title: Coordinated response of phospholipids and acyl components of membrane lipids in Pseudomonas putida A (ATCC 12633) under stress caused by cationic surfactants.
abstract: The present study assessed the role of membrane components of Pseudomonas putida A (ATCC 12633) under chemical stress conditions originated by treatment with tetradecyltrimethylammonium bromide (TTAB), a cationic surfactant. We examined changes in fatty acid composition and in the fluidity of the membranes of cells exposed to TTAB at a specific point of growth as well as of cells growing with TTAB. The addition of 10-50 mg TTAB l(-1) promoted an increase in the saturated/unsaturated fatty acid ratio. By using fluorescence polarization techniques, we found that TTAB exerted a fluidizing effect on P. putida A (ATCC 12633) membranes. However, a complete reversal of induced membrane fluidification was detected after 15 min of incubation with TTAB. Consistently, the proportion of unsaturated fatty acids was lower in TTAB-treated cells as compared with non-treated cells. In the presence of TTAB, the content of phosphatidylglycerol increased (120 %), whilst that of cardiolipin decreased (60 %). Analysis of the fatty acid composition of P. putida A (ATCC 12633) showed that phosphatidylglycerol carried the major proportion of saturated fatty acids (89 %), whilst cardiolipin carried an elevated proportion of unsaturated fatty acids (18 %). The increase in phosphatidylglycerol and consequently in saturated fatty acids, together with a decrease in cardiolipin content, enabled greater membrane resistance, reversing the fluidizing effect of TTAB. Therefore, results obtained in the present study point to changes in the fatty acid profile as an adaptive response of P. putida A (ATCC 12633) cells to stress caused by a cationic surfactant.
authors.affiliation: Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina.
authors.forename: Romina Marisa
authors.initials: RM
authors.lastname: Heredia
authors.affiliation: Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina.
authors.forename: Paola Sabrina
authors.initials: PS
authors.lastname: Boeris
authors.affiliation: Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina.
authors.forename: María Alicia
authors.initials: MA
authors.lastname: Biasutti
authors.affiliation: Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina.
authors.forename: Gastón Alberto
authors.initials: GA
authors.lastname: López
authors.affiliation: Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina.
authors.forename: Natalia Soledad
authors.initials: NS
authors.lastname: Paulucci
authors.affiliation: Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina.
authors.forename: Gloria Inés
authors.initials: GI
authors.lastname: Lucchesi
mesh_terms: D002412:Cations / Q000378:metabolism / Q000633:toxicity; D002462:Cell Membrane / Q000737:chemistry* / Q000502:physiology; D008560:Membrane Fluidity / Q000187:drug effects; D008563:Membrane Lipids / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis*; D016958:Pseudomonas putida / Q000187:drug effects* / Q000502:physiology; D013312:Stress, Physiological; D013501:Surface-Active Agents / Q000378:metabolism* / Q000633:toxicity; D050337:Trimethyl Ammonium Compounds / Q000378:metabolism* / Q000633:toxicity
chemical_list: D002412:Cations; D008563:Membrane Lipids; D010743:Phospholipids; D013501:Surface-Active Agents; D050337:Trimethyl Ammonium Compounds; C009410:tetradecyltrimethylammonium