Survival of yeasts stored after freeze-drying or liquid-drying.
We investigated the survival mechanisms of freeze-dried or liquid-dried (L-dried) yeast cells in ampoules. Type strains of various yeasts were freeze-dried or L-dried and sealed in ampoules under high vacuum (< 1 Pa) or low vacuum (4.8 x 10(4) Pa), then stored at 37 degrees C (accelerated storage test) for up to 17 weeks. Among strains in each of the genera Saccharomyces, Saccharomycopsis, Debaryomyces, and Pichia, survival rates immediately after freeze-drying varied more widely than those after L-drying. Freeze-dried cells stored at 4.8 x 10(4) Pa had lower survival rates than those stored at < 1 Pa. L-dried cells stored at 4.8 x 10(4) Pa also had lower survival rates than those stored at < 1 Pa, but the decrease in survival was not as marked as in freeze-dried cells. Strains that had high survival rates immediately after freeze-drying tended to have small cells, to be osmotolerant, and to be able to utilize many kinds of carbohydrates. L-dried cells of most Candida strains had stable survival rates regardless of the vacuum pressure. In basidiomycetous yeasts, strains forming extracellular polysaccharides had markedly lower survival.
Miyamoto-Shinohara
Yukie
Y
International Patent Organism Depositary, National Institute of Advanced Industrial Science and Technology, Tsukuba Central, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan. y.miyamoto@aist.go.jp
Nozawa
Fumie
F
Sukenobe
Junji
J
Imaizumi
Takashi
T
D002473:Cell Wall / Q000737:chemistry; D015169:Colony Count, Microbial; D003890:Desiccation / Q000379:methods*; D005612:Freeze Drying / Q000379:methods*; D008828:Microbiological Techniques; D011134:Polysaccharides / Q000032:analysis; D011309:Preservation, Biological / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000254:growth & development; D004718:Saccharomycetales / Q000145:classification / Q000254:growth & development*; D013045:Species Specificity
D011134:Polysaccharides