title: Optimization of extraction conditions and fatty acid characterization of Lactobacillus pentosus cell-bound biosurfactant/bioemulsifier.
abstract: BACKGROUND
  There is currently much interest in the use of natural biosurfactants and bioemulsifiers, mainly in the cosmetic, pharmaceutical and food industries. However, there are no studies on the optimization of the extraction conditions of cell-bound biosurfactants. In this work, a biosurfactant with emulsifier properties was extracted from Lactobacillus pentosus cells, under different extraction conditions, and characterized.
  
  
  RESULTS
  During extraction, the most influential independent variable, concerning the emulsifying capacity of biosurfactant, was the operation time, followed by temperature and salt concentration. Biosurfactant from L. pentosus was evaluated by Fourier transform infrared spectroscopy and the composition of fatty acids was analyzed by gas chromatography-mass spectrometry. The hydrophobic chain of the biosurfactant from L. pentosus comprises 548 g kg(-1) linoelaidic acid (C18:2), 221 g kg(-1) oleic or elaidic acid (C18:1), 136 g kg(-1) palmitic acid (C16) and 95 g kg(-1) stearic acid (C18). In addition, emulsions of water and rosemary oil were stabilized with a biosurfactant produced by L. pentosus and compared with emulsions stabilized with polysorbate 20.
  
  
  CONCLUSIONS
  The optimum extraction conditions of biosurfactant were achieved at 45 °C at 120 min and using 9 g kg(-1) of salt. In all the assays biosurfactant from L. pentosus yielded more stable emulsions and higher emulsion volumes than polysorbate 20.
authors.affiliation: Chemical Engineering Department, School of Industrial Engineering (EEI), University of Vigo, Campus As Lagoas-Marcosende, 36310, Vigo-Pontevedra, Spain.
authors.forename: Xanel
authors.initials: X
authors.lastname: Vecino
authors.forename: Letricia
authors.initials: L
authors.lastname: Barbosa-Pereira
authors.forename: Rosa
authors.initials: R
authors.lastname: Devesa-Rey
authors.forename: José M
authors.initials: JM
authors.lastname: Cruz
authors.forename: Ana B
authors.initials: AB
authors.lastname: Moldes
mesh_terms: D045703:Emulsifying Agents / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D057927:Hydrophobic and Hydrophilic Interactions; D007778:Lactobacillus / Q000737:chemistry*; D011136:Polysorbates / Q000737:chemistry; D012965:Sodium Chloride; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature
chemical_list: D045703:Emulsifying Agents; D004655:Emulsions; D005227:Fatty Acids; D011136:Polysorbates; D013501:Surface-Active Agents; D012965:Sodium Chloride
keywords: Lactobacillus pentosus; biosurfactant; fatty acids; rosemary emulsion