The effect of protective ingredients on the survival of immobilized cells of Streptococcus thermophilus to air and freeze-drying



Document title: The effect of protective ingredients on the survival of immobilized cells of Streptococcus thermophilus to air and freeze-drying
Journal: Electronic journal of biotechnology
Database: PERIÓDICA
System number: 000266059
ISSN: 0717-3458
Authors: 1
Institutions: 1Center Agriculture and Agri-food, Saint-Hyacinthe, Qué. Canadá
Year:
Season: Dic
Volumen: 4
Number: 3
Pages: 7-8
Country: Chile
Language: Inglés
Document type: Artículo
Approach: Experimental, aplicado
English abstract Streptococcus thermophilus cultures were grown either on trehalose or lactose, immobilized in alginate beads, dipped in various protective solutions and dried by either convection air-drying (CAD) or freeze-drying (FD). Immobilized cultures dipped in the 0.1% peptone solution did not show good survival to CAD or FD, as mortality was over 99%. There was no significant difference in mortality levels, in both methods of drying, when lactose or trehalose were used as protective ingredients. The highest survival levels (50 to 98%) were with a whey-sucrose protective medium, but this was potentially related to a higher pH and solids of the solution. Mortality levels were higher in FD than CAD, and this did not appear to be related to the fact that FD cultures had lower residual moisture contents than those dried under CAD. Cells grown on lactose had slightly higher survival rates to drying than those obtained from CAD. Trehalose-positive and trehalose-negative cultures of S. thermophilus did not show different mortality patterns to CAD or FD
Disciplines: Biología
Keyword: Bacterias,
Biotecnología,
Streptococcus thermophilus,
Acido láctico,
Conservación,
Liofilización
Keyword: Biology,
Bacteria,
Streptococcus thermophilus,
Lactic acid,
Lyophilization,
Preservation
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