Thiol compounds induction kinetics in marine phytoplankton during and after mercury exposure

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

19 Scopus Citations
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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)271-278
Journal / PublicationJournal of Hazardous Materials
Volume217-218
Online published20 Mar 2012
Publication statusPublished - 30 May 2012
Externally publishedYes

Abstract

We investigated the kinetics of Hg(II) and MeHg accumulation and the synthesis of phytochelatins (PCs), cysteine (Cys), glutathione (GSH), and γ-glutamylcysteine (γ-EC) in a marine diatom Thalassiosira weissflogii during a 3-h (short-term) and a 96-h (long-term) exposure period, and during a subsequent 96-h recovery period. MeHg induced the synthesis of a significant level of GSH, but it was Hg(II) that gave rise to significant levels of other non-protein thiol compounds. The thiol compounds Cys, γ-EC, and PC2-3 were induced in T. weissflogii within the first 30min of exposure, followed by PC4, but the concentrations of all six compounds returned to the control levels after the 96-h recovery period. The kinetics of these non-protein thiol compounds pointed to a rapid cellular response to environmental mercury pollution. After a first decrease, the molar ratio of PC-SH (sulfhydryl in PCs) to intracellular Hg increased slightly which demonstrated the role of PCs in Hg(II) detoxification. However, PC-SH was bound with Hg(II) at a stoichiometric ratio of 0.1-0.3, indicating the involvement of other detoxification mechanisms. Elucidating the effects of mercury on intracellular non-protein thiol pools may help us better understand the metal detoxification in phytoplankton. © 2012 Elsevier B.V.

Research Area(s)

  • Inorganic mercury, Kinetics, Marine phytoplankton, Methylmercury, Phytochelatin