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1. Effect of the fatty acid composition of acclimated oenological Lactobacillus plantarum on the resistance to ethanol

Author

Bárbara M. Bravo-Ferrada, Andrea Gómez-Zavaglia, E. E. Tymczyszyn, and Liliana Semorile

Subjects
Chromatography, Gas, Malates, Wine, INGENIERÍAS Y TECNOLOGÍAS, Applied Microbiology and Biotechnology, Acclimatization, Biotecnología Industrial, chemistry.chemical_compound, ACCLIMATION, Drug Resistance, Bacterial, Food science, ETHANOL STRESS, chemistry.chemical_classification, Microbial Viability, Ethanol, biology, Fatty Acids, food and beverages, Fatty acid, WINE, biology.organism_classification, Adaptation, Physiological, chemistry, Biochemistry, Saturated fatty acid, Fatty Acids, Unsaturated, FATTY ACID, Composition (visual arts), Malic acid, Lactobacillus plantarum
Abstract

The aim of this work was to evaluate the changes due to acclimation to ethanol on the fatty acid composition of three oenological Lactobacillus plantarum strains and their effect on the resistance to ethanol and malic acid consumption (MAC). Lactobacillus plantarum UNQLp 133, UNQLp 65.3 and UNQLp 155 were acclimated in the presence of 6 or 10% v/v ethanol, for 48 h at 28°C. Lipids were extracted to obtain fatty acid methyl esters and analysed by gas chromatography interfaced with mass spectroscopy. The influence of change in fatty acid composition on the viability and MAC in synthetic wine was analysed by determining the Pearson correlation coefficient. Acclimated strains showed a significant change in the fatty composition with regard to the nonacclimated strains. Adaptation to ethanol led to a decrease in the unsaturated/saturated ratio, mainly resulting from an increase in the contribution of short-length fatty acid C12:0 and a decrease of C18:1. The content of C12:0 was related to a higher viability after inoculation of synthetic wine. The MAC increased at higher contents in saturated fatty acid, but its efficiency was strain dependent. Fil: Bravo Ferrada, Barbara Mercedes. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gomez Zavaglia, Andrea. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Semorile, Liliana Carmen. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina Fil: Tymczyszyn, Emma Elizabeth. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Published
2014
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2. FTIR spectroscopy structural analysis of the interaction between Lactobacillus kefir S-layers and metal ions

Author

Andrea Gómez-Zavaglia, E. E. Tymczyszyn, Rui Fausto, Esteban Gerbino, and Pablo Mobili

Subjects
S-LAYER, Otras Ingenierías y Tecnologías, Stereochemistry, Chemistry, Organic Chemistry, SECONDARY-STRUCTURE, Lactobacillus kefir, INGENIERÍAS Y TECNOLOGÍAS, METAL-PROTEIN, Analytical Chemistry, Inorganic Chemistry, LACTOBACILLUS, Spectroscopy, Nuclear chemistry
Abstract

FTIR spectroscopy was used to structurally characterize the interaction of S-layer proteins extracted from two strains of Lactobacillus kefir (the aggregating CIDCA 8348 and the non-aggregating JCM 5818) with metal ions (Cd+2, Zn+2, Pb+2 and Ni+2). The infrared spectra indicate that the metal/protein interaction occurs mainly through the carboxylate groups of the side chains of Asp and Glut residues, with some contribution of the NH groups belonging to the peptide backbone. The frequency separation between the mCOO anti-symmetric and symmetric stretching vibrations in the spectra of the S-layers in presence of the metal ions was found to be ca. 190 cm 1 for S-layer CIDCA 8348 and ca. 170 cm 1 for JCM 5818, denoting an unidentate coordination in both cases. Changes in the secondary structures of the S-layers induced by the interaction with the metal ions were also noticed: a general trend to increase the amount of b-sheet structures and to reduce the amount of a-helices was observed. These changes allow the proteins to adjust their structure to the presence of the metal ions at minimum energy expense, and accordingly, these adjustments were found to be more important for the bigger ions. Fil: Gerbino, Oscar Esteban. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad de Coimbra; Portugal Fil: Mobili, Pablo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad de Coimbra; Portugal Fil: Tymczyszyn, Emma Elizabeth. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Fausto, Rui. Universidad de Coimbra. Facultad de Ciencias E Tecnología. Department Of Chemistry; Portugal Fil: Gomez Zavaglia, Andrea. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad de Coimbra; Portugal

Published
2011

3. Structural and functional properties of hydration and confined water in membrane interfaces.

Author

Disalvo EA, Lairion F, Martini F, Tymczyszyn E, Frías M, Almaleck H, and Gordillo GJ

Subjects
Biophysical Phenomena, Cell Membrane chemistry, Hydrogen Bonding, Lipid Bilayers chemistry, Membrane Lipids chemistry, Models, Biological, Structure-Activity Relationship, Surface Properties, Membranes chemistry, Water chemistry
Abstract

The scope of the present review focuses on the interfacial properties of cell membranes that may establish a link between the membrane and the cytosolic components. We present evidences that the current view of the membrane as a barrier of permeability that contains an aqueous solution of macromolecules may be replaced by one in which the membrane plays a structural and functional role. Although this idea has been previously suggested, the present is the first systematic work that puts into relevance the relation water-membrane in terms of thermodynamic and structural properties of the interphases that cannot be ignored in the understanding of cell function. To pursue this aim, we introduce a new definition of interphase, in which the water is organized in different levels on the surface with different binding energies. Altogether determines the surface free energy necessary for the structural response to changes in the surrounding media. The physical chemical properties of this region are interpreted in terms of hydration water and confined water, which explain the interaction with proteins and could affect the modulation of enzyme activity. Information provided by several methodologies indicates that the organization of the hydration states is not restricted to the membrane plane albeit to a region extending into the cytoplasm, in which polar head groups play a relevant role. In addition, dynamic properties studied by cyclic voltammetry allow one to deduce the energetics of the conformational changes of the lipid head group in relation to the head-head interactions due to the presence of carbonyls and phosphates at the interphase. These groups are, apparently, surrounded by more than one layer of water molecules: a tightly bound shell, that mostly contributes to the dipole potential, and a second one that may be displaced by proteins and osmotic stress. Hydration water around carbonyl and phosphate groups may change by the presence of polyhydroxylated compounds or by changing the chemical groups esterified to the phosphates, mainly choline, ethanolamine or glycerol. Thus, surface membrane properties, such as the dipole potential and the surface pressure, are modulated by the water at the interphase region by changing the structure of the membrane components. An understanding of the properties of the structural water located at the hydration sites and the functional water confined around the polar head groups modulated by the hydrocarbon chains is helpful to interpret and analyze the consequences of water loss at the membranes of dehydrated cells. In this regard, a correlation between the effects of water activity on cell growth and the lipid composition is discussed in terms of the recovery of the cell volume and their viability. Critical analyses of the properties of water at the interface of lipid membranes merging from these results and others from the literature suggest that the interface links the membrane with the aqueous soluble proteins in a functional unit in which the cell may be considered as a complex structure stabilized by water rather than a water solution of macromolecules surrounded by a semi permeable barrier.

Published
2008
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4. Action of trehalose on the preservation of Lactobacillus delbrueckii ssp. bulgaricus by heat and osmotic dehydration.

Author

Gómez Zavaglia A, Tymczyszyn E, De Antoni G, and Aníbal Disalvo E

Subjects
Animals, Dehydration, Dose-Response Relationship, Drug, Hot Temperature, Lactobacillus growth & development, Lactobacillus physiology, Membrane Potentials drug effects, Milk microbiology, Osmosis drug effects, Food Microbiology, Lactobacillus drug effects, Preservation, Biological methods, Trehalose pharmacology
Abstract

Aim: This work determines the efficiency of trehalose on the preservation by heat or osmotic drying of a strain of Lactobacillus delbrueckii ssp. bulgaricus. Cell recovery at different trehalose concentrations during drying correlated with the surface properties and osmotic response of cells after rehydration., Methods and Results: Bacteria were dried in the presence of glycerol, trehalose, sucrose at 70 degrees C and at 20 degrees C. Trehalose attenuates the loss of viability at 0.25 m. At this concentration, the osmotic response and zeta potential of the bacteria were comparable with the nondried ones., Conclusions: Trehalose diminishes significantly the damage produced by dehydration both when the bacteria are dried by heating or subjected to osmotic dehydration. This effect appears related to the preservation of the permeability to water and the surface potential of the bacteria., Significance and Impact of the Study: Dehydration occurring during heating or during osmosis appears to have similar effects. As dehydration-induced damage is in correlation with osmotic response recovery and is hindered or buffered by the presence of trehalose, it may be related to water eliminated from biological structures involved in water permeation.

Published
2003
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