LanzaTech Inc., Skokie, IL, USA.
Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.
Nat Biotechnol. 2022 Mar;40(3):335-344. doi: 10.1038/s41587-021-01195-w. Epub 2022 Feb 21.
Many industrial chemicals that are produced from fossil resources could be manufactured more sustainably through fermentation. Here we describe the development of a carbon-negative fermentation route to producing the industrially important chemicals acetone and isopropanol from abundant, low-cost waste gas feedstocks, such as industrial emissions and syngas. Using a combinatorial pathway library approach, we first mined a historical industrial strain collection for superior enzymes that we used to engineer the autotrophic acetogen Clostridium autoethanogenum. Next, we used omics analysis, kinetic modeling and cell-free prototyping to optimize flux. Finally, we scaled-up our optimized strains for continuous production at rates of up to ~3 g/L/h and ~90% selectivity. Life cycle analysis confirmed a negative carbon footprint for the products. Unlike traditional production processes, which result in release of greenhouse gases, our process fixes carbon. These results show that engineered acetogens enable sustainable, high-efficiency, high-selectivity chemicals production. We expect that our approach can be readily adapted to a wide range of commodity chemicals.
许多由化石资源生产的工业化学品可以通过发酵更可持续地制造。在这里，我们描述了一种从丰富且低成本的废气原料（如工业排放物和合成气）生产工业上重要的化学品丙酮和异丙醇的碳负发酵途径的开发。我们使用组合途径文库方法，首先从历史工业菌株库中挖掘出更优异的酶，并用这些酶来工程化自养产丙酮菌 Clostridium autoethanogenum。接下来，我们使用组学分析、动力学建模和无细胞原型设计来优化通量。最后，我们对优化的菌株进行放大，以高达约 3 g/L/h 的速率和 90%的选择性进行连续生产。生命周期分析证实了产品的碳足迹为负。与导致温室气体排放的传统生产工艺不同，我们的工艺固定了碳。这些结果表明，经过工程改造的产丙酮菌能够实现可持续、高效率、高选择性的化学品生产。我们预计我们的方法可以很容易地适应广泛的大宗商品化学品。
