Cargill’s CB1 yeast platform for cellulosic ethanol production

Cargill’s CB1 yeast platform has many characteristics required in cost effective, robust industrial fermentation processes. Since the first commercial deployment of this technology in 2008 for lactic acid production at low pH, Cargill has partnered with industry leaders and developed CB1 as a biocatalyst for industrial production of a variety of biofuels and chemicals. Commercially important characteristics of the CB1 yeast include high product yield and productivity, tolerance to low pH, ethanol, high temperature and common inhibitors in hydrolysates. Using metabolic engineering, mutagenesis and selection and evolution. Cargill has developed CB1 for cellulosic sugar utilization and has demonstrated mixed sugar ethanol fermentation in non-detoxified corn stover hydrolysate (NRELl) resulting in a combination of  >70 g/L ethanol, ethanol production rate >1.25 g/L*h  and an ethanol yield >90% theoretical from dextrose and xylose operating under commercially relevent conditions. Cargill has further improved these CB1 strains and tailored them for fermentation of other types of mixed sugar hydrolysates. The physiology of CB1 and an extensive toolbox for strain improvement make this yeast a very useful platform organism for the production of biofuels and chemicals from cellulosic feedstocks.