排序方式: 共有5条查询结果,搜索用时 15 毫秒
1
1.
Martin Blumenberg Richard Seifert Bernd Buschmann Steffen Kiel Volker Thiel 《Geomicrobiology journal》2013,30(1):66-75
The steep biogeochemical gradients near deep sea hydrothermal vents provide various niches for microbial life. Here we present biosignatures of such organisms enclosed in a modern and an ancient hydrothermal sulfide deposit (Turtle Pits, Mid-Atlantic Ridge, Recent; Yaman Kasy, Russia, Silurian). In the modern sulfide we found high amounts of specific bacterial and archaeal biomarkers with δ13C values between ?8 and ?37‰ VPDB. Our data indicate the presence of thermophilic members of the autotrophic Aquificales using the reductive tricarboxylic acid (rTCA) cycle as well as of methanogenic and chemolithoheterotrophic Archaea. In the ancient sample, most potential biomarkers of thermophiles were obscured by compounds derived from allochthonous organic matter (OM), except for an acyclic C40 biphytane and its C39 breakdown product. Both samples contained high amounts of unresolved complex mixtures (UCM) of hydrocarbons. Apparently, OM in the sulfides had to withstand high thermal stress, indicated by highly mature hopanes, steranes, and cheilanthanes with up to 41 carbon atoms. 相似文献
2.
Phylogenetic characterization of the blue filamentous bacterial community from an Icelandic geothermal spring 总被引:3,自引:0,他引:3
Takacs CD Ehringer M Favre R Cermola M Eggertsson G Palsdottir A Reysenbach A 《FEMS microbiology ecology》2001,35(2):123-128
Molecular phylogenetic analysis of a blue filamentous community from an alkaline thermal spring (79-83 degrees C) in Iceland revealed that the blue filaments were affiliated with the Aquificales. The dominant sequence type, pIce1, was most closely related to a sequence (SRI-48) found in a white filamentous community from a separate Icelandic thermal spring and the pink filaments (EM17) from Yellowstone National Park. Fluorescent in situ hybridization with clone-specific oligonucleotide probes showed that the sample analyzed was essentially a monoculture of a single phylotype. 相似文献
3.
Purcell D Sompong U Yim LC Barraclough TG Peerapornpisal Y Pointing SB 《FEMS microbiology ecology》2007,60(3):456-466
Hyperthermophilic community diversity was assessed in hot-spring streamers along gradients of temperature, pH and sulphide in northern Thailand. A hierarchical sampling design was employed to obtain biomass for culture-independent estimates of 16S rRNA gene-defined prokaryotic diversity. All springs supported several archaeal and bacterial phylotypes, including novel phylotypes that expand the known phylogenetic diversity of terrestrial hyperthermophiles. Diversity appeared significantly greater than that observed for several other geographic locations. Phylotypes belonging to the Aquificales were ubiquitous, further supporting the hypothesis that these chemolithoautotrophs are key members of all hyperthermophilic communities. The chemoorganotrophic genus Thermus was also represented by phylotypes in all springs. Other bacterial taxa represented by environmental sequences included Bacillus, Thermotoga and various unidentified Alphaproteobacteria and Betaproteobacteria. Archaeal phylotypes included the Crenarchaea Desulfurococcus, Pyrobaculum, plus several unidentified hyperthermophilic lineages. A Methanothermococcus-like Euryarchaeon was also identified, with this genus not previously known from streamer communities. A multivariate approach to the analysis of biotic and abiotic data revealed that diversity patterns were best explained by a combination of temperature and sulphide rather than by any other abiotic variable either individually or in combination. 相似文献
4.
5.
Reysenbach AL Ehringer M Hershberger K 《Extremophiles : life under extreme conditions》2000,4(1):61-67
The use of molecular phylogenetic approaches in microbial ecology has revolutionized our view of microbial diversity at high
temperatures and led to the proposal of a new kingdom within the Archaea, namely, the "Korarchaeota." We report here the occurrence
of another member of this archaeal group and a deeply rooted bacterial sequence from a thermal spring in Yellowstone National
Park (USA). The DNA of a mixed community growing at 83°C, pH 7.6, was extracted and the small subunit ribosomal RNA gene (16S
rDNA) sequences were obtained using the polymerase chain reaction. The products were cloned and five different phylogenetic
types ("phylotypes") were identified: four archaeal phylotypes, designated pBA1, pBA2, pBA3, and pBA5, and only one bacterial
phylotype, designated pBB. pBA5 is very closely related to the korarchaeotal phylotype, pJP27, from Obsidian Pool in Yellowstone
National Park. The pBB phylotype is a lineage within the Aquificales and, based on 16S rRNA sequence, is different enough from the members of the Aquificales to constitute a different genus. In situ hybridization with bacterial-specific and Aquificales-specific fluorescent oligonucleotide probes indicated the bacterial population dominated the community and most likely contributed
significantly to biogeochemical cycling within the community.
Received: August 29, 1999 / Accepted: November 16, 1999 相似文献
1