Procédé de fermentation microbienne

Dihydroxyacetone is prepared by microbial fermentation from glycerol by preparing an inoculum by growing Acetobacter suboxydans in a growth medium which contains glycerol and has a pH of from 5.0 to 5.9, introducing the inoculum into a fermentation medium which contains corn steep liquor, or the inorganic material obtained by ashing corn steep liquor, and more than 6% by weight of glycerol, and allowing fermentation to proceed. Preferably the pH of the fermentation medium also is 5.0 to 5.9; more preferably the pH of the growth medium and the fermentation medium is 5.4 to 5.7. The fermentation medium and the growth medium may each contain 0.1 to 5.0% by weight of corn steep liquor or the ash of such an amount of liquor. The fermentation medium may contain 6 to 15% by weight of glycerol. In examples Acetobacter suboxydans is grown in media containing KH2PO4, brewer's yeast, CaCO3, corn steep liquor or ash obtained therefrom, and 6% glycerol, and the inoculum so prepared is added to fermentation media of similar compositions but containing 11%, 10% and 13.5% of glycerol.