The global energy crisis and limited supply of petroleum fuels have rekindled the interest in utilizing a sustainable biomass to produce biofuel. Butanol, an advanced biofuel, is a superior renewable resource as it has a high energy content and is less hygroscopic than other candidates. At present, the biobutanol route, employing acetone-butanol-ethanol (ABE) fermentation in Clostridium species, is not economically competitive due to the high cost of feedstocks, low butanol titer, and product inhibition. Based on an analysis of the physiological characteristics of solventogenic clostridia, current advances that enhance ABE fermentation from strain improvement to product separation were systematically reviewed, focusing on: (1) elucidating the metabolic pathway and regulation mechanism of butanol synthesis; (2) enhancing cellular performance and robustness through metabolic engineering, and (3) optimizing the process of ABE fermentation. Finally, perspectives on engineering and exploiting clostridia as cell factories to efficiently produce various chemicals and materials are also discussed.

中文翻译：

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途径剖析、调节、工程和应用：产溶剂梭菌生产生物丁醇的经验教训。

全球能源危机和石油燃料供应有限重新燃起了利用可持续生物质生产生物燃料的兴趣。丁醇是一种先进的生物燃料，是一种优质的可再生资源，因为它具有高能量含量，并且比其他候选燃料吸湿性更小。目前，由于原料成本高、丁醇滴度低和产物抑制，采用丙酮-丁醇-乙醇（ABE）在梭状芽胞杆菌属中发酵的生物丁醇路线在经济上不具有竞争力。在分析产溶剂梭状芽胞杆菌生理特性的基础上，系统综述了增强ABE发酵从菌株改良到产物分离的最新进展，重点包括：（1）阐明丁醇合成的代谢途径和调控机制；(2) 通过代谢工程增强细胞性能和稳健性，(3) 优化 ABE 发酵过程。最后，还讨论了工程和利用梭菌作为细胞工厂以有效生产各种化学品和材料的观点。