| CPC C12P 7/54 (2013.01) [C12P 7/52 (2013.01)] | 14 Claims |
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1. A process comprising:
providing a gaseous substrate to a bioreactor, the gaseous substrate comprising CO2 and containing about 5 to about 90 mole % CO2, and about 0 to about 5 mole % CO;
providing acetogenic bacteria to the bioreactor;
providing sodium ions to the bioreactor through one or more sodium ion sources; and
fermenting the gaseous substrate with the acetogenic bacteria in a fermentation broth comprising the acetogenic bacteria and the one or more sodium ion sources to produce one or more organic acids;
wherein the acetogenic bacteria includes a sodium translocating ATPase that is active during fermentation in the bioreactor,
wherein the fermentation broth includes less than about 0.01 grams per liter yeast extract, and less than about 0.01 grams per liter carbohydrate,
wherein the sodium ions are provided with a sodium feed rate of about 290 to about 8750 μg/gram of cells/minute,
wherein the fermentation broth is maintained at a pH in a range of about 4 to about 6.9,
wherein the process provides a CO2 conversion of about 75% to about 100%, and
wherein the process provides a specific organic acid productivity of about 10 to about 50 grams organic acid/day/gram of cells.
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