A review on biological systems for CO₂ sequestration: Organisms and their pathways

Abstract

The concentration of carbon dioxide, a major greenhouse gas, has been increasing in the atmosphere due to various anthropogenic activities. This review aims at summarizing different organisms, including eukaryotes and prokaryotes that have the ability to assimilate CO2. In addition, the metabolic pathway via which an organism sequesters CO2 is explained in brief. The adaptations of different organisms for efficient CO2 sequestration have also been explained in the current review. An important advantage of applying biological systems to manage CO2 is that it synthesizes industrially useful byproducts such as bioplastics, medicinal compounds, and biofuels. Hence, this review helps in understanding diverse biological systems that can be utilized to develop a sustainable technology to mitigate CO2 at an industrial level. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 127–136, 2019

Photosynthetic Carbon Partitioning and Metabolic Regulation in Response to Very-Low and High CO2 in Microchloropsis gaditana NIES 2587

“…Capturing of the atmospheric CO 2 and converting them into reduced form without contributing to global warming by maintaining the balance in the environment is referred as carbon sequestration (Lal, 2008;Zeng, 2008). These photosynthetic cell factories are capable of sequestering atmosphere CO 2 for the production of biofuel precursors (Rittmann, 2008;Mistry et al, 2019). Henceforth, the potential of industrially relevant oleaginous microalgae to minimize the excess CO 2 present in the atmosphere can be employed via carbon concentrating mechanism (CCM) (Long et al, 2016).…”

“…The use of fossil fuels is primarily in three economic sectors, namely: energy, transportation, and industry leading to CO 2 emissions. Increase in atmospheric CO 2 may be caused due to following reasons such as deforestation (9%), burning of fossil fuels (87%), and remaining (4%) presumably by others like industrial manufacturing ( Le Quere et al., 2013 ; Mistry et al., 2019 ).…”

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

“…If this pump can be activated in algal systems, the exogenous gene expression strategy can provide several merits. Because of its host-independent property, the expression of PMA4 holds the potential to be a versatile approach for various microalgal species suffering from stagnant H + extrusion and consequent CO 2 intolerance, which is a general but critical issue that interferes with the practical application of microalgae-based CO 2 conversion technology 3 , 8 . In addition, PMA4 could help prevent cosuppression, which often occurs in homologous overexpression cases 32 .…”

“…The wide range of product portfolios is another merit of this platform 2 . Despite their promising potential, the low tolerance of microalgae to high concentrations of CO 2 is one of the crucial thresholds that precludes the real-world application of microalgae for CO 2 removal 3 . In particular, this issue of CO 2 tolerance becomes more serious if phototrophic microalgae cultivation occurs in concert with an industrial exhaust gas stream, which is the most economically and energetically efficient biological process for removing CO 2 from air based on a life-cycle perspective 4 because the proportion of CO 2 in waste streams is commonly higher than 10%, a level that can significantly inhibit algal growth and unavoidably deteriorate the biological CO 2 conversion efficiency 5 , 6 .…”

Bioprospecting wild South African microalgae as a potential third-generation biofuel feedstock, biological carbon-capture agent and for nutraceutical applications

“…Therefore, the world is currently in search of a sustainable carbon mitigation technology and carbon-neutral or carbon-negative alternative energy source to fossil fuel, whose source might even be depleted soon. Currently, researchers have identified microalgae-based technologies as having an efficient photosynthesis mechanism capable of effectively biosequestering CO 2 from a point source into a biomass that could be considered a potential source of biofuels, a promising but currently expensive alternative to fossil fuels [11][12][13]. Research data compiled by Sidney et al [12] on carbon fixation rates by species of microalgae, whilst assessing the role of microalgae technologies in the global carbon market, revealed that genera-Anabaena, Chlorococcum, Spirulina, Chlorella, Botryococcus and Haematococcus have the greatest carbon fixation potential.…”