Freezing and freeze-drying of microorganisms

Nei, Tokio

doi:10.1016/0011-2240(64)90026-4

Cited by 24 publications

(14 citation statements)

References 1 publication

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“…Since the dehydration model demands that all freezable intracellular water leave the cells during cooling, it requires that the whole cell or the protoplast shrink by a volume equal to that of the 90 per cent of the water in a cell that is potentially freezable. Rapidly cooled cells do not shrink by that amount nor do they plasmolyze (Nei, 1960;Mazur, 1961b;Eddy, 1958). Nei observed no shrinkage in rapidly cooled yeast photographed on the freezing stage of a microscope.…”

Section: Discussionmentioning

confidence: 99%

Studies on Rapidly Frozen Suspensions of Yeast Cells by Differential Thermal Analysis and Conductometry

Mazur¹

1963

Biophysical Journal

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Few, if any, yeast cells survived rapid cooling to -196 degrees C and subsequent slow warming. After rapid freezing, the suspensions absorbed latent heat of fusion between -15 degrees and 0 degrees C during warming, and the relation between the amount of heat absorbed and the concentration of cells was the same as that in equivalent KCl solutions, indicating that frozen suspensions behave thermally like frozen solutions. The amount of heat absorbed was such that more than 80 per cent of the intracellular solution had to be frozen. The conductometric behavior of frozen suspensions showed that cell solutes were still inside the cells and surrounded by an intact cell membrane at the time heat was being absorbed. Two models are consistent with these findings. The first assumes that intracellular freezing has taken place; the second that all freezable water has left the cells and frozen externally. The latter model is ruled out because rapidly cooled cells do not shrink by an amount equal to the volume of water that would have to be withdrawn to prevent internal freezing.

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Section: Discussionmentioning

confidence: 99%

Studies on Rapidly Frozen Suspensions of Yeast Cells by Differential Thermal Analysis and Conductometry

Mazur¹

1963

Biophysical Journal

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“…There is an extensive literature on the freeze-drying of microorganisms including bacteria (249). Freeze-drying and desiccation of E. coli both lead to the induction of mutations (16).…”

Section: Vol 58 1994mentioning

confidence: 99%

Desiccation tolerance of prokaryotes.

Potts

1994

Microbiological Reviews

841

598

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“…Denatura tion of protein by removal of bound water has also been suggested. The limit of survival from desiccation in some cells has been shown to correspond with the amount of free water present (99) . Two basically different interactions of water-stabilizing polymer structure have been considered.…”

Section: Olienmentioning

confidence: 99%

“…A variety of specific internal changes may occur as a result of frost des iccation (98,99,152). Denaturation of proteins from increased concentra tion of solutes has been considered a possible deleterious effect (3,75,91,95).…”

Section: Relation Of Micro Redistribution Patterns To Cytological Effmentioning

confidence: 99%