Global responses of Escherichia coli to adverse conditions determined by microarrays and FT-IR spectroscopy

Research output: Contribution to journalArticle

Authors

  • B Moen
  • AO Janbu
  • S Langsrud
  • O Langsrud
  • A Kohler
  • K Rudi

Colleges, School and Institutes

Abstract

The global gene expression and biomolecular composition in an Escherichia coli model strain exposed to 10 adverse conditions (sodium chloride, ethanol, glycerol, hydrochloric and acetic acid, sodium hydroxide, heat (46 degrees C), and cold (15 degrees C), as well as ethidium bromide and the disinfectant benzalkonium chloride) were determined using DNA microarrays and Fourier transform infrared (FT-IR) spectroscopy. In total, approximately 40% of all investigated genes (1682/4279 genes) significantly changed expression, compared with a nonstressed control. There were, however, only 3 genes (ygaW (unknown function), rmf (encoding a ribosomal modification factor), and ghrA (encoding a glyoxylate/hydroxypyruvate reductase)) that significantly changed expression under all conditions (not including benzalkonium chloride). The FTIR analysis showed an increase in unsaturated fatty acids during ethanol and cold exposure, and a decrease during acid and heat exposure. Cold conditions induced changes in the carbohydrate composition of the cell, possibly related to the upregulation of outer membrane genes (glgAP and rcsA). Although some covariance was observed between the 2 data sets, principle component analysis and regression analyses revealed that the gene expression and the biomolecular responses are not well correlated in stressed populations of E. coli, underlining the importance of multiple strategies to begin to understand the effect on the whole cell.

Details

Original languageEnglish
Pages (from-to)714-728
Number of pages15
JournalCanadian Journal of Microbiology
Volume55
Issue number6
Publication statusPublished - 1 Jun 2009

Keywords

  • multivariate data analysis, global responses, FT-IR spectroscopy, Escherichia coli, microarray