Maximize microalgal carbon dioxide utilization and lipid productivity by using toxic flue gas compounds as nutrient source

Deepesh Singh Chauhan; Lingaraj Sahoo; Kaustubha Mohanty

doi:10.1016/j.biortech.2022.126784

Maximize microalgal carbon dioxide utilization and lipid productivity by using toxic flue gas compounds as nutrient source

Bioresour Technol. 2022 Mar:348:126784. doi: 10.1016/j.biortech.2022.126784. Epub 2022 Jan 29.

Authors

Deepesh Singh Chauhan¹, Lingaraj Sahoo², Kaustubha Mohanty³

Affiliations

¹ School of Energy Science and Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India.
² School of Energy Science and Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India; Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India.
³ School of Energy Science and Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India; Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India. Electronic address: kmohanty@iitg.ac.in.

PMID: 35104656
DOI: 10.1016/j.biortech.2022.126784

Abstract

NOx and SOx present in flue gas inhibit microalgal based CO₂ mitigation process. In this work, 13 microalgal strains were screened to evaluate their gradual acclimation capacity to toxic flue gas compounds, by testing their growth capability and photosynthetic ability in dissolved flue gas compounds. Six strains out of them were evaluated for their acclimation to bicarbonate and 15% CO₂ as sole carbon sources. Two strains, Micractinium pusillum KMC8 and Scenedesmus acutus NCIM5584 were found to accumulate nitrite as fixed nitrogen and showed improved growth performance in photobioreactor upon stepwise acclimation to bisulphite/sulphite. Notably, the strain KMC8 showed a high tolerance and rapidly acclimated dissolved flue gas compounds with higher biomass yield (1.32 g L^-1) and neutral lipid accumulation (32%), enhanced CO₂ utilization efficiency (3.07%) and CO₂ fixation rate (136.79 mg L^-1 d^-1) post acclimation. KMC8 sustained its stability in biomass and lipid productivity while simultaneously bio-mitigated CO₂ under semi-continuous mode.

Keywords: Acclimation; CO(2) fixation; Microalgae; Neutral lipid; Toxic flue gas compounds.

MeSH terms

Biomass
Carbon Dioxide
Lipids
Microalgae*
Nutrients
Scenedesmus*

Substances

Lipids
Carbon Dioxide