The production of ethanol plus fructose sweetener using fructose utilization negative mutants of Zymomonas mobilis

Two mutants, unable to utilize fructose (Fru super(-)) as a sole source of carbon and energy, were isolated from Zymomonas mobilis) following ethyl methane sulfonate (EMS) mutagenesis. The frequency of stable Fru super(-) mutants among survivors of mutagenesis was 1 in 10 super(4). The two Fru super(-) mutants were able to cleave sucrose to glucose and fructose, and then ferment only the glucose to ethanol while accumulating fructose close to the theoretical value. Under controlled fermentation conditions, sucrose was converted to ethanol plus 80% or higher purity fructose syrup in a single-stage batch fermentation process, improving the Sucrotech Process significantly.