Statistical Evaluation of Bacterial 16S rRNA Gene Sequences in Relation to Travertine Mineral Precipitation and Water Chemistry at Mammoth Hot Springs, Yellowstone National Park, USA

Author(s):  
Héctor García Martín ◽  
John Veysey ◽  
George T. Bonheyo ◽  
Nigel Goldenfeld ◽  
Bruce W. Fouke
2018 ◽  
Author(s):  
Karen G. Lloyd ◽  
Joshua Ladau ◽  
Andrew D. Steen ◽  
Junqi Yin ◽  
Lonnie Crosby

AbstractTo unequivocally determine a microbe’s physiology, including its metabolism, environmental roles, and growth characteristics, it must be grown in a laboratory culture. Unfortunately, many phylogenetically-novel groups have never been cultured, so their physiologies have only been inferred from genomics and environmental characteristics. Although the diversity, or number of different taxonomic groups, of uncultured clades has been well-studied, their global abundances, or number of cells in any given environment, have not been assessed. We quantified the degree of similarity of 16S rRNA gene sequences from diverse environments in publicly-available metagenome and metatranscriptome databases, which we show are largely free of the culture-bias present in primer-amplified 16S rRNA gene surveys, to their nearest cultured relatives. Whether normalized to scaffold read depths or not, the highest abundance of metagenomic 16S rRNA gene sequences belong to phylogenetically novel uncultured groups in seawater, freshwater, terrestrial subsurface, soil, hypersaline environments, marine sediment, hot springs, hydrothermal vents, non-human hosts, snow and bioreactors (22-87% uncultured genera to classes and 0-64% uncultured phyla). The exceptions were human and human-associated environments which were dominated by cultured genera (45-97%). We estimate that uncultured genera and phyla could comprise 7.3 × 1029(81%) and 2.2 × 1029(25%) microbial cells, respectively. Uncultured phyla were over-represented in meta transcript omes relative to metagenomes (46-84% of sequences in a given environment), suggesting that they are viable, and possibly more active than cultured clades. Therefore, uncultured microbes, often from deeply phylogenetically divergent groups, dominate non-human environments on Earth, and their undiscovered physiologies may matter for Earth systems.


2007 ◽  
Vol 74 (4) ◽  
pp. 942-949 ◽  
Author(s):  
M. Kozubal ◽  
R. E. Macur ◽  
S. Korf ◽  
W. P. Taylor ◽  
G. G. Ackerman ◽  
...  

ABSTRACT Novel thermophilic crenarchaea have been observed in Fe(III) oxide microbial mats of Yellowstone National Park (YNP); however, no definitive work has identified specific microorganisms responsible for the oxidation of Fe(II). The objectives of the current study were to isolate and characterize an Fe(II)-oxidizing member of the Sulfolobales observed in previous 16S rRNA gene surveys and to determine the abundance and distribution of close relatives of this organism in acidic geothermal springs containing high concentrations of dissolved Fe(II). Here we report the isolation and characterization of the novel, Fe(II)-oxidizing, thermophilic, acidophilic organism Metallosphaera sp. strain MK1 obtained from a well-characterized acid-sulfate-chloride geothermal spring in Norris Geyser Basin, YNP. Full-length 16S rRNA gene sequence analysis revealed that strain MK1 exhibits only 94.9 to 96.1% sequence similarity to other known Metallosphaera spp. and less than 89.1% similarity to known Sulfolobus spp. Strain MK1 is a facultative chemolithoautotroph with an optimum pH range of 2.0 to 3.0 and an optimum temperature range of 65 to 75°C. Strain MK1 grows optimally on pyrite or Fe(II) sorbed onto ferrihydrite, exhibiting doubling times between 10 and 11 h under aerobic conditions (65°C). The distribution and relative abundance of MK1-like 16S rRNA gene sequences in 14 acidic geothermal springs containing Fe(III) oxide microbial mats were evaluated. Highly related MK1-like 16S rRNA gene sequences (>99% sequence similarity) were consistently observed in Fe(III) oxide mats at temperatures ranging from 55 to 80°C. Quantitative PCR using Metallosphaera-specific primers confirmed that organisms highly similar to strain MK1 comprised up to 40% of the total archaeal community at selected sites. The broad distribution of highly related MK1-like 16S rRNA gene sequences in acidic Fe(III) oxide microbial mats is consistent with the observed characteristics and growth optima of Metallosphaera-like strain MK1 and emphasizes the importance of this newly described taxon in Fe(II) chemolithotrophy in acidic high-temperature environments of YNP.


mSystems ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Karen G. Lloyd ◽  
Andrew D. Steen ◽  
Joshua Ladau ◽  
Junqi Yin ◽  
Lonnie Crosby

ABSTRACTTo describe a microbe’s physiology, including its metabolism, environmental roles, and growth characteristics, it must be grown in a laboratory culture. Unfortunately, many phylogenetically novel groups have never been cultured, so their physiologies have only been inferred from genomics and environmental characteristics. Although the diversity, or number of different taxonomic groups, of uncultured clades has been studied well, their global abundances, or numbers of cells in any given environment, have not been assessed. We quantified the degree of similarity of 16S rRNA gene sequences from diverse environments in publicly available metagenome and metatranscriptome databases, which we show have far less of the culture bias present in primer-amplified 16S rRNA gene surveys, to those of their nearest cultured relatives. Whether normalized to scaffold read depths or not, the highest abundances of metagenomic 16S rRNA gene sequences belong to phylogenetically novel uncultured groups in seawater, freshwater, terrestrial subsurface, soil, hypersaline environments, marine sediment, hot springs, hydrothermal vents, nonhuman hosts, snow, and bioreactors (22% to 87% uncultured genera to classes and 0% to 64% uncultured phyla). The exceptions were human and human-associated environments, which were dominated by cultured genera (45% to 97%). We estimate that uncultured genera and phyla could comprise 7.3 × 1029(81%) and 2.2 × 1029(25%) of microbial cells, respectively. Uncultured phyla were overrepresented in metatranscriptomes relative to metagenomes (46% to 84% of sequences in a given environment), suggesting that they are viable. Therefore, uncultured microbes, often from deeply phylogenetically divergent groups, dominate nonhuman environments on Earth, and their undiscovered physiologies may matter for Earth systems.IMPORTANCEIn the past few decades, it has become apparent that most of the microbial diversity on Earth has never been characterized in laboratory cultures. We show that these unknown microbes, sometimes called “microbial dark matter,” are numerically dominant in all major environments on Earth, with the exception of the human body, where most of the microbes have been cultured. We also estimate that about one-quarter of the population of microbial cells on Earth belong to phyla with no cultured relatives, suggesting that these never-before-studied organisms may be important for ecosystem functions.


Geoderma ◽  
2012 ◽  
Vol 181-182 ◽  
pp. 45-55 ◽  
Author(s):  
C.W. Chong ◽  
D.A. Pearce ◽  
P. Convey ◽  
W.C. Yew ◽  
I.K.P. Tan

Anaerobe ◽  
2010 ◽  
Vol 16 (4) ◽  
pp. 426-432 ◽  
Author(s):  
Cai-Xia Pei ◽  
Qiang Liu ◽  
Chang-Sheng Dong ◽  
HongQuan Li ◽  
Jun-Bing Jiang ◽  
...  

2014 ◽  
Vol 64 (Pt_2) ◽  
pp. 650-656 ◽  
Author(s):  
Hong Ming ◽  
Yi-Rui Yin ◽  
Shuai Li ◽  
Guo-Xing Nie ◽  
Tian-Tian Yu ◽  
...  

Two thermophilic bacterial strains, designated YIM 77925T and YIM 77777, were isolated from two hot springs, one in the Hydrothermal Explosion (Shuirebaozhaqu) area and Frog Mouth Spring in Tengchong county, Yunnan province, south-western China. The taxonomic positions of the two isolates were investigated by a polyphasic approach. Cells of the two strains were Gram-stain-negative, aerobic and rod-shaped. They were able to grow at 50–70 °C, pH 6.0–8.0 and with a NaCl tolerance up to 0.5 % (w/v). Colonies are circular, convex, non-transparent and produce yellow pigment. Phylogenetic analyses based on 16S rRNA gene sequences comparison clearly demonstrated that strains YIM 77925T and YIM 77777 represent members of the genus Thermus , and they also detected low-level similarities of 16S rRNA gene sequences (below 97 %) compared with all other species in this genus. Their predominant menaquinone was MK-8. The genomic DNA G+C contents of strains YIM 77925T and YIM 77777 were 65.6 mol% and 67.2 mol%, respectively. Based on the results of physiological and biochemical tests and phylogenetic analyses, strains YIM 77925T and YIM 77777 could not be classified as representing any species of the genus Thermus with a validly published name. Thus the two strains are considered to represent a novel species of the genus Thermus , for which the name Thermus caliditerrae sp. nov. is proposed. The type strain is YIM 77925T ( = DSM 25901T = CCTCC 2012061T).


2020 ◽  
Author(s):  
CC Kim ◽  
WJ Kelly ◽  
ML Patchett ◽  
GW Tannock ◽  
Z Jordens ◽  
...  

© 2017 IUMS. A novel anaerobic pectinolytic bacterium (strain 14T) was isolated from human faeces. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 14T belonged to the family Ruminococcaceae, but was located separately from known clostridial clusters within the taxon. The closest cultured relative of strain 14T was Acetivibrio cellulolyticus (89.7% sequence similarity). Strain 14T shared ~99% sequence similarity with cloned 16S rRNA gene sequences from uncultured bacteria derived from the human gut. Cells were Gram-stain-positive, non-motile cocci approximately 0.6μm in diameter. Strain 14T fermented pectins from citrus peel, apple, and kiwifruit as well as carbohydrates that are constituents of pectins and hemicellulose, such as galacturonic acid, xylose, and arabinose. TEM images of strain 14T, cultured in association with plant tissues, suggested extracellular fibrolytic activity associated with the bacterial cells, forming zones of degradation in the pectin-rich regions of middle lamella. Phylogenetic and phenotypic analysis supported the differentiation of strain 14T as a novel genus in the family Ruminococcaceae. The name Monoglobus pectinilyticus gen. nov., sp. nov. is proposed; the type strain is 14T (JCM 31914T=DSM 104782T).


2007 ◽  
Vol 73 (20) ◽  
pp. 6682-6685 ◽  
Author(s):  
Daniel P. R. Herlemann ◽  
Oliver Geissinger ◽  
Andreas Brune

ABSTRACT The bacterial candidate phylum Termite Group I (TG-1) presently consists mostly of “Endomicrobia,” which are endosymbionts of flagellate protists occurring exclusively in the hindguts of termites and wood-feeding cockroaches. Here, we show that public databases contain many, mostly undocumented 16S rRNA gene sequences from other habitats that are affiliated with the TG-1 phylum but are only distantly related to “Endomicrobia.” Phylogenetic analysis of the expanded data set revealed several diverse and deeply branching lineages comprising clones from many different habitats. In addition, we designed specific primers to explore the diversity and environmental distribution of bacteria in the TG-1 phylum.


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