Cytochrome c Reductase is a Key Enzyme Involved in the Extracellular Electron Transfer Pathway towards Transition Metal Complexes in Pseudomonas Putida. Issue 19 (17th August 2020)

• Record Type: Journal Article
• Authors: Lai, Bin; Bernhardt, Paul V.; Krömer, Jens O.
• Is Part Of: ChemSusChem. Volume 13:Issue 19(2020)
• Page Start: 5308
• Page End: 5317
• Publication Date: 2020-08-17
• Subjects: bioelectrochemical system -- cytochrome c reductase -- electron transfer -- proteomics -- redox mediator; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202001645
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Mediator‐based extracellular electron transfer (EET) pathways can balance the redox metabolism of microbes. However, such electro‐biosynthesis processes are constrained by the unknown underlying EET mechanisms. In this paper, Pseudomonas putida was studied to systematically investigate its EET pathway to transition metal complexes (i. e., [Fe(CN)6 ] 3−/4− and [Co(bpy)3 ] 3+/2+ ; bpy=2, 2′‐bipyridyl) under anaerobic conditions. Comparative proteomics showed the aerobic respiratory components were upregulated in a bioelectrochemical system without oxygen, suggesting their potential contribution to EET. Further tests found inhibiting cytochrome c oxidase activity by NaN3 and NADH dehydrogenase by rotenone did not significantly change the current output. However, the EET pathway was completely blocked, while cytochrome c reductase activity was inhibited by antimycin A. Although it cannot be excluded that cytochrome c and the periplasmic subunit of cytochrome c oxidase donate electrons to the transition metal complexes, these results strongly demonstrate that cytochrome c reductase is a key complex for the EET pathway. Abstract : Liquid wires for biohybrid systems : The electron transfer pathway between redox metal‐complexes and biological respiratory proteins is systematically investigated and revealed. Such a pathway can be readily applied to many non‐electrogenic microorganisms and thus expand the application of microbial electrochemical technology in many fields such as industrial biotechnology and biosensors.