FIG 4.

In vivo CO oxidation by C. acetobutylicum expressing either the CODH/ACS complex or the CODH subunit alone. (A) C. acetobutylicum strains grown on defined medium in the presence of 5% ¹³CO (balance N₂) in the headspace (5 lb/in²). CO concentration was measured for the CODH/ACS, the CODH, and an empty vector strain (n = 2). The empty vector control strain did not oxidize CO during the 72 h of monitoring. (B) ¹³C-labeling in CO₂ as a function of time. (C) GC-MS analysis of the headspace demonstrating CO oxidization by the C. acetobutylicum strain expressing CODH/ACS. Error bars indicate the standard error of two biological replicates.