The biorefinery concept, consisting in using renewable biomass with economical and energy goals, appeared in response to the ongoing exhaustion of fossil reserves. Bioethanol is the most prominent biofuel and has been considered one of the top chemicals to be obtained from biomass. Saccharomyces cerevisiae, the preferred microorganism for ethanol production, has been the target of extensive genetic modifications to improve the production of this alcohol from renewable biomasses. Additionally, S. cerevisiae strains from harsh industrial environments have been exploited due to their robust traits and improved fermentative capacity. Nevertheless, there is still not an optimized strain capable of turning second generation bioprocesses economically viable. Considering this, and aiming to facilitate and guide the future development of effective S. cerevisiae strains, this work reviews genetic engineering strategies envisioning improvements in 2nd generation bioethanol production, with special focus in process-related traits, xylose consumption, and consolidated bioprocessing. Altogether, the genetic toolbox described proves S. cerevisiae to be a key microorganism for the establishment of a bioeconomy, not only for the production of lignocellulosic bioethanol, but also having potential as a cell factory platform for overall valorization of renewable biomasses.

中文翻译：

---

用于木质纤维素价值化的工程酿酒酵母：生物乙醇生产的回顾和展望。

生物精炼概念包括使用具有经济和能源目标的可再生生物质，以应对化石储量的持续枯竭。生物乙醇是最突出的生物燃料，被认为是从生物质中获得的顶级化学品之一。Saccharomyces cerevisiae 是乙醇生产的首选微生物，已成为广泛遗传修饰的目标，以提高可再生生物质中这种酒精的生产。此外，来自恶劣工业环境的酿酒酵母菌株因其强大的特性和改进的发酵能力而被开发利用。尽管如此，仍然没有一种优化的菌株能够使第二代生物过程在经济上可行。考虑到这一点，旨在促进和指导有效 S. 酿酒酵母菌株，这项工作回顾了设想改进第二代生物乙醇生产的基因工程策略，特别关注与工艺相关的性状、木糖消耗和综合生物加工。总而言之，所描述的遗传工具箱证明酿酒酵母是建立生物经济的关键微生物，不仅用于生产木质纤维素生物乙醇，而且还具有作为可再生生物质整体价值化的细胞工厂平台的潜力。