Augmented CO2 tolerance by expressing a single H+-pump enables microalgal valorization of industrial flue gas

Hong Il Choi, Sung Won Hwang, Jongrae Kim, Byeonghyeok Park, Eon Seon Jin, In Geol Choi, Sang Jun Sim

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)


Microalgae can accumulate various carbon-neutral products, but their real-world applications are hindered by their CO2 susceptibility. Herein, the transcriptomic changes in a model microalga, Chlamydomonas reinhardtii, in a high-CO2 milieu (20%) are evaluated. The primary toxicity mechanism consists of aberrantly low expression of plasma membrane H+-ATPases (PMAs) accompanied by intracellular acidification. Our results demonstrate that the expression of a universally expressible PMA in wild-type strains makes them capable of not only thriving in acidity levels that they usually cannot survive but also exhibiting 3.2-fold increased photoautotrophic production against high CO2 via maintenance of a higher cytoplasmic pH. A proof-of-concept experiment involving cultivation with toxic flue gas (13 vol% CO2, 20 ppm NOX, and 32 ppm SOX) shows that the production of CO2-based bioproducts by the strain is doubled compared with that by the wild-type, implying that this strategy potentially enables the microalgal valorization of CO2 in industrial exhaust.

Original languageEnglish
Article number6049
JournalNature communications
Issue number1
Publication statusPublished - 2021 Dec 1

Bibliographical note

Funding Information:
We are grateful for the funds provided by Korea Carbon to X R&D Center (2020M3H7A1098295) and the National Research Foundation (NRF-2019R1A2C3009821 / NRF-2020R1A5A1018052) of the Ministry of Science and ICT of Korea. The authors express special thanks to Korea University and Korea Western Power Co., Ltd. for supporting this research. We are also appreciative of Hong Ki Yoon at Korea University, Hyunjin Ko at the Korea Western Power Co., Ltd., and Dr. Jong-Kyun You and Dr. Dae Ho Lim at the Korea Institute of Energy Research for helping with the outdoor microalgal cultivation.

Publisher Copyright:
© 2021, The Author(s).

ASJC Scopus subject areas

  • General Chemistry
  • General Biochemistry,Genetics and Molecular Biology
  • General
  • General Physics and Astronomy


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