RAPISARDA Viviana Andrea
congresos y reuniones científicas
PHYSIOLOGICAL ADAPTATIONS IN Lactobacillus paraplantarum CRL 1905 INDUCED BY DIFFERENTIAL CONCENTRATIONS OF PHOSPHATE IN THE MEDIUM
ARAOZ, M.; GRILLO-PUERTAS, M.; HEBERT, E. M.; INTERDONATO, R.; VILLEGAS, J. M.; RAPISARDA, V. A.
Tafí del Valle, Tucumán
Congreso; Sociedad de Biología de Tucumán; 2018
Asociación de Biología de Tucumán
Lactic acid bacteria (BL) are a heterogeneous group of microorganisms that present industrial and probiotic applications. Polyphosphate (polyP) is a linear polymer formed by orthophosphate (Pi) residues that plays an important role in response to stressful conditions in bacteria. In our laboratory, the ability of Lactobacillus paraplantarum CRL 1905 to maintain high polyP levels in the stationary phase was evidenced in a chemically defined media (CDM) with high Pi content. The aim of this work was to expand the studies with respect to the modulation of polyP in this BL and its survival against different environmental conditions to which it is usually exposed. The assays were performed in CDM containing sufficient and high Pi concentrations (2 and 60mM, respectively). Flow cytometry showed a higher percentage of dead and damaged cells in sample grown with sufficient Pi with respect to those grown with high Pi. An analysis by scanning microscopy showed that cells grown in Pi 2mM had a larger size than the ones grown in 60mM, and revealed the presence of superficial membrane vesicles in them. Finally, the cells grown for 48 hours in differential media were exposed to different stressors (pH and bile sales) for 3 and 6 hours, and greater tolerance in the medium with 60mM Pi was observed. These phenotypes could be related to the maintenance of polyP in the stationary phase. This study contributes to a better understanding of alternative mechanisms by which beneficial bacteria can counteract several stress conditions and colonize different niches.