Document Detail

Preservation of frozen yeast cells by trehalose.
MedLine Citation:
PMID:  10516583     Owner:  NLM     Status:  MEDLINE    
Two different methods commonly used to preserve intact yeast cells-freezing and freeze-drying-were compared. Different yeast cells submitted to these treatments were stored for 28 days and cell viability assessed during this period. Intact yeast cells showed to be less tolerant to freeze-drying than to freezing. The rate of survival for both treatments could be enhanced by exogenous trehalose (10%) added during freezing and freeze-drying treatments or by a combination of two procedures: a pre-exposure of cells to 40 degrees C for 60 min and addition of trehalose. A maximum survival level of 71.5 +/- 6.3% after freezing could be achieved at the end of a storage period of 28 days, whereas only 25.0 +/- 1.4% showed the ability to tolerate freeze-drying treatment, if both low-temperature treatments were preceded by a heat exposure and addition of trehalose to yeast cells. Increased survival ability was also obtained when the pre-exposure treatment of yeast cells was performed at 10 degrees C for 3 h and trehalose was added: these treatments enhanced cell survival following freezing from 20.5 +/- 7. 7% to 60.0 +/- 3.5%. Although both mild cold and heat shock treatments could enhance cell tolerance to low temperature, only the heat treatment was able to increase the accumulation of intracellular trehalose whereas, during cold shock exposure, the intracellular amount of trehalose remained unaltered. Intracellular trehalose levels seemed not to be the only factor contributing to cell tolerance against freezing and freeze-drying treatments; however, the protection that this sugar confers to cells can be exerted only if it is to be found on both sides of the plasma membrane.
L Diniz-Mendes; E Bernardes; P S de Araujo; A D Panek; V M Paschoalin
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Biotechnology and bioengineering     Volume:  65     ISSN:  0006-3592     ISO Abbreviation:  Biotechnol. Bioeng.     Publication Date:  1999 Dec 
Date Detail:
Created Date:  1999-11-30     Completed Date:  1999-11-30     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  7502021     Medline TA:  Biotechnol Bioeng     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  572-8     Citation Subset:  IM    
Copyright Information:
Copyright 1999 John Wiley & Sons, Inc.
Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21949-900, Rio de Janeiro, RJ, Brazil.
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MeSH Terms
Biological Transport, Active
Cryopreservation / methods*
Cryoprotective Agents / pharmacokinetics
Evaluation Studies as Topic
Freeze Drying / methods*
Hot Temperature
Saccharomyces cerevisiae* / metabolism
Trehalose / pharmacokinetics
Reg. No./Substance:
0/Cryoprotective Agents; 99-20-7/Trehalose

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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