Xu Zhaoxian, Sha Yuanyuan, Li Muzi, Chen Sitong, Li Jie, Ding Boning, Zhang Yuwei, Li Pingping, Yan Kang, Jin Mingjie
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China; Biorefinery Research Institution, Nanjing University of Science and Technology, Nanjing 210094, China.
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China; Biorefinery Research Institution, Nanjing University of Science and Technology, Nanjing 210094, China.
Int J Biol Macromol. 2025 Jan;284(Pt 1):138155. doi: 10.1016/j.ijbiomac.2024.138155. Epub 2024 Nov 27.
Ethanol tolerant Saccharomyces cerevisiae is compulsory for ethanol production in starch based biorefinery, especially during high-gravity fermentation. In this study, adaptive evolution with increased initial ethanol concentrations as a driving force was harnessed for achieving ethanol tolerant S. cerevisiae. After evolution, an outstanding ethanol tolerant strain was screened, which contributed to significant improvements in glucose consumption and ethanol production in scenarios of 300 g/L initial glucose, high solid loadings (30 wt%, 33 wt%, 35 wt% and 40 wt%) of corn, and high solid loadings (30 wt% and 33 wt%) of cassava, compared with the original strain. Genome re-sequencing was applied for the evolved strain, and 504 sense mutations in 205 genes were detected, among which PAM1 gene was demonstrated related to the elevated ethanol tolerance. In sum, this study provided a practical approach for obtaining ethanol tolerant strain and the identified PAM1 gene enhanced our understanding on ethanol tolerant mechanism, as well as provided a target basis for rational metabolic engineering.
耐乙醇酿酒酵母对于基于淀粉的生物炼制中的乙醇生产至关重要，尤其是在高浓度发酵过程中。在本研究中，以增加初始乙醇浓度为驱动力进行适应性进化，以获得耐乙醇的酿酒酵母。进化后，筛选出了一株出色的耐乙醇菌株，与原始菌株相比，该菌株在初始葡萄糖浓度为300 g/L、玉米高固含量（30 wt%、33 wt%、35 wt%和40 wt%）以及木薯高固含量（30 wt%和33 wt%）的情况下，显著提高了葡萄糖消耗和乙醇产量。对进化后的菌株进行了基因组重测序，检测到205个基因中的504个有义突变，其中PAM1基因被证明与乙醇耐受性提高有关。总之，本研究为获得耐乙醇菌株提供了一种实用方法，鉴定出的PAM1基因增进了我们对乙醇耐受机制的理解，并为合理的代谢工程提供了靶点依据。
