Fig 5.

Catalase activity as a potential biomarker for mild-stress-induced robustness for Bacillus weihenstephanensis cells precultured at 7°C. Cells were exposed to mild oxidative stress (0.05 mM H₂O₂) for 0.25 to 4 h, and the induction of catalase activity and the induction of robustness for mild-stress-treated cells (s) were expressed relative to those of untreated cells (un) (log s/un). The robustness of untreated and mild-stress-treated cells was defined as the number of cells that survived the severe-stress treatment compared to the initial number of cells.