Effect of UVB Radiation on Utilization of Inorganic Nitrogen by Antarctic Microalgae

• Published in: Photochemistry and Photobiology
• Main Author: Döhler, G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1997
• Subjects: Physical and Theoretical Chemistry; General Medicine; Biochemistry; Antarctic; Weddell; Weddell Sea; Antarc*; Antarctica; ice algae; Sea ice
• Online Access: http://dx.doi.org/10.1111/j.1751-1097.1997.tb03233.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1751-1097.1997.tb03233.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1751-1097.1997.tb03233.x

Abstract— The impact of UVB (280‐315 nm) radiation (WG 305) on uptake of 15 N‐ammonium and 15 N‐nitrate of marine phytoplankton from station 219 (47°W, 61.5°S) and sea ice‐algae from station 265 (22.6°W, 73.29°S) was studied during the Polarstern Cruise (EPOS III, Leg 3) to the Weddell Sea, Antarctica 1989. Uptake rates of 15 NH 4 + were higher and more affected by UVB radiation than those of 15 N0 3 ‐. Pool sizes of the main amino acids changed in response to the used inorganic nitrogen source and UV exposure. Pools of glutamine, serine and glycine decreased, whereas those of alanine, asparagine and glutamate increased after UVB irradiation. The 15 N‐incorporation into the amino acids was reduced as a result of UVB exposure of phytoplankton and ice algae. Results are discussed with reference to an inhibitory effect on the enzymes of both carbon and nitrogen metabolism as well as to adaptation strategies.