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.
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
Yukie
Y
Miyamoto-Shinohara
Fumie
F
Nozawa
Junji
J
Sukenobe
Takashi
T
Imaizumi
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