In this work, biosurfactants produced by two Pseudomonas aeruginosa strains isolated from Brazilian crude oils were identified by proton nuclear magnetic resonance ((1)H NMR) and further characterized by mass spectrometry (MS) coupled with electrospray ionization (ESI) and tandem mass spectrometry (MS/MS) analysis in positive mode and their surface activities evaluated. Mono-rhamnolipids and di...

Petroleum hydrocarbons are important energy resources. However, petroleum is also a major pollutant of the environment. Contamination by oil and oil products has caused serious harm, and increasing attention has been paid to the development and implementation of innovative technologies for the removal of these contaminants. Biosurfactants have been extensively used in the remediation of water a...

The newly isolated from industrial wastewater Pseudomonas fluorescens strain HW-6 produced glycolipid biosurfactants at high concentrations (1.4-2.0 g l(-1)) when grown on hexadecane as a sole carbon source. Biosurfactants decreased the surface tension of the air/ water interface by 35 mN m(-1) and possessed a low critical micelle concentration value of 20 mg l(-1), which indicated high surface...

Biosurfactants are surface-active compounds from biological sources, usually extracellular, produced by bacteria, yeast or fungi. Research on biological surfactant production has grown significantly due to the advantages they present over synthetic compounds such as biodegradability, low toxicity, diversity of applications and functionality under extreme conditions. Although the majority of mic...

We characterized a newly isolated bacterium, designated as IR1, with respect to its ability to degrade polycyclic aromatic hydrocarbons (PAHs) and to produce biosurfactants. Isolated IR1 was identified as Pseudomonas putida by analysis of 16S rRNA sequences (99.6% homology). It was capable of utilizing two-, three- and four-ring PAHs but not hexadecane and octadecane as a sole carbon and energy...

In this study, 15 Lactobacillus isolates were found to produce biosurfactants in the mid-exponential and stationary growth phases. The stationary-phase biosurfactants from lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54, and Lactobacillus acidophilus RC14 were investigated further to determine their capacity to inhibit the initial adhesion of uropathogenic Ent...

Biosurfactants are a group of microbial molecules identified by their unique capabilities to interact with hydrocarbons. Emulsification and de-emulsification, dispersion, foaming, wetting and coating are some of the numerous surface activities that biosurfactants can achieve when applied within systems such as immiscible liquid/liquid (e.g., oil/water), solid/ liquid (e.g., rock/oil and rock/wa...

The capacity of polycyclic aromatic hydrocarbon (PAH)-utilizing bacteria to produce biosurfactants was investigated. Twenty-three bacteria isolated from a soil contaminated with petroleum wastes were able to form clearing zones on mineral salt agar plates sprayed with solutions of PAHs. Naphthalene and phenanthrene were utilized as sole substrates. Biosurfactant production was detected by surfa...

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 ...

Bioremediation of metal-contaminated wastestreams has been successfully demonstrated. Normally, whole cells or microbial exopolymers are used to concentrate and/or precipitate metals in the wastestream to aid in metal removal. Analogous remediation of metal-contaminated soils is more complex because microbial cells or large exopolymers do not move freely through the soil. The use of microbially...