0000000000460489
AUTHOR
Galina Khroustalyova
showing 14 related works from this author
Dehydration of yeast: Changes in the intracellular content of Hsp70 family proteins
2008
Abstract Yeast is known to experience in natural and industrial conditions cycles of dehydration–rehydration. Several molecular mechanisms can be triggered in response to this and other environmental stressors and to rescue yeast cells of the cytotoxic effect. Since heat shock proteins constitute one of the most important systems of the response to stress we studied whether the pre-induced major stress protein, Hsp70, can cope with yeast cell drying. To induce Hsp70 expression the cells of two yeast species, Saccharomyces cerevisiae and Debaryomyces hansenii , were subjected to non-lethal heat shock. It was found that during yeast culture growth Hsp70 accumulation occurred at the exponentia…
Anhydrobiosis in yeasts: Psychrotolerant yeasts are highly resistant to dehydration.
2018
Yeast cells are able to transition into a state of anhydrobiosis (temporary reversible suspension of metabolism) under conditions of desiccation. One of the most efficient approaches for understanding the mechanisms underlying resistance to dehydration-rehydration is to identify yeasts, which are stable under such treatments, and compare them with moderately resistant species and strains. In the current study, we investigated the resistance to dehydration-rehydration of six psychrotolerant yeast strains belonging to two species. All studied strains of Solicoccozyma terricola and Naganishia albida were found to be highly resistant to dehydration-rehydration. The viability of S. terricola str…
Anhydrobiosis in yeast: Glutathione overproduction improves resistance to dehydration of a recombinant Ogataea (Hansenula) polymorpha strain
2018
Abstract We show for the first time that a recombinant strain of yeast Ogataea (Hansenula) polymorpha is at least as tolerant to dehydration-rehydration treatment as the wild type strain. It is believed that this unusual characteristic of this recombinant yeast strain is linked with its ability to overproduce glutathione. Based on plasma membrane permeability analysis, we hypothesise that glutathione, in addition to its powerful antioxidative protective effects on membrane lipids, may also protect membrane proteins and/or nucleic acids. The combination of yeast cell dehydration with immobilisation and subsequent preliminary slow rehydration in water vapour gave good results in terms of reco…
Thermotolerance in Saccharomyces cerevisiae is linked to resistance to anhydrobiosis
2014
Abstract We have demonstrated that a thermotolerant yeast strain ( Saccharomyces cerevisiae TS1) is much more resistant to dehydration–rehydration treatments than a mesophilic strain of S. cerevisiae . Yeast resistance to dehydration–rehydration was found to be similar in cells from exponential and stationary growth phases. Under controlled rehydration conditions involving gradual rehydration in water vapour, yeast cell viability was maintained at 90–95%. When S. cerevisiae TS1 cells were pre-grown at 37 °C and then dried, controlled rehydration lead to restoration of plasma membrane integrity, indicating important differences in cell envelope architechture of mesophilic and thermotolerant …
Anhydrobiosis in yeasts: Glutathione synthesis by yeast Ogataea (Hansenula) polymorpha cells after their dehydration-rehydration.
2019
The possibility of using active dry microbial preparations in biotechnological processes is essential for the development of new modern industrial technologies. In this study, we show the possibility of obtaining such preparations of the genetically engineered yeast strain Ogataea (Hansenula) polymorpha with glutathione overproduction. Special pre-treatment involving the gradual rehydration of dry cells in water vapour led to the restoration/reactivation of almost 100% of dehydrated cells. Furthermore, dry cells do not lose their viability during storage at room temperatures. Application of dry cells as the inoculum provides the same levels of glutathione synthesis as that of a native yeast…
Physiological engineering of Pseudomonas aurantiaca antimicrobial activity: effects of sodium chloride treatment
2012
The influence of sodium chloride (NaCl) treatment on the antifungal activity of the bacterium Pseudomonas aurantiaca, a producer of biopesticide for vegetable plants, was investigated. It was shown that an increase in the NaCl concentration in incubation solutions from 1 M to 3 M led to a significant increase in the antifungal activity of this bacterium. Antifungal activity continued to increase with prolonged treatment of bacteria in fresh nutrient medium from 72 h to 96 h. These findings could be very important for the further development of biotechnological processes directed not only to the production of new active biopesticides but also of other valuable resources.
Engineering of sugar transporters for improvement of xylose utilization during high-temperature alcoholic fermentation in Ogataea polymorpha yeast
2020
Abstract Background Xylose transport is one of the bottlenecks in the conversion of lignocellulosic biomass to ethanol. Xylose consumption by the wild-type strains of xylose-utilizing yeasts occurs once glucose is depleted resulting in a long fermentation process and overall slow and incomplete conversion of sugars liberated from lignocellulosic hydrolysates. Therefore, the engineering of endogenous transporters for the facilitation of glucose-xylose co-consumption is an important prerequisite for efficient ethanol production from lignocellulosic hydrolysates. Results In this study, several engineering approaches formerly used for the low-affinity glucose transporters in Saccharomyces cerev…
Evaluation of the enhanced resistance of Ogataea (Hansenula) polymorpha to benzalkonium chloride as a resource for bioremediation technologies
2019
Abstract Benzalkonium chloride (BAC) is highly abundant in wastewaters due to its wide application in household and industrial products. The aim of this research was to compare the resistance of two genetically related strains, Ogataea polymorpha (wild type) and O. polymorpha cat8Δ (recombinant strain), to enhanced concentrations of BAC (≥ 100 mg/L) in terms of its appearance in wastewaters. Inhibition of the respiration activity of wt and cat8Δ by 100 mg/L and 300 mg/L BAC in a xylose-containing broth (4 g/L xylose) was dependent on the carbon source used for obtaining the yeast biomass through ethanol fermentation. The respiration activity of wt in a liquid broth was inhibited by BAC, whi…
Resistance of a recombinant Escherichia coli to dehydration.
2009
International audience; Dehydration of microorganisms, rendering them anhydrobiotic, is often an efficient method for the short and long term conservation of different strain-producers. However, some biotechnologically important recombinant bacterial strains are extremely sensitive to conventional treatment. We describe appropriate conditions during dehydration of the recombinant Escherichia coli strain HB 101 (GAPDH) that can result dry cells having a 88% viability on rehydration. The methods entails air-drying after addition of 100 mM trehalose to the cultivation medium or distilled water (for short term incubation).
Exponential growth phase cells of the osmotolerant yeast Debaryomyces hansenii are extremely resistant to dehydration stress
2001
Abstract The osmotolerant yeast Debaryomyces hansenii is highly resistant to dehydration stress and this tolerance was more pronounced for cells taken from the exponential growth phase than from the stationary phase. Growth of D. hansenii in medium containing 10% (w v −1 ) NaCl, resulted in an additional increase in cellular resistance to dehydration, which was most marked for stationary phase cells. It is expected that further investigations of the mechanisms behind this exceptional dehydrational tolerance will reveal new approaches for improvement of the quality of dry yeast.
Anhydrobiosis in Yeasts: Changes in Mitochondrial Membranes Improve the Resistance of Saccharomyces cerevisiae Cells to Dehydration–Rehydration
2019
Anhydrobiosis is a unique state of live organisms in which their metabolism is temporary reversibly suspended as the result of strong dehydration of their cells. This state is widely used currently during large-capacity production of active dry baker&rsquo
Changes in Energy Status of Saccharomyces cerevisiae Cells During Dehydration and Rehydration
2021
Anhydrobiosis is the state of life when cells are exposed to waterless conditions and gradually cease their metabolism. In this study, we determined the sequence of events in Saccharomyces cerevisiae energy metabolism during processes of dehydration and rehydration. The intensities of respiration and acidification of the medium, the amounts of phenyldicarbaundecaborane (PCB−) bound to yeast membranes, and the capabilities of cells to accumulate K+ were assayed using an electrochemical monitoring system, and the intracellular content of ATP was measured using a bioluminescence assay. Mesophilic, semi-resistant to desiccation S. cerevisiae strain 14 and thermotolerant, very resistant to desic…
Additional file 2 of Engineering of sugar transporters for improvement of xylose utilization during high-temperature alcoholic fermentation in Ogatae…
2020
Additional file 2: Table S1. List of primers used in this study.
Additional file 1 of Engineering of sugar transporters for improvement of xylose utilization during high-temperature alcoholic fermentation in Ogatae…
2020
Additional file 1: Figure S1. Alignment of amino acid sequences of O. polymorpha Hxt1 and S. cerevisiae Hxt1, Hxt3, Hxt6, Hxt7 transporters. Figure S2. Sequence of O. polymorpha Hxt1 transporter. The lysine residues substituted for arginine are shaded grey. The position of the asparagine residue that was mutated to an alanine to obtain Hxt1-N358A mutant is underlined. Figure S3. Linear schemes of plasmids for overexpression of the modified versions of Hxt1, Gal2 and Hxt7 transporters.