Accumulation of Polyphosphate in Lactobacillus spp. and Its Involvement in Stress Resistance

• DOI: 10.1128/aem.03997-13
• Publication Date: 2013-12-28T03:28:48Z
• Authors: Cristina Alcántara; Amalia Blasco; Manuel Zúñiga; Vicente Monedero
• Keywords: Lactobacillus casei; Polyphosphate; Strain (injury)

ABSTRACT Polyphosphate (poly-P) is a polymer of phosphate residues synthesized and in some cases accumulated by microorganisms, where it plays crucial physiological roles such as the participation response to nutritional stringencies environmental stresses. Poly-P metabolism has received little attention Lactobacillus , genus lactic acid bacteria relevance for food production health humans animals. We show that among 34 strains 18 them intracellular poly-P granules, revealed specific staining electron microscopy. accumulation was generally dependent on presence elevated concentrations culture medium, correlated with polyphosphate kinase ( ppk ) genes genomes. The gene from displayed genetic arrangement which flanked two encoding exopolyphosphatases Ppx-GppA family. functionality corroborated its disruption (LCABL_27820 gene) casei BL23 strain. constructed mutant showed lack granules drastic reduction synthesis. Resistance several stresses tested -disrupted strain, showing presented diminished growth under high-salt or low-pH conditions an increased sensitivity oxidative stress. These results characteristic lactobacilli may thus play important physiology these microorganisms.