title: Natural communities of novel archaea and bacteria growing in cold sulfurous springs with a string-of-pearls-like morphology.
abstract: We report the identification of novel archaea living in close association with bacteria in the cold (approximately 10 degrees C) sulfurous marsh water of the Sippenauer Moor near Regensburg, Bavaria, Germany. These microorganisms form a characteristic, macroscopically visible structure, morphologically comparable to a string of pearls. Tiny, whitish globules (the pearls; diameter, about 0.5 to 3.0 mm) are connected to each other by thin, white-colored threads. Fluorescent in situ hybridization (FISH) studies have revealed that the outer part of the pearls is mainly composed of bacteria, with a filamentous bacterium predominating. Internally, archaeal cocci are the predominant microorganisms, with up to 10(7) cells estimated to be present in a single pearl. The archaea appear to be embedded in a polymer of unknown chemical composition. According to FISH and 16S rRNA gene sequence analysis, the archaea are affiliated with the euryarchaeal kingdom. The new euryarchaeal sequence represents a deep phylogenetic branch within the 16S rRNA tree and does not show extensive similarity to any cultivated archaea or to 16S rRNA gene sequences from environmental samples.
authors.affiliation: Lehrstuhl für Mikrobiologie und Archaeenzentrum, Universität Regensburg, Universitätsstr. 32, D-93053 Regensburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Rudolph
authors.forename: G
authors.initials: G
authors.lastname: Wanner
authors.forename: R
authors.initials: R
authors.lastname: Huber
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D003080:Cold Temperature; D004275:DNA, Ribosomal / Q000032:analysis / Q000235:genetics; D017753:Ecosystem; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D020459:Genes, rRNA; D017404:In Situ Hybridization, Fluorescence; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013455:Sulfur / Q000737:chemistry
chemical_list: D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D013455:Sulfur