BACKGROUND Pseudomonas aeruginosa frequently colonises intubated patients and causes life-threatening ventilator-associated pneumonia (VAP). The role of quorum sensing (QS), regulating virulence in this pathogen, during colonisation and development of VAP is unknown. METHODS P aeruginosa isolates and tracheal aspirates were prospectively collected from intubated patients. Genotypes and QS-ind...

Rhamnolipid as a potent natural biosurfactant has a wide range of potential applications, including enhanced oil recovery, biodegradation, and bioremediation. Observation of tensio-active indicated that biosurfactants were produced by the newly isolated and promising strain Pseudomonas putida. The biosurfactants were identified as rhamnolipids, the amphiphilic surfaceactive glycolipids usually ...

Abstract Surfactants represent a large group of industrial relevant substances and can be generated chemically, but also biologically. Important microbial producers are several Pseudomonas species, mainly known for their ability to produce rhamnolipids. For safety reasons, recombinant putida is preferred heterologous production rhamnolipids as well its precursor 3-(3-hydroxyalkanoyloxy) alkanoi...

Elastase LasB, an important extracellular virulence factor, is shown to play an important role in the pathogenicity of Pseudomonas aeruginosa during host infection. However, the role of LasB in the life cycle of P. aeruginosa is not completely understood. This report focuses on the impact of LasB on biofilm formation of P. aeruginosa PAO1. Here, we reported that the lasB deletion mutant (ΔlasB)...

Quorum sensing (QS) is a cell density-dependent mechanism which enables a population of bacteria to coordinate cooperative behaviors in response to the accumulation of self-produced autoinducer signals in their local environment. An emerging framework is that the adaptive significance of QS in the regulation of production of costly extracellular metabolites ("public goods") is to maintain the h...

The aim of this work was to demonstrate the effectiveness of hydrolysis pretreatment of olive mill (OMW) waste before use as a carbon source in biosurfactant production by fermentation. Three hydrolysis methods were assessed: enzymatic hydrolysis, acid pretreatment plus enzymatic hydrolysis, and acid hydrolysis. Fermentation was carried out using two bacterial species: Pseudomonas aeruginosa an...

Rhamnolipids are biosurfactants with potential for diversified industrial and environmental uses. The present study evaluated three strategies for increasing the production of rhamnolipid-type biosurfactants produced by Pseudomonas aeruginosa strain PA1. The influence of pH, the addition of P. aeruginosa spent culture medium and the use of a fed-batch process were examined. The culture medium a...

Rsan-ver, a strain of Pseudomonas aeruginosa isolated at this department, was used for the development of a continuous process for biosurfactant production. The active compounds were identified as rhamnolipids. A final medium for production was designed in continuous culture by means of medium shifts, since the formation of surface-active compounds was decisively influenced by the composition a...

BACKGROUND Vibrational spectroscopic techniques are becoming increasingly important and popular because they have the potential to provide rapid and convenient solutions to routine analytical problems. Using these techniques, a variety of substances can be characterized, identified and also quantified rapidly. RESULTS The rapid ATR-FTIR (Attenuated Total Reflectance Fourier Transform Infrared...