Back to Search Start Over

Effect of Environmental Factors on the trans/cis Ratio of Unsaturated Fatty Acids in Pseudomonas putida S12

Authors :
G. Meulenbeld
Hermann J. Heipieper
J.A.M. de Bont
Q. van Oirschot
Source :
Applied and Environmental Microbiology 62 (1996), Applied and Environmental Microbiology, 62, 2773-2777
Publication Year :
1996
Publisher :
American Society for Microbiology, 1996.

Abstract

The membrane reactions of Pseudomonas putida S12 to environmental stress were investigated. Cells reacted to the addition of six different heavy metals with an increase in the ratio of trans to cis unsaturated fatty acids. A correlation among the increase in the trans/cis ratio, the toxic effects of the heavy metals, and nonspecific permeabilization of the cytoplasmic membrane, as indicated by an efflux of potassium ions, was measured. Cells previously adapted to toxic concentrations of toluene exhibited increased tolerance to all applied concentrations of zinc compared with nonadapted cells. Cells exposed to different temperatures grew optimally at 30(deg)C. The degree of saturation of the membrane fatty acids of these cells decreased with decreasing temperature. An increase in the trans/cis ratio of unsaturated fatty acids took place only at higher temperatures. Osmotic stress, expressed as reduced water activity, was obtained by using different types of solutes. Only in the presence of toxic concentrations of sodium chloride or sucrose did the trans/cis ratio increase. At no applied water activity a significant effect of glycerol on the trans/cis ratio was measured. When cells were exposed to different pHs, a distinct optimum cis/trans isomerase activity was measured at pHs between 4.0 and 5.0, whereas at higher or lower pHs no reaction occurred. This optimum coincided with a loss of viability between pH 4 and 5.

Details

ISSN :
10985336 and 00992240
Volume :
62
Database :
OpenAIRE
Journal :
Applied and Environmental Microbiology
Accession number :
edsair.doi.dedup.....9357a8239a18f8b8cb9a8b5a83f3d9f8
Full Text :
https://doi.org/10.1128/aem.62.8.2773-2777.1996