[生物技術] 改造大腸桿菌來固碳，能否為環境變遷帶來新的契機？ 20191129 Cell

Plasmodesmata
Nov 29, 2019
2 min read

Conversion of Escherichia coli to Generate All Biomass Carbon from CO2

Shmuel Gleizer, Roee Ben-Nissan, Yinon M. Bar-On, Niv Antonovsky, Elad Noor, Yehudit Zohar, Ghil Jona, Eyal Krieger, Melina Shamshoum, Arren Bar-Even, and Ron Milo

SUMMARY

The living world is largely divided into autotrophs that convert CO2 into biomass and heterotrophs that consume organic compounds. In spite of widespread interest in renewable energy storage and more sustainable food production, the engineering of industrially relevant heterotrophic model organisms to use CO2 as their sole carbon source has so far remained an outstanding challenge. Here, we report the achievement of this transformation on laboratory timescales. We constructed and evolved Escherichia coli to produce all its biomass carbon from CO2. Reducing power and energy, but not carbon, are supplied via the one-carbon molecule formate, which can be produced electrochemically. Rubisco and phosphoribulokinase were co-expressed with formate dehydrogenase to enable CO2 fixation and reduction via the Calvin-Benson- Bassham cycle. Autotrophic growth was achieved following several months of continuous laboratory evolution in a chemostat under intensifying organic carbon limitation and confirmed via isotopic labeling.

將大腸桿菌轉化成利用二氧化碳來生成所有的生物碳

總結

現今的生物界可以被大致區分為將二氧化碳轉化成生物質量的自營性生物，以及消耗有機物質的異營性生物。雖然近年來，在綠能的儲存以及永續食物的製程上，整體國際社會有相當大的興趣。在工業上，發展單純利用二氧化來當做完元的碳源的系統，到目前為止仍然是有非常大的挑戰性。在此，我們報導在實驗室的時間規模下，我們達到了這一個目標。我們建構並且利用演化來改變大腸桿菌，使得它利用二氧化碳來生成所有的生物質量。利用提供單碳的分子（可以利用電化學來合成）來提供較少的能量但是卻沒有減少碳的來源。同時表達Rubisoc、phosphoribulokinase以及formate dehydrogenase使得細菌可以經由克式循環來固定並還原二氧化碳。在化學恆定器中，將大腸桿菌養殖在有限的有機碳狀態，經過數個月持續的實驗室演化，我們成功地讓大腸桿菌演化成自源性的生長，最終也經由同位素標定的方式確定了大腸桿菌可以自源性的生長。