Deoxyribonucleic acid strand breaks during drying of Escherichia coli on a hydorohobic filter membrane.
Appl Environ Microbiol
; 37(2): 266-73, 1979 Feb.
Article
em En
| MEDLINE
| ID: mdl-373625
ABSTRACT
Cells of Escherichia coli mounted on a hydrophobic filter membrane were dried under various vapor pressures. A mutant defective in deoxyribonucleic acid repair (uvrA recA) was more sensitive to drying at a water activity of 0.53 or below than the parent strain but not at a water activity of 0.75 and above. Sucrose gradient studies showed that single- and double-strand breaks of deoxyribonucleic acid occurred at a water activity of 0.53 or below, but no breaks could be observed at a water activity of 0.75 or above. These results were observed in all cells rehydrated with 0.03 M tris (hydroxymethyl) aminomethane-hydrocholoride buffer solution at 0 or 37 degrees C, in the presence or absence of oxygen, with saturated water vapor or with a hypertonic solution followed by a gradual dilution. Freezable water was detected in the cells only at a water activity above 0.75 by differential scanning calorimetry. Removal of unfreezable water of cells in the drying, therfore, might induce deoxyribonucleic acid strand breaks.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Dessecação
/
Escherichia coli
/
Desnaturação de Ácido Nucleico
Idioma:
En
Revista:
Appl Environ Microbiol
Ano de publicação:
1979
Tipo de documento:
Article