FIG 3.
Changing the sparge gas composition to avoid off-gas flammability. (A) Off-gas composition profile time course with air as sparge gas. Nitrogen and trace components are not shown. (B) Off-gas composition profile time course with the 5% O2 gas mixture as sparge gas. Nitrogen and trace components are not shown. (C) Comparison of ethanol production profiles for fermentations using sparged air and those using sparged 5% O2 gas. Experiments were conducted in Sartorius Biostat A Plus 7-liter reactors. GB5/pGB1002 was grown in MM29 minimal medium at pH 6.3 and a kLa of 16/h for 72 h.