Open AccessIsotope effects associated with the anaerobic oxidation of sulfite and thiosulfate by the photosynthetic bacterium, Chromatium vinosum
Author(s) -
Fry Brian,
Gest Howard,
Hayes J.M.
Publication year - 1985
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1985.tb00672.x
Subject(s) - thiosulfate , sulfite , sulfur , chromatium , chemistry , sulfate , sulfur metabolism , sulfide , tetrathionate , inorganic chemistry , sulfur cycle , sulfate reducing bacteria , organic chemistry
The purple photosynthetic bacterium Chromatium vinosum , strain D, catalyzes several oxidations of reduced sulfur compounds under anaerobic conditions in the light: e.g., sulfide → sulfur → sulfate, sulfite → sulfate, and thiosulfate → sulfur + sulfate. Here it is shown that no sulfur isotope effect is associated with the last of these processes; isotopic compositions of the sulfur and sulfate produced can differ, however, if the sulfane and sulfonate positions within the thiosulfate have different isotopic compositions. In the second process, an observed change from an inverse to a normal isotope effect during oxidation of sulfite may indicate the operation of 2 enzymatic pathways. In contrast to heterotrophic anaerobic reduction of oxidized sulfur compounds, anaerobic oxidations of inorganic sulfur compounds by photosynthetic bacteria are characterized by relatively small isotope effects.