In the present study, the attempt made on biodegradation of crude oil in a laboratory scale experimental setup revealed that maximum biodegradation rate was found with biosurfactant and fertilizer addition. Strain-engineering may be a promising strategy to improve manufacturing output, and the production by recombinant and non-pathogenic strains has been shown as possible and favorable [ 8 ]. Time course of biosurfactant production kinetics in optimal medium The kinetics of biosurfactant was followed in a modified MS medium at optimum conditions. In addition, these methods can operate in continuous mode for recovering biosurfactants with high level of purify [ 4 ]. Nevertheless, the potential of rhamnolipids production from renewable resources is so far not fully exploited. Mixture of different surfactants often presents better properties than the individual surfactants, due to synergistic effect. The rhlAB operon and rhlR are controlled indirectly and directly, respectively, by RpoN [ 93 ], since under nitrogen-limiting conditions, P.

There are two known conventional QS systems in P. MEL-A produced by Pseudozyma antartica T has been shown to have cell differentiation activities against human leukemia cells, mouse melanoma and PC12 cells [ 54 ]. The great adaptability of P. The results of the characterization of sugar cane molasses obtained in this study suggest the suitability of this substrate for fermentative processes involving lactobacilli. Although the environmental stimuli that trigger BqsS-BqsR activity are still unknown, evidences support the existence of opposite effects of AlgR and BqsS-BqsR on rhamnolipid production in the context of biofilm formation [ ]. Chemical Composition The chemical composition of crude biosurfactants produced by lactobacilli strains using sugar cane molasse or glycerol as substrates was assessed following standard methods.

The sugar cane molasses is composed of total sugars of Oil-contaminated soil is especially difficult for bioremediation since oil excess forms droplets or films on soil particles, which is a powerful barrier against microbial degradation [ 41 ].

This study deals with production and characterization of biosurfactant from renewable resources by Pseudomonas aeruginosa. It affects the expression of multiple virulence factors downstream in the QS cascade, including rhamnolipid production.

BioMed Research International

The major advantage of using microorganisms or their products over prosuction products is the disposal of the de-emulsifier in the aqueous phase and its removal from the oil phase, since emulsion formation is required in further processing steps. Firstly, PQS production occurs in the late logarithmic phase and reaches its maximum in the late stationary phase [ 8788 ], with a similar profile to that of rhamnolipid biosynthesis. 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.


The carbon and nitrogen sources are important factors in the production of these biosurfactants and have great influence their production cost and considerable efforts have been done towards the use of agro-industrial byproducts and renewable resources as substrates in thedis production process [ 3 ]. These procedures take advantage of biosurfactant properties, such as their surface activity or their ability to form micelles or vesicles, and are particularly applicable for large-scale continuous recovery of extracellular biosurfactants from culture broth.

Hemolytic and chelating agent. From a practical point of view, it is important to differentiate effective and efficient biosurfactan. In order to confirm this hypothesis, biosrufactant were extracted from each supernatant.

The possibility of biosurfactant production using cheaper carbon sources was already reported by earlier workers; Mercade et al. National Center for Biotechnology InformationU.

The Thesia and the surface tension values herein obtained for the three lactobacilli strains are in good agreement with the values reported in the literature for biosurfactants produced by other lactobacilli. 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 [ 2021242425 ].

Biosurfactant Production by Pseudomonas aeruginosa from Renewable Resources

Currently, the main application is for enhancement of oil recovery and hydrocarbon bioremediation due to their biodegradability and low critical micelle concentration CMC [ 13 ]. Biosurfactant production by the strain isolated from contaminated soil. Besides these, twenty-five rhamnolipid congeners have been described in P.

biosurfactant production thesis

Correlation circle of the different parameters assessed to screen the production of biosurfactants. Thus, the research effort has been directed towards the development of low-cost extraction and purification procedures, avoiding the use of hazardous and costly organic solvents [ 13 ].

Table 5 presents the inhibition diameters of the different supernatants against some pathogenic and spoilage microorganisms isolated from fresh ground beef sold in Adamawa region of Cameroon.


biosurfactant production thesis

Strain-engineering may be a promising strategy to improve manufacturing output, and the production by recombinant and non-pathogenic strains has been shown as possible and favorable [ 8 ]. A typical bioremediation process consists of application of nutrients containing nitrogen and phosphorousunder controlled pH and water content, together with an emulsifier and surface-active agents.

It was shown that rhamnolipids can be used to remove soaked oil from the used bisourfactant sorbents [ 30 ]. View at Google Scholar G. In gidA mutants, the levels of rhlR mRNA are similar to the levels in wild-type, whereas rhlA mRNA levels were significantly decreased, suggesting that the rhamnolipid production is controlled via posttranscriptional modulation of RhlR levels by GidA [ 82 ].

biosurfactant production thesis

On the other side biosurfactant application in processes such as washing, biorremadiation and MEOR, requires a thoroughly research on a case-by-case basis taking in account the physical chemical properties of biosurfactants and the environmental conditions. Material and methods 2. PqsR is activated by las QS system and repressed by rhl QS system, evidencing a complex network of regulation [ 89 ]. Moreover, pre-coated vinyl urethral catheters with surfactin were shown to reduce biofilm formation by several Salmonella species and other infectious bacteria [ 56 ].

Several approaches have been applied in order to improve biosurfactant productivity such as optimization of growth conditions e. Interestingly, rhamnolipids combined with a pool of enzyme produced by Penicillium simplicissimum enhanced the biodegradation of effluent with high fat content from poultry thesiw plant, biosurfactaant a synergistic interaction between biosurfactant and enzymes in waste treatment [ biosurfactxnt ].

Indigenous or injected biosurfactant-producing microorganisms are exploited in oil recovery in oil-producing wells. As PqsR controls PQS production and rhamnolipid production is abolished in the absence of PQS signaling [ 87 ], it is possible that this effect is indirect.

When the substrates are considered, sugar cane molasses seems to be the best among the studied substrates.