Selenate bioaccumulation and toxicity in Chlamydomonas reinhardtii: Influence of ambient sulphate ion concentration.

Aquat Toxicol

Laboratoire de Radioécologie et Ecotoxicologie, Institut de Radioprotection et de Sûreté Nucléaire Bât 186, BP 3, 13115 Saint-Paul-Lez-Durance cedex, France.

Published: April 2010


Category Ranking

98%

Total Visits

921

Avg Visit Duration

2 minutes

Citations

20

Article Abstract

The aim of the present study was to investigate selenate toxicity in the unicellular green algae Chlamydomonas reinhardtii as a function of sulphate ion concentration and the relationship with intracellular bioaccumulation. The toxicity of selenate was evaluated by measuring the effect of different selenate concentrations on algal growth during a 96h exposure period. A non-linear regression according to the Hill model was used to describe the dose-effect relationship and estimate the effect concentrations (EC) of selenate. EC(50) values of 0.40[0.24-0.52]micromolL(-1) and of 3.10[1.65-4.86]micromolL(-1) of ambient selenate were obtained, at 8 and 80micromolL(-1) of sulphate ions in the medium, respectively. For non-toxic and low-level ambient selenate concentrations, bioaccumulation in presence of 80micromolL(-1) was one tenth that of 8micromolL(-1) of sulphate ions. When expressed as intracellular selenium burden, EC(50) values determined at 8 and 80micromolL(-1) of sulphate ions were not significantly different (126 and 67nmolSe.10(9)cells(-1), respectively). In conclusion, toxicity appeared to be correlated to selenate bioaccumulation which suggests that toxicity must be linked to intracellular selenium accumulation that is directly dependent on ambient sulphate ions that may compete with selenate for transport sites.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.aquatox.2009.12.003DOI Listing

Publication Analysis

Top Keywords

sulphate ions
16
selenate
9
selenate bioaccumulation
8
bioaccumulation toxicity
8
chlamydomonas reinhardtii
8
ambient sulphate
8
sulphate ion
8
ion concentration
8
selenate concentrations
8
ec50 values
8

Similar Publications

Gel-based electronic skin (e-skin) has recently emerged as one of the most promising interfaces for human-machine interaction and wearable devices, owing to its exceptional flexibility, extensibility, transparency, biocompatibility, high-quality physiological signal monitoring, and system integration suitability. However, conventional hydrogel-based e-skins may exhibit limitations in mechanical strength and stretchability compatibility, as well as poor environmental stability. To address these challenges, following a top-down fabrication strategy, this study innovatively integrates poly(methacrylic acid), titanium sulfate, and ethylene glycol (EG) into the three-dimensional collagen fiber network structure of zeolite-tanned sheepskin to successfully develop an organogel (SMEMT) e-skin, which exhibits superior high toughness, environmental stability, high transparency (74% light transmittance at 550 nm), antibacterial properties and ecological compatibility.

View Article and Find Full Text PDF

The rheological behavior of ulvan/kappa-carrageenan, ulvan/funoran and ulvan/gelatin mixtures is investigated using dynamic rheology to provide insights into the phase aggregation behavior of each ulvan-based network. The average molecular weight of extracted ulvan was between 436 and 573 kDa, and contained varying amounts of sulfate (10.3-28.

View Article and Find Full Text PDF

Kappa carrageenan (KC), a sulfated polysaccharide derived from red seaweed, exhibits distinct gelation properties that are influenced by ionic strength and thermal conditions. While its behavior in aqueous media is well-established, understanding KC's gelation mechanisms in non-aqueous solvents (like glycerol) remains limited. This study investigates the conformational and rheological properties of kappa carrageenan in glycerol, focusing on the effects of sodium salts (NaCl, NaHPO, NaPO) at varying concentrations and preparation temperatures (60 °C and 80 °C).

View Article and Find Full Text PDF

Marine-derived sulfated glycans display a potent virostatic mechanism to block herpes simplex virus type-1 (HSV-1) entry and spread.

Carbohydr Polym

November 2025

Departments of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.. Electronic address:

A naturally derived library of glycomimetic mimicking the structure-function of heparan sulfate (HS) remains an untapped reservoir for drug discovery against viral infections. In this work we screened a library of marine-derived sulfated glycans from seaweeds and sea cucumbers to investigate if they can compete for the ligand/receptor binding sites to prevent virus entry. Multiple promising candidates were identified, such as RPI-27 (IC: 1.

View Article and Find Full Text PDF

Hydroxymethyl-methyl-α-lactone (HMML) is a key epoxide precursor in forming tracer compounds 2-methylglyceric acid (2-MG) or 2-methylglyceric acid sulfate (2-MGOS) from isoprene under high-NOx conditions. Despite its importance, the formation and transformation of HMML─particularly under acidic aerosol conditions─are still poorly understood, limiting comprehensive knowledge of secondary organic aerosol (SOA) formation. In this study, quantum chemical calculations, Born-Oppenheimer molecular dynamics (BOMD), and metadynamics (MTD) simulations are employed to investigate both the formation of HMML from methacryloyl peroxynitrate (MPAN) and its interfacial transformation mechanisms on sulfuric acid aerosols.

View Article and Find Full Text PDF