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1.
J Environ Manage ; 370: 122479, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39288492

RESUMO

Coastal areas are acknowledged to be significant reservoirs of microplastics, while limited research on their presence and migration in the intertidal zones. This study investigated in a tourist beach in northern China, to reveal the occurrence of microplastics at different intertidal heights, elucidates their migration patterns, and discusses the impact of tourist activities on microplastics. Results showed that the mean microplastic abundance was 2114.8 ± 933.2 items/kg in sediments and 30,670.8 ± 15,094.9 items/m3 in seawater. Fibers were the most common shape; transparent, blue, green and black prevailed in color; and cellulose and PET were the most common components. Microplastic abundances decreased from high tide zone to low tide zone, and the abundances of microplastics in seawater were positively correlated with those in the high tide zone and negatively correlated with those in the low tide zone. Compared to wave disturbance, human activities have a relatively limited impact on microplastic abundance. However, intensive tourist activities contribute to a higher diversity of microplastic types on tourist beaches. This study enhances the understanding of the occurrence and migration patterns of microplastics in tourist beaches, and provides a valuable dataset and theoretical basis for subsequent research on microplastic pollution in coastal areas.

2.
Small ; : e2401735, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39126177

RESUMO

Lithium-ion batteries (LIBs) are paramount in energy storage in consumer electronics and electric vehicles. However, a narrow operating temperature range severely constrains their evolution. In this study, a wide-temperature operating LIB system is constructed utilizing carbon nanotube (CNT)-based electrodes and a "constructive alliance" electrolyte. The unique microstructure of the CNT current collector, with high electrical and thermal conductivity, accelerates the reaction kinetics of active materials at subzero temperatures and optimizes the thermal management of the entire electrode at elevated temperatures. Furthermore, a strategy employing the "constructive alliance" electrolyte is proposed, demonstrating that a simple combination of commercially available electrolytes can enhance resilience to harsh thermal conditions. Molecular dynamics simulations and density functional theory calculations reveal that the hybrid electrolyte predominantly adopts aggregate solvation structures and possesses low Li+ desolvation barriers regardless of thermal variations. Consequently, the assembled Li4Ti5O12//LiCoO2 full cell, with a negative/positive electrode material ratio of 1.2, exhibits outstanding electrochemical performance in the wide temperature range of -40 and 60 °C. This innovative strategy overcomes challenges in wide-temperature electrolyte research and offers promise for next-generation wide-temperature LIBs.

3.
3 Biotech ; 14(9): 202, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39157422

RESUMO

Synthetic dyes pose a significant environmental threat due to their complex structures and resistance to microbial degradation. S. commune 15R-5-F01 exhibited over 96% degradation efficiency of Methyl Red in a medium with 100 mg L-1 Methyl Red within 3 h. The fungus demonstrated adaptability to various environmental conditions, including different pH levels, temperatures, oxygen concentrations, salinity, and heavy metals. S. commune 15R-5-F01 is capable of achieving repeated cycles of Methyl Red reduction with sustained degradation duration minimum of 6 cycles. It showed a maximum Methyl Red biodegradation capacity of at least 558 mg g-1 dry mycelia and a bioadsorption capacity of 57 mg g-1. Gas chromatography-mass spectrometry analysis confirmed the azo reduction of Methyl Red into N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Enzymatic activity assays indicated the involvement of lignin peroxidases, laccases, and manganese peroxidase in the biodegradation process. Phytotoxicity tests on Triticum eastivum, Oryza sativa, and Vigna umbellata seeds revealed reduced toxicity of the degradation products compared to Methyl Red. This study identifies S. commune 15R-5-F01 as a viable candidate for the sustainable degradation of synthetic dyes in industrial wastewater.

4.
Food Chem ; 458: 140223, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38954956

RESUMO

Fresh-cut pear fruit is greatly impacted by enzymatic browning, and maintaining quality remains a challenge. This study examined the impact of exogenous α-lipoic acid (α-LA) treatment on enzymatic browning and nutritional quality of fresh-cut pears. Results revealed that 0.5 g/L α-LA treatment effectively maintained color and firmness, and inhibited the increase in microbial number. The α-LA treatment also reduced MDA and H2O2 contents, decreased PPO activity, and enhanced SOD, CAT, and PAL activities. The α-LA treatment notably upregulated phenolic metabolism-related gene expression, including PbPAL, Pb4CL, PbC4H, PbCHI and PbCHS, and then increasing total phenols and flavonoids contents. Furthermore, it also influenced carbohydrate metabolism-related gene expression, including PbSS, PbSPS, PbAI and PbNI, maintaining a high level of sucrose content. These findings indicated that α-LA treatment showed promise in reducing browning and enhancing fresh-cut pears quality, offering a potential postharvest method to prolong the lifespan and maintain nutritional quality.


Assuntos
Metabolismo dos Carboidratos , Frutas , Valor Nutritivo , Fenóis , Pyrus , Ácido Tióctico , Pyrus/química , Pyrus/metabolismo , Pyrus/genética , Frutas/química , Frutas/metabolismo , Frutas/efeitos dos fármacos , Fenóis/metabolismo , Fenóis/análise , Metabolismo dos Carboidratos/efeitos dos fármacos , Ácido Tióctico/metabolismo , Ácido Tióctico/farmacologia , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
5.
Int J Biol Macromol ; 276(Pt 1): 133844, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39004249

RESUMO

Chlorella pyrenoidos polysaccharides (CPPs) are the main active components of Chlorella pyrenoidos. They possess beneficial health properties, such as antioxidant, anti-inflammatory, and immune-enhancing. This study aims to investigate the protective function and mechanism of CPPs against high-temperature stress injury. Results showed that supplementation with 20 mg/mL CPPs significantly extended the lifespan of Drosophila melanogaster under high-temperature stress, improved its motility, and enhanced its resistance to starvation and oxidative stress. These effects were mainly attributed to the activation of Nrf2 signaling and enhanced antioxidant capacity. Additionally, it has been discovered that CPPs supplementation enhanced Drosophila resilience by preventing the disruption of the intestinal barrier and accumulation of reactive oxygen species caused by heat stress. Overall, these studies suggest that CPPs could be a useful natural therapy for preventing heat stress-induced injury.


Assuntos
Antioxidantes , Chlorella , Drosophila melanogaster , Temperatura Alta , Longevidade , Estresse Oxidativo , Polissacarídeos , Animais , Drosophila melanogaster/efeitos dos fármacos , Polissacarídeos/farmacologia , Polissacarídeos/química , Longevidade/efeitos dos fármacos , Chlorella/química , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/farmacologia , Suplementos Nutricionais , Espécies Reativas de Oxigênio/metabolismo , Resposta ao Choque Térmico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo
6.
Materials (Basel) ; 17(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38793388

RESUMO

In this study, the rolling process of the warm-rolled duplex-phase Mg-8.3Li-3.1Al-1.09Si alloy and the strengthening mechanism of as-rolled Mg-Li alloy were investigated. The highest ultimate tensile strength (UTS, 323.66 ± 19.89 MPa) could be obtained using a three-pass rolling process with a 30% thickness reduction for each pass at 553 K. The strength of the as-rolled LAS831 alloy is determined by a combination of second-phase strengthening, grain refinement strengthening, dislocation strengthening, and load-transfer reinforcement. Of these factors, dislocation strengthening, which is caused by strain hardening of the α-Mg phase, can produce a good strengthening effect but also cause a decrease in plasticity. The Mg2Si phase is broken up into particles or strips during the rolling process. After three passes, the AlLi particles were transformed into an AlLi phase, and the Mg2Si particles and nanosized AlLi particles strengthened the second phase to form a hard phase. The average size of the DRXed ß-Li grains decreased with each successive rolling pass, and the average size of recrystallized grains in the three-pass-rolled LAS831 alloy became as low as 0.27 µm. The interface between the strip-like Mg2Si phase and the α-Mg phase is characterized by semicoherent bonding, which can promote the transfer of tensile and shear forces from the matrix to the strip-like Mg2Si phase, thereby improving the strength of the matrix and thus strengthening the LAS831 alloy.

7.
Sci Total Environ ; 933: 173057, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38729372

RESUMO

Dimethylsulfoniopropionate (DMSP), a key organic sulfur compound in marine and subseafloor sediments, is degraded by phytoplankton and bacteria, resulting in the release of the climate-active volatile gas dimethylsulfide (DMS). However, it remains unclear if dominant eukaryotic fungi in subseafloor sediments possess specific abilities and metabolic mechanisms for DMSP degradation and DMS formation. Our study provides the first evidence that fungi from coal-bearing sediments ∼2 km below the seafloor, such as Aspergillus spp., Chaetomium globosum, Cladosporium sphaerospermum, and Penicillium funiculosum, can degrade DMSP and produce DMS. In Aspergillus sydowii 29R-4-F02, which exhibited the highest DMSP-dependent DMS production rate (16.95 pmol/µg protein/min), two DMSP lyase genes, dddP and dddW, were identified. Remarkably, the dddW gene, previously observed only in bacteria, was found to be crucial for fungal DMSP cleavage. These findings not only extend the list of fungi capable of degrading DMSP, but also enhance our understanding of DMSP lyase diversity and the role of fungi in DMSP decomposition in subseafloor sedimentary ecosystems.


Assuntos
Fungos , Compostos de Sulfônio , Compostos de Sulfônio/metabolismo , Fungos/metabolismo , Sedimentos Geológicos/microbiologia , Sulfetos/metabolismo , Biodegradação Ambiental , Liases de Carbono-Enxofre/metabolismo
8.
Front Hum Neurosci ; 18: 1361368, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38784524

RESUMO

Although prior research has implied that emotional contagion occurs automatically and unconsciously, convincing evidence suggests that it is significantly influenced by individuals' perceptions of their relationships with others or with collectives within specific social contexts. This implies a role for self-representation in the process. The present study aimed to offer a novel explanation of the interplay between social contexts and emotional contagion, focusing on the contextualized nature of self-representation and exploring the social factors that shape emotional contagion. It further posits a causal loop among social contexts, self-representation, and emotional contagion. Drawing from the lens of self-representation, this study concludes with a discussion on potential research directions in this field, commencing with an exploration of the antecedents and consequences of emotional contagion and self-representation.

9.
Heliyon ; 10(8): e29463, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38638973

RESUMO

Background: Pyogenic liver abscess (PLA) is a potentially life-threatening intra-abdominal infection. We compared the clinical features, treatments, and prognoses of patients who had Klebsiella pneumonia pyogenic liver abscess (KPPLA) and non-Klebsiella pneumonia pyogenic liver abscess (non-KPPLA). Methods: A retrospective analysis was used to compare the medical records of KPPLA and non-KPPLA patients with positive pus cultures at a single hospital in China from January 2017 to December 2019. Results: We examined 279 patients with definitively established PLA, 207 (74.2 %) with KPPLA, and 72 with non-KPPLA. The non-KPPLA group had a higher Charlson comorbidity index, longer hospital stay, longer duration of fever, and greater hospital costs. Multivariate analysis showed that alcohol intake (OR: 2.44, P = 0.048), cancer (OR: 4.80, P = 0.001), ICU admission (OR: 10.61, P = 0.026), resolution of fever OR: 1.04, P = 0.020), and a positive blood culture (OR: 2.87, P = 0.029) were independent predictors of primary treatment failure. Percutaneous needle aspiration (PNA) and pigtail catheter drainage (PCD) provided satisfactory outcomes, but PNA led to shorter hospital stays and reduced costs, especially in KPPLA patients whose abscesses were smaller than 10 cm. Conclusion: KPPLA and non-KPPLA patients had some differences in comorbidities and treatment strategies, and non-KPPLA patients had a significantly worse prognosis.

10.
BMJ Open ; 14(4): e084704, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38658011

RESUMO

INTRODUCTION: Various approaches are employed to expedite the passage of meconium in preterm infants within the neonatal intensive care unit (NICU), with glycerine enemas being the most frequently used. Due to the potential risk of high osmolality-induced harm to the intestinal mucosa, diluted glycerine enema solutions are commonly used in clinical practice. The challenge lies in the current lack of knowledge regarding the safest and most effective concentration of glycerine enema. This research aims to ascertain the safety of different concentrations of glycerine enema solution in preterm infants. METHODS AND ANALYSIS: This study protocol is for a single-centre, two-arm, parallel-group, double-blind and non-inferiority randomised controlled trial. Participants will be recruited from a NICU in a teriary class A hospital in China, and eligible infants will be randomly allocated to either the glycerine (mL): saline (mL) group in a 3:7 ratio or the 1:9 ratio group. The enema procedure will adhere to the standardised operational protocols. Primary outcomes encompass necrotising enterocolitis and rectal bleeding, while secondary outcomes encompass feeding parameters, meconium passage outcomes and splanchnic regional oxygen saturation. Analyses will compare the two trial arms based on an intention-to-treat allocation. ETHICS AND DISSEMINATION: This trial is approved by the ethics committee of the Medical Ethics Committee of West China Second University Hospital of Sichuan University. The results will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ChiCTR2300079199.


Assuntos
Enema , Glicerol , Recém-Nascido Prematuro , Mecônio , Feminino , Humanos , Recém-Nascido , Masculino , China , Método Duplo-Cego , Enema/métodos , Enterocolite Necrosante/prevenção & controle , Glicerol/administração & dosagem , Unidades de Terapia Intensiva Neonatal , Ensaios Clínicos Controlados Aleatórios como Assunto
11.
Food Chem Toxicol ; 186: 114563, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38442787

RESUMO

Broccoli contains an amount of biologically active substances, which bring beneficial effects on human health. Plant extracellular vesicles have been shown to be novel key factors in cancer diagnosis and tumor therapy. To date, the challenge of overcoming chemoresistance to 5-fluorouracil (5-FU) to facilitate the clinical management of colorectal cancer (CRC) has not been successful. Nevertheless, the functions of broccoli extracellular vesicles (BEVs) in the progression of CRC and 5-FU resistance are predominantly unclear. Herein, we showed that BEVs isolated from broccoli juice were effectively taken up by colorectal cancer HT-29 cells. The co-administration of BEVs and 5-FU significantly inhibited the proliferation and migration of colorectal cancer HT-29 cells, effectively blocking cell cycle progression. Furthermore, the co-administration of BEVs and 5-FU induced apoptosis by stimulating ROS production and disrupting mitochondrial function. Importantly, we found that BEVs reversed 5-FU resistance in HT-29 cells by suppressing the abnormal activation of the PI3K/Akt/mTOR signaling pathway. Collectively, our findings represent a novel strategy for utilizing BEVs to improve the efficacy of colorectal cancer treatment and enhance 5-FU chemosensitivity.


Assuntos
Brassica , Neoplasias do Colo , Neoplasias Colorretais , Humanos , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Neoplasias Colorretais/metabolismo , Brassica/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Resistencia a Medicamentos Antineoplásicos , Neoplasias do Colo/tratamento farmacológico , Apoptose , Linhagem Celular Tumoral , Proliferação de Células
12.
Org Biomol Chem ; 22(10): 2075-2080, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38363158

RESUMO

The installation of selenium groups has become an essential step across a number of industries such as agrochemicals, drug discovery, and materials. However, direct C(sp3)-H selenation, which is most atom economical, remains a formidable challenge, and only a few examples have been reported to date. In this article, we introduce the transition metal-free C(sp3)-H selenation with the easily available ß-ketosulfones and diselenides as the material source. This benign protocol permits access to a broad spectrum of α-aryl(alkyl) seleno-ß-ketosulfones in high yields with outstanding functional group compatibility. Distinct advantages of this protocol over all previous methods encompass the utilization of base and air as an oxidant, room temperature, and enhanced green chemistry matrices.

13.
ACS Appl Mater Interfaces ; 16(8): 9980-9988, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38358294

RESUMO

Thermal evaporation generators exhibit remarkable output performance, sustainability, and economy and, as a result, have attracted considerable interest as a prospective energy-converting technology for harvesting renewable energy. Here, we investigate power generation induced by water evaporation within a button supercapacitor with a simple sandwich structure. For conventional water evaporation devices, the thermodiffusion direction of hydrated ions driven by the Soret effect is opposite to the migration direction of hydrated ions driven by the streaming potential effect during thermal evaporation, which could reduce the output performance of the device. By tuning the thermodiffusion direction to be consistent with the thermal evaporation direction, our button supercapacitor achieves enhanced output performance as high as 674.4 mV, 70.7 mA, and 4.68 mW cm-2 due to the synergistic mechanism of the streaming potential effect and the Soret effect. Moreover, the system could effectively achieve in situ energy generation and storage owing to the device's ability to act as a supercapacitor. Our findings supply a feasible strategy for the synergistic integration of waste energy sources (low-grade waste heat, etc.) to generate electricity.

14.
J Org Chem ; 89(5): 3049-3057, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38332634

RESUMO

Peroxygenated compounds have wide applications in various fields, including chemistry, pharmaceutical chemistry, medicine, and materials science. However, there is still a need for more efficient and environmentally friendly synthesis methods for such compounds. Herein, we investigated the two-step, one-pot, regioselective synthesis of α/ß-aromatic peroxy thiols. We explored various substrates and solvents for the reaction and identified the optimal reaction conditions. We successfully obtained several peroxy thiols in moderate to good yields via the selective generation of effective intermediates of iodoalkyl peroxides at room temperature without the need for metal catalysts.

15.
BMC Genomics ; 25(1): 4, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166640

RESUMO

BACKGROUND: Penicillium chrysogenum is a filamentous fungal species with diverse habitats, yet little is known about its genetics in adapting to extreme subseafloor sedimental environments. RESULTS: Here, we report the discovery of P. chrysogenum strain 28R-6-F01, isolated from deep coal-bearing sediments 2306 m beneath the seafloor. This strain possesses exceptional characteristics, including the ability to thrive in extreme conditions such as high temperature (45 °C), high pressure (35 Mpa), and anaerobic environments, and exhibits broad-spectrum antimicrobial activity, producing the antibiotic penicillin at a concentration of 358 µg/mL. Genome sequencing and assembly revealed a genome size of 33.19 Mb with a GC content of 48.84%, containing 6959 coding genes. Comparative analysis with eight terrestrial strains identified 88 unique genes primarily associated with penicillin and aflatoxins biosynthesis, carbohydrate degradation, viral resistance, and three secondary metabolism gene clusters. Furthermore, significant expansions in gene families related to DNA repair were observed, likely linked to the strain's adaptation to its environmental niche. CONCLUSIONS: Our findings provide insights into the genomic and biological characteristics of P. chrysogenum adaptation to extreme anaerobic subseafloor sedimentary environments, such as high temperature and pressure.


Assuntos
Penicillium chrysogenum , Penicillium chrysogenum/genética , Genômica , Genoma Fúngico , Genes Fúngicos , Penicilinas/metabolismo
16.
Fish Shellfish Immunol ; 142: 109155, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37827248

RESUMO

Zebrafish possesses robust caudal fin regeneration which depends on multiple factors to maintain body integrity. However, it is uncertain whether the caudal fin regeneration is related to gut microbiota. Here, we investigated the effect of Lacticaseibacillus rhamnosus GG (LGG) on the regeneration of caudal fin under oxytetracycline (OTC) exposure. The results demonstrated that 1000 µg/L OTC exposure for 4 days decreased reactive oxygen species (ROS) production at 1 and 3 h post amputation (hpa), increased neutrophil recruitment at 6 hpa, enhanced the number of apoptotic cells at 1, 3, 6 and 12 hpa and inhibited Wnt signaling pathway at 48 hpa in wound site. Furthermore, OTC exposure caused dysbacteriosis by elevating level of Proteobacteria and decreasing the abundance of Firmicutes, particularly Lacticaseibacillus, thereby negatively impacting wound healing and repair. Additionally, the administration of 106 CFU/mL of LGG for 48 h could improve intestinal environment through increasing the colonization rate of LGG in OTC-treated larvae intestines. The regenerative process restored by LGG was accompanied with increased ROS production at 1, 3 and 6 hpa, inhibited neutrophil recruitment at 6 hpa, decreased the number of apoptotic cells at 1 hpa, and activated Wnt signaling pathway at 48 hpa in OTC-treated fish. LGG is a promising bacterium for restoring fin regeneration and provides new insights regarding the correlation among the gut microbiota and fin regeneration.


Assuntos
Microbioma Gastrointestinal , Lacticaseibacillus rhamnosus , Oxitetraciclina , Probióticos , Animais , Via de Sinalização Wnt , Peixe-Zebra , Lacticaseibacillus , Oxitetraciclina/farmacologia , Espécies Reativas de Oxigênio , Cicatrização
17.
Fish Shellfish Immunol ; 142: 109146, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37832747

RESUMO

Quercetin is a kind of flavonoid substance extensively existing in the plant, which has antioxidant, anti-inflammatory, and anti-apoptosis effects. It was reported that the higher concentration of spores present in the environment could cause abnormal development in zebrafish larvae. Therefore, this study set out to investigate whether quercetin could reduce the zebrafish larvae damage caused by Botrytis cinerea exposure as well as to examine the molecular basis for this action. The findings demonstrated that 50 µM quercetin improved the developmental dysplasia of zebrafish larvae induced by 102 CFU/mL Botrytis cinerea spore suspension, reduced abnormal apoptosis, enhanced antioxidant system, relieved inflammation, reshaped intestinal morphology and recovered intestinal motility. At the molecular level, quercetin decreased the transcriptional abundance of pro-apoptotic factors (bax, p53, caspase3, and caspase9) and up-regulated the anti-apoptotic gene (bcl-2) expression to reduce apoptosis. Moreover, quercetin enhanced the activities of downstream antioxidant enzymes (SOD and CAT) to clear excess ROS and MDA due to Botrytis cinerea exposure by up-regulating the expression of antioxidant genes (nrf2, ho-1, sod, and cat) in the Keap1-Nrf2 pathway. Additionally, quercetin inhibited the elevation of TNF-α by regulating the gene expression of key targets (jak3, pi3k, pdk1, akt, and ikk2) and the content of major proteins NF-κB (P65) and IκB in the NF-κB pathway. In conclusion, this work enriched the contents of the biological research of Botrytis cinerea and provided a new direction for the drug development and targeted therapy of quercetin.


Assuntos
Antioxidantes , Quercetina , Animais , Quercetina/farmacologia , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Peixe-Zebra/metabolismo , Estresse Oxidativo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , NF-kappa B/metabolismo , Larva/metabolismo , Fator 2 Relacionado a NF-E2/genética , Superóxido Dismutase/metabolismo
18.
Environ Sci Technol ; 57(45): 17312-17323, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37907425

RESUMO

Plants have developed an adaptive strategy for coping with biotic or abiotic stress by recruiting specific microorganisms from the soil pool. Recent studies have shown that the foliar spraying of pesticides causes oxidative stress in plants and leads to changes in the rhizosphere microbiota, but the mechanisms by which these microbiota change and rebuild remain unclear. Herein, we provide for the first-time concrete evidence that rice plants respond to the stress of application of the insecticide chlorpyrifos (CP) by enhancing the release of amino acids, lipids, and nucleotides in root exudates, leading to a shift in rhizosphere bacterial community composition and a strong enrichment of the genus Sphingomonas sp. In order to investigate the underlying mechanisms, we isolated a Sphingomonas representative isolate and demonstrated that it is both attracted by and able to consume linolenic acid, one of the root exudates overproduced after pesticide application. We further show that this strain selectively colonizes roots of treated plants and alleviates pesticide stress by degrading CP and releasing plant-beneficial metabolites. These results indicate a feedback loop between plants and their associated microbiota allowing to respond to pesticide-induced stress.


Assuntos
Clorpirifos , Praguicidas , Sphingomonas , Clorpirifos/metabolismo , Sphingomonas/metabolismo , Rizosfera , Bactérias/metabolismo , Plantas/metabolismo , Ácidos Linolênicos/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Microbiologia do Solo
19.
Int J Biol Macromol ; 253(Pt 6): 127339, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37820905

RESUMO

Exopolysaccharides (EPS) produced by microorganisms play a vital role in physiological and ecological processes. However, the mechanisms of EPS synthesis and release in anaerobic environments remain poorly understood. Here, we provide the first evidence of anaerobic EPS synthesis by the fungus Schizophyllum commune 20R-7-F01, isolated from coal-bearing sediments ~2.0 km below the seafloor. Under anaerobic conditions, the fungus exhibited significantly higher specific EPS production (1.57 times) than under aerobic conditions. Transcriptomic analysis revealed 2057 differentially expressed genes (DEGs) in the strain cultured anaerobically for 7 days compared to aerobically. Among these genes, 642 were significantly upregulated, while 1415 were significantly downregulated, mainly associated with carbon metabolism pathways. Genes involved in glycolysis and EPS synthesis, including hexokinase (HK), phosphoglucomutase (PGM), and (1 â†’ 3)-ß-glucan synthase (GLS), were significantly upregulated, while those related to the TCA cycle, respiratory chain, and pentose phosphate pathway were downregulated under anaerobic conditions. These findings highlight the oxygen-dependent regulation of EPS synthesis and suggest that EPS may serve as a key mechanism for fungal adaptation to anaerobic environments.


Assuntos
Schizophyllum , beta-Glucanas , Schizophyllum/genética , Schizophyllum/metabolismo , Anaerobiose , Glicólise , beta-Glucanas/metabolismo
20.
Sci Total Environ ; 897: 165374, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37422230

RESUMO

Fungi represent the dominant eukaryotic group of organisms in anoxic marine sedimentary ecosystems, ranging from a few centimeters to ~ 2.5 km below seafloor. However, little is known about how fungi can colonize anaerobic subseafloor environments for tens of millions of years and whether they play a role in elemental biogeochemical cycles. Based on metabolite detection, isotope tracer and gene analysis, we examined the anaerobic nitrogen conversion pathways of 19 fungal species (40 strains) isolated from1.3 to 2.5 km coal-bearing sediments below seafloor. Our results show for the first time that almost all fungi possess anaerobic denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and nitrification pathways, but not anaerobic ammonium oxidation (anammox). Moreover, the distribution of fungi with different nitrogen-conversion abilities in subseafloor sediments was mainly determined by in situ temperature, CaCO3, and inorganic carbon contents. These findings suggest that fungi have multiple nitrogen transformation processes to cope with their requirements for a variety of nitrogen sources in nutrient deficient anaerobic subseafloor sedimentary environments.


Assuntos
Compostos de Amônio , Ecossistema , Nitrogênio/análise , Nitratos/análise , Compostos de Amônio/metabolismo , Fungos/metabolismo , Oxirredução , Desnitrificação
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