A method to increase silver biosorption by an industrial strain of Saccharomyces cerevisiae.
Appl Microbiol Biotechnol
; 45(1-2): 278-85, 1996 Mar.
Article
em En
| MEDLINE
| ID: mdl-8920202
ABSTRACT
Ag+ biosorption by an industrial strain of Saccharomyces cerevisiae was investigated. Older (96 h old) biomass had half the biosorption capacity of younger (24 h old) biomass (0.187 and 0.387 mmol Ag+/g dry mass respectively). Comparisons of cell walls isolated from biomass of either age indicated that chemical composition and Ag+ biosorption capacity varied little over the time span examined and that cell walls from either age of culture had small Ag+ biosorption capacities compared to whole cells of a similar age. Silver-containing precipitates were observed both on the cell wall and within the cell, indicating that intracellular components sorbed Ag+. The concentration of these precipitates within the cell appeared visually to decrease with age in Ag(+)-exposed cells. Incorporation of L-cysteine into the growth medium resulted in biomass with increased silver biosorption capacities, protein and sulphydryl group content. Increasing the concentration of L-cysteine in the growth medium from 0 to 5.0 mM increased silver biosorption from 0.389 to 0.556 mmol Ag+/g dry mass. Isolated cell walls of biomass grown in supplemented media also showed a possible link between silver biosorption capacities, protein and sulphydryl group content. No precipitates were observed in silver-exposed biomass that had been grown in the presence of 5.0 mM L-cysteine.
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Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
/
Prata
Idioma:
En
Revista:
Appl Microbiol Biotechnol
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Irlanda