Biosurfactant production by a soil pseudomonas strain growing on polycyclic aromatic hydrocarbons

Déziel, Éric; Paquette, Gilles; Villemur, Richard; Lépine, François; Bisaillon, Jean‐Guy

doi:10.1128/aem.62.6.1908-1912.1996

Cited by 284 publications

(111 citation statements)

References 49 publications

(47 reference statements)

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“…The secondary metabolite rhamnolipid is expressed in the onset of the stationary phase (Deziel et al, 1996) and similar effects of the mild heat treatment on the bacterial surface were reported for the biosurfactant rhamnolipid of P. aeruginosa (Al Tahhan et al, 2000;Sotirova et al, 2007).…”

Section: Discussionsupporting

confidence: 71%

Rhamnolipid-induced shedding of flagellin fromPseudomonas aeruginosaprovokes hBD-2 and IL-8 response in human keratinocytes

Gerstel

Czapp

Bartels

et al. 2009

Cellular Microbiology

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SummarySeveral 'pathogen-associated molecular pattern' (PAMP) of the opportunistic pathogen Pseudomonas aeruginosa activate the innate immune system in epithelial cells. Particularly the production of antimicrobial peptides such as the human betadefensin-2 (hBD-2) and proinflammatory cytokines as the interleukin (IL)-8 is boosted. In the present study culture supernatants of static grown P. aeruginosa were found to be potent hBD-2 and IL-8 inducers, indicating a soluble or shedded PAMP, comparable to that of heat-killed bacterial supernatants. In subsequent analyses this PAMP was identified as flagellin, the major structural protein of the flagella. Flagellin is known to be an immunostimulatory potent factor, but the mechanisms by which P. aeruginosa is able to remove flagellin from the flagella remain unknown. Here we provide evidence for the presence of a factor responsible for release of flagellin from the flagella. Purification of this factor and subsequent mass spectrometry analyses identified rhamnolipids as responsible agents. Our findings indicate that maybe upon adhesion to surfaces P. aeruginosa alters the outer membrane composition in a rhamnolipid-depending manner, thereby shedding flagellin from the flagella. In turn epithelial cells recognize flagellin and cause the synthesis of antimicrobial peptides as well as recruitment of inflammatory cells by induction of proinflammatory cytokines.

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Section: Discussionsupporting

confidence: 71%

Rhamnolipid-induced shedding of flagellin fromPseudomonas aeruginosaprovokes hBD-2 and IL-8 response in human keratinocytes

Gerstel

Czapp

Bartels

et al. 2009

Cellular Microbiology

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“…Organisms from the Pseudomonas genus are common in freshwater ecosystems and are known for their ability to produce biofilms (Palleroni 2010) and for their ability to degrade a large variety of organic molecules (Palleroni 2010). Some Pseudomonas strains can degrade common urban pollutants such as benzene and toluene (Reardon et al 2000), polycyclic aromatic hydrocarbons (Deziel et al 1996), and polychlorinated biphenyls (Hickey and Focht 1990). Therefore, the decrease in abundance of Pseudomonas within biofilms in response to ciprofloxacin exposure that was observed in our study could have significant implications for the ability of urban stream biofilms to process a number of urban contaminants.…”

Section: Discussionmentioning

confidence: 99%

Urban stream microbial communities show resistance to pharmaceutical exposure

et al. 2018

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Abstract. Residues of pharmaceuticals are increasingly detected in surface waters throughout the world.In four streams in Baltimore, Maryland, USA, we detected analgesics, stimulants, antihistamines, and antibiotics using passive organic samplers. We exposed biofilm communities in these streams to the common drugs caffeine, cimetidine, ciprofloxacin, and diphenhydramine. Respiration rates in the least urban stream were suppressed when exposed to these drugs, but biofilm functioning in the most urban stream was resistant to drug exposure. Exposure to the antibiotic ciprofloxacin altered bacterial community composition at all sites, with the greatest change occurring in the most urban stream. These results indicated that continuous exposure to drugs in urban streams may select for sub-populations of highly resistant bacteria that maintain community function in response to urban contaminants.

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“…Bacterial cells increase the aqueous concentrations of organic compounds by the active production of a surfactant [24]. In addition, through passive adsorption of compounds to colloidal bacterial cells, the partitioning of a compound between the adsorbed and aqueous phase may be altered.…”

Section: Discussionmentioning

confidence: 99%

INTERACTIONS BETWEEN SOIL, TOXICANT, AND A lux-MARKED BACTERIUM DURING SOLID PHASE–CONTACT TOXICITY TESTING

Shaw¹,

Beaton²,

Glover³

et al. 2000

Environ Toxicol Chem

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Abstract-Bioluminescence-based, solid-contact toxicity assays allow test bacterium and toxicant to interact at the solid-solution interface. A lux-marked bacterium, Burkholderia sp. RASC, and 2,4-dichlorophenol (2,4-DCP) were used to characterize these interactions. In the basic bioassay, cells were added to soil slurries containing 2,4-DCP (0-120 g ml Ϫ1 ). After 15 min, soil was removed by centrifugation, and bioluminescence in the supernatant was determined. Investigation of 2,4-DCP adsorption to soil revealed that sorption was linear and not significantly (p Ͼ 0.1) affected by the presence of Burkholderia cells. The numbers of culturable Burkholderia cells in the assay supernatant were 48.2 to 64.8% of the inoculum and independent of the soil weight. The effect of soil on 2,4-DCP toxicity was investigated by comparing soil aqueous extract and contact assays. The percentage bioluminescence for the contact assay was consistently higher than the extract assay at all test concentrations, and counts of viable Burkholderia cells were enhanced by the presence of 2,4-DCP in the contact assay. Expressing results as specific bioluminescence decreased the variability in response and the discrepancy in results between the two protocols. We suggest that solid-contact assays need improvement to ensure defined contact between cells and solid phase, and that the reporting of specific activity should be emphasized.

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Biosurfactant production by a soil pseudomonas strain growing on polycyclic aromatic hydrocarbons

Cited by 284 publications

References 49 publications

Rhamnolipid-induced shedding of flagellin fromPseudomonas aeruginosaprovokes hBD-2 and IL-8 response in human keratinocytes

Rhamnolipid-induced shedding of flagellin fromPseudomonas aeruginosaprovokes hBD-2 and IL-8 response in human keratinocytes

Urban stream microbial communities show resistance to pharmaceutical exposure

INTERACTIONS BETWEEN SOIL, TOXICANT, AND A lux-MARKED BACTERIUM DURING SOLID PHASE–CONTACT TOXICITY TESTING

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