Cell Size versus Taxonomic Composition as Determinants of As (III & V) Sensitivity in the Estuarine Diatom Communities

 

Journal of Water Resource and Protection, 2011, 3, 363-369 doi:10.4236/jwarp.2011.36046 Published Online June 2011 (http://www.scirp.org/journal/jwarp) Copyright © 2011 SciRes. JWARP

 Cell Size versus Taxonomic Composition as Determinants of As (III & V) Sensitivity in the Estuarine Diatom Communities

Chumki Chowdhury, Natasha Majumder, Sanjay Kumar Mandal, Manab Kumar Dutta, Raghab Ray, Tapan Kumar Jana*

Department of Marine Science, Calcutta University, Kolkata, India

E-mail: tkjana@hotmail.com

Received March 15, 2011; revised April 17, 2011; accepted May 20, 2011

Abstract

Despite scarce studies have analyzed the relative growth inhibition of As (III) and As (V) to diatom, clear pattern of interspecies difference have been shown, identifying cell size as a key property determining the sensitivity of diatom to As. Evidence from cultures suggests that cell size is a key factor in determining the extent of arsenic (III) & (V) stress of diatom, with relatively lesser effects of As (V) than As (III) on small cells. Cent percent growth inhibition was observed for large size group (Coscinodiscus radiatus, Surirella., Amphipleura, Thalassiothrix, Cyclotella and Thalassiosira decipiens) relative to smaller size group (Skele-tonema cf. costatum, Navicula rhombica, Amphora hyalina Nitzschia longissima except Thalassisira. Inter-species differences in As tolerance by diatom in the mangrove ecosystem indicates cell size could be only one factor contributing to these differences. The results show that 81.7% of total arsenic was uptaken from culture media originally amended with arsenic. Looking to the extreme tolerance and arsenic removal effi-ciency, application of the species with smaller cell size relative to the other tested diatom for bioremediation purpose can be envisaged.

Keywords: Diatoms, Cell Size, Arsenic (III&V), Mangrove