In a simple phosphate buffer or a sodium chloride solution resting cells of Pseudomonas spec. DSM 2874 produced up to 15 g/l of different rhamnolipids. The rhamnolipid composition of the organic crude extract depended on the temperature during the cultivation and on the C-source. The optimal sodium chloride concentration for rhamnolipid formation was about 100 mM/l and the optimal phosphate buf...

This study describes the biological degradation of TNT by using induced aeration. Three plastic reactors were used. In each reactor 3 kg of soil were used. In order to increase the porosity of the soil, sawdust was added to soil. Textile wastewater treatment plant sludge was also added to soil. TNT at the concentrations of 1000 mg/kg of soil was added thereafter. Rhamnolipid biosurfactant at th...

The application of iron-silica (Fe-Si) nanoparticles for the enhancement of the Pseudomonas aeruginosa growth and rhamnolipid production in molasses medium was studied. The experiments were designed based on the response surface method (RSM) to optimize growth and rhamnolipid production. The concentration of nanoparticles and the time required to add nanoparticles to culture medium were conside...

A microbial surfactant (biosurfactant) was investigated for its potential to enhance bioavailability and, hence, the biodegradation of octadecane. The rhamnolipid biosurfactant used in this study was extracted from culture supernatants after growth of Pseudomonas aeruginosa ATCC 9027 in phosphate-limited proteose peptone-glucose-ammonium salts medium. Dispersion of octadecane in aqueous solutio...

Bio-based rhamnolipid production from waste streams is gaining momentum nowadays because of increasing market demand, huge range applications and its economic environment friendly nature. Rhamnolipid type biosurfactants are produced by microorganisms as secondary metabolites have been used to reduce surface/interfacial tension between two different phases. Biosurfactants reported be an alternat...

The present paper envisages the multi-response optimization of certain process parameters like total sugars concentration, C/N ratio and incubation time on rhamnolipid yield, surface tension reduction, biomass formation and substrate utilization, in rhamnolipid production by a Pseudomonas aeruginosa mutant strain grown on clarified blackstrap molasses, under L9 orthogonal array in Taguchi desig...

The las quorum-sensing system of Pseudomonas aeruginosa controls the expression of elastase and rhamnolipid. We report that starvation can select a mutant producing these virulence factors in spite of a lasR deletion. Expression of the autoinducer synthase gene rhlI was increased in this suppressor mutant, suggesting compensation by the rhl system. These data show that P. aeruginosa can restore...

Methylene blue was efficiently removed from aqueous solution by foam flotation using a rhamnolipid a biosurfactant as a dye collector. The effects of four parameters, namely, pH (1.5–11.5), frother concentration (5–65 ppm), aeration rate (2–6 L/min) and rhamnolipid to methylene blue weight ratio (0.5–6.5), on dye removal were studied and optimized using response surface methodology. Results...

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 ...

The relation between hydrocarbon degradation and biosurfactant (rhamnolipid) production by a new Bacillus subtilis 22BN strain was investigated. The strain was isolated for its capacity to utilize n-hexadecane and naphthalene and at the same time to produce surface-active compound at high concentrations (1.5 - 2.0 g l(-1)). Biosurfactant production was detected by surface tension lowering and e...