Are UV-induced nonculturable Escherichia coli K-12 cells alive or dead?
Eur J Biochem
; 270(12): 2689-95, 2003 Jun.
Article
em En
| MEDLINE
| ID: mdl-12787036
ABSTRACT
Cells that have lost the ability to grow in culture could be defined operationally as either alive or dead depending on the method used to determine cell viability. As a consequence, the interpretation of the state of 'nonculturable' cells is often ambiguous. Escherichia coli K12 cells inactivated by UV-irradiation with a low (UV1) and a high (UV2) dose were used as a model of nonculturable cells. Cells inactivated by the UV1 dose lost 'culturability' but they were not lysed and maintained the capacity to respond to nutrient addition by protein synthesis and cell wall synthesis. The cells also retained both a high level of glucose transport and the capacity for metabolizing glucose. Moreover, during glucose incorporation, UV1-treated cells showed the capacity to respond to aeration conditions modifying their metabolic flux through the Embden-Meyerhof and pentose-phosphate pathways. However, nonculturable cells obtained by irradiation with the high UV2 dose showed several levels of metabolic imbalance and retained only residual metabolic activities. Nonculturable cells obtained by irradiation with UV1 and UV2 doses were diagnosed as active and inactive (dying) cells, respectively.
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Base de dados:
MEDLINE
Assunto principal:
Raios Ultravioleta
/
Escherichia coli
Idioma:
En
Revista:
Eur J Biochem
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
França