Abstract: The present invention relates to a method of producing at least one amino acid from a carbon source in aerobic conditions, the method comprising: (a)step of producing ethanol and/or acetate from the carbon source in aerobic conditions, comprising (i)contacting a reaction mixture comprising—a first acetogenic microorganism in an exponential growth phase; —free oxygen; and —a second acetogenic microorganism in a stationary phase wherein the first and second acetogenic microorganism is capable of converting the carbon source to the acetate and/or ethanol; and (b)step of contacting the acetate and/or ethanol from step (a) with a third microorganism capable of converting the acetate and/or ethanol to at least one amino acid.