Effect of a carbon source on polyphosphate accumulation inSaccharomyces cerevisiae

Abstract

The cells of Saccharomyces cerevisiae accumulate inorganic polyphosphate (polyP) when reinoculated on a phosphate-containing medium after phosphorus starvation. Total polyP accumulation was similar at cultivation on both glucose and ethanol. Five separate fractions of polyP: acid-soluble fraction polyP1, salt-soluble fraction polyP2, weakly alkali-soluble fraction polyP3, alkali-soluble fraction polyP4, and polyP5, have been obtained from the cells grown on glucose and ethanol under phosphate overplus. The dynamics of polyP fractions depend on a carbon source. The accumulation rates for fractions polyP2 and polyP4 were independent of the carbon source. The accumulation rates of polyP1 and polyP3 were higher on glucose, while fraction polyP5 accumulated faster on ethanol. As to the maximal polyP levels, they were independent of the carbon source for fractions polyP2, polyP3, and polyP4. The maximal level of fraction polyP1 was higher on glucose than on ethanol, but the level of fraction polyP5 was higher on ethanol. It was assumed that accumulation of separate polyP fractions has a metabolic interrelation with different energy-providing pathways. The polyphosphate nature of fraction polyP5 was demonstrated for the first time by (31)P nuclear magnetic resonance spectroscopy, enzymatic assay, and electrophoresis.

Improvement of biochemical methods of polyP quantification

“…Reported evidence indicated that different extraction methods may result in size fractionation of recovered polyP 29. To test possible purification method-dependent differences in the length and recovery of polyP, we extracted polyP from two aliquots of yeast cultures by the phenol/chloroform (pH 8.0) method and samples were purified either by ethanol precipitation or by column chromatography (see Materials and Methods).…”

The early stage of polyphosphate accumulation in <i>saccharomyces cerevisiae</i>: comparative study by extraction and DAPI staining

“…In the parent strain, with ethanol used as a carbon source, the content of acid-soluble fractions was lesser than that on glucose, while the content of PolyP3 and PolyP5 was higher. Such effect was observed earlier in the wild type strain [9]. The results of electrophoresis of PolyP accumulated during 30 min in the (+P) medium with glucose are shown in Figure 3.…”

“…PolyP plays the key role in the processes of biomineralization and phosphorus homeostasis [6,7]. The cells of Saccharomyces cerevisiae under certain growth conditions are able to accumulate PolyP in great amounts strongly depending on the growth stage, culture conditions, and a carbon source [8,9].…”

Enzymes of Inorganic Polyphosphate Metabolism

“…-In view of the great role of PolyP in cell metabolism, bone tissue development, and blood coagulation, it is necessary to control its amounts in food. Enzymatic methods using polyphosphate kinase and exopolyphosphatases are of interest for PolyP detection in biological samples (Ault-Riché et al 1998;Vagabov et al 2008). -The importance of polyphosphate kinases ppk1 and ppk2 in bacterial metabolism and virulence of pathogens is of interest for the development of new inhibitors that may be prospective antibacterial compounds.…”