Extended exposure of Escherichia coli to temperatures above and below their growth optimum led to significant changes in oxidant production and antioxidant defense. At 20 °C an increase in the intracellular H2O2 concentration and oxidized glutathione (GSSG) level was observed against a background of low levels of reduced glutathione (GSH) and decreased catalase and glutathione reductase (GOR) activities. The intracellular H2O2 and GSSG concentrations had minimal values at 30 and 37 °C, but rose again at 42 °C, suggesting that oxidative processes were intensified at high temperatures. An increase in temperature from 20 to 42 °C led to an elevation in the oxygen respiration rate and superoxide production; a 5-fold increase in the intracellular GSH concentration and in the GSH:GSSG ratio occurred simultaneously. Catalase HPI and GOR activities were elevated 4.4- and 1.5-fold, respectively. Prolonged exposure to sublethal temperatures facilitated an adaptation to subsequent oxidative stress produced by the addition of H2O2. © 2007 Elsevier Ltd. All rights reserved.
Smirnova, G. V., Muzyka, N. G., & Oktyabrsky, O. N. (2007). Enhanced resistance to peroxide stress in Escherichia coli grown outside their niche temperatures. Journal of Thermal Biology, 32(6), 321–327. https://doi.org/10.1016/j.jtherbio.2007.04.002