ABSTRACT
The bacteria respond to environmental changes modifying their composition. One of the most important modifications is the variation on fatty acid composition of cellular membranes to maintain the homeoviscosity. The action of temperature, hydrostatic pressure and solvents on Pseudomonas putida has been thoroughly studied. In this paper, the combined action of the temperature and salinity on fatty acid composition of cellular membranes of Pseudomonas fluorescens GNP-OHP-3, a bacterial strain isolated from a petroleum contaminated habitat, was studied. The modifications in the fatty acid composition of Pseudomonas fluorescens GNP-OHP-3 membrane were similar to those described for other members of Pseudomonas: an increase in saturated fatty acids and a decrease in unsaturated fatty acids were observed with the increase of the temperature. Variations of main fatty acids were in general erratic in the range of assayed saline concentrations. The variation of cyclopropane fatty acids could be expressed with mathematic equations that allowed to predict their percentage in relation to sodium chloride concentration.
Subject(s)
Cell Membrane/chemistry , Fatty Acids/analysis , Pseudomonas fluorescens/chemistry , Sodium Chloride/analysis , Temperature , Adaptation, Physiological , Cell Membrane/drug effects , Culture Media/pharmacology , Cyclopropanes/analysis , Dose-Response Relationship, Drug , Fatty Acids, Unsaturated/analysis , Membrane Lipids/analysis , Osmolar Concentration , Pseudomonas fluorescens/drug effects , Pseudomonas fluorescens/growth & development , Pseudomonas fluorescens/metabolism , Sodium Chloride/pharmacology , Substrate SpecificityABSTRACT
Las bacterias responden a los cambios ambientales modificando su composición, para evitar el daño que dichos cambios podrían ejercer. Una de las modificaciones más importantes es la variación de la composición de los ácidos grasos de las membranas celulares, que le permite mantener la homeoviscosidad ante situaciones de estrés. Trabajos previos han estudiado la acción de la temperatura, presión hidrostática y diferentes solventes sobre cepas de Pseudomonas putida. En este trabajo se estudió la acción conjunta de la temperatura y la salinidad sobre la composición de ácidos grasos de membranas celulares de Pseudomonas fluorescens GNP-OHP-3, una cepa bacteriana aislada de un hábitat contaminado con petróleo. Pseudomonas fluorescens GNP-OHP-3 respondió a las variaciones de temperatura modificando los ácidos grasos de sus membranas de manera similar a lo descripto en otros integrantes de su género: ante el aumento de temperatura se observó un incremento de ácidos grasos saturados y una disminución de los ácidos grasos insaturados. En el rango de concentraciones salinas ensayadas las variaciones de los ácidos grasos mayoritarios fueron en general erráticas. La respuesta de los ácidos grasos ciclo propano pudo expresarse con ecuaciones matemáticas que permitieron predecir el porcentaje de estos ácidos en relación a la concentración de cloruro de sodio.
The bacteria respond to environmental changes modifying their composition. One of the most important modifications is the variation on fatty acid composition of cellular membranes to maintain the homeoviscosity. The action of temperature, hydrostatic pressure and solvents on Pseudomonas putida has been thoroughly studied. In this paper, the combined action of the temperature and salinity on fatty acid composition of cellular membranes of Pseudomonas fluorescens GNP-OHP-3, a bacterial strain isolated from a petroleum contaminated habitat, was studied. The modifications in the fatty acid composition of Pseudomonas fluorescens GNP-OHP-3 membrane were similar to those described for other members of Pseudomonas: an increase in saturated fatty acids and a decrease in unsaturated fatty acids were observed with the increase of the temperature. Variations of main fatty acids were in general erratic in the range of assayed saline concentrations. The variation of cycle propane fatty acids could be expressed with mathematic equations that allowed to predict their percentage in relation to sodium chloride concentration.
Subject(s)
Cell Membrane/chemistry , Fatty Acids/analysis , Pseudomonas fluorescens/chemistry , Sodium Chloride/analysis , Temperature , Adaptation, Physiological , Cell Membrane/drug effects , Culture Media/pharmacology , Cyclopropanes/analysis , Dose-Response Relationship, Drug , Fatty Acids, Unsaturated/analysis , Membrane Lipids/analysis , Osmolar Concentration , Pseudomonas fluorescens/drug effects , Pseudomonas fluorescens/growth & development , Pseudomonas fluorescens/metabolism , Substrate Specificity , Sodium Chloride/pharmacologyABSTRACT
A procedure for detection and measurement of Hypoglycin A in biological material is described, based on reaction of the amino acid with 1-dimethylaminonaphthalene-5-sulphonyl chloride (Dansyl chloride). The desired flourescent derivative can be separated from others by paper chromatography and measured by flourimetry after elution. Less than 0.2 microgram of hypoglycin A is detectable on chromatograms (AU)