Identification of O 2 ‐induced peptides in an obligatory anaerobe, Clostridium acetobutylicum

Clostridium acetobutylicum DSM792 (=ATCC824), a solvent producing obligate anaerobe, grew well after a shift in growth conditions from anoxic to microoxic at the mid exponential phase. In two‐dimensional gel electrophoresis, a spot migrating at 45 kDa and three spots at 23 kDa accumulated after 30 min of flushing with 5% O 2 /95% N 2 . Based on peptide mass fingerprints, the 45 kDa polypeptide was determined to be NP_347663 (A‐type flavoprotein homologue) and the 23 kDa polypeptides were determined to be NP_350180 or NP_350181 (novel type rubrerythrin homologue). Northern blot analysis indicated that the expressions of these peptide transcripts were upregulated within 10 min after flushing with 5% O 2 /95% N 2 .