Different speciation for bromine in brown and red algae, revealed by in vivo X‐ray absorption spectroscopic studies

• Published in: Journal of phycology Vol. 50; no. 4; pp. 652 - 664
• Main Authors: Küpper, Frithjof C, Leblanc, Catherine, Meyer‐Klaucke, Wolfram, Potin, Philippe, Feiters, Martin C, Amsler, C
• Format: Journal Article
• Language: English
• Published: United States Blackwell Pub 01.08.2014; Blackwell Publishing Ltd; Wiley Subscription Services, Inc
• Subjects: abiotic stress; absorption; Ascophyllum nodosum; Asparagopsis; bromides; bromine; brown algae; Chondrus crispus; Corallina; Corallina officinalis; Dinophyceae; Ectocarpus; emissions; extended X-ray absorption fine structure; Fucus serratus; Gracilaria; hydrocarbons; Laminaria; Lingulodinium polyedrum; microalgae; phytoplankton; Polysiphonia; potassium chloride; red algae; spectroscopy; Stramenopiles; Thalassiosira; Thalassiosira rotula; X-ray absorption spectroscopy; microalgae; extended X-ray absorption fine structure; red algae; X-ray absorption spectroscopy; brown algae
• ISSN: 0022-3646; 1529-8817
• DOI: 10.1111/jpy.12199

Members of various algal lineages are known to be strong producers of atmospherically relevant halogen emissions, that is a consequence of their capability to store and metabolize halogens. This study uses a noninvasive, synchrotron‐based technique, X‐ray absorption spectroscopy, for addressing in vivo bromine speciation in the brown algae Ectocarpus siliculosus, Ascophyllum nodosum, and Fucus serratus, the red algae Gracilaria dura, G. gracilis, Chondrus crispus, Osmundea pinnatifida, Asparagopsis armata, Polysiphonia elongata, and Corallina officinalis, the diatom Thalassiosira rotula, the dinoflagellate Lingulodinium polyedrum and a natural phytoplankton sample. The results highlight a diversity of fundamentally different bromine storage modes: while most of the stramenopile representatives and the dinoflagellate store mostly bromide, there is evidence for Br incorporated in nonaromatic hydrocarbons in Thalassiosira. Red algae operate various organic bromine stores – including a possible precursor (by the haloform reaction) for bromoform in Asparagopsis and aromatically bound Br in Polysiphonia and Corallina. Large fractions of the bromine in the red algae G. dura and C. crispus and the brown alga F. serratus are present as Br⁻ defects in solid KCl, similar to what was reported earlier for Laminaria parts. These results are discussed according to different defensive strategies that are used within algal taxa to cope with biotic or abiotic stresses.