Carbon limitation enhances CO₂ concentrating mechanism but reduces trichome size in Arthrospira platensis (cyanobacterium)

• Published in: Journal of applied phycology Vol. 26; no. 3; pp. 1465 - 1472
• Main Authors: Ma, Zengling, Gao, Kunshan
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.06.2014; Springer Netherlands; Springer Nature B.V
• Subjects: air; Arthrospira; Biomedical and Life Sciences; carbon; Carbon dioxide; carotenoids; Cyanobacterium; Ecology; Freshwater & Marine Ecology; Inorganic carbon; Life Sciences; Photochemicals; photosynthesis; Plant Physiology; Plant Sciences; Spirulina platensis; transporters; trichomes; Inorganic carbon (Ci); CO; concentration mechanism (CCM); Photosynthesis; Morphology
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-013-0181-6

Arthrospira species grow well under highly enriched inorganic carbon concentrations, but little is known on the effects of inorganic carbon (Ci) limitation on its physiological performance. When Arthrospira platensis D-0083 was grown in a modified medium without NaHCO₃ under ambient air of 380 ppm CO₂, its trichomes became disassembled while the growth and photosynthetic rates were severely reduced. Phycocyanin and allophycocyanin contents decreased but the carotenoid content increased under the Ci limitation. Compared with the cells grown in Zarrouk medium, the trichomes grown under the Ci limitation increased their photosynthetic apparent affinity for Ci by about 14 times but photochemical quenching capacity was reduced. It appeared that A. platensis increased its CO₂ concentrating mechanism by inducing HCO₃ ⁻ transporters and reducing the trichome size which increased filamentous surface to volume ratio.