Environmental effects on arsenosugars and arsenolipids in Ectocarpus (Phaeophyta)

Pétursdóttir, Ásta H.; Fletcher, Kyle; Gunnlaugsdóttir, Helga; Krupp, Eva M.; Küpper, Frithjof C.; Feldmann, Jörg

doi:10.1071/en14229

Cited by 31 publications

(13 citation statements)

References 45 publications

(52 reference statements)

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“…A residual, non-extractable fraction often remains following speciation analysis, and can contain a significant proportion of total As in some samples (Leufroy et al 2012, Petursdottir et al 2016). The form of As in this fraction remains unclear.…”

Section: Sources and Distribution Of Organic As Species In Marine mentioning

confidence: 99%

“…The form of As in this fraction remains unclear. Seaweeds can contain variable amounts of un-extractable or residual As (Lai et al 1998, Raab et al 2005, van Elteren et al 2007, Petursdottir et al 2016), which is thought to be bound to thiol-containing structural compounds (Thomson et al 2007). Molluscs frequently have high levels of residual As (8–58%; (Fricke et al 2004, Whaley-Martin et al 2012, Berges-Tiznado et al 2013)), and while As in crustaceans is mostly water soluble, the residual fraction can also be significant (9–17% (Li et al 2003)).…”

Section: Sources and Distribution Of Organic As Species In Marine mentioning

confidence: 99%

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Human exposure to organic arsenic species from seafood

Taylor

Goodale

Raab

et al. 2017

Science of The Total Environment

370

256

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Seafood, including finfish, shellfish, and seaweed, is the largest contributor to arsenic (As) exposure in many human populations. In contrast to the predominance of inorganic As in water and many terrestrial foods, As in marine-derived foods is present primarily in the form of organic compounds. To date, human exposure and toxicological assessments have focused on inorganic As, while organic As has generally been considered to be non-toxic. However, the high concentrations of organic As in seafood, as well as the often complex As speciation, can lead to complications in assessing As exposure from diet. In this report, we evaluate the presence and distribution of organic As species in seafood, and combined with consumption data, address the current capabilities and needs for determining human exposure to these compounds. The analytical approaches and shortcomings for assessing these compounds are reviewed, with a focus on the best practices for characterization and quantitation. Metabolic pathways and toxicology of two important classes of organic arsenicals, arsenolipids and arsenosugars, are examined, as well as individual variability in absorption of these compounds. Although determining health outcomes or assessing a need for regulatory policies for organic As exposure is premature, the extensive consumption of seafood globally, along with the preliminary toxicological profiles of these compounds and their confounding effect on assessing exposure to inorganic As, suggests further investigations and process-level studies on organic As are needed to fill the current gaps in knowledge.

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Section: Sources and Distribution Of Organic As Species In Marine mentioning

confidence: 99%

Section: Sources and Distribution Of Organic As Species In Marine mentioning

confidence: 99%

Human exposure to organic arsenic species from seafood

Taylor

Goodale

Raab

et al. 2017

Science of The Total Environment

370

256

View full text Add to dashboard Cite

show abstract

“…Several studies have contributed to our understanding of the occurrence of arsenolipids [16][17][18][19][20][21][22], but we still have only limited knowledge about the metabolism of these compounds and their behavior in natural systems. In this regard, two recent studies by Glabonjat et al [19,22] have revealed the likely significance of phytyl 2-O-methyl arsenosugars in the natural cycling of arsenic.…”

Section: Introductionmentioning

confidence: 99%

Arsenolipids in Cultured Picocystis Strain ML and Their Occurrence in Biota and Sediment from Mono Lake, California

Glabonjat

Blum

Miller

et al. 2020

Life

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Primary production in Mono Lake, a hypersaline soda lake rich in dissolved inorganic arsenic, is dominated by Picocystis strain ML. We set out to determine if this photoautotrophic picoplankter could metabolize inorganic arsenic and in doing so form unusual arsenolipids (e.g., arsenic bound to 2-O-methyl ribosides) as reported in other saline ecosystems and by halophilic algae. We cultivated Picocystis strain ML on a seawater-based medium with either low (37 µM) or high (1000 µM) phosphate in the presence of arsenite (400 µM), arsenate (800 µM), or without arsenic additions (ca 0.025 µM). Cultivars formed a variety of organoarsenic compounds, including a phytyl 2-O-methyl arsenosugar, depending upon the cultivation conditions and arsenic exposure. When the cells were grown at low P, the organoarsenicals they produced when exposed to both arsenite and arsenate were primarily arsenolipids (~88%) with only a modest content of water-soluble organoarsenic compounds (e.g., arsenosugars). When grown at high P, sequestration shifted to primarily water-soluble, simple methylated arsenicals such as dimethylarsinate; arsenolipids still constituted ~32% of organoarsenic incorporated into cells exposed to arsenate but < 1% when exposed to arsenite. Curiously, Picocystis strain ML grown at low P and exposed to arsenate sequestered huge amounts of arsenic into the cells accounting for 13.3% of the dry biomass; cells grown at low P and arsenite exposure sequestered much lower amounts, equivalent to 0.35% of dry biomass. Extraction of a resistant phase with trifluoroacetate recovered most of the sequestered arsenic in the form of arsenate. Uptake of arsenate into low P-cultivated cells was confirmed by X-ray fluorescence, while XANES/EXAFS spectra indicated the sequestered arsenic was retained as an inorganic iron precipitate, similar to scorodite, rather than as an As-containing macromolecule. Samples from Mono Lake demonstrated the presence of a wide variety of organoarsenic compounds, including arsenosugar phospholipids, most prevalent in zooplankton (Artemia) and phytoplankton samples, with much lower amounts detected in the bottom sediments. These observations suggest a trophic transfer of organoarsenicals from the phytoplankton (Picocystis) to the zooplankton (Artemia) community, with efficient bacterial mineralization of any lysis-released organoarsenicals back to inorganic oxyanions before they sink to the sediments.

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“…Despite arsenic-containing lipids (arsenolipids; the major classes are depicted in Fig. S1) originally being identified over 30 years ago by Morita and Shibata (1988), far less information exists on the production and biosynthesis of arsenolipid species by marine organisms (Sele et al 2012;Amayo et al 2014;Petursdottir et al 2015;Glabonjat et al 2018). In recent years, however, there has been renewed interest in the characterization of arsenolipids in marine organisms; and as a result, over 80 arsenolipids including As-hydrocarbons (AsHCs) (Taleshi et al 2008), As-fatty acids (Rumpler et al 2008), As-fatty alcohols (Amayo et al 2013), As-phospholipids (AsPLs) (Morita and Shibata 1988;Viczek et al 2016), and methoxy As-sugar phytol (Glabonjat et al 2017) have been identified from a range of organisms such as marine algae, squid, and fish.…”

Section: Introductionmentioning

confidence: 99%

Transformation of arsenic lipids in decomposing Ecklonia radiata

et al. 2019

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To investigate the release and degradation of arsenolipids present in the marine brown macroalga Ecklonia radiata, tissues were collected in various stages of decomposition from intertidal environments, while tissues were also decomposed in laboratorybased microcosms prepared using combinations of autoclaved and natural (non-autoclaved) seawater and sand. Field collected macroalgae samples contained 20-120 μg g −1 total As of which 1-10% were arsenolipids comprising mainly an arsenic hydrocarbon (AsHC; 3-13% of total arsenolipids) and four di-acyl arsenic phospholipids (AsPLs; 86-95%). Additionally, a mono-acyl AsPL was found in all water-column decomposing samples. Arsenolipid concentrations in live tissues were similar to those in tissues decomposing in the water-column (1.3-2.9 μg g −1 dry mass), which were both up to four times higher than those in decomposing tissues collected from intertidal environments (0.7-1.3 μg g −1 dry mass). In the microcosm experiments, the arsenolipid content of E. radiata decreased substantially as decomposition proceeded. In the majority of microcosms, more than 75% of the arsenolipids present initially disappeared within 5 days with only the AsHC persisting until day 60 (the length of the experiment). This study demonstrates that the habitat in which decomposition occurs influences the release and degradation of arsenolipids with the greatest losses occurring when tissues decompose in intertidal environments. Microbial diversity, biomass, and overall activity are thus likely to play important roles in the persistence of arsenolipids in decomposing algae.

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Environmental effects on arsenosugars and arsenolipids in Ectocarpus (Phaeophyta)

Cited by 31 publications

References 45 publications

Human exposure to organic arsenic species from seafood

Human exposure to organic arsenic species from seafood

Arsenolipids in Cultured Picocystis Strain ML and Their Occurrence in Biota and Sediment from Mono Lake, California

Transformation of arsenic lipids in decomposing Ecklonia radiata

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