fermentation of organic pollutants, is featured with fast reaction speed, good treatment effect, no need to add any chemical reagents, and no secondary pollution. This study explores the mechanism of improving anaerobic fermentation performance of rice samples pretreated by cobalt-60 gamma irradiation through the influence on fermentation substrate, acidogenic phase and methanogenic phase. The results reveal that the soluble chemical oxygen demand of the irradiated rice sample at an absorbed dose of 9.6 kGy increases by 12.4 times due to the dissolution of small molecules of fat-soluble organic matter. The yield of biogas in the acidogenic phase increases by 22.2% with a slight increase in hydrogen gas content. The yield of biogas and methane gas content in the methanogenic phase increases by 27.3% and 15%, respectively. Microbial genome analysis, performed with MiSeq high-throughput sequencing and metagenomic methods, suggests the microbial abundance and metabolic functions in the anaerobic fermentation process change significantly as a result of the pretreatment by gamma irradiation.


Assuntos
Oryza , Fermentação , Anaerobiose , Oryza/metabolismo , Biocombustíveis/análise , Ácidos , Metano/análise , Reatores Biológicos , Esgotos
20.
J Biotechnol ; 385: 42-48, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38479472

RESUMO

Oryzamutaic acids, possessing a nitrogen-containing heterocyclic skeleton, have been isolated and identified from a rice mutant. Although oryzamutaic acids are expected to be functional ingredients, their functionality is difficult to evaluate, because of their wide variety and presence in trace amounts. Furthermore, how oryzamutaic acid is synthesized in vivo is unclear. Therefore, we developed a simple enzymatic synthesis method for these compounds in vitro. We focused on L-lysine ε-dehydrogenase (LysDH) from Agrobacterium tumefaciens, which synthesizes α-aminoadipate-δ-semialdehyde-a precursor of oryzamutaic acids. LysDH was cloned and expressed in Escherichia coli. Analysis of activity revealed that LysDH catalyzed the synthesis of oryzamutaic acid H at neutral pH in vitro. We synthesized 1.6 mg oryzamutaic acid H from 100 mg L-lysine. The synthesized oryzamutaic acid H exhibited UVA absorption, stability of temperature, and stability at a wide pH range. To our knowledge, this study is the first to report the enzymatic synthesis of oryzamutaic acid H in vitro and provides a basis for understanding the mechanisms of oryzamutaic acid synthesis in vivo.


Assuntos
Agrobacterium tumefaciens , Aminoácido Oxirredutases , Agrobacterium tumefaciens/genética , Lisina , Ácidos
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