scholarly journals Dissecting the dominant hot spring microbial populations based on community-wide sampling at single-cell genomic resolution

2021 ◽  
Author(s):  
Robert M. Bowers ◽  
Stephen Nayfach ◽  
Frederik Schulz ◽  
Sean P. Jungbluth ◽  
Ilona A. Ruhl ◽  
...  
Keyword(s):  
Population Structure ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Single Cell ◽  
Community Composition ◽  
Hot Spring ◽  
Population Heterogeneity ◽  
Rrna Gene ◽  
Community Members ◽  
Shotgun Metagenomics

AbstractWith advances in DNA sequencing and miniaturized molecular biology workflows, rapid and affordable sequencing of single-cell genomes has become a reality. Compared to 16S rRNA gene surveys and shotgun metagenomics, large-scale application of single-cell genomics to whole microbial communities provides an integrated snapshot of community composition and function, directly links mobile elements to their hosts, and enables analysis of population heterogeneity of the dominant community members. To that end, we sequenced nearly 500 single-cell genomes from a low diversity hot spring sediment sample from Dewar Creek, British Columbia, and compared this approach to 16S rRNA gene amplicon and shotgun metagenomics applied to the same sample. We found that the broad taxonomic profiles were similar across the three sequencing approaches, though several lineages were missing from the 16S rRNA gene amplicon dataset, likely the result of primer mismatches. At the functional level, we detected a large array of mobile genetic elements present in the single-cell genomes but absent from the corresponding same species metagenome-assembled genomes. Moreover, we performed a single-cell population genomic analysis of the three most abundant community members, revealing differences in population structure based on mutation and recombination profiles. While the average pairwise nucleotide identities were similar across the dominant species-level lineages, we observed differences in the extent of recombination between these dominant populations. Most intriguingly, the creek’s Hydrogenobacter sp. population appeared to be so recombinogenic that it more closely resembled a sexual species than a clonally evolving microbe. Together, this work demonstrates that a randomized single-cell approach can be useful for the exploration of previously uncultivated microbes from community composition to population structure.

scholarly journals Crenobacter luteus gen. nov., sp. nov., isolated from a hot spring

2015 ◽  
Vol 65 (Pt_1) ◽  
pp. 214-219 ◽  
Author(s):  
Lei Dong ◽  
Hong Ming ◽  
En-Min Zhou ◽  
Yi-Rui Yin ◽  
Lan Liu ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
Hot Spring ◽  
Polar Lipids ◽  
16S Rrna Gene Sequence ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Content Type ◽  
The Family

A slightly thermophilic, Gram-staining-negative and strictly aerobic bacteria, designated strain YIM 78141T, was isolated from a sediment sample collected at Hehua hot spring, Tengchong, Yunnan province, south-west China. Cells of the strain were short-rod-shaped and colonies were yellowish and circular. The strain grew at pH 6.0–10.0 (optimum, pH 8.0–9.0) and 10–55 °C (optimum, 40–50 °C). Phylogenetic analyses based on 16S rRNA gene sequence comparison demonstrated that strain YIM 78141T belongs to the family Neisseriaceae , and strain YIM 78141T also showed low levels of 16S rRNA gene sequence similarity (below 93.4 %) with all other genera in this family. The only quinone was ubiquinone 8 and the genomic DNA G+C content was 67.3 mol%. Major fatty acids (>5 %) were C12 : 0, C16 : 0, C18 : 1ω7c and summed feature 3. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phospholipids of unknown structure containing aminoglycophospholipid and three unidentified polar lipids. On the basis of the morphological, physiological and biochemical characteristics as well as genotypic data, this strain should be classified as a representative of a novel genus and species of the family Neisseriaceae , for which the name Crenobacter luteus gen. nov., sp. nov. is proposed. The type strain is YIM 78141T ( = BCRC 80650T = KCTC 32558T = DSM 27258T).

scholarly journals GAL08, an Uncultivated Group of Acidobacteria, Is a Dominant Bacterial Clade in a Neutral Hot Spring

2022 ◽  
Vol 12 ◽  
Author(s):  
Ilona A. Ruhl ◽  
Andriy Sheremet ◽  
Chantel C. Furgason ◽  
Susanne Krause ◽  
Robert M. Bowers ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
Hot Spring ◽  
Gc Content ◽  
Gene Copy ◽  
Marker Genes ◽  
Rrna Gene ◽  
Separate Species ◽  
Distinct Subgroup

GAL08 are bacteria belonging to an uncultivated phylogenetic cluster within the phylum Acidobacteria. We detected a natural population of the GAL08 clade in sediment from a pH-neutral hot spring located in British Columbia, Canada. To shed light on the abundance and genomic potential of this clade, we collected and analyzed hot spring sediment samples over a temperature range of 24.2–79.8°C. Illumina sequencing of 16S rRNA gene amplicons and qPCR using a primer set developed specifically to detect the GAL08 16S rRNA gene revealed that absolute and relative abundances of GAL08 peaked at 65°C along three temperature gradients. Analysis of sediment collected over multiple years and locations revealed that the GAL08 group was consistently a dominant clade, comprising up to 29.2% of the microbial community based on relative read abundance and up to 4.7 × 105 16S rRNA gene copy numbers per gram of sediment based on qPCR. Using a medium quality threshold, 25 single amplified genomes (SAGs) representing these bacteria were generated from samples taken at 65 and 77°C, and seven metagenome-assembled genomes (MAGs) were reconstructed from samples collected at 45–77°C. Based on average nucleotide identity (ANI), these SAGs and MAGs represented three separate species, with an estimated average genome size of 3.17 Mb and GC content of 62.8%. Phylogenetic trees constructed from 16S rRNA gene sequences and a set of 56 concatenated phylogenetic marker genes both placed the three GAL08 bacteria as a distinct subgroup of the phylum Acidobacteria, representing a candidate order (Ca. Frugalibacteriales) within the class Blastocatellia. Metabolic reconstructions from genome data predicted a heterotrophic metabolism, with potential capability for aerobic respiration, as well as incomplete denitrification and fermentation. In laboratory cultivation efforts, GAL08 counts based on qPCR declined rapidly under atmospheric levels of oxygen but increased slightly at 1% (v/v) O2, suggesting a microaerophilic lifestyle.

scholarly journals Changes in the Active, Dead, and Dormant Microbial Community Structure across a Pleistocene Permafrost Chronosequence

2019 ◽  
Vol 85 (7) ◽  
Author(s):  
Alexander Burkert ◽  
Thomas A. Douglas ◽  
Mark P. Waldrop ◽  
Rachel Mackelprang
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Microbial Communities ◽  
Community Composition ◽  
Environmental Conditions ◽  
Microbial Community Composition ◽  
Rrna Gene ◽  
Subzero Temperatures ◽  
Dormant Cells

ABSTRACTPermafrost hosts a community of microorganisms that survive and reproduce for millennia despite extreme environmental conditions, such as water stress, subzero temperatures, high salinity, and low nutrient availability. Many studies focused on permafrost microbial community composition use DNA-based methods, such as metagenomics and 16S rRNA gene sequencing. However, these methods do not distinguish among active, dead, and dormant cells. This is of particular concern in ancient permafrost, where constant subzero temperatures preserve DNA from dead organisms and dormancy may be a common survival strategy. To circumvent this, we applied (i) LIVE/DEAD differential staining coupled with microscopy, (ii) endospore enrichment, and (iii) selective depletion of DNA from dead cells to permafrost microbial communities across a Pleistocene permafrost chronosequence (19,000, 27,000, and 33,000 years old). Cell counts and analysis of 16S rRNA gene amplicons from live, dead, and dormant cells revealed how communities differ between these pools, how they are influenced by soil physicochemical properties, and whether they change over geologic time. We found evidence that cells capable of forming endospores are not necessarily dormant and that members of the classBacilliwere more likely to form endospores in response to long-term stressors associated with permafrost environmental conditions than members of theClostridia, which were more likely to persist as vegetative cells in our older samples. We also found that removing exogenous “relic” DNA preserved within permafrost did not significantly alter microbial community composition. These results link the live, dead, and dormant microbial communities to physicochemical characteristics and provide insights into the survival of microbial communities in ancient permafrost.IMPORTANCEPermafrost soils store more than half of Earth’s soil carbon despite covering ∼15% of the land area (C. Tarnocai et al., Global Biogeochem Cycles 23:GB2023, 2009, https://doi.org/10.1029/2008GB003327). This permafrost carbon is rapidly degraded following a thaw (E. A. G. Schuur et al., Nature 520:171–179, 2015, https://doi.org/10.1038/nature14338). Understanding microbial communities in permafrost will contribute to the knowledge base necessary to understand the rates and forms of permafrost C and N cycling postthaw. Permafrost is also an analog for frozen extraterrestrial environments, and evidence of viable organisms in ancient permafrost is of interest to those searching for potential life on distant worlds. If we can identify strategies microbial communities utilize to survive in permafrost, it may yield insights into how life (if it exists) survives in frozen environments outside of Earth. Our work is significant because it contributes to an understanding of how microbial life adapts and survives in the extreme environmental conditions in permafrost terrains.

Dynamics of the bacterial community in a channel catfish nursery pond with a cage–pond integration system

2018 ◽  
Vol 64 (12) ◽  
pp. 954-967 ◽  
Author(s):  
Liqiang Zhong ◽  
Daming Li ◽  
Minghua Wang ◽  
Xiaohui Chen ◽  
Wenji Bian ◽  
...  
Keyword(s):  
Bacterial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Community Composition ◽  
Channel Catfish ◽  
Bacterial Community Composition ◽  
Rrna Gene ◽  
Integration System ◽  
Nursery Pond ◽  
Site Variation

The changes in the bacterial community composition in a channel catfish nursery pond with a cage–pond integration system were investigated by sequencing of the 16S rRNA gene through Illumina MiSeq sequencing platforms. A total of 1 362 877 sequences and 1440 operational taxonomic units were obtained. Further analysis showed that the dominant phyla in the cage and pond groups were similar, including Actinobacteria, Cyanobacteria, Proteobacteria, and Bacteroidetes, although a significant difference was detected between them by ANOSIM (P < 0.05). Temporal changes and site variation were significantly related to the variation of the bacterial community. A comprehensive analysis of the diversity and evenness of the bacterial 16S rRNA gene, redundancy analysis (RDA), and partial Mantel test showed that the bacterial community composition in a cage–pond integration system was shaped more by temporal variation than by site variation. RDA also indicated that water temperature, total dissolved solids, and Secchi depth had the largest impact on bacterial populations.

scholarly journals Highly Specific Sewage-DerivedBacteroidesQuantitative PCR Assays Target Sewage-Polluted Waters

2019 ◽  
Vol 85 (6) ◽  
Author(s):  
Shuchen Feng ◽  
Sandra L. McLellan
Keyword(s):  
Population Structure ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Water Samples ◽  
Rrna Gene ◽  
Content Type ◽  
Hypervariable Regions ◽  
Animal Hosts ◽  
Pcr Assays ◽  
The 16S Rrna Gene

ABSTRACTThe identification of sewage contamination in water has primarily relied on the detection of human-associatedBacteroidesusing markers within the V2 region of the 16S rRNA gene. Despite the establishment of multiple assays that target the HF183 cluster (i.e.,Bacteroides dorei) and otherBacteroidesorganisms (e.g.,Bacteroides thetaiotaomicron), the potential for more human-associated markers in this genus has not been explored in depth. We examined theBacteroidespopulation structure in sewage and animal hosts across the V4V5 and V6 hypervariable regions. Using near-full-length cloned sequences, we identified the sequences in the V4V5 and V6 hypervariable regions that are linked to the HF183 marker in the V2 region and found these sequences were present in multiple animals. In addition, the V4V5 and V6 regions contained human fecal marker sequences for organisms that were independent of the HF183 cluster. The most abundantBacteroidesin untreated sewage was not human associated but pipe derived. Two TaqMan quantitative PCR (qPCR) assays targeting the V4V5 and V6 regions of this organism were developed. Validation studies using fecal samples from seven animal hosts (n = 76) and uncontaminated water samples (n = 30) demonstrated the high specificity of the assays for sewage. FreshwaterBacteroideswere also identified in uncontaminated water samples, demonstrating that measures of totalBacteroidesdo not reflect fecal pollution. A comparison of two previously described humanBacteroidesassays (HB and HF183/BacR287) in municipal wastewater influent and sewage-contaminated urban water samples revealed identical results, illustrating the assays target the same organism. The detection of sewage-derivedBacteroidesprovided an independent measure of sewage-impacted waters.IMPORTANCEBacteroidesare major members of the gut microbiota, and host-specific organisms within this genus have been used extensively to gain information on pollution sources. This study provides a broad view of the population structure ofBacteroideswithin sewage to contextualize the well-studied HF183 marker for a human-associatedBacteroides. The study also delineates host-specific sequence patterns across multiple hypervariable regions of the 16S rRNA gene to improve our ability to use sequence data to assess water quality. Here, we demonstrate that regions downstream of the HF183 marker are nonspecific but other potential human-associated markers are present. Furthermore, we show the most abundantBacteroidesin sewage is free living, rather than host associated, and specifically found in sewage. Quantitative PCR assays that target organisms specific to sewer pipes offer measures that are independent of the human microbiome for identifying sewage pollution in water.

scholarly journals Phylogenetic Analysis and In Situ Identification of Bacteria Community Composition in an Acidic Sphagnum Peat Bog

2006 ◽  
Vol 72 (3) ◽  
pp. 2110-2117 ◽  
Author(s):  
Svetlana N. Dedysh ◽  
Timofei A. Pankratov ◽  
Svetlana E. Belova ◽  
Irina S. Kulichevskaya ◽  
Werner Liesack
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Community Composition ◽  
Significant Proportion ◽  
Peat Bog ◽  
Rrna Gene ◽  
Bacterial Phyla ◽  
Cell Counts ◽  
Novel Strategy

ABSTRACT The Bacteria community composition in an acidic Sphagnum peat bog (pH 3.9 to 4.5) was characterized by a combination of 16S rRNA gene clone library analysis, rRNA-targeted fluorescence in situ hybridization (FISH), and cultivation. Among 84 environmental 16S rRNA gene clones, a set of only 16 cloned sequences was closely related (≥95% similarity) to taxonomically described organisms. Main groups of clones were affiliated with the Acidobacteria (24 clones), Alphaproteobacteria (20), Verrucomicrobia (13), Actinobacteria (8), Deltaproteobacteria (4), Chloroflexi (3), and Planctomycetes (3). The proportion of cells that hybridized with oligonucleotide probes specific for members of the domains Bacteria (EUB338-mix) and Archaea (ARCH915 and ARC344) accounted for only 12 to 22% of the total cell counts. Up to 24% of the EUB338-positive cells could be assigned by FISH to specific bacterial phyla. Alphaproteobacteria and Planctomycetes were the most numerous bacterial groups (up to 1.3 × 107 and 1.1 × 107 cells g−1 peat, respectively). In contrast to conventional plating techniques, a novel biofilm-mediated enrichment approach allowed us to isolate some representatives of predominant Bacteria groups, such as Acidobacteria and Planctomycetes. This novel strategy has great potential to enable the isolation of a significant proportion of the peat bog bacterial diversity.

Caldicoprobacter guelmensis sp. nov., a thermophilic, anaerobic, xylanolytic bacterium isolated from a hot spring

2013 ◽  
Vol 63 (Pt_6) ◽  
pp. 2049-2053 ◽  
Author(s):  
Amel Bouanane-Darenfed ◽  
Wajdi Ben Hania ◽  
Hocine Hacene ◽  
Jean-Luc Cayol ◽  
Bernard Ollivier ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Species ◽  
Gene Sequence ◽  
Hot Spring ◽  
16S Rrna Gene Sequence ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Content Type ◽  
Link Type

A hyperthermophilic anaerobic bacterium, designated D2C22T, was isolated from the hydrothermal hot spring of Guelma in north-east Algeria. The isolate was a Gram-stain-positive, non-sporulating, non-motile rod, appearing singly or in pairs (0.3–0.4×8.0–9.0 µm). Strain D2C22T grew anaerobically at 45–85 °C (optimum 65 °C), at pH 5–9 (optimum pH 6.8) and with 0–20 g NaCl l−1. Strain D2C22T used glucose, galactose, lactose, fructose, ribose, xylose, arabinose, maltose, cellobiose, mannose, melibiose, sucrose, xylan and pyruvate (only in the presence of yeast extract or biotrypticase) as electron donors. The end products from glucose fermentation were acetate, lactate, CO2 and H2. Nitrate, nitrite, thiosulfate, elemental sulfur, sulfate and sulfite were not used as electron acceptors. The predominant cellular fatty acids were iso-C15 : 0 and iso-C17 : 0. The DNA G+C content was 41.6 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain D2C22T was most closely related to Caldicoprobacter oshimai JW/HY-331T, Caldicoprobacter algeriensis TH7C1T and Acetomicrobium faecale DSM 20678T (95.5, 95.5 and 95.3 % 16S rRNA gene sequence similarity, respectively). Based on phenotypic, phylogenetic and chemotaxonomic characteristics, strain D2C22T is proposed to be a representative of a novel species of the genus Caldicoprobacter within the order Clostridiales , for which the name Caldicoprobacter guelmensis sp. nov. is proposed. The type strain is D2C22T ( = DSM 24605T = JCM 17646T).

Sphingomicrobium lutaoense gen. nov., sp. nov., isolated from a coastal hot spring

2012 ◽  
Vol 62 (Pt_6) ◽  
pp. 1326-1330 ◽  
Author(s):  
Peter Kämpfer ◽  
A. B. Arun ◽  
Chiu-Chung Young ◽  
Hans-Jürgen Busse ◽  
Johannes Kassmannhuber ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Gene Sequence ◽  
Hot Spring ◽  
16S Rrna Gene Sequence ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Content Type ◽  
Link Type

A yellowish pigmented, Gram-negative, rod-shaped, non-spore-forming bacterium (strain CC-TBT-3T), was isolated on marine agar 2216 from a coastal hot spring of Green Island (Lutao), located off Taituang, Taiwan. 16S rRNA gene sequence analysis of strain CC-TBT-3T showed a relatively low similarity (<95.5 %) to representatives of the genera Novosphingobium , Sphingosinicella and Sphingomonas of the Sphingomonadaceae , with the most related strain being the type strain of Novosphingobium soli . In addition to the relatively low 16S rRNA gene sequence similarity to members of established species, the isolate also showed some unique chemotaxonomic features, including the presence of some glycolipids with unusual chromatographic behaviour. The major components of the polar lipid profile were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and three unidentified glycolipids. The major respiratory quinone was ubiquinone Q-10. The polyamine pattern was characterized by the triamine sym-homospermidine as a major component. Although the predominant fatty acids were C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), the isolate did not show the typical hydroxyl fatty acids, such as C14 : 0 2-OH, C15 : 0 2-OH and C16 : 0 2-OH, found in members of the genera Novosphingobium , Sphingomonas and Sphingosinicella , but showed instead high amounts of C18 : 1 2-OH (12.0 %). The DNA G+C content of strain CC-TBT-3T was 63.4 mol%. 16S rRNA gene sequence, chemotaxonomic and physiological analyses revealed that strain CC-TBT-3T represents a novel species in a new genus in the family Sphingomonadaceae for which the name Sphingomicrobium lutaoense gen. nov., sp. nov. is proposed; the type strain is of the type species S. lutoaense, CC-TBT-3T ( = DSM 24194T = CCM 7794T).

scholarly journals Intrinsic challenges in ancient microbiome reconstruction using 16S rRNA gene amplification

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Kirsten A. Ziesemer ◽  
Allison E. Mann ◽  
Krithivasan Sankaranarayanan ◽  
Hannes Schroeder ◽  
Andrew T. Ozga ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Dna Amplification ◽  
Amplicon Sequencing ◽  
Universal Primers ◽  
Rrna Gene ◽  
Dental Calculus ◽  
Shotgun Metagenomics ◽  
Variable Regions ◽  
V3 Region

Abstract To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli 341–534) of this gene has been suggested as an excellent candidate for ancient DNA amplification and microbial community reconstruction. However, in practice this metataxonomic approach often produces highly skewed taxonomic frequency data. In this study, we use non-targeted (shotgun metagenomics) sequencing methods to better understand skewed microbial profiles observed in four ancient dental calculus specimens previously analyzed by amplicon sequencing. Through comparisons of microbial taxonomic counts from paired amplicon (V3 U341F/534R) and shotgun sequencing datasets, we demonstrate that extensive length polymorphisms in the V3 region are a consistent and major cause of differential amplification leading to taxonomic bias in ancient microbiome reconstructions based on amplicon sequencing. We conclude that systematic amplification bias confounds attempts to accurately reconstruct microbiome taxonomic profiles from 16S rRNA V3 amplicon data generated using universal primers. Because in silico analysis indicates that alternative 16S rRNA hypervariable regions will present similar challenges, we advocate for the use of a shotgun metagenomics approach in ancient microbiome reconstructions.

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