Search results for "Pseudomona"
showing 10 items of 370 documents
Diversity and Evolution of the Phenazine Biosynthesis Pathway
2010
ABSTRACT Phenazines are versatile secondary metabolites of bacterial origin that function in biological control of plant pathogens and contribute to the ecological fitness and pathogenicity of the producing strains. In this study, we employed a collection of 94 strains having various geographic, environmental, and clinical origins to study the distribution and evolution of phenazine genes in members of the genera Pseudomonas , Burkholderia , Pectobacterium , Brevibacterium , and Streptomyces . Our results confirmed the diversity of phenazine producers and revealed that most of them appear to be soil-dwelling and/or plant-associated species. Genome analyses and comparisons of phylogenies inf…
Shedding light on biogas: a transparent reactor triggers the development of a biofilm dominated by Rhodopseudomonas faecalis that holds potential for…
2019
AbstractConventional anaerobic digesters intended for the production of biogas usually operate in complete darkness. Therefore, little is known about the effect of light on microbial communities operating in anaerobic digesters. In the present work, we have studied through 16S rRNA gene amplicon Nanopore sequencing and shotgun metagenomic sequencing the taxonomic and functional structure of the microbial community forming a biofilm on the inner wall of a lab-scale transparent anaerobic biodigester illuminated with natural sunlight. The biofilm was composed of microorganisms involved in the four metabolic processes needed for biogas production. The biofilm proved surprisingly rich in Rhodops…
Antimicrobial peptides from echinoderms as antibiofilm agents: a natural strategy to combat bacterial infections
2014
AbstractIncreased attention has been focused on marine invertebrates as a source of bioactive molecules for biomedical applications. Many bioactive molecules are part of the innate immune system. Some more recently isolated compounds, mainly from the sea urchin and the sea cucumber, are antimicrobial peptides (AMPs) active against Gram-positive and Gram-negative bacteria, and fungi. In this review we described the most recent studies on AMPs isolated from echinoderms. AMPs are small peptides (< 10 kDa) with cationic charge and amphipathic structure. Recently, it was demonstrated that in the coelomocyte lysates of Paracentrotus lividus and Holothuria tubulosa, AMPs possess activity against s…
Development of a Higee bioreactor (HBR) for production of polyhydroxyalkanoate: Hydrodynamics, gas–liquid mass transfer and fermentation studies
2010
Abstract This study addresses the hydrodynamics and mass transfer characterisation of a Higee bioreactor (HBR) for application to polyhydroxyalkanoate (PHA) production from Pseudomonas putida KT2442 fermentation. The motivation for this work is to address the potential oxygen transfer limitations which can severely impede the progress of this aerobic fermentation process and reduce PHA productivity in conventional bioreactors. It is shown that a maximum of 2.5 transfer units can be achieved in an oxygen-stripping operation where the presence of packing, higher rotor speeds, higher air flowrates and lower liquid flowrates all have a positive influence on the number of transfer units (NTU). W…
Multiresistant waterborne pathogens isolated from water reservoirs and cooling systems
2008
Aims: To determine the incidence of multiple antibiotic-resistant strains of the emergent human pathogens Legionella pneumophila, Pseudomonas aeruginosa and mesophilic Aeromonas species among those isolated from water reservoirs and industrial cooling systems. Methods and Results: Water from four natural water reservoirs and four industrial cooling towers was sampled for 1 year period. The total heterotrophs, mesophilic Aeromonas, Pseudomonas spp. and Legionella spp. counts were performed as recommended by standard procedures, and the sensitivity of the isolates to 27 antibiotics was tested. A total of 117 Aeromonas, 60 P. aeruginosa and 15 L. pneumophila strains were isolated and identif…
The establishment of an introduced community of fluorescent pseudomonads in the soil and in the rhizosphere is affected by the soil type
1999
Indigenous populations of fluorescent pseudomonads were previously shown to vary in two different soils (Châteaurenard and Dijon) and in the rhizosphere of a plant species (Linum usitatissimum L.) cultivated in these two soils. These differences could be related to the soil type and to their crop history. In the present study, the influence of the soil type on the diversity of fluorescent pseudomonads in bulk and rhizospheric soils was evaluated. The soils of Châteaurenard and Dijon were sterilized before being inoculated with the same community of fluorescent pseudomonads. Bacterial isolates from bulk and rhizospheric soils were characterized on the basis of their repetitive extragenic pal…
The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugata
2018
Cyclic lipopeptides (CLPs) are considered as some of the most important secondary metabolites in different plant-associated bacteria, thanks to their antimicrobial, cytotoxic, and surfactant properties. In this study, our aim was to investigate the role of the Quorum Sensing (QS) system, PcoI/PcoR, and the LuxR-type transcriptional regulator RfiA in CLP production in the phytopatogenic bacterium, Pseudomonas corrugata based on our previous work where we reported that the pcoR and rfiA mutants were devoid of the CLPs cormycin and corpeptin production. Due to the close genetic link between the QS system and the RfiA (rfiA is co-transcribed with pcoI), it was difficult to ascertain the specifi…
Evaluation of the in-vitro cidal activity and toxicity of a novel peroxygen biocide: 2-butanone peroxide
2007
The monomer of 2-butanone peroxide is a novel peroxygen derivative with potential use as biocide in the hospital environment. The aim of this study was to test the biocidal activity of different concentrations of the compound against American Tissue Culture Collection strains from 11 different micro-organisms, including bacteria, mycobacteria, spores, fungi and virus, following the European Standard guidelines. Toxicity tests were also carried out following United States Environmental Protection Agency Standards. 2-Butanone peroxide exhibited biocidal activity at 0.12% against Legionella pneumophila, at 0.5% against Escherichia coli, Pseudomonas aeruginosa and Enterococcus hirae, and at 1% …
Suppression of Saprolegnia infections in rainbow trout (Oncorhynchus mykiss) eggs using protective bacteria and ultraviolet irradiation of the hatche…
2014
Since formalin is widely used in prevention of Sapro- legnia infections in salmonid fish hatcheries, there is a need for more environmentally safe treatment methods. Therefore, we screened 360 bacterial iso- lates against their ability to antagonize the growth of Saprolegnia parasitica hyphae in vitro, and best strains were selected according to their antagonistic proper- ties and colonization capability on rainbow trout egg surface. Protective bacterial cultures of Pseudomonas sp. M162, Pseudomonas sp. M174 and Janthinobacte- rium M169 were tested for prevention of Saprolegnia sp. infections during incubation trials of rainbow trout (Oncorhynchus mykiss )e ggs with UV irradiated (400 mWs c…
Epidemiología molecular y genómica de aislados resistentes de Pseudomonas aeruginosa de origen hospitalario.
2019
Pseudomonas aeruginosa es un patógeno frecuente en entornos hospitalarios que acumula multitud de resistencias a antibióticos. Ante la dificultad de encontrar tratamiento efectivo, los pacientes están mucho tiempo colonizados y aumenta la probabilidad de transmisión. El principal objetivo del presente trabajo ha sido mostrar cómo el estudio evolutivo a nivel de genomas completos puede ser útil para la detección de transmisiones a diferentes niveles. Se decidió aplicar la misma metodología de reconstrucción de la filogenia a partir de las variantes encontradas en genomas completos que además se dataron por métodos bayesianos. Para ello, hemos contado con muestras de P. aeruginosa multirresis…