Effect of pulsed electric fields upon accumulation of magnesium in Saccharomyces cerevisiae

Abstract

Cultures of Saccharomyces cerevisiae were treated with PEF to improve accumulation of magnesium in the biomass. Under optimized conditions, that is, on 15-min exposure of the 20-h grown culture to PEF of the 2,000 V and 20-ls pulse width, accumulation of magnesium in the yeast biomass reached maximum 3.98 mg/g dm. It constituted 40% of the total magnesium in the medium. That accumulation significantly correlated against magnesium concentration in the medium. Neither multiple exposure of the cultures to PEF nor intermittent supplementation of the cultures with magnesium increased the magnesium accumulation. The intermittent supplementation of the cultures with magnesium could even reduce the accumulation efficiency by 30%.

Effect of Pulsed Electric Fields (PEF) on Accumulation of Magnesium in Lactobacillus rhamnosus B 442 Cells

“…Biomass content was in the range 0.2–0.3 g/g d.m. Pankiewicz and Jamroz ( 2010 ) obtained the highest accumulation of magnesium in S. cerevisiae cells treated with PEF at twice the field strength than the one used in this study (4.0 kV/cm). At lower values of electric field strength (0.1–1.0 kV/cm) higher accumulation was not observed.…”

“…Turbidimetric measurements were run against pure water at λ = 600 nm, in 2 mm measurement cell. Amount of biomass was calculated using equation for the standard curve c (mg/mL) = (Ap + 0.1053):1.1511, where Ap apparent absorbance (Pankiewicz and Jamroz 2010 ).…”

“…Permeability of cell membrane increases secretion of compounds inside a cell or accumulation of ions in a protoplast. At the optimized parameters of the process electroporation is reversible (Pankiewicz and Jamroz 2010 ; Pankiewicz et al 2014 ; Barba et al 2015 ). Electric field strength of 0.7–3.0 kV/cm may cause irreversible membrane breakage and destruction of cellular structures.…”

Pulsed Electric Field (PEF) Enhances Iron Uptake by the Yeast Saccharomyces cerevisiae

“…To prevent these adverse changes, the microencapsulation process is used [10]. One of the encapsulation methods is the accumulation of minerals in the yeast cells of S. cerevisiae [11][12][13][14]. In the study of Kyyaly et al [15] it was demonstrated that feeding anemic rats with iron-enriched yeast is more efficient than inorganic treatment in recovery from iron deficiency.…”

“…This process is also used to assist drying and can also cause stress reactions in plant systems or cell cultures [21]. Previous research has shown that this technique can be used for enriching S. cerevisiae yeast with metal ions [11,22,23]. Iron enriched yeast biomass can potentially be an additional source of this element in diet, especially for vegans and vegetarians.…”