Crude yeast autolysate (10 g/l; 5.8 g solubles/l) supplemented with minerals and vitamins served as a nutrient supplement for ethanol production by the recombinant bacterium, Escherichia coli KO11. Ethanol production in this medium (46 +/- 1.7 g ethanol/l) was equivalent to that obtained using 5-15 g/l of purified, soluble, commercial protein hydrolysates (44-48 g ethanol/l). On site production of autolysates from spent yeast offers the potential for synergy between grain-based and lignocellulose-based ethanol plants.