This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Aiking, H. Articles by VAN 'T Riet, J. Search for Related Content PubMed PubMed Citation Articles by Aiking, H. Articles by VAN 'T Riet, J. Agricola Articles by Aiking, H. Articles by VAN 'T Riet, J.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1982 October; 44(4): 938-944

Adaptation to Cadmium by Klebsiella aerogenes Growing in Continuous Culture Proceeds Mainly via Formation of Cadmium Sulfide

¹ Instituut voor Milieuvraagstukken and Biochemisch Laboratorium, ² Vrije Universiteit, 1007 MC Amsterdam, The Netherlands

ABSTRACT

The adaptation of Klebsiella aerogenes to high levels of cadmium was studied in continuous culture under conditions of glucose limitation. When up to 6 x 10^–4 M cadmium was added to a culture in steady state, growth ceased instantaneously but resumed within 5 h (dilution rate, 0.1 h^–1). When again in steady state, these adapted cells exhibited a far greater tolerance to cadmium than did unadapted cells (not previously exposed to cadmium) when tested on solid media containing different concentrations of cadmium. This relative insensitivity of adapted cells to cadmium was subsequently lost in continuous culture within 5 days after omitting cadmium from the influent medium. Thus, the phenomenon was an inducible physiological process. Adapted cells contained substantial amounts of cadmium (up to 2.4% of the bacterial dry weight). The cadmium content of the cells was dependent on growth conditions and was found to be proportional to the inorganic sulfide content of the cells in all cases. This suggested that formation of CdS is probably the most important mechanism of detoxification in this organism. The presence of large numbers of electron-dense granules on the cell surface (absent in cultures without added cadmium) provided additional support for this conclusion.

This article has been cited by other articles:

• Wang, C. L., Maratukulam, P. D., Lum, A. M., Clark, D. S., Keasling, J. D. (2000). Metabolic Engineering of an Aerobic Sulfate Reduction Pathway and Its Application to Precipitation of Cadmium on the Cell Surface. Appl. Environ. Microbiol. 66: 4497-4502 [Abstract] [Full Text]