Patent ID: 8158396

Claim:
A process for co-producing ethanol and yeast cells comprising: (a) providing a culture of fresh yeast cells that can produce ethanol from fermentable sugars under suitable conditions; (b) providing a ferment medium that is substantially free of particulate matter and which comprises a fermentable sugar; (c) combining the fresh yeast cells and ferment medium at a concentration of 5-60 yeast cells g/L and incubating the fresh yeast cells anaerobically in the ferment medium for a time and under conditions suitable for the yeast cells to effect conversion of the substrate to ethanol; (d) continuing the incubation until ethanol is produced in a concentration of 8-18% v/v, and the yeast cells in the ferment medium have a protein content of 35-65%; and (e) recovering the yeast cells in a manner such that their protein content is 35-65%.