Search results for "Anhydrobiosis"
showing 9 items of 9 documents
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 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…
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).
Anhydrobiosis: Inside yeast cells
2018
International audience; Under natural conditions yeast cells as well as other microorganisms are regularly subjected to the influence of severe drought, which leads to their serious dehydration. The dry seasons are then changed by rains and there is a restoration of normal water potential inside the cells. To survive such seasonal changes a lot of vegetative microbial cells, which belong to various genera and species, may be able to enter into a state of anhydrobiosis, in which their metabolism is temporarily and reversibly suspended or delayed. This evolutionarily developed adaptation to extreme conditions of the environment is widely used for practical goals - for conservation of microorg…
Activity of the α-glucoside transporter Agt1 in Saccharomyces cerevisiae cells during dehydration-rehydration events
2018
Microbial cells can enter a state of anhydrobiosis under desiccating conditions. One of the main determinants of viability during dehydration-rehydration cycles is structural integrity of the plasma membrane. Whereas much is known about phase transitions of the lipid bilayer, there is a paucity of information on changes in activity of plasma membrane proteins during dehydration-rehydration events. We selected the α-glucoside transporter Agt1 to gain insights into stress mechanisms/responses and ecophysiology during anhydrobiosis. As intracellular water content of S. cerevisiae strain 14 (a strain with moderate tolerance to dehydration-rehydration) was reduced to 1.5 g water/g dry weight, th…
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.
Anhydrobiosis of yeast: changes of cell surface structures and non-conventional applications of anhydrobiosis
2014
Darba mērķis bija veikt pētījumus par anhidrobiozi jaunu teorētisku faktu atklāšanai un plašināt raugu anhidrobiozes praktisku izmantošanu. Atklāta atsevišķu šūnas sieniņas proteīnu un citoplazmatiskās membrānas transportieru nozīmīga loma raugu dzīvotspējas saglabāšanā anhidrobiozes stāvoklī. Parādīts, ka citoplazmatiskās membrānas transportiera Agt1 izmaiņas dehidratācijas/rehidratācijas laikā ir raugu celmu specifiskās. Izstrādāta jauna mikroorganismu immobilizācijas metode. Parādīta iegūto immobilizēto preparātu efektīvā izmantošana etanola ražošanā un notekūdeņu attīrīšanā, ka arī konstatēta šo preparātu augsta stabilitāte. Atzīmēts, ka immobilizācija ievērojami paaugstina šūnu reziste…
Recovery Estimation of Dried Foodborne Pathogens Is Directly Related to Rehydration Kinetics.
2016
International audience; Drying is a common process which is used to preserve food products and technological microorganisms, but which is deleterious for the cells. The aim of this study is to differentiate the effects of drying alone from the effects of the successive and necessary rehydration. Rehydration of dried bacteria is a critical step already studied in starter culture but not for different kinetics and not for pathogens. In the present study, the influence of rehydration kinetics was investigated for three foodborne pathogens involved in neonatal diseases caused by the consumption of rehydrated milk powder: Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enteri…