Influence of heat shock and osmotic stresses on the growth and viability of Saccharomyces cerevisiae SUBSC01

Abstract

BackgroundWith a preceding scrutiny of bacterial cellular responses against heat shock and oxidative stresses, current research further investigated such impact on yeast cell. Present study attempted to observe the influence of high temperature (44–46 °C) on the growth and budding pattern of Saccharomyces cerevisiae SUBSC01. Effect of elevated sugar concentrations as another stress stimulant was also observed. Cell growth was measured through the estimation of the optical density at 600 nm (OD600) and by the enumeration of colony forming units on the agar plates up to 450 min.ResultsSubsequent transformation in the yeast morphology and the cellular arrangement were noticed. A delayed and lengthy lag phase was observed when yeast strain was grown at 30, 37, and 40 °C, while at 32.5 °C, optimal growth pattern was noticed. Cells were found to lose culturability completely at 46 °C whereby cells without the cytoplasmic contents were also observed under the light microscope. Thus the critical growth temperature was recorded as 45 °C which was the highest temperature at which S. cerevisiae SUBSC01 could grow. However, a complete growth retardation was observed at 45 °C with the high concentrations of dextrose (0.36 g/l) and sucrose (0.18 g/l). Notably, yeast budding was found at 44 and 45 °C up to 270 min of incubation, which was further noticed to be suppressed at 46 °C.ConclusionsPresent study revealed that the optimal and the critical growth temperatures of S. cerevisiae SUBSC01 were 32.5 and 45 °C, respectively; and also projected on the inhibitory concentrations of sugars on yeast growth at that temperature.

Survival of Bacillus spp. SUBB01 at high temperatures and a preliminary assessment of its ability to protect heat-stressed Escherichia coli cells

“…Recently the response within yeast cells against heat stress and osmotic shock has also been observed [47]. While the mechanisms of survival of E. coli cells have clearly been chalked out very recently [48], the retrieval of a heterogeneous E. coli population consisting of viable cells and defective cells (incapable of forming colonies on agar plates) by the Bacillus extracts as found in the current study is being reported for the first time so far to our knowledge.…”

Demonstration of Antimicrobial Activity of Commercial Oolong Tea and Green Tea Against Pathogenic Bacteria

“…(SkV01) were used. Mueller Hinton agar (MHA) (Sigma-Aldrich Corporation, USA), Mueller Hinton broth (Sigma-Aldrich Corporation, USA) were used [33]. Pre-cultures were prepared by inoculating 5 ml Mueller Hinton broth by a loopful of a colony from the freshly prepared bacterial culture plates, followed by incubation at 37 °C in static condition up to 24 hours [33].…”

Yeast two‐ and three‐species hybrids and high‐sugar fermentation

“…The effect of hyperosmotic stress on the Saccharomyces cells Upon being exposed to hyperosmotic conditions, yeast cells cease growing and propagating, rapidly lose intracellular water, thereby resulting in a loss of turgor pressure followed by shrinkage of the cytoplasm (Slaninova et al, 2000;Schaber and Klipp, 2008;Munna et al, 2015). In the shrinking cytoplasm, the microtubular and actin-based cytoskeletal structures become disorganized and deep plasma membrane invaginations are formed which the cells can fill up with amorphous cell wall material (Chowdhury et al, 1992;Slaninova et al, 2000).…”

“…The overall cell volume is also reduced, and the yeast cells have to adapt their internal osmolarity to the hyperosmotic external conditions to restore the optimal cell volume (e.g. Pratt et al, 2003;Munna et al, 2015;Talemi et al, 2016).…”