Official websites use. Share sensitive information only on official, secure websites. Corresponding author. Phone: 49 Fax: 49 E-mail: robert.
It forms characteristic, macroscopically visible globules, the pearls, containing microcolonies of novel euryarchaeota, which are surrounded by mainly filamentous bacteria C.
Rudolph, G. Wanner, and R. Huber, Appl. Single pearls in series are connected by white threads. Here we report the first detailed molecular investigations of the taxonomic affiliation of the bacteria contributing to the strings of pearls. Phylogenetic analysis showed the dominance of a single phylotype clone sipK4 within single pearls most closely related to Thiothrix unzii.
The presence of Thiothrix sipK4 as a major constituent of single pearls and of the pearl-connecting white threads was verified by fluorescence in situ hybridization.
Microbial communities growing as biofilms 7 , 13 , 25 , 33 , 37 , microbial mats 22 , 32 , 35 , and consortia 1 , 26 are a widespread phenomenon in nature. Such microbial associations are mostly found in natural aquatic systems, in artificial medical environments, and as epi- or endoliths 6 , Living in a community provides many advantages for the constituent microorganisms: environmental changes are buffered, nutrient uptake is easier, and horizontal gene transfer is possible 9 , 23 , Sulfide-oxidizing, filamentous bacteria like Beggiatoa , Thioploca , and Thiomargarita species frequently form an integral part of microbial mats 11 , 20 , 29 ; Thiothrix is often associated with activated sludge bulking 10 , 34 , but is also found in mats in natural aquatic environments In the last few years, molecular methods have been developed that allow the study of complex microbial associations without cultivation.
