Soy-based medium for ethanol production by Escherichia coli KO11

An optimized soy-based medium was developed for ethanol production by Escherichia coli KO11. The medium consists of mineral salts, vitamins, crude enzymatic hydrolysate of soy and fermentable sugar. Ethanol produced after 24 h was used as an endpoint in bioassays to optimize hydrolysate preparation. Although longer fermentation times were required with soy medium than with LB medium, similar final ethanol concentrations were achieved (44-45 g ethanol L(-1) from 100 g glucose L(-1)). The cost of materials for soy medium (excluding sugar) was estimated to be $0.003 L(-1) broth, $0.06 L(-1) ethanol.