Patent ID: 8183022

Claim:
A method for making ethanol by fermentation, comprising: (a) growing an ethanol producing microorganism under first growth conditions in a first medium consisting of a backset comprising a carbon source having at least one member selected from the group consisting of organic acid and glycerol to form an inoculation broth, said backset being obtained by growing the microorganism in a second medium to produce ethanol by fermentation and distillation of the second medium to remove the ethanol in accordance with steps (b) and (c) below, said second medium comprising a carbon source comprising at least one member of the group consisting of a sugar or polysaccharide of at least 5 carbon atoms; (b) inoculating the second medium with the inoculation broth obtained from step (a) and growing the microorganism in the second medium under second conditions suitable for producing ethanol: (c) distilling the ethanol and removing said microorganisms from the second medium to obtain the backset; and (d) repeating step (a) using the backset obtained from step (c).