Monitoring Photosynthetic Performance in Cyanobacteria by a Modulated Fluorometer

Abstract

Photoautotrophs are the only biological organisms that are capable of reducing atmospheric carbon dioxide (CO2) using sunlight as a source of energy during photosynthesis. Being the primary producers in the ecosystems, photoautotrophs are a suitable source of energy for higher trophic levels (Bryant 1994). In addition to higher plants, algae and cyanobacteria are the major contributors to the production of oxygen on the Earth. Also, these photosynthetic microorganisms are emerging as a model system for the sequestration of CO2 and production of biofuels and valuable chemicals in a carbon-neutral manner (Field et al. 1998a; Barber 2009; Maurya et al. 2021). Cyanobacteria, formerly known as blue-green algae, are oxygen-producing, photosynthetic, Gram-negative bacteria that use proteinaceous macrocomplexes called phycobilisomes (PBSs) for harvesting solar radiation to drive photosynthesis. PBSs are composed of chromophore-binding phycobiliproteins such as allophycocyanin (APC; λmax ∼650 nm), phycocyanin (PC; λmax ∼620 nm) and phycoerythrin (PE; λmax ∼565 nm) (Sanfilippo et al. 2019). © 2024 selection and editorial matter, Shailendra P. Singh, Rajeshwar P. Sinha and Donat-P. Häder; individual chapters, the contributors.