Biosurfactant

Biosurfactants and Biotechnology, edited by Naim Kosaric, W. L. Cairns, and Neil C. C. Gray... 

Biosurfactants Production Properties Applications, edited by Naim Ko-saric... 

Metabolites that are composed of structures of quite different oxidation states. Certain secondary metabolites and biosurfactants fell into this dass since they have both carbohydrates and fatty adds in their structures. 

Different mechanisms have therefore clearly emerged and it seems premature to draw general conclusions especially in the application of synthetic and natural surfactants to bioremediation, which is discussed in greater detail in Chapter 14. It is important to note, however, that the production of biosurfactants may not be the only mechanism for facilitating the uptake of substrates with... 

Deziel E, G Paquette, R Villemur, F Lepine, J-G Bisaillon (1996) Biosurfactant production by a soil Pseudomonas strain growing on polycyclic aromatic hydrocarbons. Appl Environ Microbiol 62 1908-1912. 

Hommel RK (1994) Formation and function of biosurfactants for degradation of water-insoluble substrates. In Biochemistry of Microbial Degradation (Ed C Rattledge), pp. 63-87. Kluwer Academic Publishers, Dordrecht, The Netherlands. 

Phale PS, HS Savithri, NA Rao, CS Vaidyanathan (1995) Production of biosurfactant Biosur-Pm by Pseudomonas maltophilia CSV89 characterization and role in hydrocarbon uptake. Arch Microbiol 163 424-431. 

Singer MEV, WR Einnerty (1990) Physiology of biosurfactant synthesis by Rhodococcus species H13-A. Can J Microbiol 36 741-745. 

Zhang Y, RM Miller (1992) Enhanced octadecane dispersion and biodegradation hy a Pseudomonas rhamno-lipid surfactant (biosurfactant). Appl Environ Microbiol 58 3276-3282. 

Deschenes L, P Lafrance, J-P Villeneuve, R Samson (1996) Adding sodium dodecyl sulfate and Pseudomonas aeruginosa UG2 biosurfactants inhibits polycyclic hydrocarbon biodegradation in a weathered creosote-contaminated soil. Appl Microbiol Biotechnol 46 638-646. 

Increased removal of phenanthrene from soil columns spiked with the rhamnolipid mixture synthesized by Pseudomonas aeruginosa UG2 has been demonstrated, and shown to depend both on the increased desorption of the substrate and on partitioning into micelles (Noordman et al. 1998). However, the addition of the biosurfactant from the same strain of Pseudomonas aeruginosa UG2 or of sodium dodecyl sulfate had no effect on the rate of biodegradation of anthracene and phenanthrene from a chronically contaminated soil. 

The addition of a rhamnolipid biosurfactant produced by Pseudomonas aeruginosa stain ATIO apparently reduced the extent of degradation by endogenous bacteria of benz[fl]anthracene and chrysene in a creosote-contaminated soil (Vinas et al. 2005). 

Noordman WH, W Ji, ML Briusseau, DB Janssen (1998) Effects of rhamnolipid biosurfactants on removal of phenanthrene from soil. Environ Sci Technol 32 1806-1812. 

A., Tripodi, V. P., Sdoscia, S. L, Carducd, C. N. Relation between retention fadors of immunosuppressive drugs in microemulsion electrokinetic chromatography with biosurfactants and octanol-water partition coeffidents. 

Improvement of the relative mobility of oil to water by biosurfactants and biopolymers... 

The B. licheniformis JF-2 strain produces a very effective surfactant under conditions typical of oil reservoirs. The partially purified biosurfactant from JF-2 was shown to be the most active microbial surfactant found, and it gave an interfacial tension against decane of 0.016 mN/m. An optimal production of the surfactant was obtained in cultures grown in the presence of 5% NaCl at a temperature of 45° C and pH of 7. TTie major endproducts of fermentation were lactic acid and acetic acid, with smaller amounts of formic acid and acetoin. The growth and biosurfactant formation were also observed in anaerobic cultures supplemented with a suitable electron acceptor, such as NaNO3[1106]. 

S. C. Lin, J. C. Goursaud, P. J. Kramer, G. Georgiou, and M. M. Sharma. Production of biosurfactant by Bacillus licheniformis strain JF-2. In E. C. Donaldson, editor. Microbial enhancement of oil recovery recent advances Proceedings of the 1990 International Conference on Microbial Enhancement of Oil Recovery, volume 31 of Developments in Petroleum Science, pages 219-226. Elsevier Science Ltd, 1991. 

Surfactant Solutions New Methods of Investigation, edited by Raoul Zana Nonionic Surfactants Physical Chemistry, edited by Martin J. Schick Microemulsion Systems, edited by Henri L Rosano and Marc Clausse Biosurfactants and Biotechnology, edited by Naim Kosaric, W. L. Cairns, and Neil C. C. Gray... 

Defoaming Theory and Industrial Applications, edited by P. R. Garrett Mixed Surfactant Systems, edited by Keizo Ogino and Masahiko Abe Coagulation and Flocculation Theory and Applications, edited by Bohusiav DobiaD Biosurfactants Production Properties Applications, edited by Naim Kosaric Wettability, edited by John C. Berg... 

Sandrin, T.R., Chech, A.M., and Maier, R.M., A rhamnolipid biosurfactant reduces cadmium toxicity during naphthalene biodegradation, Appl Environ Microbiol, 66 (10), 4585-4588, 2000. 

Nalum Naess S, Elgsaeter A, Foss BJ, Li BJ, Sliwka HR, Partali V, Mel0 TB, and Naqvi KR. 2006. Hydrophilic carotenoids Surface properties and aggregation of crocin as a biosurfactant. Helvetica Chimica Acta 89(1) 45-53. 

The alkane rc-tetradecane was found to have significant effect on desulfurization ability, with the rate being 10 times more than that obtained when using glucose for biocatalyst growth. This effect was associated with production of rhamnolipids by the strain. However, the mechanism by which alkane actually enhances desulfurization activity, whether it is by assisting in biosurfactant production or by some other mechanism was not reported. However, this biocatalyst was found to be active for only a short period (4h) during its desulfurization test with oils. 

In addition to desulfurization activity, several other parameters are important in selecting the right biocatalyst for a commercial BDS application. These include solvent tolerance, substrate specificity, complete conversion to a desulfurized product (as opposed to initial consumption/removal of a sulfur substrate), catalyst stability, biosurfactant production, cell growth rate (for biocatalyst production), impact of final desulfurized oil product on separation, biocatalyst separation from oil phase (for recycle), and finally, ability to regenerate the biocatalyst. Very few studies have addressed these issues and their impact on a process in detail [155,160], even though these seem to be very important from a commercialization point of view. While parameters such as activity in solvent or oil phase and substrate specificity have been studied for biocatalysts, these have not been used as screening criteria for identifying better biocatalysts. 

The draft-tube airlift bioreactor was studied using water-in-kerosene microemulsions [263], The effect of draft tube area vs. the top-section area on various parameters was studied. The effect of gas flow rates on recirculation and gas carry over due to incomplete gas disengagement were studied [264], Additionally, the effect of riser to downcomer volume was also studied. The effect of W/O ratio and viscosity was tested on gas hold-up and mass transfer coefficient [265], One limitation of these studies was the use of plain water as the aqueous phase in the cold model. The absence of biocatalyst or any fermentation broth from the experiments makes these results of little value. The effect of the parameters studied will greatly depend on the change in viscosity, hold-up, phase distribution caused due to the presence of biocatalyst, such as IGTS8, due to production of biosurfactants, etc., by the biocatalyst. Thus, further work including biocatalyst is necessary to truly assess the utility of the draft-tube airlift bioreactor for biodesulfurization. 

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