Algae and cyanobacteria as agents for carbon dioxide removal: production of long-term carbon compounds

[Geoengineering News]

https://www.sciencedirect.com/science/article/pii/S2772656826000436

Authors: Eduardo Gorron Gomez, Kim J. Lee Chang, Matthew C. Taylor, Dion M.F. Frampton

09 April 2026

https://doi.org/10.1016/j.ccst.2026.100610

Abstract

Among the potential options for greenhouse gas reductions, carbon dioxide removal (CDR) mediated by photosynthetic algae and cyanobacteria (collectively termed “algae”) is worthy of consideration. These organisms have properties that enable alternative thinking to the canonical processes of biological carbon cycling and sequestration: they can be microscopic, unicellular, vegetative, transformable, capable of taking up and converting CO2 and producing long-term carbon compounds. Algae are the primary producers of a variety of precursor and end-point compounds that can be classified as long-term and useful for permanent carbon capture, including inorganic carbonates and organic molecules such as dinosporin, RDOM, and algaenan, with algaenan perhaps being the foremost among these for CDR purposes. In this review, we explore algal-derived long-term carbon compounds with potential for CDR purposes. Considered to be a major contributor to type I kerogen via the process of selective preservation, algaenan is a complex polymer found in the cell walls of a limited number of algal species that has biosynthetic similarities to that of cutin and suberin in some higher plants. Studies concerning the structure and characterisation of algaenan and potential precursor compounds, including hydroxy fatty acids, long-chain alkenols, and long-chain alkyl diols, have had challenges related to the complexity of the chemistry involved, historical methodological inconsistencies, and misleading findings due to the generation of methodological artefacts, yet their algal origin is undeniable. Indeed, the intentional production and use of algaenan for CDR shows promise when compared with equivalent plant production processes and, if combined with the production of other agro-industrial products and/or environmental management processes, would provide even greater value for society. The proposed algal-mediated CDR is relatively underexplored and deserves further investigation to fully realise its potential in the context of negative CO2 emissions.

Source: ScienceDirect