In-depth two-stage transcriptional reprogramming and evolutionary engineering of Saccharomyces cerevisiae for efficient bioethanol production from xylose with acetate
Journal of agricultural and food chemistry | 10 Oct 2019
C Zhang, Q Xue, J Hou, A Mohsin, M Zhang, M Guo, Y Zhu, J Bao, J Wang, W Xiao and L Cao
In order to achieve rapid xylose utilization in the presence of acetate, improved yeast strains were engineered for higher bioethanol production. Firstly, a six-gene cluster including XYL1/XYL2/XKS1/TAL1/PYK1/MGT05196 was generated by using an in depth two-stage (glucose and xylose) transcription reprogramming strategy in an evolutionary adapted strain of CE7, resulting in two improved engineered strains WXY46 and WXY53. Through a combined screening of xylose and glucose stage-specific promoters between TCA/HSP and constitutive types respectively, WXY46 with the constitutive promoters showed much higher ethanol yield than that of WXY53 with the TCA/HSP promoters. Secondly, an optimized strain WXY74 was obtained by using more copies of six gene cluster, which resulted in higher ethanol yield of 0.500 g/g total sugars with acetate condition. At last, simultaneous saccharification and co-fermentation was perfmored by using the evolved WXY74 strain, which produced 58.4 g/L of ethanol from wheat straw waste, which outperformed previous haploid XR-XDH strains.
* Data courtesy of Altmetric.com