Oxidative balance in macroalgae from Antarctic waters. Role of Fe

PAULA MARIELA GONZÁLEZ; DEREGIBUS, DOLORES; GABRIELA MALANGA; CAMPANA, GABRIELA LAURA; QUARTINO, MARÍA LILIANA; SUSANA PUNTARULO

Congreso; Second International Conference on Oxidative Stress in Aquatic Ecosystems; 2015

Excess in Fe content was identified as responsible for seaweed stress. In Potter Cove, Antarctic, the particulate Fe content at 0 m near the glacier in D Island (B4) is significantly higher than inPeñón Pesca (A1). The hypothesis of this work was that the basal oxidative profile of Gigartina skottsbergii and Himantothallus grandifolius follows a differential pattern due to adaptive factors.Daily metabolic carbon balance was significantly lower in both macroalgae taken from B4 as compared to those from A1. Lipid radical (LR●) content, measured by EPR, was significantly higher inG. skottsbergii from B4 as compared to A1 samples. However, H. grandifolius showed significantly lower values in B4 in comparison to those from A1. b-Carotene (b-C) content (measured byHPLC) was significantly lower in G. skottsbergii from B4 as compared to A1, and the ratio LR● content/b-C content was increased by 6-fold in samples from B4 as compared to samples obtainedfrom A1. However, the b-C content showed no significantly differences in H. grandifolius from both areas. The LR● content/b-C content index in this alga was significantly lower (26%) in samplesobtained from B4 as compared to A1. Total Fe content (measured spectrophotometrically) in G. skotsbergii was significantly different, 1.0±0.5 and 2.9±0.7 nmol/mg FW, in samples from A1 andB4, respectively. However, in H. grandifolius this parameter showed no significantly differences between both areas. The presented results in G. skottsbergii suggested changes in the oxidativecellular balance at the lipophilic level probably related to the higher environmental Fe in the B4, as compared to the A1 region. Contrary to the subtidal red alga G. skottsbergii, the brownmacroalga H. grandifolius, that is an endemic species from Antarctic waters predominating on vertical rocks, could be better adapted to the environmental changes of the region.