ACCUMULATION OF POLYPHOSPHATE IN LACTIC ACID BACTERIA AND ITS INVOLVEMENT IN STRESS RESISTANCE

VILLEGAS JOSEFINA MARÍA; ARAOZ MARIO; GRILLO-PUERTAS MARIANA; HEBERT ELVIRA MARÍA

Cordoba

Congreso; LII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2016

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Polyphosphate (polyP), an ubiquitous linear polymer of hundreds of orthophosphate (Pi) residues, plays an important role in the response to nutritional stringencies and against oxidative, osmotic and acid stresses. Lactic acid bacteria (LAB) are a heterogeneous group of bacteria useful to produce fermented foods that are normal inhabitants of the oral cavity and the digestive tract in humans. The presence of polyP in these bacteria was previously demonstrated; however, there is scarce information about its role in LAB physiology. We have previously reported that stationary Escherichia coli cells grown in >37 mM Pi media presented high viability and elevated tolerance to exogenous H2O2, when compare to cells grown in sufficient Pi media. Here, we determined intracellular polyP levels of three lactobacilli strains grown in media with different Pi concentrations. Among them, Lactobacillus paraplantarum CRL 1905 was selected for studies since it maintained high polyP levels up to 96 h when cells were grown in 60 mM Pi medium. It was observed that cells grown for 48 h and 96 h in high Pi medium were more viable than those grown in sufficient Pi condition. Since polyP is involved in stress responses in other bacteria, we tested the resistance of L. paraplantarum CRL 1905 cells grown in low or high Pi media to several exogenous stress agents.