Intracellular physiological events of yeast Rhodotorula glutinis during storage at +4 degrees C.
Int J Food Microbiol
; 105(2): 97-109, 2005 Nov 25.
Article
in En
| MEDLINE
| ID: mdl-16253365
ABSTRACT
Samples of the cheese yeast Rhodotorula glutinis were analysed during storage at +4 degrees C for cultivability, viability, vitality (metabolic activity), membrane potential state, intracellular pH, and carbohydrate content. The results have allowed to describe cellular events occurring during storage. The loss of vitality came with the decrease of carbohydrate content. The fall of trehalose content under a threshold value induced the deterioration of the membrane potential. Later, when all the cells were depolarised, the intracellular pH decreased and the cultivability dropped, whereas viable cells still decreased slowly. Then, it led to an intermediate physiological state similar to the viable but non-cultivable state. Finally, the fall of viability dropped. In this work, we have defined rapid methods relevant to describe the sequence of intracellular events in the cheese yeast R. glutinis during storage, and we applied them to understand the weak vitality without fall of viability of yeast samples. These methods might allow to rapidly test yeast sample quality before use and to predict, at the moment of the harvesting, the conservation of the yeast.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Rhodotorula
/
Cheese
/
Food Handling
/
Food Preservation
Type of study:
Prognostic_studies
Language:
En
Journal:
Int J Food Microbiol
Journal subject:
CIENCIAS DA NUTRICAO
/
MICROBIOLOGIA
Year:
2005
Document type:
Article
Affiliation country:
France