Propagation conditions have been shown to be of considerable importance for the fermentation ability of Saccharomyces cerevisiae. The limited tolerance of yeast to inhibitors present in lignocellulosic hydrolysates is a major challenge in second-generation bioethanol production. We have investigated the hypothesis that the addition of nutrients during propagation leads to yeast cultures with improved ability to subsequently ferment lignocellulosic materials. This hypothesis was tested with and without short-term adaptation to wheat straw or corn stover hydrolysates during propagation of the yeast. The study was performed using the industrial xylose-fermenting S. cerevisiae strain CR01. Adding a mixture of pyridoxine, thiamine, and biotin to unadapted propagation cultures improved cell growth and ethanol yields during fermentation in wheat straw hydrolysate from 0.04 g g⁻¹ to 0.19 g g⁻¹ and in corn stover hydrolysate from 0.02 g g⁻¹ to 0.08 g g⁻¹. The combination of short–term adaptation and supplementation with the vitamin mixture during propagation led to ethanol yields of 0.43 g g⁻¹ in wheat straw hydrolysate fermentation and 0.41 g g⁻¹ in corn stover hydrolysate fermentation. These ethanol yields were improved compared to ethanol yields from cultures that were solely short-term adapted (0.37 and 0.33 g g⁻¹). Supplementing the propagation medium with nutrients in combination with short-term adaptation was thus demonstrated to be a promising strategy to improve the efficiency of industrial lignocellulosic fermentation.

中文翻译：

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营养补充的酿酒酵母的繁殖提高了其木质纤维素的发酵能力。

繁殖条件已被证明对酿酒酵母的发酵能力具有重要意义。酵母对木质纤维素水解物中存在的抑制剂的有限耐受性是第二代生物乙醇生产中的主要挑战。我们研究了以下假设：在繁殖过程中添加营养会导致酵母培养物具有提高的随后发酵木质纤维素材料的能力。在酵母繁殖过程中是否对小麦秸秆或玉米秸秆水解产物进行短期适应和不短期适应的情况下测试了该假设。该研究是使用工业木糖发酵酿酒酵母进行的。菌株CR01。加入吡哆醇的混合物，硫胺素和生物素不适应传播培养物为0.04克克小麦秸秆水解产物的发酵过程中提高细胞生长和乙醇产量^-1至0.19克克^-1和玉米秸秆水解产物0.02克克^-1至0.08克克^{- 1}。在繁殖过程中短期适应和补充维生素混合物的结合在麦秸水解产物发酵中产生0.43 g g ^-1的乙醇产量，在玉米秸秆水解产物发酵中产生0.41 g g ^-1的乙醇产量。与仅短期适应的培养物的乙醇产率（0.37和0.33 gg ^-1）相比，这些乙醇的产率得到了提高）。因此，在营养繁殖培养基中补充短期适应性营养补充剂是提高工业木质纤维素发酵效率的一种有前途的策略。