Saccharomyces cerevisiae glycerol-H symporter Stl1p is essential for cold-near-freeze and freeze stress adaptation. A simple recipe with high biotechnological potential is givenReportar como inadecuado




Saccharomyces cerevisiae glycerol-H symporter Stl1p is essential for cold-near-freeze and freeze stress adaptation. A simple recipe with high biotechnological potential is given - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Microbial Cell Factories

, 9:82

First Online: 03 November 2010Received: 23 July 2010Accepted: 03 November 2010

Abstract

BackgroundFreezing is an increasingly important means of preservation and storage of microbial strains used for many types of industrial applications including food processing. However, the yeast mechanisms of tolerance and sensitivity to freeze or near-freeze stress are still poorly understood. More knowledge on this regard would improve their biotechnological potential. Glycerol, in particular intracellular glycerol, has been assigned as a cryoprotectant, also important for cold-near-freeze stress adaptation. The S. cerevisiae glycerol active transporter Stl1p plays an important role on the fast accumulation of glycerol. This gene is expressed under gluconeogenic conditions, under osmotic shock and stress, as well as under high temperatures.

ResultsWe found that cells grown on STL1 induction medium YPGE and subjected to cold-near-freeze stress, displayed an extremely high expression of this gene, also visible at glycerol-H symporter activity level. Under the same conditions, the strains harbouring this transporter accumulated more than 400 mM glycerol, whereas the glycerol-H symporter mutant presented less than 1 mM. Consistently, the strains able to accumulate glycerol survive 25-50% more than the stl1Δ mutant.

ConclusionsIn this work, we report the contribution of the glycerol-H symporter Stl1p for the accumulation and maintenance of glycerol intracellular levels, and consequently cell survival at cold-near-freeze and freeze temperatures. These findings have a high biotechnological impact, as they show that any S. cerevisiae strain already in use can become more resistant to cold-freeze-thaw stress just by simply adding glycerol to the broth. The combination of low temperatures with extracellular glycerol will induce the transporter Stl1p. This solution avoids the use of transgenic strains, in particular in food industry.

Electronic supplementary materialThe online version of this article doi:10.1186-1475-2859-9-82 contains supplementary material, which is available to authorized users.

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Autor: Joana Tulha - Ana Lima - Cândida Lucas - Célia Ferreira

Fuente: https://link.springer.com/



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