Synthesis of catalase by "Streptococcus faecalis subsp. zymogenes".

"Streptococcus faecalis subsp. zymogenes" was grown aerobically and anaerobically with glycerol as the source of carbon, and in the presence and absence of haematin. Catalase activity was found only during aerobic growth in the presence of haematin. The rate of appearance of catalase activity was measured on (a) addition of haematin to haematin-less aerobic cultures, and (b) aeration of haematin-containing anaerobic cultures in the presence or absence of chloramphenicol. These experiments suggested that apocatalase synthesis was induced by aeration and was not dependent on the presence of haematin in the growth medium. The binding of haem to apocatalase was oxygen dependent.