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Bacterial extracellular polymeric substances (EPS): A carrier of heavy metals in the marine food-chain

IR@NIO: CSIR-National Institute Of Oceanography, Goa

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Field Value
 
Creator Bhaskar, P.V.
Bhosle, N.B.
 
Date 2006-05-16T08:46:31Z
2006-05-16T08:46:31Z
2006
 
Identifier Environment International, vol. 32(2); 191-198
http://drs.nio.org/drs/handle/2264/103
 
Description The ecological implications of metal binding properties of bacterial EPS and its possible role in the bioaccumulation of pollutants in the marine food-chain was investigated using a partially purified and chemically characterized microbial EPS isolated from a species of Marinobacter. Various factors influencing metal sorption by the EPS including the influence of initial metal concentrations, incubation time, pH and sodium chloride concentrations on binding of lead (Pb++) and copper (Cu++) were evaluated. The bacterial EPS selectively bound more amount of Cu2+ per mg of EPS than Pb2+. Both copper and lead were sorbed more at near neutral pH than acidic pH. The sorption of Cu2+ increased with increasing copper concentration. The estimated maximum binding ability (MBA) of the EPS was 182 nmol copper and 13 nmol lead mg-1 EPS. However, the sorption of these metals decreased with the increase in sodium chloride concentration. Furthermore, up to 35% of 14C-labeled Marinobacter was ingested by a benthic polychaete Hediste diversicolor. On an average, 29% of the ingested EPS was absorbed into tissues and 49% of the EPS was respired. It was apparent that the animals used the EPS as a source of energy and nutrition. The labile nature of the bacterial EPS and its ability to bind heavy metals might route the bound metals through the marine food chain, thereby transferring and aiding bioaccumulation of metal pollutants in the higher trophic animals.
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Format 1373184 bytes
application/msword
 
Language en
 
Publisher Elsevier
 
Subject Extracellular polymeric substances
EPS
metal binding
lead
copper
polychaete
 
Title Bacterial extracellular polymeric substances (EPS): A carrier of heavy metals in the marine food-chain
 
Type Article