Vfr, the global regulator of the virulence in P. The main factor that contributes to the rhamnolipid production in stationary phase appears to be the rhl system. The better control over dissolved oxygen also allowed the demonstration that rhamnolipid production by P. Delivery of siRNA into the cytoplasm is still a challenge and a barrier for more gene silencing-based individualized drugs. Recent advances in high-throughput experimental techniques supported by bioinformatics genomic, transcriptomic, proteomic, metabolomic have resulted in rapid accumulation of data, providing a basis for in-depth understanding of biological processes. This study revealed the possibility of biosurfactant production using cheaper carbon sources like waste motor lubricant oil and peanut oil cake. Urum and Pekdemir [ 41 ] applied different biosurfactants rhamnolipid, aescin, saponin, lecithin and tannin in washing oil-contaminated soil and observed significant removal of crude oil with different concentrations of biosurfactant solution.

Moreover, nitrate has been shown to provide the highest yields of rhamnolipid production [ 7 ], related to upregulation of glutamine synthase under nitrogen-limiting conditions by RpoN [ 97 ]. Strategies for improvement of biosurfactant production 5. Rhamnolipids play a major role in the architecture of biofilms produced by P. GacS-GacA is a well characterized two-component system in P. A simple method for the isolation and quantification of total lipids from animal tissues. The production is repressed in exponential phase and low cell density while is activated in stationary phase and high cell densities. The characterization of biosurfactants produced by lactobacilli reveals that they are generally glycolipid, lipopeptide, glycoprotein, glycolipopeptide, and phosphoglycoprotein independent of the strain, the culture conditions, and the medium composition [ 20 , 21 , 24 , 24 , 25 ].

Comparison of methods to detect biosurfactant production by diverse microorganisms. Drops of a cell suspension or of culture supernatant are placed on an oil-coated, solid surface.

There has been postulated that sequences conserved in some promoters regions of RhlR and LasR-regulated genes are responsible by these regulation [ 75 ].

Both biosurfactants and surfactin were shown to be able to reduce bacterial adhesion to polystyrene surfaces more efficient than the chemical surfactant sodium dodecyl sulfate. The drop collapse test and oil displace test are indicative of surface wetting activity Youssef et al. The trace element thesi was added after the production media were prodhction, prior to inoculation by filtering it through 0.


Surface Tension and Critical Micelle Concentration Critical micelle concentration CMC is known as the concentration of an amphiphilic component in solution at which the formation of micelles is spontaneously initiated. Both A-8 and A strains were isolated together with other 15 aerobic microbial isolates from oil-contaminated sites in Antarctica and appear to be very promising source for application in accelerated environmental bioremediation at low temperatures. Biosurfactants are, therefore, very suitable for applications in the oil industry and this is reflected in the market, where the large majority of biosurfactants produced are in petroleum-related applications [ 21 ].

Prodution phenanthrene-degrading strain B-UM lacks the ability to produce surfactants for dissolution of phenanthrene, and the biosuractant adhesion of cells prodduction phenanthrene surface might be the major pathway for B-UM to take up this PAH [ 33 ].

Whereas their interaction with organic compounds increases their bioavailability or aids their mobilization and removing in a washing treatment.

Bacterial isolates were obtained from different sources such as oil contaminated soil, uncontaminated soil and from Red sea water from Jeddah region at KSA. Subscribe to Table of Contents Alerts. The isolation of a new biosurfactant producing bacterium was carried out in soil tuesis water samples collected from Jeddah region, KSA.

BioMed Research International

Screening of Biosurfactants Produced To evaluate the production of biosurfactants by the different Lactobacillus strains while using sugar cane molasses and glycerol as substrates, emulsification activity, surface activities, and antimicrobial producttion of the stored supernatants were determined.

Effect of temperature ApH B and salinity C on biosurfactant stability. More statistics for thessis and authors Login to your personal dashboard for more detailed statistics on your publications. Microbial surfactant-enhanced mineral oil recovery under laboratory conditions. Solubilization of hydrophobic contaminants is improved by using mixtures of anionic and nonionic surfactants, which was shown to exhibit synergistic interaction, suggesting that appropriate biosurfadtant of surfactants have the potential to enhance the ;roduction of soil washing and flushing and to facilitate the bioavailability of pollutants [ 2829 ].


Conditions such as nutrient deprivation and nitrogen exhaustion, even in a QS-independent manner, contribute to an increase in rhamnolipid production. Biosurfactants have the potential to replace the use of chemical de-emulsifiers in situ, saving on transport of the oil emulsion and providing a more environmentally-friendly solution.

However, when glycerol is used as substrate Lb. The above information from the respective wave numbers confirmed the lipopeptide nature of the biosurfactant.

biosurfactant production thesis

Biosurfactant production was studied using 2. The potential of three indigenous bacterial strains Lactobacillus delbrueckii N2, Lactobacillus cellobiosus TM1, and Lactobacillus plantarum G88 for the production of biosurfactants using sugar cane molasses or glycerol as substrates was investigated through bioeurfactant, surface tension, and antimicrobial activities. The highest yield of biosurfactants was recorded with molasses as substrate.

The biosurfactant production by V. Formation and identification of interfacial-active glycolipids from resting microbial cells. The drop collapse test was conducted for the primary screening of biosurfactants production.

Biosurfactant Production by Pseudomonas aeruginosa from Renewable Resources

The species concept for prokaryotes. BoxJeddahSaudi Arabia. The results showed that biosurfactants present in the different supernatants caused biosurdactant significant reduction of surface tensions.

biosurfactant production thesis

The emulsifying activity observed could be due to the fact that adsorption of biosurfactants at the interface between water and oil allows a decrease in energy required to generate interfacial area, thus facilitating obtainment of drops with small diameter during emulsification step and allowing the formation of emulsions.

Besides the research efforts, the cost for biosurfactant production is approximately three to ten times more than the cost to produce a chemical surfactant. No such effect was reported on planktonic growth so far, therefore, it was hypothesized that AlgR acts through a contact-dependent or biofilm-specific mode of regulation.