FIG. 3.

Anaerobic cultures (10⁷ cells/ml) of RS112 were halved in an anaerobic glove box; one half was exposed to atmospheric oxygen immediately prior to a 50°C heat stress for the times indicated, while the other half was heat stressed in the absence of oxygen. Crude extract was obtained by glass bead lysis, and total sulfhydryl content was measured with Ellman reagent. Data represent the average of three experiments ± SD.