期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2021
卷号：118
期号：9
页码：1
DOI：10.1073/pnas.2020552118
出版社：The National Academy of Sciences of the United States of America
摘要：Acetogenic bacteria use cellular redox energy to convert CO 2 to acetate using the Wood–Ljungdahl (WL) pathway. Such redox energy can be derived from electrons generated from H 2 as well as from inorganic materials, such as photoresponsive semiconductors. We have developed a nanoparticle-microbe hybrid system in which chemically synthesized cadmium sulfide nanoparticles (CdS-NPs) are displayed on the cell surface of the industrial acetogen Clostridium autoethanogenum . The hybrid system converts CO 2 into acetate without the need for additional energy sources, such as H 2 , and uses only light-induced electrons from CdS-NPs. To elucidate the underlying mechanism by which C. autoethanogenum uses electrons generated from external energy sources to reduce CO 2 , we performed transcriptional analysis. Our results indicate that genes encoding the metal ion or flavin-binding proteins were highly up-regulated under CdS-driven autotrophic conditions along with the activation of genes associated with the WL pathway and energy conservation system. Furthermore, the addition of these cofactors increased the CO 2 fixation rate under light-exposure conditions. Our results demonstrate the potential to improve the efficiency of artificial photosynthesis systems based on acetogenic bacteria integrated with photoresponsive nanoparticles.
关键词：acetogenic bacteria ; artificial photosynthesis ; cadmium sulfide nanoparticle ; extracellular electron transfer ; Clostridium autoethanogenum
