Sulfide utilization by purple nonsulfur bacteria

✍ Scribed by Hansen, Theo A. ;Gemerden, Hans

• Publisher: Springer-Verlag
• Year: 1972
• Weight: 510 KB
• Volume: 86
• Category: Article
• ISSN: 0003-9276
• DOI: 10.1007/bf00412399

✦ Synopsis

The purple nonsulfur bacteria Rhodospirillum rubrum SMG 107, Rhodopseudomonas ca/psulata SMG 155, Rps. sphaeroides SMG 158 and RTs. palustris SMG 124 were tested for a possible utilization of sulfide. The first three strains were found to oxidize sulfide to extracellular elemental sulfur only, whereas Rps. palustris SMG 124 converted sulfide into sulfate without intermediate accumulation of elemental sulfur. Growth ceased at lower sulfide concentrations than usually found with purple sulfur bacteria. In consequence of the low sulfide tolerance information on the specific growth rates obtainable with sulfide as photosynthetic electron donor could not be provided by cultivation in batch cultures. Sulfide-limited chemostat cultures of Rps. capsulata SMG 155 showed that the maximum specific growth rate was close to 0.14 h -1 (doubling time 5 h). Sulfide was converted into extracellular elemental sulfur at all dilution rates tested. The maximum specific growth rate of/~2~s, palustris SMG 124 was found to be much lower (less than