Halogens in Seaweeds: Biological and Environmental Significance

Abstract

Many marine algae are strong accumulators of halogens. Commercial iodine production started by burning seaweeds in the 19th century. The high iodine content of certain seaweeds has potential pharmaceutical and nutritional applications. While the metabolism of iodine in brown algae is linked to oxidative metabolism, with iodide serving the function of an inorganic antioxidant protecting the cell and thallus surface against reactive oxygen species with implications for atmospheric and marine chemistry, rather little is known about the regulation and homoeostasis of other halogens in seaweeds in general and the ecological and biological role of marine algal halogenated metabolites (except for organohalogen secondary metabolites). The present review covers these areas, including the significance of seaweed-derived halogens and of halogens in general in the context of human diet and physiology. Furthermore, the understanding of interactions between halogenated compound production by algae and the environment, including anthropogenic impacts, effects on the ozone layer and global climate change, is reviewed together with the production of halogenated natural products by seaweeds and the potential of seaweeds as bioindicators for halogen radionuclides.

The role of plant hormones on the reproductive success of red and brown algae

“…Halogens also play an important role in protecting brown algae from grazing and fungal and bacterial attacks ( Al-Adilah et al., 2022 ). Treatment with oligosaccharides derived from alginate, the main brown algal cell wall polysaccharide, shows that Laminariales has a high capacity to release iodide during oxidative bursts ( Shimizu et al., 2018 ) that induce subsequent defense responses ( Küpper et al., 2002 ; Thomas et al., 2014 ).…”

Dietary exposure assessment of mineral and trihalomethane in the major Korean seaweeds

“…금속 위해도 평가 연구는 부족하였고 [2,[13][14][15], 인체 발암물질이 지만, 기능성 사료의 원인물질인 trihalomethane에 대한 해조류 중 잔류와 식이섭취 위해평가는 국내에서 보고된 바 없었다 [16][17][18]. 이에 따라, 본 연구에서는 주요 식용 해조류인 김, 미역, 파래, 감태, 청각 등 5종을 대상으로 미네랄 함량과 중금속, trihalomethane 함량을 조사하고, 식이섭취에 따른 영양학적 기 여도와 위해도를 평가하였다.…”