title: High bacterial diversity in permanently cold marine sediments.
abstract: A 16S ribosomal DNA (rDNA) clone library from permanently cold marine sediments was established. Screening 353 clones by dot blot hybridization with group-specific oligonucleotide probes suggested a predominance of sequences related to bacteria of the sulfur cycle (43.4% potential sulfate reducers). Within this fraction, the major cluster (19.0%) was affiliated with Desulfotalea sp. and other closely related psychrophilic sulfate reducers isolated from the same habitat. The cloned sequences showed between 93 and 100% similarity to these bacteria. Two additional groups were frequently encountered: 13% of the clones were related to Desulfuromonas palmitatis, and a second group was affiliated with Myxobacteria spp. and Bdellovibrio spp. Many clones (18.1%) belonged to the gamma subclass of the class Proteobacteria and were closest to symbiotic or free-living sulfur oxidizers. Probe target groups were further characterized by amplified rDNA restriction analysis to determine diversity within the groups and within the clone library. Rarefaction analysis suggested that the total diversity assessed by 16S rDNA analysis was very high in these permanently cold sediments and was only partially revealed by screening of 353 clones.
authors.affiliation: Molecular Ecology Group, Max-Planck-Institute for Marine Microbiology, D-28359 Bremen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Ravenschlag
authors.forename: K
authors.initials: K
authors.lastname: Sahm
authors.forename: J
authors.initials: J
authors.lastname: Pernthaler
authors.forename: R
authors.initials: R
authors.lastname: Amann
mesh_terms: D001110:Arctic Regions; D001419:Bacteria / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D003080:Cold Temperature; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D015723:Gene Library; D019015:Geologic Sediments; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D015183:Restriction Mapping; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D016999:Sulfur-Reducing Bacteria / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S