scholarly journals Modeling rhamnolipids production by Pseudomonas aeruginosa from immiscible carbon source in a batch system

2011 ◽  
Vol 8 (3) ◽  
pp. 471-482 ◽  
Author(s):  
S. A. Medina-Moreno ◽  
D. Jiménez-Islas ◽  
J. N. Gracida-Rodríguez ◽  
M. Gutiérrez-Rojas ◽  
I. J. Díaz-Ramírez
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbon Source ◽  
Batch System

Degradation of lineal alkylbenzene sulphonate (LAS) in an acidogenic reactor bioaugmented with a Pseudomonas aeruginosa (M113) strain

2001 ◽  
Vol 44 (4) ◽  
pp. 183-188 ◽  
Author(s):  
F. J. Almendariz ◽  
M. Meráz ◽  
G. Soberón ◽  
O. Monroy
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbon Source ◽  
Two Stage ◽  
Acidogenic Reactor ◽  
Anaerobic System

The degradation of of lineal alkylbenzene sulphonate (LAS) was studied in a two-stage anaerobic system where the acidogenic reactor was bioaugmented with a strain of Pseudomonas aeruginosa (M113). This is a strain, which under aerobic and denitrifying conditions uses LAS as carbon source. Results show that LAS was only degraded within the acidogenic stage while in the methanogenic reactor there was no degradation and eventually there was an inhibition due to a LAS accumulation in the sludge. During the experiment, the M113 strain remained in the acidogenic conglomerate (at around 104 CFU/mL) although there is no evidence of their involvement in LAS degradation.

Rhamnolipids stabilize quorum sensing mediated cooperation in Pseudomonas aeruginosa

2020 ◽  
Vol 367 (10) ◽  
Author(s):  
Rodolfo García-Contreras ◽  
Daniel Loarca ◽  
Caleb Pérez-González ◽  
J Guillermo Jiménez-Cortés ◽  
Abigail Gonzalez-Valdez ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Carbon Source ◽  
Public Goods ◽  
Sole Carbon Source ◽  
Regulatory Genes ◽  
Chronic Infections ◽  
Toxic Metabolites ◽  
Serial Cultivation ◽  
Selection Of

ABSTRACT Pseudomonas aeruginosa is one of the main models to study social behaviors in bacteria since it synthesizes several exoproducts, including exoproteases and siderophores and release them to the environment. Exoproteases and siderophores are public goods that can be utilized by the individuals that produce them but also by non-producers, that are considered social cheaters. Molecularly exoprotease cheaters are mutants in regulatory genes such as lasR, and are commonly isolated from chronic infections and selected in the laboratory upon serial cultivation in media with protein as a sole carbon source. Despite that the production of exoproteases is exploitable, cooperators have also ways to restrict the growth and selection of social cheaters, for instance by producing toxic metabolites like pyocyanin. In this work, using bacterial competitions, serial cultivation and growth assays, we demonstrated that rhamnolipids which production is regulated by quorum sensing, selectively affect the growth of lasR mutants and are able to restrict social cheating, hence contributing to the maintenance of cooperation in Pseudomonas aeruginosa populations.

Carbon source effects on the mono/dirhamnolipid ratio produced by Pseudomonas aeruginosa L05, a new human respiratory isolate

2017 ◽  
Vol 39 ◽  
pp. 36-41 ◽  
Author(s):  
Marco S. Nicolò ◽  
Maria G. Cambria ◽  
Giuseppe Impallomeni ◽  
Maria G. Rizzo ◽  
Cinzia Pellicorio ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbon Source ◽  
Source Effects ◽  
Respiratory Isolate

Purification of Contaminated Water with Chromium (VI) Using Pseudomonas aeruginosa

2016 ◽  
Vol 721 ◽  
pp. 143-148 ◽  
Author(s):  
Nora Noureddine ◽  
Samia Benhammadi ◽  
Fouad Kara ◽  
Hakim Aguedal ◽  
Abdelkader Iddou ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Hexavalent Chromium ◽  
Contact Time ◽  
Culture Broth ◽  
Contaminated Water ◽  
Toxic Heavy Metals ◽  
Initial Concentration ◽  
Chromium Vi ◽  
Batch System ◽  
Uncontaminated Soil

A bacterial strain Pseudomonas aeruginosa isolated from an uncontaminated soil has been used for the removal of hexavalent chromium (Cr (VI)). The experiments were carried out in batch system in a culture broth. The results obtained have shown that 100% of Cr (VI) are removed. Contact time, initial concentration of the hexavalent chromium, temperature, as well as the nature of the culture broth have influenced this elimination. To the initial concentration of 20g/L of Cr (VI) the elimination rates are lower, while the reverse occurs for an initial concentration of 8g/L. This study allows considering the use of Pseudomonas aeruginosa in the treatment of water polluted by toxic heavy metals such as Cr (VI).

Antigenic variation and increase in pathogenicity in Pseudomonas aeruginosa as a result of growth on glucose or N-hexadecane as sole carbon source

1978 ◽  
Vol 24 (6) ◽  
pp. 675-679 ◽  
Author(s):  
Robert S. Stinson ◽  
D. E. Talburt
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbon Source ◽  
Outer Membrane ◽  
Sole Carbon Source ◽  
Antigenic Variation ◽  
Protein Composition ◽  
Cell Types ◽  
Additional Protein

When Pseudomonas aeruginosa is grown on glucose as opposed to n-hexadecane as the sole carbon source, the antigenicity, virulence, and protein composition of the outer membrane are altered. The hydrocarbon-grown cells demonstrate a 3-log increase in virulence over the glucose-grown cells (in mice). There also appears to be an additional protein present in the outer membrane of the n-hexadecane-grown cells. This protein may contribute to the observed antigenic differences between the two cell types.

scholarly journals Utilization of Crude Glycerol as a Substrate for the Production of Rhamnolipid by Pseudomonas aeruginosa

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Walaa A. Eraqi ◽  
Aymen S. Yassin ◽  
Amal E. Ali ◽  
Magdy A. Amin
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbon Source ◽  
Sodium Nitrate ◽  
Sole Carbon Source ◽  
Crude Glycerol ◽  
Screening Program ◽  
Waste Glycerol ◽  
Pharmaceutical Industries ◽  
Microbial Isolates ◽  
Biodiesel Industry

Biosurfactants are produced by bacteria or yeast utilizing different substrates as sugars, glycerol, or oils. They have important applications in the detergent, oil, and pharmaceutical industries. Glycerol is the product of biodiesel industry and the existing glycerol market cannot accommodate the excess amounts generated; consequently, new markets for refined glycerol need to be developed. The aim of present work is to optimize the production of microbial rhamnolipid using waste glycerol. We have developed a process for the production of rhamnolipid biosurfactants using glycerol as the sole carbon source by a local Pseudomonas aeruginosa isolate that was obtained from an extensive screening program. A factorial design was applied with the goal of optimizing the rhamnolipid production. The highest production yield was obtained after 2 days when cells were grown in minimal salt media at pH 6, containing 1% (v/v) glycerol and 2% (w/v) sodium nitrate as nitrogen source, at 37°C and at 180 rpm, and reached 2.164 g/L after 54 hours (0.04 g/L h). Analysis of the produced rhamnolipids by TLC, HPLC, and FTIR confirmed the nature of the biosurfactant as monorhamnolipid. Glycerol can serve as a source for the production of rhamnolipid from microbial isolates providing a cheap and reliable substrate.

scholarly journals The Pseudomonas aeruginosa devB/SOL Homolog,pgl, Is a Member of the hex Regulon and Encodes 6-Phosphogluconolactonase

2000 ◽  
Vol 182 (14) ◽  
pp. 3934-3941 ◽  
Author(s):  
Paul W. Hager ◽  
M. Worth Calfee ◽  
Paul V. Phibbs
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbon Source ◽  
Normal Growth ◽  
Wild Type ◽  
Reading Frame ◽  
Cell Extracts ◽  
Genes Encoding ◽  
Type Rate ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Wild Type Rate

ABSTRACT A cyclic version of the Entner-Doudoroff pathway is used byPseudomonas aeruginosa to metabolize carbohydrates. Genes encoding the enzymes that catabolize intracellular glucose to pyruvate and glyceraldehyde 3-phosphate are coordinately regulated, clustered at 39 min on the chromosome, and collectively form thehex regulon. Within the hex cluster is an open reading frame (ORF) with homology to the devB/SOLfamily of unidentified proteins. This ORF encodes a protein of either 243 or 238 amino acids; it overlaps the 5′ end of zwf (encodes glucose-6-phosphate dehydrogenase) and is followed immediately by eda (encodes the Entner-Doudoroff aldolase). The devB/SOL homolog was inactivated in P. aeruginosa PAO1 by recombination with a suicide plasmid containing an interrupted copy of the gene, creating mutant strain PAO8029. PAO8029 grows at 9% of the wild-type rate using mannitol as the carbon source and at 50% of the wild-type rate using gluconate as the carbon source. Cell extracts of PAO8029 were specifically deficient in 6-phosphogluconolactonase (Pgl) activity. The cloned devB/SOL homolog complemented PAO8029 to restore normal growth on mannitol and gluconate and restored Pgl activity. Hence, we have identified this gene as pgland propose that the devB/SOL family members encode 6-phosphogluconolactonases. Interestingly, three eukaryotic glucose-6-phosphate dehydrogenase (G6PDH) isozymes, from human, rabbit, and Plasmodium falciparum, contain Pgl domains, suggesting that the sequential reactions of G6PDH and Pgl are incorporated in a single protein. 6-Phosphogluconolactonase activity is induced in P. aeruginosa PAO1 by growth on mannitol and repressed by growth on succinate, and it is expressed constitutively in P. aeruginosa PAO8026 (hexR). Taken together, these results establish that Pgl is an essential enzyme of the cyclic Entner-Doudoroff pathway encoded by pgl, a structural gene of the hex regulon.

Sign in / Sign up

Export Citation Format

Share Document