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1.
Gene ; 850: 146926, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36191825

RESUMO

Arsenic transforming bacterial strains belong to genus Pseudomonas sp.AK9 (KY569424), were isolated from the middle Gangetic plains of Bihar, India. The Pseudomonas sp. AK9 strains were able to transform toxic arsenite to a less toxic arsenate. In the present work, the presence of different arsenic resistance genes (aoxB, arsB, acr3 and aoxAB) were observed in isolated strain. Furthermore, the aoxB gene was amplified from genomic DNA of AK9, cloned in E.coli/DH5αcells, and sequenced. The BLASTn results and phylogenetic study of the aoxB gene showed 95.32 % and 90.07 % identity with the large subunit of aoxB gene of previous reported Thiomonas arsenivorans strain DSM16361 and Thiomonas arsenivorans strain b6, respectively. Further overhang primers were designed for amplifications of full length aoxB gene (∼1200 bp), and cloned in to the expression vector and host E.coli/BL21 cells. The GST-aoxB gene was expressed in BL21 cells, and a profound expression product of âˆ¼ 72 kDa was observed in SDS PAGE. The detection of a large subunit (aoxB) of arsenate oxidase protein in western blotting assay affirmed the expression of aoxB gene in recombinant E.coli/BL21 clone. Further, the recombinant E.coli/BL21cells showed increased growth than the normal E.coli/BL21 cells against As (III). Thus, this study showed the presence of aoxB gene in Pseudomonas sp. AK9 genome which regulates the resistant ability to arsenic toxicity.


Assuntos
Arsênio , Arsenitos , Oxirredutases , Arseniatos/metabolismo , Arsênio/toxicidade , Arsenitos/metabolismo , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Filogenia , Pseudomonas/genética , Pseudomonas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
2.
Chemosphere ; 310: 136754, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36228733

RESUMO

Lignin is the most abundant heterogeneous aromatic polymer present on planet Earth and is recalcitrant to degradation due to its complex structure, therefore, imposing a challenge to biorefinery procedures. Identifying new microbial strains with the potential to valorize lignin into useful compounds is indispensable to achieving green sustainable consumption. In this study, a novel Pseudomonas strain designated as Hu109A was isolated from the termite gut and the genome was sequenced and analyzed further. The genome contains a circular chromosome with the size of 5,131,917 bp having a GC content of 62.6% and 4698 genes. Genome annotation reveals that the strain possesses lignin-oxidizing enzymes such as DyP-type peroxidases, laccase, dioxygenase, and aromatic degradation gene clusters. The genome also contains O-methyltransferases which function in accelerating the lignin degradation by methylating the free hydroxyl phenolic compounds which in high concentration can inhibit the lignin peroxidase. Furthermore, the genome exhibits two gene clusters encoding the enzymes related to polyhydroxyalkanoates (PHA) synthesis. Pseudomonas strains are generally assumed to produce medium chain length PHAs (mcl-PHAs) only, however, strain Hu109A contains both Class II PHA synthase genes involved in mcl-PHAs and Class III PHA synthase gene involved in short-chain length PHAs (scl-PHAs). Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that using 1 g/L lignin as the sole carbon source, the maximum production of PHA observed was 103.68 mg/L, which increased to 186 mg/L with an increase in lignin concentration to 3 g/L. However, PHA production while using glucose as the sole carbon source was significantly lower than the lignin source, and maximum production was 125.6 mg/L with 3 g/L glucose. The strain Hu109A can tolerate a broad range of solvents including methanol, isopropanol, dimethylformamide, and ethanol, revealing its potential for industrial applications.


Assuntos
Poli-Hidroxialcanoatos , Poli-Hidroxialcanoatos/química , Pseudomonas/genética , Pseudomonas/metabolismo , Lignina/química , Bactérias/metabolismo , Genômica , Carbono/metabolismo
3.
Chemosphere ; 310: 136826, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36243087

RESUMO

This study aimed to carry out the bioaugmentation of crude oil/motor oil contaminated soil. The mixture of novel strains Pseudomonas aeruginosa PP3 and Pseudomonas aeruginosa PP4 were used in this bioaugmentation studies. The four different bioaugmentation systems (BS 1-4) were carried out in this experiment labelled as BS 1 (Crude oil contaminated soil), BS 2 (BS 1 + bacterial consortia), BS 3 (Motor oil sludge contaminated soil), and BS 4 (BS 3 + bacterial consortia). The total petroleum hydrocarbon (TPH) was investigated for monitor the effectiveness of bioaugmentation process. The highest TPH removal rate was recorded on BS 4 (9091 mg Kg -1) was about 67% followed by 52% on BS 2 (8584 mg Kg -1) respectively. The percentage of biodegradation efficiency (BE) of residual crude and motor oil contaminated soil were evaluated by GCMS analysis and the results showed that 65% (BS 2) and 83% (BS 4) respectively. Further the bioaugmented soil was subjected to the plant cultivation (Lablab purpureus) and the results revealed that the L. purpureus was rapidly grown in the systems BS 4 and BS 2 than the system BS 1 and BS 2 which was due to the lesser biodegradation of the crude oil contents. In resultant, it can be concluded that the soil was suitable for the cultivation of plant. Overall, this study revealed that the selected bacterial consortia were effectively degraded the hydrocarbon and act as a potential bioremediator in the hydrocarbon polluted soil in a short period.


Assuntos
Petróleo , Poluentes do Solo , Petróleo/metabolismo , Solo/química , Pseudomonas/metabolismo , Poluentes do Solo/análise , Microbiologia do Solo , Hidrocarbonetos/metabolismo , Biodegradação Ambiental , Bactérias/metabolismo
4.
BMC Genomics ; 23(1): 784, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36451103

RESUMO

BACKGROUND: Climate change will result in more frequent droughts that can impact soil-inhabiting microbiomes (rhizobiomes) in the agriculturally vital North American perennial grasslands. Rhizobiomes have contributed to enhancing drought resilience and stress resistance properties in plant hosts. In the predicted events of more future droughts, how the changing rhizobiome under environmental stress can impact the plant host resilience needs to be deciphered. There is also an urgent need to identify and recover candidate microorganisms along with their functions, involved in enhancing plant resilience, enabling the successful development of synthetic communities. RESULTS: In this study, we used the combination of cultivation and high-resolution genomic sequencing of bacterial communities recovered from the rhizosphere of a tallgrass prairie foundation grass, Andropogon gerardii. We cultivated the plant host-associated microbes under artificial drought-induced conditions and identified the microbe(s) that might play a significant role in the rhizobiome of Andropogon gerardii under drought conditions. Phylogenetic analysis of the non-redundant metagenome-assembled genomes (MAGs) identified a bacterial genome of interest - MAG-Pseudomonas. Further metabolic pathway and pangenome analyses recovered genes and pathways related to stress responses including ACC deaminase; nitrogen transformation including assimilatory nitrate reductase in MAG-Pseudomonas, which might be associated with enhanced drought tolerance and growth for Andropogon gerardii. CONCLUSIONS: Our data indicated that the metagenome-assembled MAG-Pseudomonas has the functional potential to contribute to the plant host's growth during stressful conditions. Our study also suggested the nitrogen transformation potential of MAG-Pseudomonas that could impact Andropogon gerardii growth in a positive way. The cultivation of MAG-Pseudomonas sets the foundation to construct a successful synthetic community for Andropogon gerardii. To conclude, stress resilience mediated through genes ACC deaminase, nitrogen transformation potential through assimilatory nitrate reductase in MAG-Pseudomonas could place this microorganism as an important candidate of the rhizobiome aiding the plant host resilience under environmental stress. This study, therefore, provided insights into the MAG-Pseudomonas and its potential to optimize plant productivity under ever-changing climatic patterns, especially in frequent drought conditions.


Assuntos
Andropogon , Poa , Rizosfera , Secas , Pseudomonas , Filogenia , Nitrogênio , Nitrato Redutases
5.
Mar Genomics ; 66: 100995, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36400548

RESUMO

Pseudomonas sp. strain DNDY-54, a denitrifying bacterium, was isolated from a deep-sea sediment sample from Ninety East Ridge in the Indian Ocean. Here, we show that the complete genome of DNDY-54 has one circular chromosome of 4,412,895 bp with mean 60.57% GC content. The complete genome contains 4111 predicted protein-coding genes, 59 tRNAs, and 4 rRNA operons as 16S-23S-5S rRNA. On the basis of the annotation results, we identified genes that encode 27 proteins related to nitrogen metabolism, including enzymes that make up a complete denitrifying pathway. This work will improve the understanding of nitrogen cycling in the deep biosphere and provides a new candidate for protection of the environment and applications in waste water disposal.


Assuntos
Genoma Bacteriano , Pseudomonas , Pseudomonas/genética , Poliéster Sulfúrico de Pentosana , Análise de Sequência de DNA , RNA Ribossômico 16S/genética , Nitrogênio
6.
Front Immunol ; 13: 1001956, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36389710

RESUMO

Many invasive micro-organisms produce 'quorum sensor' molecules which regulate colony expansion and may modulate host immune responses. We have examined the ability of Pseudomonas Quorum Sensor (PQS) to influence cytokine expression under conditions of inflammatory stress. The administration of PQS in vivo to mice with collagen-induced arthritis (CIA) increased the severity of disease. Blood and inflamed paws from treated mice had fewer regulatory T cells (Tregs) but normal numbers of Th17 cells. However, PQS (1µM) treatment of antigen-stimulated lymph node cells from collagen-immunised mice in vitro inhibited the differentiation of CD4+IFNγ+ cells, with less effect on CD4+IL-17+ cells and no change in CD4+FoxP3+Tregs. PQS also inhibited T cell activation by anti-CD3/anti-CD28 antibodies. PQS reduced murine macrophage polarisation and inhibited expression of IL1B and IL6 genes in murine macrophages and human THP-1 cells. In human monocyte-derived macrophages, IDO1 gene, protein and enzyme activity were all inhibited by exposure to PQS. TNF gene expression was inhibited in THP-1 cells but not murine macrophages, while LPS-induced TNF protein release was increased by high PQS concentrations. PQS is known to have iron scavenging activity and its suppression of cytokine release was abrogated by iron supplementation. Unexpectedly, PQS decreased the expression of indoleamine-2, 3-dioxygenase genes (IDO1 and IDO2), IDO1 protein expression and enzyme activity in mouse and human macrophages. This is consistent with evidence that IDO1 inhibition or deletion exacerbates arthritis, while kynurenine reduces its severity. It is suggested that the inhibition of IDO1 and cytokine expression may contribute to the quorum sensor and invasive actions of PQS.


Assuntos
Cinurenina , Pseudomonas , Humanos , Camundongos , Animais , Cinurenina/metabolismo , Pseudomonas aeruginosa , Ferro/metabolismo , Citocinas/metabolismo
7.
Mar Drugs ; 20(11)2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36422006

RESUMO

Biofilms, responsible for many serious drawbacks in the medical and marine environment, can grow on abiotic and biotic surfaces. Commercial anti-biofilm solutions, based on the use of biocides, are available but their use increases the risk of antibiotic resistance and environmental pollution in marine industries. There is an urgent need to work on the development of ecofriendly solutions, formulated without biocidal agents, that rely on the anti-adhesive physico-chemical properties of their materials. In this context, exopolysaccharides (EPSs) are natural biopolymers with complex properties than may be used as anti-adhesive agents. This study is focused on the effect of the EPS MO245, a hyaluronic acid-like polysaccharide, on the growth, adhesion, biofilm maturation, and dispersion of two pathogenic model strains, Pseudomonas aeruginosa sp. PaO1 and Vibrio harveyi DSM19623. Our results demonstrated that MO245 may limit biofilm formation, with a biofilm inhibition between 20 and 50%, without any biocidal activity. Since EPSs have no significant impact on the bacterial motility and quorum sensing factors, our results indicate that physico-chemical interactions between the bacteria and the surfaces are modified due to the presence of an adsorbed EPS layer acting as a non-adsorbing layer.


Assuntos
Ácido Hialurônico , Vibrio , Ácido Hialurônico/farmacologia , Biofilmes , Percepção de Quorum , Pseudomonas
8.
Int J Mol Sci ; 23(22)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36430408

RESUMO

The B12-producing strains Pseudomonas nitroreducens DSM 1650 and Pseudomonas sp. CCUG 2519 (both formerly Pseudomonas denitrificans), with the most distributed pathway among bacteria for exogenous choline/betaine utilization, are promising recombinant hosts for the endogenous production of B12 precursor betaine by direct methylation of bioavailable glycine or non-proteinogenic ß-alanine. Two plasmid-based de novo betaine pathways, distinguished by their enzymes, have provided an expression of the genes encoding for N-methyltransferases of the halotolerant cyanobacterium Aphanothece halophytica or plant Limonium latifolium to synthesize the internal glycine betaine or ß-alanine betaine, respectively. These betaines equally allowed the recombinant pseudomonads to grow effectively and to synthesize a high level of cobalamin, as well as to increase their protective properties against abiotic stresses to a degree comparable with the supplementation of an exogenous betaine. Both de novo betaine pathways significantly enforced the protection of bacterial cells against lowering temperature to 15 °C and increasing salinity to 400 mM of NaCl. However, the expression of the single plant-derived gene for the ß-alanine-specific N-methyltransferase additionally increased the effectiveness of exogenous glycine betaine almost twofold on cobalamin biosynthesis, probably due to the Pseudomonas' ability to use two independent pathways, their own choline/betaine pathway and the plant ß-alanine betaine biosynthetic pathway.


Assuntos
Betaína , Colina , Betaína/metabolismo , Pseudomonas/genética , Pseudomonas/metabolismo , Estresse Fisiológico/genética , Metiltransferases/metabolismo , beta-Alanina , Vitamina B 12
10.
Int J Syst Evol Microbiol ; 72(11)2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36322606

RESUMO

Five bacterial strains were isolated from symptomatic leaves of Achillea millefolium, Delphinium sp. and Hydrangea sp. in California. Colonies isolated on King's medium B (KMB) appeared white, mucoid and round, similar to Pseudomonas species. Phylogenetic analyses based on 16S rRNA, rpoB, rpoD and gyrB genes placed the bacteria into three distinct groups within Pseudomonas that were most closely related to Pseudomonas viridiflava, Pseudomonas cichorii or Pseudomonas caspiana. To further characterize the strains, phenotypic analyses and the following tests were performed: fatty acid methyl ester composition, LOPAT, fluorescence on KMB, Biolog assay, and transmission electron microscopy. Finally, whole genome sequencing of the strains was conducted, and the sequences were compared with reference genomes of Pseudomonas species based on average nucleotide identity (ANI). The first group, which consists of three strains isolated from delphinium, hydrangea and achillea, had 95.6-96.9 % pairwise ANI between each other; the second group consists of two strains isolated from delphinium that had 100 % pairwise ANI. Although comparisons of the two groups with publicly available genomes revealed closest relationships with P. viridiflava (91.6 %), P. caspiana (88.3 %) and P. asturiensis (86.7 %), ANI values were less than 95 % compared to all validly published pseudomonads. Combining genomic and phenotypic data, we conclude that these strains represent two new species and the names proposed are Pseudomonas quasicaspiana sp. nov. (type strain DSMZ 11 30 42T=LMG 32 434T) for the strains isolated from delphinium, achillea and hydrangea and Pseudomonas californiensis sp. nov. (DSMZ 11 30 43T=LMG 32 432T) for the two strains isolated from delphinium. The specific epithets quasicaspiana and californiensis were selected based on the close phylogenetic relationship of strains with P. caspiana and on the geographic location of isolation, respectively.


Assuntos
Ácidos Graxos , Pseudomonas , RNA Ribossômico 16S/genética , Filogenia , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Análise de Sequência de DNA , Composição de Bases , Hibridização de Ácido Nucleico , Ácidos Graxos/química
12.
Microbiome ; 10(1): 186, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36329505

RESUMO

BACKGROUND: Phytoremediation is a potentially cost-effective way to remediate highly contaminated mine tailing sites. However, nutrient limitations, especially the deficiency of nitrogen (N), can hinder the growth of plants and impair the phytoremediation of mine tailings. Nevertheless, pioneer plants can successfully colonize mine tailings and exhibit potential for tailing phytoremediation. Diazotrophs, especially diazotrophic endophytes, can promote the growth of their host plants. This was tested in a mine-tailing habitat by a combination of field sampling, DNA-stable isotope probing (SIP) analysis, and pot experiments. RESULTS: Bacteria belonging to the genera Herbaspirillum, Rhizobium, Devosia, Pseudomonas, Microbacterium, and Delftia are crucial endophytes for Chinese silvergrass (Miscanthus sinensis) grown in the tailing, the model pioneer plant selected in this study. Further, DNA-SIP using 15N2 identified Pseudomonas, Rhizobium, and Exiguobacterium as putative diazotrophic endophytes of M. sinensis. Metagenomic-binning suggested that these bacteria contained essential genes for nitrogen fixation and plant growth promotion. Finally, two diazotrophic endophytes Rhizobium sp. G-14 and Pseudomonas sp. Y-5 were isolated from M. sinensis. Inoculation of another pioneer plant in mine tailings, Bidens pilosa, with diazotrophic endophytes resulted in successful plant colonization, significantly increased nitrogen fixation activity, and promotion of plant growth. CONCLUSIONS: This study indicated that diazotrophic endophytes have the potential to promote the growth of pioneer plant B. pilosa in mine tailings. Video Abstract.


Assuntos
Endófitos , Poaceae , Poaceae/microbiologia , Fixação de Nitrogênio , Bactérias , Plantas/genética , Pseudomonas/genética , China , DNA , Raízes de Plantas/microbiologia
13.
Zool Res ; 43(6): 952-965, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36208122

RESUMO

Pseudomonas plecoglossicida is the pathogen responsible for visceral white spot disease in large yellow croaker (Larimichthys crocea) and orange-spotted grouper (Epinephelus coioides). Previously, RNA sequencing showed that P. plecoglossicida flgK gene expression was significantly up-regulated in orange-spotted grouper spleens during infection. To explore the role of flgK in P. plecoglossicida pathogenicity, RNA interference (RNAi) was performed to silence the P. plecoglossicida flgK gene, and the mutant (flgK-RNAi strain) with the best silencing efficiency (89.40%) was chosen for further study. Results showed that flgK gene silencing significantly attenuated P. plecoglossicida motility, adhesion, and biofilm formation. Compared to those fish infected with the wild-type strain of P. plecoglossicida, orange-spotted grouper infected with the flgK-RNAi strain showed a 55% increase in the survival rate and a one-day delay in time of first death, with fewer pathogens in the spleen and fewer white spots on the spleen surface. RNAi of flgK significantly affected the transcriptome and metabolome of the spleen in infected orange-spotted grouper. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the C-type lectin receptor signaling pathway was the most significantly changed immune-related pathway and the mitogen-activated protein kinase (MAPK) signaling pathway was related to multiple immune-related pathways. Furthermore, arginine biosynthesis and glycerophospholipid metabolism were the most significantly changed metabolism-related pathways. These findings suggest that flgK is a virulence gene of P. plecoglossicida. Furthermore, flgK appears to be involved in the regulation of motility, adhesion, and biofilm formation in P. plecoglossicida, as well as in the regulation of inflammatory and immune responses of orange-spotted grouper to P. plecoglossicida infection.


Assuntos
Bass , Perciformes , Infecções por Pseudomonas , Animais , Arginina/genética , Proteínas de Bactérias/genética , Bass/genética , Bass/metabolismo , Proteínas de Peixes/genética , Glicerofosfolipídeos , Interações Hospedeiro-Patógeno/genética , Imunidade Inata , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Perciformes/genética , Perciformes/metabolismo , Pseudomonas , Infecções por Pseudomonas/veterinária , Transcriptoma , Virulência/genética
14.
Int J Syst Evol Microbiol ; 72(10)2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36256565

RESUMO

A Gram-stain-negative, aerobic, rod-shaped and non-motile novel bacterial strain, designated MAHUQ-58T, was isolated from soil sample of a rice field. The colonies were observed to be light pink-coloured, smooth, spherical and 0.6-1.0 mm in diameter when grown on nutrient agar (NA) medium for 2 days. Strain MAHUQ-58T was found to be able to grow at 15-40 °C, at pH 5.5-10.0 and with 0-1.0 % NaCl (w/v). Cell growth occurred on tryptone soya agar, Luria-Bertani agar, NA, MacConkey agar and Reasoner's 2A agar. The strain was found to be positive for both oxidase and catalase tests. The strain was positive for hydrolysis of Tween 20 and l-tyrosine. According to the 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Pseudomonas and to be closely related to Pseudomonas oryzae WM-3T (98.9 % similarity), Pseudomonas linyingensis LYBRD3-7T (97.7 %), Pseudomonas sagittaria JCM 18195 T (97.6 %) and Pseudomonas guangdongensis SgZ-6T (97.2 %). The novel strain MAHUQ-58T has a draft genome size of 4 536 129 bp (46 contigs), annotated with 4064 protein-coding genes, 60 tRNA genes and four rRNA genes. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain MAHUQ-58T and four closely related type strains were in the range of 85.5-89.5 % and 29.5-38.0 %, respectively. The genomic DNA G+C content was determined to be 67.0 mol%. The predominant isoprenoid quinone was ubiquinone 9. The major fatty acids were identified as C16:0, summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) and summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c). On the basis of dDDH and ANI values, genotypic results, and chemotaxonomic and physiological data, strain MAHUQ-58T represents a novel species within the genus Pseudomonas, for which the name Pseudomonas oryzagri sp. nov. is proposed, with MAHUQ-58T (=KACC 22005T=CGMCC 1.18518T) as the type strain.


Assuntos
Oryza , RNA Ribossômico 16S/genética , Composição de Bases , Solo , DNA Bacteriano/genética , Filogenia , Ágar , Cloreto de Sódio , Polissorbatos , Catalase/genética , Técnicas de Tipagem Bacteriana , Análise de Sequência de DNA , Ácidos Graxos/química , Pseudomonas , Quinonas , Nucleotídeos , Terpenos , Tirosina
15.
Adv Exp Med Biol ; 1386: 117-143, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36258071

RESUMO

Pseudomonas is a bacterial genus, with a bona fide environmental habitat that comprises different species, some of them causing diseases in humans and plants, as well as some strains with biotechnological potential. Amongst them, Pseudomonas aeruginosa is currently one of the most important nosocomial pathogens. In addition, this microorganism is a prevalent cause of chronic infections in cystic fibrosis patients and in people suffering from chronic obstructive pulmonary disease. The success of P. aeruginosa in colonising different habitats largely relies on its metabolic versatility and robustness. Besides, this bacterial pathogen harbours in its core genome a large set of virulence determinants that allows it to colonise/infect a variety of hosts, from unicellular organisms to humans. Nevertheless, these are not just the only conditions needed for infecting patients at hospitals. Taking into consideration that infected patients are regularly under antibiotic treatment, the ability to avoid antibiotics' action is also needed. In this sense, P. aeruginosa displays a characteristic low susceptibility to several antibiotics currently used in therapy. This is due to the reduced permeability of its cellular envelopes and the presence in its genome of an arrangement of genes encoding multidrug efflux pumps and antibiotic-inactivating enzymes that contribute to its resilience to antibiotics. Besides intrinsic resistance, P. aeruginosa is able to evolve towards antibiotic resistance through mutations (particularly relevant in the case of chronic infections) and via acquisition of antibiotic resistance genes. It is worth mentioning that acquired resistance is not the only venue that P. aeruginosa has for avoiding the action of antibiotics. Transient resistance can also confer this phenotype. Indeed, the induction of the expression of intrinsic resistance genes by conditions or compounds that P. aeruginosa could face during infection can compromise the effectiveness of antibiotics for treating such infections. In addition, tolerant cells able to survive during the exposure to bactericidal antibiotics without an increase in their antibiotic resistance phenotype are found as well in these patients, and they are the prelude of the evolution towards antibiotic resistance. Finally, P. aeruginosa biofilms, frequently encountered in the lungs of cystic fibrosis patients, in prostheses, or in catheters, present low antibiotic susceptibility and are associated with recalcitrance and disease worsening.


Assuntos
Fibrose Cística , Infecções por Pseudomonas , Humanos , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Fibrose Cística/tratamento farmacológico , Fibrose Cística/genética , Fibrose Cística/microbiologia , Pseudomonas , Pseudomonas aeruginosa/genética , Resistência Microbiana a Medicamentos/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Testes de Sensibilidade Microbiana
16.
Int J Mol Sci ; 23(19)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36232800

RESUMO

Pyoverdines (PVDs) are a class of siderophores produced mostly by members of the genus Pseudomonas. Their primary function is to accumulate, mobilize, and transport iron necessary for cell metabolism. Moreover, PVDs also play a crucial role in microbes' survival by mediating biofilm formation and virulence. In this review, we reorganize the information produced in recent years regarding PVDs biosynthesis and pathogenic mechanisms, since PVDs are extremely valuable compounds. Additionally, we summarize the therapeutic applications deriving from the PVDs' use and focus on their role as therapeutic target themselves. We assess the current biotechnological applications of different sectors and evaluate the state-of-the-art technology relating to the use of synthetic biology tools for pathway engineering. Finally, we review the most recent methods and techniques capable of identifying such molecules in complex matrices for drug-discovery purposes.


Assuntos
Oligopeptídeos , Sideróforos , Ferro/metabolismo , Oligopeptídeos/metabolismo , Pseudomonas/metabolismo , Pseudomonas aeruginosa/metabolismo , Sideróforos/metabolismo
17.
J Microbiol Biotechnol ; 32(11): 1416-1426, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36310358

RESUMO

The need to discover new types of antimicrobial agents has grown since the emergence of antibiotic-resistant pathogens that threaten human health. The world's oceans, comprising complex niches of biodiversity, are a promising environment from which to extract new antibiotics-like compounds. In this study, we newly isolated Pseudomonas sp. NIBR-H-19 from the gut of the sea roach Ligia exotica and present both phenotypes and genomic information consisting of 6,184,379 bp in a single chromosome possessing a total of 5,644 protein-coding genes. Genomic analysis of the isolated species revealed that numerous genes involved in antimicrobial secondary metabolites are predicted throughout the whole genome. Moreover, our analysis showed that among twenty-five pathogenic bacteria, the growth of three pathogens, including Staphylococcus aureus, Streptococcus hominis and Rhodococcus equi, was significantly inhibited by the culture of Pseudomonas sp. NIBR-H-19. The characterization of marine microorganisms with biochemical assays and genomics tools will help uncover the biosynthesis and action mechanism of antimicrobial metabolites for development as antagonistic probiotics against fish pathogens in an aquatic culture system.


Assuntos
Pseudomonas , Infecções Estafilocócicas , Animais , Humanos , Pseudomonas/genética , Pseudomonas/metabolismo , Antibacterianos , Staphylococcus aureus , República da Coreia
18.
Appl Microbiol Biotechnol ; 106(23): 7699-7709, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36271255

RESUMO

Pseudomonas species are metabolically versatile bacteria able to exploit a wide range of ecological niches. Different Pseudomonas species can grow as free-living cells, biofilms, or associated with plants or animals, including humans, and their ecological success partially lies in their ability to grow and adapt to different temperatures. These bacteria are relevant for human activities, due to their clinical importance and their biotechnological potential for different applications such as bioremediation and the production of biopolymers, surfactants, secondary metabolites, and enzymes. In agriculture, some of them can act as plant growth promoters and are thus used as inoculants, whereas others, like P. syringae pathovars, can cause disease in commercial crops. This review aims to provide an overview of the temperature-response mechanisms in Pseudomonas species, looking for novel features or strategies based on techniques such as transcriptomics and proteomics. We focused on temperature-dependent traits mainly associated with virulence, host colonization, survival, and production of secondary metabolites. We analyzed human, animal, and plant pathogens and plant growth-promoting Pseudomonas species, including P. aeruginosa, P. plecoglossicida, several P. syringae pathovars, and P. protegens. Our aim was to provide a comprehensive view of the relevance of temperature-response traits in human and animal health and agricultural applications. Our analysis showed that features relevant to the bacterial-host interaction are adjusted to the environmental or host temperature regardless of the optimal growth temperature in the laboratory, and thus contribute to improving bacterial fitness. KEY POINTS: • In Pseudomonas species, temperature impacts the bacterial-host interaction. • Interaction traits are expressed at temperatures different from the optimal reported. • The bacterial-host interaction could be affected by climate change.


Assuntos
Proteínas de Bactérias , Pseudomonas , Animais , Humanos , Pseudomonas/metabolismo , Temperatura , Proteínas de Bactérias/metabolismo , Interações Hospedeiro-Patógeno , Virulência , Plantas/metabolismo , Pseudomonas syringae
19.
Int J Biol Macromol ; 222(Pt A): 1511-1521, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183760

RESUMO

In this study, 7 Pseudomonas strains were isolated from a wastewater treatment plant, and the alginate production of Pseudomonas strains under different environmental conditions was evaluated. Subsequently, alginate-biomass hydrogel beads were prepared using alginate and biomass of Pseudomonas, and their adsorption performances and mechanism to Pb2+ and Cd2+ were analyzed. The results show that weakly acidic pH and 37 °C is favorable for alginate synthesis of Pseudomonas strains, and P. alcaligenes YLS18 have the highest alginate yield (29.4 mg/g). The adsorption processes of Pb2+ and Cd2+ by hydrogel beads are well described by Langmuir model, indicating that the adsorption process is monolayer. Among the biomass of these strains, P. nitroreducens YLB32 shows the highest biosorption capacities, reaching 110.7 mg/g for Pb2+ and 54.3 mg/g for Cd2+ at pH 5. Alginate-biomass hydrogel beads obtain higher adsorption capacity to Pb2+ (184.0 mg/g) and Cd2+ (92.4 mg/g), and exhibit good reusability. The adsorption mechanism of Pb2+ and Cd2+ by hydrogel beads involves physical tapping of ions, electrostatic interactions, complexation, cation exchange and precipitation. These results provide strong support for promoting alginate recovery from activated sludge and for treating heavy metal wastewater.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Biomassa , Alginatos , Cádmio , Pseudomonas , Hidrogéis , Chumbo , Concentração de Íons de Hidrogênio , Cinética
20.
Water Sci Technol ; 86(8): 1859-1875, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36315081

RESUMO

Biosurfactant are Surfactants produced by certain microorganisms. These biosurfactants increase the biodegradability of insoluble pollutants. In this study, the fermentation products of Pseudomonas stutzeri Lh-42 (PS) and Rhodococcus sp. PR-1 (RD) were studied by Oil spreading method, emulsifying activity and infrared spectrum analysis. It was proved that these fermentation products were biosurfactant. And then the fermentation conditions of PS, RD were optimised by Placket-Burman (PB) design, hill-climbing experiment and response surface methodology (RSM). N source and liquid loading were significant factors in the fermentation of PS, while C source and speed were significant factors in the fermentation of RD. The surface tension was found to be as low as 39.53 ± 0.25 mN/m for the fermentation conditions of PS with an N source of 4.62 ± 0.41 g and a liquid loading of 28.4 ± 0.3%. The surface tension was 40.70 ± 0.47 mN/m for the incubation conditions of RD with a C source of 26.94 ± 0.62 g and a rotational speed of 210 r/min. Finally, the experimental results for the degradation of oily sludge showed that the degradation rate of oily sludge was improved when the fermentation conditions were optimised. The results of the infrared spectroscopy analysis showed that the organic matter content of the oily sludge treated with PS bacteria was significantly reduced after the optimised fermentation. This study provides a theoretical reference for further use of these bacteria to produce biosurfactants to treat organic matter.


Assuntos
Bactérias , Esgotos , Esgotos/química , Bactérias/metabolismo , Tensoativos/química , Fermentação , Pseudomonas/metabolismo
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