Acaryochloris marina (A. marina) is a distinctive cyanobacterium that contains rod-shaped phycobiliproteins (PBPs) and uses chlorophyll (Chl) d as its principal photosynthetic pigment, enabling it to absorb far-red light for photosynthesis. Under varying environmental light conditions, several cyanobacteria have been reported to exhibit decreased PBP content under red light and increased levels under green light. For A. marina, a reduction in PBP has also been observed under red and far-red light. However, the changes in light-harvesting and energy-transfer processes of A. marina in response to different light qualities remain insufficiently characterized. In the present study, A. marina cells were cultured under white, blue, green, yellow, red, or far-red LEDs. Compared with cultures grown under white-LEDs, blue-, red-, and far-red-LED-grown cells showed a decrease in the PBP/Chl d ratio, whereas green- and yellow-LED-grown cells showed an increase. The energy-transfer process of green-LED-grown cells at 77 K exhibited pronounced alterations in photosystem II. Based on these findings, we discuss the variations in light-harvesting and energy-transfer processes of A. marina under different light conditions.
Keywords: Acaryochloris; Chromatic acclimation; Cyanobacterium; Excitation energy transfer; Light harvesting; Time-resolved fluorescence spectroscopy.
© 2025. The Author(s), under exclusive licence to Springer Nature B.V.