𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Differential behaviour of two cyanobacterium species to UV radiation. Artificial UV radiation induces phycoerythrin synthesis

✍ Scribed by Rómulo Aráoz; Miranda Shelton; Michael Lebert; Donat-P. Häder


Publisher
Elsevier Science
Year
1998
Tongue
English
Weight
928 KB
Volume
44
Category
Article
ISSN
1011-1344

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✦ Synopsis


Altitude is an important factor contributing to the local UV-B climate. In the European Alps solar UV-B increases ~ 21% 1000 m -~. A Nostoc muscorum (UTEX 389) originating from Scotland and a Nostoc sp. isolated from a highland lake (Yanaqocha) located 3980 m above sea level (Cusco, Peril) have been used in a study where the tolerance to UV radiation (UVR) stress of both species was determined. Following irradiation doses of 15 kJ UV (UV-A plus UV-B, equivalent to ~ 6 h exposure to unfiltered solar light at noon for a standard midlatitude region with normal ozone concentration), the viability ofNostoc sp. is 30% compared to 3% for Nostoc muscorum. UV-B induces the reduction of the number of phycobilisomes per cell, phycobilisome disassembly and/or degradation as well as phycobilisome uncoupling. Following UV exposure, phycoerythrin (PE) fluorescence emission increases dramatically in both species, indicating accumulation of PE in the phycobilisome rods. The detected increase in PE due to UVR is confirmed using a monoclonal antibody anti-PE.