Viability of micrococci and lactobacilli upon freezing and freeze-drying in the presence of different cryoprotectants
| Autor: | R. Brankova, Ts. Tsvetkov |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Time Factors
Sucrose food.ingredient Cryoprotectant Gelatin General Biochemistry Genetics and Molecular Biology Ampoule Micrococcus chemistry.chemical_compound Freeze-drying Cryoprotective Agents food Freezing Food science Lactose biology food and beverages General Medicine biology.organism_classification Lactobacillus Freeze Drying chemistry Biochemistry General Agricultural and Biological Sciences Sodium acetate Lactobacillus plantarum |
| Zdroj: | Cryobiology. 20:318-323 |
| ISSN: | 0011-2240 |
| DOI: | 10.1016/0011-2240(83)90020-2 |
| Popis: | Studies were conducted on the viability of Micrococcus varians strain M95 and Lactobacillus plantarum strain L4 upon freezing and freeze-drying using five cryoprotectants (sucrose, lactose, sodium glutamate, peptone, dry nonfat milk) singly or in combinations with gelatin, glutamic acid, and sodium acetate. The number of survivals was determined immediately after treatment and after storage at room temperature or refrigeration temperatures, under vacuum or in air. Dry nonfat milk and peptone introduced at the levels of 8 and 5%, respectively, to broth culture, were found to be the best cryoprotectants providing a 100% viability determined immediately after the treatment of the strains under investigation. Immediately after freezing and freeze-drying, the numbers of viable micrococci remain high, the percentage viability in the presence of almost all the protectants used being 100%. During storage, those numbers decrease rapidly, reaching zero in 3 months upon storage at room temperature in air. The storage ability of lactobacilli is considerably better and, regardless of the fact that the percentage viability decreases, sufficient numbers of viable cells remain after 6 months of storage at both test temperatures. The best results are obtained on storing the microoganisms under vacuum in ampoules under reduced temperatures (+5 °C). |
| Databáze: | OpenAIRE |
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