BROMOPEROXIDASES AND HALOGENATED LIPIDS IN MARINE ALGAE¹

Abstract

ABSTRACT Using the facilities of the RIV Alpha Helix, marine algae were collected and immediately sampled for the presence of peroxidase enzymes capable of performing electrophilic bromination via the oxidation of bromide ion. Algae were also sampled for halogenated neutral lipids. A spectrophotometric assay employing monochlorodimedone was used to measure the level of enzymatic bromination, and an automated halogen analyzer was used to determine the level of lipid halogen. Of 72 algae tested for bromoperoxidase, 55 were active; moreover 27 of 102 algae contained significant levels of lipid halogen. For 67 algae there was sufficient sample to complete both assays. A comparison of the reds, browns and greens showed the Rhodophyta to be the richest in both bromoperoxidase and lipid halogen levels while the Phaeophyta was the poorest. pH optima in the range pH 5 to 8 were determined for a few of the more active algal bromoperoxidases. Cyanide inhibited the bromination of monochlorodimedone but inhibition could not be distinguished from the possibility of competition by cyanide for electrophilic bromination.