TY - JOUR
T1 - Photosynthetic biohybrid coculture for tandem and tunable CO2and N2 fixation
AU - Cestellos-Blanc, Stefano
AU - Chan, Rachel R.
AU - Shen, Yue Xiao
AU - Kim, Ji Min
AU - Tacken, Tom A.
AU - Ledbetter, Rhesa
AU - Yu, Sunmoon
AU - Seefeldt, Lance C.
AU - Yang, Peidong
N1 - Publisher Copyright:
Copyright © 2022 the Author(s).
PY - 2022/6/28
Y1 - 2022/6/28
N2 - Solar-driven bioelectrosynthesis represents a promising approach for converting abundant resources into value-added chemicals with renewable energy. Microorganisms powered by electrochemical reducing equivalents assimilate CO2, H2O, and N2 building blocks. However, products from autotrophic whole-cell biocatalysts are limited. Furthermore, biocatalysts tasked with N2 reduction are constrained by simultaneous energy-intensive autotrophy. To overcome these challenges, we designed a biohybrid coculture for tandem and tunable CO2 and N2 fixation to value-added products, allowing the different species to distribute bioconversion steps and reduce the individual metabolic burden. This consortium involves acetogen Sporomusa ovata, which reduces CO2 to acetate, and diazotrophic Rhodopseudomonas palustris, which uses the acetate both to fuel N2 fixation and for the generation of a biopolyester. We demonstrate that the coculture platform provides a robust ecosystem for continuous CO2 and N2 fixation, and its outputs are directed by substrate gas composition. Moreover, we show the ability to support the coculture on a high-surface area silicon nanowire cathodic platform. The biohybrid coculture achieved peak faradaic efficiencies of 100, 19.1, and 6.3% for acetate, nitrogen in biomass, and ammonia, respectively, while maintaining product tunability. Finally, we established full solar to chemical conversion driven by a photovoltaic device, resulting in solar to chemical efficiencies of 1.78, 0.51, and 0.08% for acetate, nitrogenous biomass, and ammonia, correspondingly. Ultimately, our work demonstrates the ability to employ and electrochemically manipulate bacterial communities on demand to expand the suite of CO2 and N2 bioelectrosynthesis products.
AB - Solar-driven bioelectrosynthesis represents a promising approach for converting abundant resources into value-added chemicals with renewable energy. Microorganisms powered by electrochemical reducing equivalents assimilate CO2, H2O, and N2 building blocks. However, products from autotrophic whole-cell biocatalysts are limited. Furthermore, biocatalysts tasked with N2 reduction are constrained by simultaneous energy-intensive autotrophy. To overcome these challenges, we designed a biohybrid coculture for tandem and tunable CO2 and N2 fixation to value-added products, allowing the different species to distribute bioconversion steps and reduce the individual metabolic burden. This consortium involves acetogen Sporomusa ovata, which reduces CO2 to acetate, and diazotrophic Rhodopseudomonas palustris, which uses the acetate both to fuel N2 fixation and for the generation of a biopolyester. We demonstrate that the coculture platform provides a robust ecosystem for continuous CO2 and N2 fixation, and its outputs are directed by substrate gas composition. Moreover, we show the ability to support the coculture on a high-surface area silicon nanowire cathodic platform. The biohybrid coculture achieved peak faradaic efficiencies of 100, 19.1, and 6.3% for acetate, nitrogen in biomass, and ammonia, respectively, while maintaining product tunability. Finally, we established full solar to chemical conversion driven by a photovoltaic device, resulting in solar to chemical efficiencies of 1.78, 0.51, and 0.08% for acetate, nitrogenous biomass, and ammonia, correspondingly. Ultimately, our work demonstrates the ability to employ and electrochemically manipulate bacterial communities on demand to expand the suite of CO2 and N2 bioelectrosynthesis products.
KW - COelectrosynthesis
KW - Nelectrosynthesis
KW - bacterial coculture
KW - biocatalysis
UR - http://www.scopus.com/inward/record.url?scp=85132255580&partnerID=8YFLogxK
U2 - 10.1073/pnas.2122364119
DO - 10.1073/pnas.2122364119
M3 - Article
C2 - 35727971
AN - SCOPUS:85132255580
SN - 0027-8424
VL - 119
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 26
M1 - e2122364119
ER -