2-18: Yeast strains for ethanol production from lignocellulosic hydrolysates in situ detoxification

Yeast strains of Y1, Y4, and Y7 exhibiting high conversion efficiency of sugars and high ability of tolerating/metabolizing inhibitors in the dilute-acid lignocellulosic hydrolysates developed in our lab were presented in this work. Strains Y1 and Y4 consumed glucose completely in dilute-acid lignocellulosic hydrolysate in situ detoxification within 24h and the highest ethanol yield reached to 0.49g and 0.45g ethanol/g glucose, corresponding to the maximum theoretical value of 96% and 88.2%, respectively. Strain Y1 could metabolize xylose to xylitol with the yield of 0.64g/g xylose, whereas, Y4 was not able to utilize xylose as a substrate. Strain Y7 could consume sugars (glucose and xylose) in hydrolysate in situ detoxification within 72h and a high ethanol yield (equivalent to 93.6% of the maximum theoretical value) was also achieved. Y7 is one of the most efficient yeast strains reported so far for ethanol production from non-detoxified dilute-acid lignocellulosic hydrolysates. It may offer huge potential for improving the economics of the bio-ethanol production from lignocellulosic hydrolysates.