Stable sulfur isotope fractionation and discrimination between the sulfur atoms of thiosulfate during oxidation by Halothiobacillus neapolitanus.
FEMS Microbiol Lett
; 282(2): 299-306, 2008 May.
Article
em En
| MEDLINE
| ID: mdl-18373645
ABSTRACT
Growing cultures and nongrowing suspensions of Halothiobacillus neapolitanus selectively fractionated (32)S and (34)S during the oxidation of the sulfane- and sulfonate-sulfur atoms of thiosulfate. Sulfate was enriched in (32)S, with delta(34)S reaching -6.3 per thousand relative to the precursor sulfonate-sulfur of thiosulfate, which was progressively resynthesized from the thiosulfate-sulfane-sulfur during thiosulfate metabolism. Polythionates, principally trithionate, accumulated during thiosulfate oxidation and showed progressive increase in the relative (34)S content of their sulfonate groups, with delta(34)S values up to +20 per thousand, relative to the substrate sulfur. The origins of the sulfur in the sulfate and polythionate products of oxidation were tracked by the use thiosulfate labelled with (35)S in each of its sulfur atoms, enabling determination of the flow of the sulfur atoms into the oxidation products. The results confirm that highly significant fractionation of stable sulfur isotopes can be catalyzed by thiobacilli oxidizing thiosulfate, but that differences in the (34)S/(32)S ratios of the nonequivalent constituent sulfur atoms of the thiosulfate used as substrate mean that the oxidative fate of each atom needs separate determination. The data are very significant to the understanding of bacterial sulfur-compound oxidation and highly relevant to the origins of biogenic sulfate minerals.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Enxofre
/
Isótopos de Enxofre
/
Tiossulfatos
/
Halothiobacillus
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
FEMS Microbiol Lett
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Reino Unido