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

VILLEGAS, JOSEFINA MARÍA; ARAOZ, MARIO; GRILLO PUERTAS, MARIANA; HEBERT, ELVIRA MARIA; RAPISARDA, VIVIANA ANDREA

Córdoba

Congreso; 52th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2016

SAIB

Polyphosphate (polyP), an ubiquitous linear polymer of hundreds of orthophosphate residues, plays an important role in the responseto nutritional stringencies and against oxidative, osmotic and acid stresses. Lactic acid bacteria (LAB) are a heterogeneous group ofbacteria useful to produce fermented foods that are normal inhabitants of the oral cavity and the digestive tract in humans. Thepresence of polyP in these bacteria was previously demonstrated; however, there is scarce information about its role in LABphysiology. We have previously reported that stationaryEscherichia colicells grown in >37 mM phosphate media presented highviability and elevated tolerance to exogenous H2O2, when compare to cells grown in sufficient phosphate media. Here, we determinedintracellular polyP levels of three lactobacilli strains grown in media with different phosphate concentrations. Amongthem,Lactobacillus paraplantarumCRL 1905 was selected for studies since it maintained high polyP levels up to 96 h when cells weregrown in 60 mM phosphate medium. It was observed that cells grown for 48 h and 96 h in high phosphate medium were more viablethan those grown in sufficient phosphate condition. Since polyP is involved in stress responses in other bacteria, we tested theresistance ofL. paraplantarumCRL 1905 cells grown in low or high phosphate media to several exogenous stress agents