Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45.078
Filtrar
1.
J Environ Sci (China) ; 147: 165-178, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003037

RESUMO

In this study, two wheat-derived cadmium (Cd)-immobilizing endophytic Pseudomonas paralactis M14 and Priestia megaterium R27 were evaluated for their effects on wheat tissue Cd uptake under hydroponic conditions. Then, the impacts of the biochar (BC), M14+R27 (MR), and BC+MR treatments on wheat Cd uptake and the mechanisms involved were investigated at the jointing, heading, and mature stages of wheat plants under field-plot conditions. A hydroponic experiment showed that the MR treatment significantly decreased the above-ground tissue Cd content compared with the M14 or R27 treatment. The BC+MR treatment reduced the grain Cd content by 51.5%-67.7% and Cd translocation factor at the mature stage of wheat plants and increased the organic matter-bound Cd content by 31%-75% in the rhizosphere soils compared with the BC or MR treatment. Compared with the BC or MR treatment, the relative abundances of the biomarkers associated with Gemmatimonas, Altererythrobacter, Gammaproteobacteria, Xanthomonadaceae, Phenylobacterium, and Nocardioides in the BC+MR-treated rhizosphere microbiome decreased and negatively correlated with the organic matter-bound Cd contents. In the BC+MR-treated root interior microbiome, the relative abundance of the biomarker belonging to Exiguobacterium increased and negatively correlated with the Cd translocation factor, while the relative abundance of the biomarker belonging to Pseudonocardiaceae decreased and positively correlated with the Cd translocation factor. Our findings suggested that the BC+MR treatment reduced Cd availability and Cd transfer through affecting the abundances of these specific biomarkers in the rhizosphere soil and root interior microbiomes, leading to decreased wheat grain Cd uptake in the contaminated soil.


Assuntos
Cádmio , Carvão Vegetal , Microbiologia do Solo , Poluentes do Solo , Triticum , Triticum/metabolismo , Triticum/microbiologia , Cádmio/metabolismo , Poluentes do Solo/metabolismo , Endófitos/fisiologia , Rizosfera , Solo/química , Biodegradação Ambiental , Microbiota/efeitos dos fármacos
2.
J Environ Sci (China) ; 147: 179-188, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003038

RESUMO

Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil. Phytoremediation of contaminated soil is an environmental and sustainable technology, and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals. However, the effects of high concentrations of multiple heavy metals (HCMHMs) on plants and native soil microorganisms remain uncertain. Thus, further clarification of the mechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required. Using the plant Sedum alfredii (S. alfredii) to restore HCMHM-contaminated soil, we further explored the mechanism of S. alfredii and native soil microorganisms in the remediation of HCMHM soils. The results showed that (i) S. alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil, which is conducive to the effect of plants on heavy metals. In addition, it can also enrich the absorbed heavy metals in its roots and leaves; (ii) native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes, such as trpE, trpG, bjaI, rpfF, ACSL, and yidC, and promote the expression of the pathway that converts serine to cysteine, then synthesize substances to chelate heavy metals. In addition, we speculated that genes such as K19703, K07891, K09711, K19703, K07891, and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals. The results provide scientific basis for S. alfredii to remediate heavy metals contaminated soils, and confirm the potential of phytoremediation of HCMHM contaminated soil.


Assuntos
Biodegradação Ambiental , Metais Pesados , Sedum , Microbiologia do Solo , Poluentes do Solo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Sedum/metabolismo , Metais Pesados/análise , Rizosfera , Solo/química
3.
J Environ Sci (China) ; 147: 370-381, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003055

RESUMO

Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were screened. The surface of the bio-Fe/Mn oxides produced by the oxidation of Fe(II) and Mn(II) by Pseudomonas taiwanensis (marked as P4) and Pseudomonas plecoglossicida (marked as G1) contains rich reactive oxygen functional groups, which play critical roles in the removal efficiency and immobilization of heavy metal(loid)s in co-contamination system. The isolated strains P4 and G1 can grow well in the following environments: pH 5-9, NaCl 0-4%, and temperature 20-30°C. The removal efficiencies of Fe, Pb, As, Zn, Cd, Cu, and Mn are effective after inoculation of the strains P4 and G1 in the simulated water system (the initial concentrations of heavy metal(loid) were 1 mg/L), approximately reaching 96%, 92%, 85%, 67%, 70%, 54% and 15%, respectively. The exchangeable and carbonate bound As, Cd, Pb and Cu are more inclined to convert to the Fe-Mn oxide bound fractions in P4 and G1 treated soil, thereby reducing the phytoavailability and bioaccessible of heavy metal(loid)s. This research provides alternatives method to treat water and soil containing high concentrations of multi-heavy metal(loid)s.


Assuntos
Metais Pesados , Poluentes do Solo , Poluentes Químicos da Água , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/análise , Poluentes do Solo/metabolismo , Oxirredução , Pseudomonas/metabolismo , Manganês , Ferro/química , Ferro/metabolismo , Solo/química , Biodegradação Ambiental , Microbiologia do Solo
4.
J Environ Sci (China) ; 147: 571-581, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003072

RESUMO

Mining and tailings deposition can cause serious heavy metal(loids) pollution to the surrounding soil environment. Soil microorganisms adapt their metabolism to such conditions, driving alterations in soil function. This study aims to elucidate the response patterns of nitrogen-cycling microorganisms under long-term heavy metal(loids) exposure. The results showed that the diversity and abundance of nitrogen-cycling microorganisms showed negative feedback to heavy metal(loids) concentrations. Denitrifying microorganisms were shown to be the dominant microorganisms with over 60% of relative abundance and a complex community structure including 27 phyla. Further, the key bacterial species in the denitrification process were calculated using a random forest model, where the top three key species (Pseudomonas stutzei, Sphingobium japonicum and Leifsonia rubra) were found to play a prominent role in nitrite reduction. Functional gene analysis and qPCR revealed that nirK, which is involved in nitrite reduction, significantly accumulated in the most metal-rich soil with the increase of absolute abundance of 63.86%. The experimental results confirmed that the activity of nitrite reductase (Nir) encoded by nirK in the soil was increased at high concentrations of heavy metal(loids). Partial least squares-path model identified three potential modes of nitrite reduction processes being stimulated by heavy metal(loids), the most prominent of which contributed to enhanced nirK abundance and soil Nir activity through positive stimulation of key species. The results provide new insights and preliminary evidence on the stimulation of nitrite reduction processes by heavy metal(loids).


Assuntos
Ouro , Metais Pesados , Mineração , Nitritos , Microbiologia do Solo , Poluentes do Solo , Metais Pesados/toxicidade , Ciclo do Nitrogênio , Desnitrificação , Nitrogênio , Solo/química
5.
J Environ Sci (China) ; 147: 538-549, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003069

RESUMO

The multi-soil-layering (MSL) systems is an emerging solution for environmentally-friendly and cost-effective treatment of decentralized rural domestic wastewater. However, the role of the seemingly simple permeable layer has been overlooked, potentially holding the breakthroughs or directions to addressing suboptimal nitrogen removal performance in MSL systems. In this paper, the mechanism among diverse substrates (zeolite, green zeolite and biological ceramsite) coupled microorganisms in different systems (activated bacterial powder and activated sludge) for rural domestic wastewater purification was investigated. The removal efficiencies performed by zeolite coupled with microorganisms within 3 days were 93.8% for COD, 97.1% for TP, and 98.8% for NH4+-N. Notably, activated sludge showed better nitrification and comprehensive performance than specialized nitrifying bacteria powder. Zeolite attained an impressive 89.4% NH4+-N desorption efficiency, with a substantive fraction of NH4+-N manifesting as exchanged ammonium. High-throughput 16S rRNA gene sequencing revealed that aerobic and parthenogenetic anaerobic bacteria dominated the reactor, with anaerobic bacteria conspicuously absent. And the heterotrophic nitrification-aerobic denitrification (HN-AD) process was significant, with the presence of denitrifying phosphorus-accumulating organisms (DPAOs) for simultaneous nitrogen and phosphorus removal. This study not only raises awareness about the importance of the permeable layer and enhances comprehension of the HN-AD mechanism in MSL systems, but also provides valuable insights for optimizing MSL system construction, operation, and rural domestic wastewater treatment.


Assuntos
Eliminação de Resíduos Líquidos , Eliminação de Resíduos Líquidos/métodos , Nitrificação , Nitrogênio/metabolismo , Solo/química , Desnitrificação , Águas Residuárias/química , Esgotos/microbiologia , Microbiologia do Solo , Zeolitas/química , Fósforo/metabolismo , Reatores Biológicos/microbiologia , Bactérias/metabolismo
6.
J Environ Sci (China) ; 147: 597-606, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003074

RESUMO

Harnessing bacteria for superoxide production in bioremediation holds immense promise, yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide. This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain, a prevalent soil bacterial genus. Our research reveals that introducing a carbon source along with specific iron-binding ligands, including deferoxamine (DFO), diethylenetriamine pentaacetate (DTPA), citrate, and oxalate, robustly augments microbial superoxide generation. Moreover, our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(III)/Fe(II) and superoxide. Remarkably, among the tested ligands, only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(III). We identify an optimal Fe(III) to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture. This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals, significantly elevating bioremediation performance. Furthermore, our study reveals that DTPA augments superoxide production in cultures of diverse soils, with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation. This emphasizes the universal applicability of DTPA across multiple bacterial genera. In conclusion, our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals. These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation, offering innovative solutions for addressing environmental contamination challenges.


Assuntos
Arthrobacter , Biodegradação Ambiental , Radical Hidroxila , Ferro , Superóxidos , Radical Hidroxila/metabolismo , Superóxidos/metabolismo , Arthrobacter/metabolismo , Ferro/metabolismo , Ligantes , Microbiologia do Solo , Poluentes do Solo/metabolismo , Desferroxamina/metabolismo
7.
J Environ Sci (China) ; 147: 498-511, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003065

RESUMO

The land application of livestock manure has been widely acknowledged as a beneficial approach for nutrient recycling and environmental protection. However, the impact of residual antibiotics, a common contaminant of manure, on the degradation of organic compounds and nutrient release in Eutric Regosol is not well understood. Here, we studied, how oxytetracycline (OTC) and ciprofloxacin (CIP) affect the decomposition, microbial community structure, extracellular enzyme activities and nutrient release from cattle and pig manure using litterbag incubation experiments. Results showed that OTC and CIP greatly inhibited livestock manure decomposition, causing a decreased rate of carbon (28%-87%), nitrogen (15%-44%) and phosphorus (26%-43%) release. The relative abundance of gram-negative (G-) bacteria was reduced by 4.0%-13% while fungi increased by 7.0%-71% during a 28-day incubation period. Co-occurrence network analysis showed that antibiotic exposure disrupted microbial interactions, particularly among G- bacteria, G+ bacteria, and actinomycetes. These changes in microbial community structure and function resulted in decreased activity of urease, ß-1,4-N-acetyl-glucosaminidase, alkaline protease, chitinase, and catalase, causing reduced decomposition and nutrient release in cattle and pig manures. These findings advance our understanding of decomposition and nutrient recycling from manure-contaminated antibiotics, which will help facilitate sustainable agricultural production and soil carbon sequestration.


Assuntos
Antibacterianos , Gado , Esterco , Microbiologia do Solo , Animais , Solo/química , Sequestro de Carbono , Carbono/metabolismo , Fósforo , Reciclagem , Poluentes do Solo/metabolismo , Bovinos , Suínos , Nitrogênio/análise , Oxitetraciclina
8.
Sci Rep ; 14(1): 15027, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951138

RESUMO

Plant growth and high yields are secured by intensive use of nitrogen (N) fertilizer, which, however, pollutes the environment, especially when N is in the form of nitrate. Ammonium is oxidized to nitrate by nitrifiers, but roots can release biological nitrification inhibitors (BNIs). Under what conditions does root-exudation of BNIs facilitate nitrogen N uptake and reduce pollution by N loss to the environment? We modeled the spatial-temporal dynamics of nitrifiers, ammonium, nitrate, and BNIs around a root and simulated root N uptake and net rhizosphere N loss over the plant's life cycle. We determined the sensitivity of N uptake and loss to variations in the parameter values, testing a broad range of soil-plant-microbial conditions, including concentrations, diffusion, sorption, nitrification, population growth, and uptake kinetics. An increase in BNI exudation reduces net N loss and, under most conditions, increases plant N uptake. BNIs decrease uptake in the case of (1) low ammonium concentrations, (2) high ammonium adsorption to the soil, (3) rapid nitrate- or slow ammonium uptake by the plant, and (4) a slowly growing or (5) fast-declining nitrifier population. Bactericidal inhibitors facilitate uptake more than bacteriostatic ones. Some nitrification, however, is necessary to maximize uptake by both ammonium and nitrate transporter systems. An increase in BNI exudation should be co-selected with improved ammonium uptake. BNIs can reduce N uptake, which may explain why not all species exude BNIs but have a generally positive effect on the environment by increasing rhizosphere N retention.


Assuntos
Nitrificação , Nitrogênio , Raízes de Plantas , Nitrogênio/metabolismo , Raízes de Plantas/metabolismo , Microbiologia do Solo , Nitratos/metabolismo , Plantas/metabolismo , Compostos de Amônio/metabolismo , Solo/química , Rizosfera , Fertilizantes
9.
Appl Microbiol Biotechnol ; 108(1): 401, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951176

RESUMO

Haloarchaea are extremophilic microorganisms belonging to the Archaea domain that require high salt concentrations to be alive, thus inhabiting ecosystems like salty ponds, salty marshes, or extremely salty lagoons. They are more abundantly and widely distributed worldwide than initially expected. Most of them are grouped into two families: Halobacteriaceae and Haloferacaceae. The extreme conditions under which haloarchaea survive contribute to their metabolic and molecular adaptations, thus making them good candidates for the design of bioremediation strategies to treat brines, salty water, and saline soils contaminated with toxic compounds such as nitrate, nitrite, oxychlorates such as perchlorate and chlorate, heavy metals, hydrocarbons, and aromatic compounds. New advances in understanding haloarchaea physiology, metabolism, biochemistry, and molecular biology suggest that biochemical pathways related to nitrogen and carbon, metals, hydrocarbons, or aromatic compounds can be used for bioremediation proposals. This review analyses the novelty of the most recent results showing the capability of some haloarchaeal species to assimilate, modify, or degrade toxic compounds for most living beings. Several examples of the role of these microorganisms in the treatment of polluted brine or salty soils are also discussed in connection with circular economy-based processes. KEY POINTS: • Haloarchaea are extremophilic microorganisms showing genuine metabolism • Haloarchaea can metabolise compounds that are highly toxic to most living beings • These metabolic capabilities are useful for designing soil and water bioremediation strategies.


Assuntos
Biodegradação Ambiental , Archaea/metabolismo , Halobacteriaceae/metabolismo , Halobacteriaceae/genética , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Microbiologia do Solo
10.
Glob Chang Biol ; 30(7): e17391, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38946293

RESUMO

Heat released from soil organic carbon (SOC) decomposition (referred to as microbial heat hereafter) could alter the soil's thermal and hydrological conditions, subsequently modulate SOC decomposition and its feedback with climate. While understanding this feedback is crucial for shaping policy to achieve specific climate goal, it has not been comprehensively assessed. This study employs the ORCHIDEE-MICT model to investigate the effects of microbial heat, referred to as heating effect, focusing on their impacts on SOC accumulation, soil temperature and net primary productivity (NPP), as well as implication on land-climate feedback under two CO2 emissions scenarios (RCP2.6 and RCP8.5). The findings reveal that the microbial heat decreases soil carbon stock, predominantly in upper layers, and elevates soil temperatures, especially in deeper layers. This results in a marginal reduction in global SOC stocks due to accelerated SOC decomposition. Altered seasonal cycles of SOC decomposition and soil temperature are simulated, with the most significant temperature increase per unit of microbial heat (0.31 K J-1) occurring at around 273.15 K (median value of all grid cells where air temperature is around 273.15 K). The heating effect leads to the earlier loss of permafrost area under RCP8.5 and hinders its restoration under RCP2.6 after peak warming. Although elevated soil temperature under climate warming aligns with expectation, the anticipated accelerated SOC decomposition and large amplifying feedback on climate warming were not observed, mainly because of reduced modeled initial SOC stock and limited NPP with heating effect. These underscores the multifaceted impacts of microbial heat. Comprehensive understanding of these effects would be vital for devising effective climate change mitigation strategies in a warming world.


Assuntos
Carbono , Mudança Climática , Temperatura Alta , Solo , Solo/química , Carbono/análise , Microbiologia do Solo , Modelos Teóricos , Estações do Ano
11.
Antonie Van Leeuwenhoek ; 117(1): 94, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954064

RESUMO

The Aeolian archipelago is known worldwide for its volcanic activity and hydrothermal emissions, of mainly carbon dioxide and hydrogen sulfide. Hydrogen, methane, and carbon monoxide are minor components of these emissions which together can feed large quantities of bacteria and archaea that do contribute to the removal of these notorious greenhouse gases. Here we analyzed the metagenome of samples taken from the Levante bay on Vulcano Island, Italy. Using a gene-centric approach, the hydrothermal vent community appeared to be dominated by Proteobacteria, and Sulfurimonas was the most abundant genus. Metabolic reconstructions highlight a prominent role of formaldehyde oxidation and the reverse TCA cycle in carbon fixation. [NiFe]-hydrogenases seemed to constitute the preferred strategy to oxidize H2, indicating that besides H2S, H2 could be an essential electron donor in this system. Moreover, the sulfur cycle analysis showed a high abundance and diversity of sulfate reduction genes underpinning the H2S production. This study covers the diversity and metabolic potential of the microbial soil community in Levante bay and adds to our understanding of the biogeochemistry of volcanic ecosystems.


Assuntos
Hidrogênio , Metagenoma , Metano , Microbiologia do Solo , Enxofre , Metano/metabolismo , Hidrogênio/metabolismo , Itália , Enxofre/metabolismo , Archaea/genética , Archaea/classificação , Archaea/metabolismo , Bactérias/genética , Bactérias/classificação , Bactérias/metabolismo , Bactérias/isolamento & purificação , Fontes Hidrotermais/microbiologia , Ilhas , Filogenia
12.
Sci Rep ; 14(1): 15096, 2024 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956049

RESUMO

Antibiotic resistance is a worldwide problem that imposes a devastating effect on developing countries and requires immediate interventions. Initially, most of the antibiotic drugs were identified by culturing soil microbes. However, this method is prone to discovering the same antibiotics repeatedly. The present study employed a shotgun metagenomics approach to investigate the taxonomic diversity, functional potential, and biosynthetic capacity of microbiomes from two natural agricultural farmlands located in Bekeka and Welmera Choke Kebelle in Ethiopia for the first time. Analysis of the small subunit rRNA revealed bacterial domain accounting for 83.33% and 87.24% in the two selected natural farmlands. Additionally, the analysis showed the dominance of Proteobacteria representing 27.27% and 28.79% followed by Actinobacteria making up 12.73% and 13.64% of the phyla composition. Furthermore, the analysis revealed the presence of unassigned bacteria in the studied samples. The metagenome functional analysis showed 176,961 and 104, 636 number of protein-coding sequences (pCDS) from the two samples found a match with 172,655 and 102, 275 numbers of InterPro entries, respectively. The Genome ontology annotation suggests the presence of 5517 and 3293 pCDS assigned to the "biosynthesis process". Numerous Kyoto Encyclopedia of Genes and Genomes modules (KEGG modules) involved in the biosynthesis of terpenoids and polyketides were identified. Furthermore, both known and novel Biosynthetic gene clusters, responsible for the production of secondary metabolites, such as polyketide synthases, non-ribosomal peptide synthetase, ribosomally synthesized and post-translationally modified peptides (Ripp), and Terpene, were discovered. Generally, from the results it can be concluded that the microbiomes in the selected sampling sites have a hidden functional potential for the biosynthesis of secondary metabolites. Overall, this study can serve as a strong preliminary step in the long journey of bringing new antibiotics to the market.


Assuntos
Metagenoma , Metagenômica , Microbiota , Família Multigênica , Metabolismo Secundário , Microbiologia do Solo , Metagenômica/métodos , Microbiota/genética , Metabolismo Secundário/genética , Fazendas , Bactérias/genética , Bactérias/classificação , Bactérias/metabolismo , Etiópia , Filogenia
13.
Sci Rep ; 14(1): 15211, 2024 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956076

RESUMO

Biological agents are getting a noticeable concern as efficient eco-friendly method for nanoparticle fabrication, from which fungi considered promising agents in this field. In the current study, two fungal species (Embellisia spp. and Gymnoascus spp.) were isolated from the desert soil in Saudi Arabia and identified using 18S rRNA gene sequencing then used as bio-mediator for the fabrication of silver nanoparticles (AgNPs). Myco-synthesized AgNPs were characterized using UV-visible spectrometry, transmission electron microscopy, Fourier transform infrared spectroscopy and dynamic light scattering techniques. Their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were investigated. In atrial to detect their possible antibacterial mechanism, Sodium dodecyl sulfate (SDS-PAGE) and TEM analysis were performed for Klebsiella pneumoniae treated by the myco-synthesized AgNPs. Detected properties of the fabricated materials indicated the ability of both tested fungal strains in successful fabrication of AgNPs having same range of mean size diameters and varied PDI. The efficiency of Embellisia spp. in providing AgNPs with higher antibacterial activity compared to Gymnoascus spp. was reported however, both indicated antibacterial efficacy. Variations in the protein profile of K. pneumoniae after treatments and ultrastructural changes were observed. Current outcomes suggested applying of fungi as direct, simple and sustainable approach in providing efficient AgNPs.


Assuntos
Nanopartículas Metálicas , Prata , Microbiologia do Solo , Prata/química , Prata/farmacologia , Arábia Saudita , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/química , Clima Desértico , Fungos/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química
14.
Sci Rep ; 14(1): 15114, 2024 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956155

RESUMO

Wheat straw returning is a common agronomic measure in the farmland. Understanding organic carbon transformation is of great significance for carbon budget under the premise of widespread distribution of cadmium (Cd) contaminated soils. An incubation experiment was conducted to assess the influence of Cd contamination on the decomposition and accumulation of total organic carbon (TOC) as well as the composition and abundance of bacterial communities in eight soil types with wheat straw addition. The results showed that inhibition of Cd contamination on microbially mediated organic carbon decomposition was affected by soil types. The lower cumulative C mineralization and higher TOC content could be observed in the acidic soils relative to that in the alkaline soils. The content of Cd in soil exhibits different effects on the inhibition in decomposition of TOC. The high dosage level of Cd had stronger inhibitory impact due to its high toxicity. The decomposition of TOC was restricted by a reduction in soil bacterial abundance and weakening of bacterial activities. Redundancy analysis (RDA) indicated that Proteobacteria and Gemmatimonadetes were abundant in alkaline Cd-contaminated soils with wheat straw addition, while Bacteroidetes dominated cumulative C mineralization in acidic Cd-contamination soils. Moreover, the abundance of predicted functional bacteria indicated that high-dose Cd-contamination and acid environment all inhibited the decomposition of TOC. The present study suggested that pH played an important role on carbon dynamics in the Cd-contaminated soils with wheat straw addition.


Assuntos
Cádmio , Carbono , Microbiologia do Solo , Poluentes do Solo , Solo , Triticum , Cádmio/metabolismo , Cádmio/análise , Triticum/metabolismo , Triticum/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Carbono/metabolismo , Carbono/análise , Solo/química , Bactérias/metabolismo , Biodegradação Ambiental , Concentração de Íons de Hidrogênio
15.
Artigo em Inglês | MEDLINE | ID: mdl-38963413

RESUMO

A Gram-stain-negative, yellow-pigmented, and facultatively aerobic bacterium, designated strain GPA1T, was isolated from plastic waste landfill soil in the Republic of Korea. The cells were non-motile short rods exhibiting oxidase-negative and catalase-positive activities. Growth was observed at 15-40 °C (optimum, 30 °C), at pH 6.0-9.0 (optimum, pH 7.0-8.0) and in the presence of 0-2.5 % (w/v) NaCl (optimum, 0 %). Menaquinone-7 was the sole respiratory quinone, and iso-C15 : 0, C16 : 1 ω5c, and iso-C17 : 0 3-OH were the major cellular fatty acids (>10 % of the total fatty acids). Phosphatidylethanolamine was identified as a major polar lipid. Phylogenetic analyses based on 16S rRNA gene sequences and 120 concatenated marker protein sequences revealed that strain GPA1T formed a distinct lineage within the genus Chitinophaga. The genome of strain GPA1T was 6078 kb in size with 53.8 mol% G+C content. Strain GPA1T exhibited the highest similarity to Chitinophaga rhizosphaerae T16R-86T, with a 98.6 % 16S rRNA gene sequence similarity, but their average nucleotide identity and digital DNA-DNA hybridization values were 82.5 and 25.9 %, respectively. Based on its phenotypic, chemotaxonomic, and phylogenetic characteristics, strain GPA1T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga pollutisoli sp. nov. is proposed. The type strain is GPA1T (=KACC 23415T=JCM 36644T).


Assuntos
Técnicas de Tipagem Bacteriana , Bacteroidetes , Composição de Bases , DNA Bacteriano , Ácidos Graxos , Sedimentos Geológicos , Fosfatidiletanolaminas , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , Microbiologia do Solo , Vitamina K 2 , RNA Ribossômico 16S/genética , República da Coreia , Ácidos Graxos/química , Vitamina K 2/análogos & derivados , Vitamina K 2/química , Vitamina K 2/análise , DNA Bacteriano/genética , Sedimentos Geológicos/microbiologia , Bacteroidetes/isolamento & purificação , Bacteroidetes/classificação , Bacteroidetes/genética , Hibridização de Ácido Nucleico , Instalações de Eliminação de Resíduos , Genoma Bacteriano
16.
Environ Geochem Health ; 46(8): 282, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38963450

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants with carcinogenic, mutagenic and teratogenic effects. The white-rot fungi in the fungal group have significant degradation ability for high molecular weight organic pollutants. However, exogenous fungi are easily antagonized by indigenous microorganisms. Low molecular weight organic acids, a small molecular organic matter secreted by plants, can provide carbon sources for soil microorganisms. Combining organic acids with white rot fungi may improve the nutritional environment of fungi. In this study, immobilized Trametes versicolor was used to degrade benzo[a]pyrene in soil, and its effect on removing benzo[a]pyrene in soil mediated by different low molecular weight organic acids was investigated. The results showed that when the degradation was 35 days, the removal effect of the experimental group with citric acid was the best, reaching 43.7%. The degradation effect of Trametes versicolor on benzo[a]pyrene was further investigated in the liquid medium when citric acid was added, and the effects of citric acid on the biomass, extracellular protein concentration and laccase activity of Trametes versicolor were investigated by controlling different concentrations of citric acid. In general, citric acid can act as a carbon source for Trametes versicolor and promote its extracellular protein secretion and laccase activity, thereby accelerating the mineralization of benzo[a]pyrene by Trametes versicolor. Therefore, citric acid can be used as a biostimulant in the remediation of PAHs contaminated soil with Trametes versicolor.


Assuntos
Benzo(a)pireno , Biodegradação Ambiental , Ácido Cítrico , Poluentes do Solo , Benzo(a)pireno/toxicidade , Benzo(a)pireno/metabolismo , Ácido Cítrico/metabolismo , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Lacase/metabolismo , Microbiologia do Solo , Polyporaceae/metabolismo , Trametes/metabolismo , Biomassa
17.
Microb Ecol ; 87(1): 90, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958675

RESUMO

Endophytes play an important role in plant development, survival, and establishment, but their temporal dynamics in young conifer plants are still largely unknown. In this study, the bacterial community was determined by metabarcoding of the 16S rRNA gene in the rhizoplane, roots, and aerial parts of 1- and 5-month-old seedlings of natural populations of Abies religiosa (Kunth) Schltdl. & Cham. In 1-month-old seedlings, Pseudomonas dominated aerial parts (relative abundance 71.6%) and roots (37.9%). However, the roots exhibited significantly higher bacterial species richness than the aerial parts, with the dissimilarity between these plant sections mostly explained by the loss of bacterial amplification sequence variants. After 5 months, Mucilaginibacter dominated in the rhizoplane (9.0%), Streptomyces in the roots (12.2%), and Pseudomonas in the aerial parts (18.1%). The bacterial richness and community structure differed significantly between the plant sections, and these variations were explained mostly by 1-for-1 substitution. The relative abundance of putative metabolic pathways significantly differed between the plant sections at both 1 and 5 months. All the dominant bacterial genera (e.g., Pseudomonas and Burkholderia-Caballeronia-Paraburkholderia) have been reported to have plant growth-promoting capacities and/or antagonism against pathogens, but what defines their role for plant development has still to be determined. This investigation improves our understanding of the early plant-bacteria interactions essential for natural regeneration of A. religiosa forest.


Assuntos
Abies , Bactérias , Endófitos , Raízes de Plantas , RNA Ribossômico 16S , Plântula , Plântula/microbiologia , Plântula/crescimento & desenvolvimento , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Endófitos/classificação , Endófitos/isolamento & purificação , Endófitos/fisiologia , Endófitos/genética , RNA Ribossômico 16S/genética , Abies/microbiologia , Raízes de Plantas/microbiologia , Microbiologia do Solo , Biodiversidade , Microbiota , DNA Bacteriano/genética
18.
NPJ Biofilms Microbiomes ; 10(1): 55, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38961111

RESUMO

Climate changes significantly impact greenhouse gas emissions from wetland soil. Specifically, wetland soil may be exposed to oxygen (O2) during droughts, or to sulfate (SO42-) as a result of sea level rise. How these stressors - separately and together - impact microbial food webs driving carbon cycling in the wetlands is still not understood. To investigate this, we integrated geochemical analysis, proteogenomics, and stoichiometric modeling to characterize the impact of elevated SO42- and O2 levels on microbial methane (CH4) and carbon dioxide (CO2) emissions. The results uncovered the adaptive responses of this community to changes in SO42- and O2 availability and identified altered microbial guilds and metabolic processes driving CH4 and CO2 emissions. Elevated SO42- reduced CH4 emissions, with hydrogenotrophic methanogenesis more suppressed than acetoclastic. Elevated O2 shifted the greenhouse gas emissions from CH4 to CO2. The metabolic effects of combined SO42- and O2 exposures on CH4 and CO2 emissions were similar to those of O2 exposure alone. The reduction in CH4 emission by increased SO42- and O2 was much greater than the concomitant increase in CO2 emission. Thus, greater SO42- and O2 exposure in wetlands is expected to reduce the aggregate warming effect of CH4 and CO2. Metaproteomics and stoichiometric modeling revealed a unique subnetwork involving carbon metabolism that converts lactate and SO42- to produce acetate, H2S, and CO2 when SO42- is elevated under oxic conditions. This study provides greater quantitative resolution of key metabolic processes necessary for the prediction of CH4 and CO2 emissions from wetlands under future climate scenarios.


Assuntos
Dióxido de Carbono , Metano , Oxigênio , Proteômica , Sulfatos , Áreas Alagadas , Sulfatos/metabolismo , Oxigênio/metabolismo , Proteômica/métodos , Metano/metabolismo , Dióxido de Carbono/metabolismo , Microbiologia do Solo , Microbiota , Bactérias/metabolismo , Bactérias/classificação , Bactérias/genética , Mudança Climática
19.
Sci Rep ; 14(1): 15383, 2024 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965309

RESUMO

The drought can cause a decrease in food production and loss of biodiversity. In northern Mexico, an arid region, the chiltepin grows as a semi-domesticated crop that has been affected in its productivity and yield. An alternative to mitigate the effect of drought and aid in its conservation could be using Plant Growth-Promoting Bacteria (PGPB). The present study evaluated the capacity of native Bacillus spp., isolated from arid soils, as PGPBs and drought stress tolerance inducers in chiltepin under controlled conditions. Chiltepin seeds and seedlings were inoculated with native strains of Bacillus spp. isolated from arid soils, evaluating germination, vegetative, and drought stress tolerance parameters. The PGPBs improved vegetative parameters such as height, stem diameter, root length, and slenderness index in vitro. B. cereus (Bc25-7) improved in vitro survival of stressed seedlings by 68% at -1.02 MPa. Under greenhouse conditions, seedlings treated with PGPBs exhibited increases in root length (9.6%), stem diameter (13.68%), leaf fresh weight (69.87%), and chlorophyll content (38.15%). Bc25-7 alleviated severe water stress symptoms (7 days of water retention stress), and isolates B. thuringiensis (Bt24-4) and B. cereus (Bc25-7, and Bc30-2) increased Relative Water Content (RWC) by 51%. Additionally, the treated seeds showed improved germination parameters with a 46.42% increase in Germination Rate (GR). These findings suggest that using PGPBs could be an alternative to mitigate the effect of drought on chiltepin.


Assuntos
Bacillus , Capsicum , Secas , Plântula , Capsicum/crescimento & desenvolvimento , Capsicum/microbiologia , Capsicum/fisiologia , Bacillus/fisiologia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Estresse Fisiológico , Germinação , Sementes/crescimento & desenvolvimento , Sementes/microbiologia , Microbiologia do Solo , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , México
20.
Curr Microbiol ; 81(8): 247, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951210

RESUMO

Stenotrophomonas species are recognized as rhizobacteria that play a pivotal role in promoting plant growth by making substantial contributions to enhanced soil fertility, nutrient recycling, and phytopathogen control. Employing them as bioinputs constitutes an environmentally sound strategy, particularly within the rhizospheric community. This study revealed the draft genome sequence of Stenotrophomonas geniculata LGMB417, which was originally isolated from root samples of maize (Zea mays L.). This research assessed the potential of a bacterial strain at the molecular level through genome mining, aiming to identify genes with biotechnological significance for promoting plant growth and protection. The assembly findings indicate that strain LGMB417 possesses a genome size of 4,654,011 bp, with a G + C content of 66.50%. The draft genome sequence revealed the presence of gene clusters responsible for the synthesis of secondary metabolites and carbohydrate active enzymes (CAZymes), glycoside hydrolases (23), glycosyltransferases (18), carbohydrate esterases (5), polysaccharide lyases (2), carbohydrate-binding modules (2), and auxiliary activities (1). Several genes related to growth promotion were found in the genome, including those associated with phosphate transport and solubilization, nitrogen metabolism, siderophore production and iron transport, hormonal modulation, stress responses (such as to drought, temperature fluctuations, osmotic challenges, and oxidative conditions), and volatile organic compounds (VOCs). Subsequent phases will encompass investigations utilizing gene expression methodologies, with future explorations concentrating on facets pertinent to agricultural production, including comprehensive field studies.


Assuntos
Genoma Bacteriano , Stenotrophomonas , Zea mays , Zea mays/microbiologia , Stenotrophomonas/genética , Stenotrophomonas/metabolismo , Biotecnologia , Composição de Bases , Raízes de Plantas/microbiologia , Microbiologia do Solo , Agricultura , Filogenia , Família Multigênica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...