Utilization of reducing power in growing cultures of Chromatium

✍ Scribed by Gemerden, H.

• Book ID: 104760902
• Publisher: Springer-Verlag
• Year: 1968
• Weight: 326 KB
• Volume: 64
• Category: Article
• ISSN: 0003-9276
• DOI: 10.1007/bf00406969

✦ Synopsis

The overall composition of cell material in the stationary growth phase of cultures of Chromatium strain 6d12 cultivated with sulfide as electron donor is approximately (CsHsO~N). At the moment that sulfide became depleted, 42~ had been oxidized to sulfur and 58~ to sulfate. Thus at this time 69~ of the reducing power initially present had been utilized. However, the amount of structural cell material produced was only 56~ of the amount present in the stationary phase of growth. This discrepancy appeared to be due to the accumulation of storage carbohydrate. Storage carbohydrate was synthesized as long as sulfide was available and consumed after sulfide depletion. Increase in structural cell material after sulfide depletion could not be accounted for by CO 2 fixation only, which indicates that storage carbohydrate can be converted into structural cell material. When stationary-phase cultures were again supplied with sulfide, growth was not observable in the first few hours, even though sulfide was oxidized, mainly to sulfur. Under these conditions reducing power was utilized for the synthesis of storage carbohydrate from CO 2.