Complex rhamnolipid mixture characterization and its influence on DPPC bilayer organization.
Rhamnolipids (RL) are one of the most important classes of biosurfactants produced by microorganisms using a wide range of carbon sources, from a simple carbon source like glucose to complex wastes such as the used cooking oils used in this work. The objective of this work was to learn about the rhamnolipid-phospholipid dipalmitoyl phosphatidyl choline (DPPC) molecular interactions through the behaviour observed in the neat products and four RL/DPPC mixtures. Size and z-potential were used to characterize the size and the charge of the vesicles, and small angle X-ray scattering (SAXS) was used to measure the vesicle bilayer characteristics, and the release of carboxyfluorescein to study the bilayer disrupting effect promoted by rhamnolipids. The results show that rhamnolipids are disposed in ordered bilayers with long repeating distances, which are stabilized by the charging of the bilayer and also by a strong fluidity of the bilayers. The ability of rhamnolipids to increase the fluidity of DPPC bilayers may be related with the strong haemolytic power of these molecules.
Laboratorio de Microbiología, Facultad de Farmacia, Universidad de Barcelona, Joan XXIII s/n, E-08028 Barcelona, Spain.
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Haba
Departament de Tecnologia Química i de Tensioactius, Institut de Química Avançada de Catalunya, IQAC-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain.
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Pinazo
Departament de Tecnologia Química i de Tensioactius, Institut de Química Avançada de Catalunya, IQAC-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain. Electronic address: ramon.pons@iqac.csic.es.
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Pons
Departament de Tecnologia Química i de Tensioactius, Institut de Química Avançada de Catalunya, IQAC-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain.
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Pérez
Laboratorio de Microbiología, Facultad de Farmacia, Universidad de Barcelona, Joan XXIII s/n, E-08028 Barcelona, Spain. Electronic address: amanresa@ub.edu.
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Manresa
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry / Q000378:metabolism*; D002152:Calorimetry, Differential Scanning; D004912:Erythrocytes / Q000378:metabolism*; D006017:Glycolipids / Q000737:chemistry / Q000378:metabolism*; D006461:Hemolysis; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D008081:Liposomes; D053838:Scattering, Small Angle; D014867:Water / Q000737:chemistry / Q000378:metabolism*; D014961:X-Ray Diffraction
D006017:Glycolipids; D008051:Lipid Bilayers; D008081:Liposomes; C418382:rhamnolipid; D014867:Water; D015060:1,2-Dipalmitoylphosphatidylcholine
Bilayer formation; Biosurfactant; DPPC; Physico-chemical property; Rhamnolipid; SAXS