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Title: Nitrogenase Bioelectrocatalysis: ATP-Independent Ammonia Production Using a Redox Polymer/MoFe Protein System

Abstract

Nitrogenase is the only biological catalyst that is understood to be able to convert nitrogen gas to ammonia. In microorganisms, the MoFe catalytic protein of nitrogenase is reduced by a transient Fe protein binding and separate hydrolysis of ATP. Yet, the requirement of 16 ATP molecules by the Fe protein for the 8 electron transfer is an energy-intense caveat to the enzymatic synthesis of NH 3 and is challenging from an electrochemical perspective. Thus, we report the redox polymer-based ATP-free mediated electron-transfer system of MoFe nitrogenase using cobaltocene-functionalized poly(allylamine) (Cc-PAA), which is able to reduce the MoFe nitrogenase directly with a low redox potential of -0.58 V vs SHE. An efficient immobilization of MoFe nitrogenase via Cc-PAA allowed for the bioelectrocatalytic reduction of N 3 , NO 2 , and N 2 to NH 3. Bulk bioelectrosynthetic experiments produced 7 ± 2 and 30 ± 5 nmol of NH 3 from NO 2 and N 3 reduction for 30 min, respectively. In addition, biosynthetic N 2 reduction to NH 3 was confirmed by 15N 2 labeling experiments with NMR analysis. This mediated electron-transfer approach of the immobilized nitrogenase using the Cc-PAA redox polymer provides a valuable technological basismore » for scale-up and industrial uses in the future of bioelectrosynthesis.« less

Authors:
 [1];  [1]; ORCiD logo [2];  [1]; ORCiD logo [1]
  1. Univ. of Utah, Salt Lake City, UT (United States)
  2. Univ. of Utah, Salt Lake City, UT (United States); Univ. of California, Berkeley, CA (United States)
Publication Date:
Research Org.:
Fulcrum Bioscience, Salt Lake City, UT (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Advanced Manufacturing Office
OSTI Identifier:
1633077
Grant/Contract Number:  
SC0017845
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
ACS Catalysis
Additional Journal Information:
Journal Volume: 10; Journal Issue: 12; Journal ID: ISSN 2155-5435
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; ammonia; nitrogenase; MoFe protein; cobaltocene; redox polymer

Citation Formats

Lee, Yoo Seok, Yuan, Mengwei, Cai, Rong, Lim, Koun, and Minteer, Shelley D. Nitrogenase Bioelectrocatalysis: ATP-Independent Ammonia Production Using a Redox Polymer/MoFe Protein System. United States: N. p., 2020. Web. doi:10.1021/acscatal.0c01397.
Lee, Yoo Seok, Yuan, Mengwei, Cai, Rong, Lim, Koun, & Minteer, Shelley D. Nitrogenase Bioelectrocatalysis: ATP-Independent Ammonia Production Using a Redox Polymer/MoFe Protein System. United States. https://doi.org/10.1021/acscatal.0c01397
Lee, Yoo Seok, Yuan, Mengwei, Cai, Rong, Lim, Koun, and Minteer, Shelley D. Fri . "Nitrogenase Bioelectrocatalysis: ATP-Independent Ammonia Production Using a Redox Polymer/MoFe Protein System". United States. https://doi.org/10.1021/acscatal.0c01397.
@article{osti_1633077,
title = {Nitrogenase Bioelectrocatalysis: ATP-Independent Ammonia Production Using a Redox Polymer/MoFe Protein System},
author = {Lee, Yoo Seok and Yuan, Mengwei and Cai, Rong and Lim, Koun and Minteer, Shelley D.},
abstractNote = {Nitrogenase is the only biological catalyst that is understood to be able to convert nitrogen gas to ammonia. In microorganisms, the MoFe catalytic protein of nitrogenase is reduced by a transient Fe protein binding and separate hydrolysis of ATP. Yet, the requirement of 16 ATP molecules by the Fe protein for the 8 electron transfer is an energy-intense caveat to the enzymatic synthesis of NH3 and is challenging from an electrochemical perspective. Thus, we report the redox polymer-based ATP-free mediated electron-transfer system of MoFe nitrogenase using cobaltocene-functionalized poly(allylamine) (Cc-PAA), which is able to reduce the MoFe nitrogenase directly with a low redox potential of -0.58 V vs SHE. An efficient immobilization of MoFe nitrogenase via Cc-PAA allowed for the bioelectrocatalytic reduction of N3–, NO2–, and N2 to NH3. Bulk bioelectrosynthetic experiments produced 7 ± 2 and 30 ± 5 nmol of NH3 from NO2– and N3– reduction for 30 min, respectively. In addition, biosynthetic N2 reduction to NH3 was confirmed by 15N2 labeling experiments with NMR analysis. This mediated electron-transfer approach of the immobilized nitrogenase using the Cc-PAA redox polymer provides a valuable technological basis for scale-up and industrial uses in the future of bioelectrosynthesis.},
doi = {10.1021/acscatal.0c01397},
url = {https://www.osti.gov/biblio/1633077}, journal = {ACS Catalysis},
issn = {2155-5435},
number = 12,
volume = 10,
place = {United States},
year = {2020},
month = {6}
}

Journal Article:
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