ISSN:
1432-072X
Keywords:
Temperature
;
Heat shock gene expression
;
htpG
;
Heat shock protein
;
Escherichia coli
;
Continuous culture
;
Dilution rate
;
Growth medium
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Most of the data concerning heat shock gene expression reported in the literature are derived from batch culture experiments under substrate and nutrient sufficient conditions. Here, the effects of dilution rate and medium composition on the steady state and heat shock induced htpG gene expression have been investigated in continuous cultures of Escherichia coli, using a chromosomal htpG-lacZ gene fusion. During steady state growth temperature dependent patterns of the relative htpG expression were found to be largely similar, irrespective of the growth condition. However, nitrogen-limited growth resulted in a markedly reduced specific steady state htpG expression as compared to growth under carbon limitation or in complex medium, correlating qualitatively with the total cellular protein content. During heat shock, tight temperature controlled expression was evident. While the relative heat shock induced expression was largely identical at various dilution rates in a given growth medium, significantly different response patterns were observed in the three growth media at any give dilution rate. From these results a clearly temperature regulated htpG expression during both, steady and transient state growth in continuous culture is evident, which is further significantly affected by the growth condition used.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00291266
Permalink