Abstract

ALCARDE, A.R.  and  BASSO, L.C.. EFEITO DA TREALOSE NA MANUTENÇÃO DA VIABILIDADE DE CÉLULAS DE LEVEDURAS DESIDRATADAS POR LIOFILIZAÇÃO. Sci. agric. [online]. 1997, vol.54, n.3, pp. 189-194. ISSN 0103-9016.  http://dx.doi.org/10.1590/S0103-90161997000200013.

To evaluate the influence of the endogenous trehalose and also the use of trehalose as a cryoprotectant medium on the maintenance of yeast cell viability, after the freeze-drying process, strains TA (M-300-A) and SA (strain isolated from Usina Santa Adélia S/A) of the yeast Saccharomyces cerevisiae and the strain IZ-1904 of the yeast Saccharomyces boulardii were tested. After accumulation of endogenous trehalose by heat treatment at 45^oC during 2 hours in a potassium citrate buffer (2M pH 4,0 with 2.0% glucose) the yeasts were suspended in one of three cryoprotectant solutions (skimmed milk 10%, sucrose 10% and trehalose 10%), freeze-dried and analysed for their cell viability after 0, 10, 40 and 90 days of storage. Higher viability maintenance after the freeze-drying process occured for all yeasts at the higher endogenous trehalose levels. The solution of skimmed milk 10% was the best cryoprotectant medium for the yeast cells.

Keywords : Saccharomyces; trehalose; viability; Saccharomyces; freeze-drying process.