Nitrate-storing sulfur bacteria in sediments of coastal upwelling.

In three eutrophic coastal environments, the Chilean coast, the Namibian coast, and the Danish Limfjorden the abundance of nitrate-storing sulfur bacteria was investigated. During a 14 months period the marine Thioploca community off the Bay of Concepcion (Chile) was studied with respect to changes in the population induced by seasonal variations in the upwelling intensity. A survey for filamentous sulfur bacteria along the coast of Namibia resulted in the discovery of an unknown giant sulfur bacterium which was named Thiomargarita namibiensis. In conclusion it was found that nitrate-storing sulfur bacteria are more abundant than previously assumed. Within this group of bacteria there were undescribed, morphologically distinct types that passed the attention in earlier studies.