On the other hand, the activation of rpoN-dependent promoters seems to be CbrB and NtrC-dependent [ 99 ]. The projection of all variables in the axis system Figure 2 shows an association between the lactobacilli strains and their ability to use substrates for the production of biosurfactants with specific properties. Physiological and biochemical characteristics of P. On the use of waste frying oil in the synthesis of sophorolipids. Van Der Mei, G.

This study aimed at isolation of some bacterial isolates from different sources Oil contaminated soil, uncontaminated soil and from Red sea water at Jeddah region in kingdom of Saudi Arabia [KSA] , then screening assays for biosurfactant production from obtained isolates. Glycerol represents a by-product which the amount of wastes has been raised year by year through the increasing production of biodiesel and other oleochemicals. Fayad NM, Overton E. Box , Jeddah , Saudi Arabia. Biosurfactant yield reached its maximum 2. It was shown that pqsR and pqsE mutants have reduced rhamnolipid production, even when exposed to wild-type levels of C4-HSL [ 78 ]. Van Hamme, and O.

Surface tension of supernatants obtained with sugar cane molasses or glycerol as substrates. Several bacterial species have been reported to produce the glycolipidic biosurfactants rhamnolipids [ 9 ].

Trehalose lipids produced by Rhodococcus erythropolis were shown to have good solubilization capacity for hydrophobic compounds such as phenanthrene, and great potential for applications in bioremediation of sites contaminated prooduction PAHs [ 30 ]. The use of plant-derived oil as carbon sources to produce biosurfactants seems to be an interesting and low cost alternative Abouseoud et al.

The increase in extra-cellular biosurfactant concentration might be the result of the cell-bound biosurfactant molecules released into the broth medium Deziel et al. Biosurfactant production was monitored by measuring surface tension and emulsification assay of supernatant samples obtained after cell separation Abouseoud et al. Bacterial Strains The biosurfactant-producing strains Lactobacillus cellobiosus TM1, Lactobacillus delbrueckii N2, and Lactobacillus plantarum G88 were isolated and identified in previous works [ 1625 ].

Biosurfactant Production by Pseudomonas aeruginosa from Renewable Resources

Physicochemical composition of clarified sugar cane molasses. Mechanic foam breakers are not very efficient, and chemical antifoams agents can alter the quality of the product and the pollutant potential of the final effluent of the bioreactor [ 6 ]. According to Syldatk and Wagner [ 68 ], the biosynthesis of a surfactant occurs through different routes which are both dependent on the substrate.


In the same way, biosurfactants derived from lactic acid bacteria strains were described as multicomponent mixtures containing protein fractions, various polysaccharides, and phosphate groups [ 2470 ]. They are very important chemical compounds which are used in a variety of products with very high volume because of their domestic and industrial applications [ 23 ].

Most of these studies involve the optimization of culture conditions in shake flasks, due to its simplicity, whereas bioreactors provides high control over the relevant parameters, such as oxygen transfer and pH during all the cultivation process, and allows upscaling studies []. It was shown that this strain is capable of utilizing up to four-ring PAHs but not hexadecane and octadecane as a sole carbon and energy source, and the authors identified the presence of both tension-active and emulsifying activities, suggesting that IR1 produces biosurfactants on both water miscible and immiscible substrates.

The isolated bacteria were selected by using biosjrfactant methods as drop collapse test, oil displacement prodkction, blue agar test, blood hemolysis test, emulsification activity and surface biosurfzctant. Author information Article notes Copyright and License information Disclaimer. Emulsifying Activities The method of Abouseoud et al. It can be verified that some QS-regulated genes belong specifically to rhl regulon, and some sequences RhlR-specific can be determined biosuefactant promoters regions of some genes regulated by rhl system [ 76 ].

J Am Oil Chem Soc.

biosurfactant production thesis

This result was in agreement with Abdel-Mawgoud et al. The CMC was determined by plotting the surface tension as a function of biosurfactants concentration and was found at the point corresponding to the lower concentration in biosurfactants for which no significant variation in surface tension was observed. Biomass was estimated gravimetrically, broth culture was filtered through a Millipore filter paper 0. Another commonly found environmental hazard are the heavy metals, such as lead, mercury, chromium, iron, cadmium and copper, which are also linked to activities of our modern society.


Support Center Support Center.

biosurfactant production thesis

When the substrates are considered, sugar cane molasses seems to be the best among the studied substrates. An update on the use of unconventional substrates for biosurfactant production and their new applications.

BioMed Research International

Principal component analysis was carried out to visualize the way that the different parameters assessed to screen the production of biosurfactants by lactobacilli strains are correlated.

Recovery techniques that promote high level of purify often require application of solvents e. However, a wide variety of roles for biosurfactants have been described including their antimicrobial [ 9 — 12 ], antiadhesive [ 1314 ], emulsifying [ 512 ], and antioxidant properties [ 15 ].

Compare to Triton X emulsification activity of the biosurfactant was low against kerosene, diesel, xylene, naphthalene and anthracene. According to Henkel et al [ 3 ], use of waste substrates in the production processes is likely to increase its influence on the field of microorganism-based production, since they are usually cheaper, maximize the utilization efficiency regarding the overall production process and makes the process more environmentally friendly. The activities were attributed to biosurfactants molecules present in the culture supernatants.

This study deals with production and characterization of biosurfactant from renewable resources by Pseudomonas aeruginosa. Carbohydrate content of the biosurfactant was determined by the phenol—sulfuric acid method [ 14 ] using d -glucose as a standard.

DksA synthesis reaches its maximum during the exponential growth phase and it is posttranscriptionally downregulated during the late exponential and stationary growth phase [ 86 ]. Enhanced biosurfactant production by a mutant Bacillus subtilis strain.