Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
Department of Biology, Washington University in St. Louis, St. Louis, MO, USA.
Commun Biol. 2021 Nov 3;4(1):1257. doi: 10.1038/s42003-021-02781-z.
Anthropogenic carbon dioxide (CO) release in the atmosphere from fossil fuel combustion has inspired scientists to study CO to biofuel conversion. Oxygenic phototrophs such as cyanobacteria have been used to produce biofuels using CO. However, oxygen generation during oxygenic photosynthesis adversely affects biofuel production efficiency. To produce n-butanol (biofuel) from CO, here we introduce an n-butanol biosynthesis pathway into an anoxygenic (non-oxygen evolving) photoautotroph, Rhodopseudomonas palustris TIE-1 (TIE-1). Using different carbon, nitrogen, and electron sources, we achieve n-butanol production in wild-type TIE-1 and mutants lacking electron-consuming (nitrogen-fixing) or acetyl-CoA-consuming (polyhydroxybutyrate and glycogen synthesis) pathways. The mutant lacking the nitrogen-fixing pathway produce the highest n-butanol. Coupled with novel hybrid bioelectrochemical platforms, this mutant produces n-butanol using CO, solar panel-generated electricity, and light with high electrical energy conversion efficiency. Overall, this approach showcases TIE-1 as an attractive microbial chassis for carbon-neutral n-butanol bioproduction using sustainable, renewable, and abundant resources.
大气中因化石燃料燃烧而产生的人为二氧化碳（CO）释放激发了科学家研究 CO 向生物燃料转化。蓝藻等需氧光合生物已被用于利用 CO 生产生物燃料。然而，在需氧光合作用过程中产生氧气会降低生物燃料的生产效率。为了从 CO 生产正丁醇（生物燃料），我们将正丁醇生物合成途径引入到乏氧（不产氧）光自养生物沼泽红假单胞菌 TIE-1（TIE-1）中。使用不同的碳、氮和电子源，我们在野生型 TIE-1 和缺乏电子消耗（固氮）或乙酰辅酶 A 消耗（聚羟基丁酸酯和糖原合成）途径的突变体中实现了正丁醇的生产。缺乏固氮途径的突变体产生的正丁醇最多。与新型混合生物电化学平台结合，该突变体可使用 CO、太阳能电池板产生的电力和光，以高效率地进行电能转换来生产正丁醇。总的来说，该方法展示了 TIE-1 作为一种有吸引力的微生物底盘，可利用可持续、可再生和丰富的资源进行碳中和的正丁醇生物生产。
