ISSN:
1432-072X
Keywords:
Chromatium vinosum
;
Sulfide limitation
;
Elemental sulfur
;
Continuous culture
;
Cell volume
;
Cell density
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Average cell volume and cell buoyant density of Chromatium vinosum DSM 185 growing in sulfide limited continuous cultures, were found to increase with increasing dilution rate. It was found that the increase in buoyant density was mainly a consequence of the accumulation of elemental sulfur. The contribution of other compounds such as protein, bacteriochlorophyll a and glycogen, was almost negligible. It was concluded that the sulfur globule is constituted by at least two fractions, sulfur and an unidentified moiety with a density lower than that of sulfur, probably water. A model was developed to explain the relation between the specific content of sulfur and cell buoyant density. The model also predicts the impact of elemental sulfur on the volume of the cell. It was found that in addition to the accumulation of sulfur the average cell volume also changes with the specific growth rate. In shift-up experiments (sulfur accumulation) the actual phenomena agreed with those predicted by the model, however, this was not so during shift-down (sulfur depletion). It is suggested that this difference is due to the fact that during the shift-down, elemental sulfur and the unidentified moiety are being depleted at different rates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00410937
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