An algal-bacterial symbiotic system of carbon fixation using formate as a carbon source

Journal Article · Mon Apr 17 00:00:00 EDT 2023 · Algal Research

DOI:https://doi.org/10.1016/j.algal.2023.103103· OSTI ID:1986446

Zheng, Yurui ^[1]; Czajka, Jeffrey J. ^[2]; Daiek, Carly ^[1]; Yang, Zhichang ^[1]; Sun, Liangliang ^[1]; Tang, Yinjie J. ^[2]; Liu, Yan ^[1]; Liao, Wei ^[1]

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1. Michigan State University, East Lansing, MI (United States)
2. Washington University in St. Louis, MO (United States)

The commercial implementation of algal cultures for efficient capture of CO₂ from fossil-derived flue gases is not a reality yet due to several major challenges, particularly low gas-liquid mass transport efficiency along with loss of productivity due to pests. This study has explored an algal-bacterial symbiotic system to utilize formate as a carbon source. The algal-bacterial assemblage, after a 400-day adaptive evolution using the formate medium, has demonstrated a new capability to assimilate both formate and CO₂ to promote biomass production. The formate tolerant culture system also addresses CO₂ mass transfer limitation under high light conditions. Continuous cultivation of the assemblage on formate led to a carbon capture efficiency of 90 % with a biomass concentration of 0.92 g L^-1 and biomass productivity of 0.31 g L^-1 day^-1, and the system did not require CO₂ aeration. In addition, ¹³C isotope tracing, proteomics, and microbial community analysis reveal a uniquely evolved community for formate utilizations and robust biomass synthesis, in which Chlorella sorokiniana is a dominant phototroph companying with highly diverse bacterial subpopulations. In the presence of formate, evidence has shown that Chlorella is able to form mutualism with formate utilizing bacteria in semi-continuous cultures, leading to a highly effective photomixotrophic metabolism. Furthermore, this study demonstrates a new route of using electrochemical-derived formate to support mutualistic algae-bacteria biorefinery while the formate as an alternative carbon source could repel pests for outdoor algal cultivations.

• Research Organization: Michigan State Univ., East Lansing, MI (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: FE0030977
• OSTI ID: 1986446
• Journal Information: Algal Research, Vol. 72; ISSN 2211-9264
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
Adaptive evolution
Mutualism
Carbon capture
Chlorella sorokiniana
Isotopic tracing