Lipids that contain arsenic in the Mediterranean mussel, Mytilus galloprovincialis

Abstract

Environmental contextAlthough arsenic-containing lipids are widespread in marine environments, their origin remains unknown. We show that the arsenolipids in a filter-feeding bivalve mollusc closely match those found in marine food sources, including unicellular algae and bacteria. The results demonstrate the role of lower trophic levels in determining the forms of arsenic found in higher organisms. AbstractArsenic-containing lipids, arsenolipids, are widely found among marine organisms, but their origin and possible biochemical roles remain unknown This work describes the diversity and abundance of arsenolipids in the digestive gland and mantle of nine specimens of the Mediterranean mussel, Mytilus galloprovincialis. By using high performance liquid chromatography (HPLC) coupled to both elemental and high-resolution molecular mass spectrometry, we identified 36 arsenolipids including arsenic derivatives of fatty acids, hydrocarbons, sugar-phospholipids and sugar-phytol; 21 of these arsenolipids were identified for the first time and included a new group comprising ether-phospholipids. The arsenic compounds in the mussels show distinct profiles depending on the tissue type, which provide insight into the arsenolipid origin. The results suggest that the presence of some arsenolipids in the mussels is from direct uptake of the compounds, presumably from food, rather than biogenesis within the mussels.