合成气乙醇发酵技术研究进展

Research progress on bioethanol production technologies through syngas fermentation

采用合成气发酵生产燃料乙醇具有反应条件温和、产物耐受性好、原料来源丰富等优点,是燃料乙醇生产的一种新型工艺。文章综述了国内外合成气厌氧发酵的微生物种类,常见合成气乙醇发酵微生物的生长、代谢特点以及底物利用范围;分析了合成气乙醇发酵的Wood-Ljungdahl代谢途径,以及Wood-Ljungdahl代谢途径中涉及的关键酶类甲酸脱氢酶和CO脱氢酶/乙酰辅酶A合成酶;探讨了过程工艺参数如培养介质、还原剂、pH、气体组成、终产物、培养基和培养方法对合成气发酵的影响;比较了不同反应器在体积传质系数等方面的差异,并重点分析了搅拌罐式反应器和柱式反应器等的反应特点。同时,对合成气发酵的未来发展方向进行了展望。

Bioethanol production through syngas fermentation has many advantages,such as mild reaction conditions,higher end-product tolerance,rich source of raw carbon materials and so on,which is a novel method for fuel ethanol productions.In this paper,the types of microorganisms for syngas fermentation,the characteristics of growth,metabolism and substrate utilization of the main microorganisms,Wood-Ljungdahl pathways,the key enzymes of formate dehydrogenase and carbon monoxide dehydrogenase/acetyl-CoA synthase,the influence factors of culture medium,reducing agent,pH,gas composition,products,medium composition and culture methods on syngas fermentation,and the types of syngas fermentation reactor were reviewed.The prospect of future development direction of syngas fermentation was proposed.