Related Experiment Video
Updated: May 23, 2026

Studying Oxidative Stress Caused by the Mitis Group Streptococci in Caenorhabditis elegans
Published on: March 23, 2019
Contribution of catalase to hydrogen peroxide resistance in Enterococcus faecalis
Michael Baureder1, Ronny Reimann, Lars Hederstedt
1Microbiology Group, Department of Biology, Lund University, Lund, Sweden. michael.baureder@biol.lu.se
Abstract:
Enterococcus faecalis exhibits high resistance to oxidative stress. Several enzymes are responsible for this trait. The role of alkyl hydroperoxide reductase (Ahp), thiol peroxidase (Tpx), and NADH peroxidase (Npr) in oxidative stress defense was recently characterized. Enterococcus faecalis, in contrast to many other streptococci, contains a catalase (KatA), but this enzyme can only be formed when the bacterium is supplied with heme. We have used this heme dependency of catalase activity and mutants deficient in KatA and Npr to investigate the role of the catalase in resistance against exogenous and endogenous hydrogen peroxide stress. The results demonstrate that in the presence of environmental heme catalase contributes to the protection against toxic effects of hydrogen peroxide.
Related Concept Videos
Peroxisomes
Peroxisomes and Mitochondria
The peroxisome is a single membrane-bound cellular organelle that can perform several different functions, including lipid metabolism and chemical detoxification. The enzymes within peroxisomes...
Development of Antibiotic Resistance
Oxygen Requirements and Growth Patterns
Catalysis
Catalysis

