NOVELTY - Recovering butanol from fermentation medium, involves: (a) providing fermentation medium comprising butanol, water, and a recombinant microorganism comprising a butanol biosynthetic pathway, where recombinant microorganism produces butanol; (b) contacting the fermentation medium with a water immiscible organic extractant composition (C1) comprising a solvent (S1) selected from 1-22C fatty alcohols, 12-22C ethers, esters of 12-22C fatty acids and/or 10-22C alkanes, to form butanol-containing organic phase and aqueous phase; and (c) recovering butanol from butanol-containing organic phase.    USE - For recovering butanol from a fermentation medium (claimed), where the butanol is used as fuel additive.    ADVANTAGE - The butanol produced according to the methods has the potential of impacting hydrogen distribution problems in the emerging fuel cell industry. The butanol can be easily reformed for its hydrogen content and can be distributed through existing gas stations in the purity required for either fuel cells or vehicles. The methods produce butanol from plant derived carbon sources, avoiding the negative environmental impact associated with standard petrochemical processes for butanol production. The method is higher butanol partition coefficient compared to solvents used in the art. The combinations of solvents obtained by the combination of first and second solvents, can provide extractants having a higher partition coefficient. The extractants having higher partition coefficients can provide more effective extraction of butanol from the fermentation medium. The method has the ability to use a solvent which has a desirably higher partition coefficient but undesirably lower biocompatibility, and to mitigate the lower biocompatibility by the combination with a solvent having higher biocompatibility. As a result, a more effective extractant is obtained, an extractant which can be used in the presence of the microorganism with continued viability of the microorganism. The solvent is biocompatible with the microorganism such that at least 90% of the microorganisms are viable after exposure to the organic extractant composition.    DETAILED DESCRIPTION - Recovering butanol from a fermentation medium, involves: (a) providing a fermentation medium comprising butanol, water, and a recombinant microorganism comprising a butanol biosynthetic pathway, where the recombinant microorganism produces butanol; (b) contacting the fermentation medium with a water immiscible organic extractant composition (C1) comprising a solvent (S1) selected from 1-22C fatty alcohols, 12-22C ethers, esters of 12-22C fatty acids and/or 10-22C alkanes, to form a butanol-containing organic phase and an aqueous phase; and (c) recovering the butanol from the butanol-containing organic phase. The solvent is biocompatible with the microorganism such that at least 90% of the microorganisms are viable after exposure to the organic extractant composition, and where the solvent has a boiling point less than 300 degrees C, with the provision that the organic extractant is not oleyl alcohol, 1-dodecanol, behenyl alcohol, cetyl alcohol, myristyl alcohol, or stearyl alcohol. An INDEPENDENT CLAIM is included for a composition comprising a solution of butanol in the water immiscible organic extractant composition (C1) containing the solvent (S1).