Metataxonomic Analysis of Bacteria Entrapped in a Stalactite’s Core and Their Possible Environmental Origins

Much is known about microbes originally identified in caves, but little is known about the entrapment of microbes (bacteria) in stalactites and their possible environmental origins. This study presents data regarding the significant environmental distribution of prokaryotic bacterial taxa of a Greek stalactite core. We investigated the involvement of those bacteria communities in stalactites using a metataxonomic analysis approach of partial 16S rRNA genes. The metataxonomic analysis of stalactite core material revealed an exceptionally broad ecological spectrum of bacteria classified as members of Proteobacteria, Actinobacteria, Firmicutes, Verrucomicrobia, and other unclassified bacteria. We concluded that (i) the bacterial transport process is possible through water movement from the upper ground cave environment, forming cave speleothems such as stalactites, (ii) bacterial genera such as Polaromonas, Thioprofundum, and phylum Verrucomicrobia trapped inside the stalactite support the paleoecology, paleomicrobiology, and paleoclimate variations, (iii) the entrapment of certain bacteria taxa associated with water, soil, animals, and plants such as Micrococcales, Propionibacteriales, Acidimicrobiales, Pseudonocardiales, and α-, β-, and γ-Proteobacteria.

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Opening a next-generation black box: ecological trends for hundreds of species-like taxa uncovered within a single bacterial >99% 16S rRNA operational taxonomic unit

10.22541/au.161368667.78191317/v1 ◽

2021 ◽

Author(s):

Martin Hahn ◽

Andrea Huemer ◽

Alexandra Pitt ◽

Matthias Hoetzinger

Keyword(s):

16S Rrna ◽

Sequence Similarity ◽

16S Rrna Genes ◽

Rrna Genes ◽

Rrna Gene ◽

Taxon Richness ◽

Large Set ◽

Free Living ◽

Environmental Distribution ◽

Living Bacteria

Current knowledge on environmental distribution and taxon richness of free-living bacteria is mainly based on cultivation-independent investigations employing 16S rRNA gene sequencing methods. Yet, 16S rRNA genes are evolutionarily rather conserved, resulting in limited taxonomic and ecological resolutions provided by this marker. We used a faster evolving protein-encoding marker to reveal ecological patterns hidden within a single OTU defined by >99% 16S rRNA sequence similarity. The studied taxon, subcluster PnecC of the genus Polynucleobacter, represents a ubiquitous group of planktonic freshwater bacteria with cosmopolitan distribution, which is very frequently detected by diversity surveys of freshwater systems. Based on genome taxonomy and a large set of genome sequences, a sequence similarity threshold for delineation of species-like taxa could be established. In total, 600 species-like taxa were detected in 99 freshwater habitats scattered across three regions representing a latitudinal range of 3400 km (42°N to 71°N) and a pH gradient of 4.2 to 8.6. Besides the unexpectedly high richness, the increased taxonomic resolution revealed structuring of Polynucleobacter communities by a couple of macroecological trends, which was previously only demonstrated for phylogenetically much broader groups of bacteria. A unexpected pattern was the almost complete compositional separation of Polynucleobacter communities of Ca-rich and Ca-poor habitats, which strongly resembled the vicariance of plant species on silicate and limestone soils. The presented new cultivation-independent approach opened a window to an incredible, previously unseen diversity, and enables investigations aiming on deeper understanding of how environmental conditions shape bacterial communities and drive evolution of free-living bacteria.

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16S rRNA Phylogenetic Investigation of the Candidate Division “Korarchaeota”

Applied and Environmental Microbiology ◽

10.1128/aem.00052-06 ◽

2006 ◽

Vol 72 (7) ◽

pp. 5077-5082 ◽

Cited By ~ 21

Author(s):

Thomas A. Auchtung ◽

Cristina D. Takacs-Vesbach ◽

Colleen M. Cavanaugh

Keyword(s):

16S Rrna ◽

Hot Springs ◽

Phylogenetic Analyses ◽

16S Rrna Genes ◽

Rrna Genes ◽

Rrna Gene ◽

Environmental Distribution ◽

Candidate Division ◽

High Level ◽

The 16S Rrna Gene

ABSTRACT The environmental distribution and phylogeny of “Korarchaeota,” a proposed ancient archaeal division, was investigated by using the 16S rRNA gene framework. Korarchaeota-specific primers were designed based on previously published sequences and used to screen a variety of environments. Korarchaeota 16S rRNA genes were amplified exclusively from high temperature Yellowstone National Park hot springs and a 9°N East Pacific Rise deep-sea hydrothermal vent. Phylogenetic analyses of these and all available sequences suggest that Korarchaeota exhibit a high level of endemicity.

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Differentiation Of Clarias Batrachus, C. Gariepinus And Heteropneustes Fossilis By Pcr-Sequencing Of Mitochondrial 16s Rrna Gene

Journal of the Asiatic Society of Bangladesh Science ◽

10.3329/jasbs.v41i1.46190 ◽

2015 ◽

Vol 41 (1) ◽

pp. 51-58

Author(s):

Mohammad Shamimul Alam ◽

Hawa Jahan ◽

Rowshan Ara Begum ◽

Reza M Shahjahan

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Fish Larva ◽

16S Rrna Genes ◽

Rrna Genes ◽

Rrna Gene ◽

Valuable Insight ◽

Multiple Sequence ◽

Pcr Rflp ◽

Alternative Means

Heteropneustesfossilis, Clariasbatrachus and C. gariepinus are three major catfishes ofecological and economic importance. Identification of these fish species becomes aproblem when the usual external morphological features of the fish are lost or removed,such as in canned fish. Also, newly hatched fish larva is often difficult to identify. PCRsequencingprovides accurate alternative means of identification of individuals at specieslevel. So, 16S rRNA genes of three locally collected catfishes were sequenced after PCRamplification and compared with the same gene sequences available from othergeographical regions. Multiple sequence alignment of the 16S rRNA gene fragments ofthe catfish species has revealed polymorphic sites which can be used to differentiate thesethree species from one another and will provide valuable insight in choosing appropriaterestriction enzymes for PCR-RFLP based identification in future. Asiat. Soc. Bangladesh, Sci. 41(1): 51-58, June 2015

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Effects of Supplement of Marichromatium gracile YL28 on Water Quality and Microbial Structures in Shrimp Mariculture Ecosystems

Genes ◽

10.3390/genes12010040 ◽

2020 ◽

Vol 12 (1) ◽

pp. 40

Author(s):

Liang Cui ◽

Bitong Zhu ◽

Xiaobo Zhang ◽

Zhuhua Chan ◽

Chungui Zhao ◽

...

Keyword(s):

Water Quality ◽

16S Rrna ◽

Relative Abundance ◽

Animal Health ◽

Denitrifying Bacteria ◽

Nitrite Reduction ◽

16S Rrna Genes ◽

Rrna Genes ◽

Sequencing Analysis ◽

Shrimp Culture

The elevated NH3-N and NO2-N pollution problems in mariculture have raised concerns because they pose threats to animal health and coastal and offshore environments. Supplement of Marichromatium gracile YL28 (YL28) into polluted shrimp rearing water and sediment significantly decreased ammonia and nitrite concentrations, showing that YL28 functioned as a novel safe marine probiotic in the shrimp culture industry. The diversity of aquatic bacteria in the shrimp mariculture ecosystems was studied by sequencing the V4 region of 16S rRNA genes, with respect to additions of YL28 at the low and high concentrations. It was revealed by 16S rRNA sequencing analysis that Proteobacteria, Planctomycete and Bacteroidetes dominated the community (>80% of operational taxonomic units (OTUs)). Up to 41.6% of the predominant bacterial members were placed in the classes Gammaproteobacteria (14%), Deltaproteobacteria (14%), Planctomycetacia (8%) and Alphaproteobacteria (5.6%) while 40% of OTUs belonged to unclassified ones or others, indicating that the considerable bacterial populations were novel in our shrimp mariculture. Bacterial communities were similar between YL28 supplements and control groups (without addition of YL28) revealed by the β-diversity using PCoA, demonstrating that the additions of YL28 did not disturb the microbiota in shrimp mariculture ecosystems. Instead, the addition of YL28 increased the relative abundance of ammonia-oxidizing and denitrifying bacteria. The quantitative PCR analysis further showed that key genes including nifH and amoA involved in nitrification and nitrate or nitrite reduction significantly increased with YL28 supplementation (p < 0.05). The supplement of YL28 decreased the relative abundance of potential pathogen Vibrio. Together, our studies showed that supplement of YL28 improved the water quality by increasing the relative abundance of ammonia-oxidizing and denitrifying bacteria while the microbial community structure persisted in shrimp mariculture ecosystems.

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Coordination of microbe–host homeostasis by crosstalk with plant innate immunity

Nature Plants ◽

10.1038/s41477-021-00920-2 ◽

2021 ◽

Author(s):

Ka-Wai Ma ◽

Yulong Niu ◽

Yong Jia ◽

Jana Ordon ◽

Charles Copeland ◽

...

Keyword(s):

Growth Inhibition ◽

Amplicon Sequencing ◽

Host Susceptibility ◽

16S Rrna Genes ◽

Rrna Genes ◽

Root Growth Inhibition ◽

Natural Soil ◽

Molecular Pattern ◽

Immune Related Genes ◽

Molecular Patterns

AbstractPlants grown in natural soil are colonized by phylogenetically structured communities of microbes known as the microbiota. Individual microbes can activate microbe-associated molecular pattern (MAMP)-triggered immunity (MTI), which limits pathogen proliferation but curtails plant growth, a phenomenon known as the growth–defence trade-off. Here, we report that, in monoassociations, 41% (62 out of 151) of taxonomically diverse root bacterial commensals suppress Arabidopsis thaliana root growth inhibition (RGI) triggered by immune-stimulating MAMPs or damage-associated molecular patterns. Amplicon sequencing of bacterial 16S rRNA genes reveals that immune activation alters the profile of synthetic communities (SynComs) comprising RGI-non-suppressive strains, whereas the presence of RGI-suppressive strains attenuates this effect. Root colonization by SynComs with different complexities and RGI-suppressive activities alters the expression of 174 core host genes, with functions related to root development and nutrient transport. Furthermore, RGI-suppressive SynComs specifically downregulate a subset of immune-related genes. Precolonization of plants with RGI-suppressive SynComs, or mutation of one commensal-downregulated transcription factor, MYB15, renders the plants more susceptible to opportunistic Pseudomonas pathogens. Our results suggest that RGI-non-suppressive and RGI-suppressive root commensals modulate host susceptibility to pathogens by either eliciting or dampening MTI responses, respectively. This interplay buffers the plant immune system against pathogen perturbation and defence-associated growth inhibition, ultimately leading to commensal–host homeostasis.

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Comparison of oral microbiome profiles in 18-month-old infants and their parents

Scientific Reports ◽

10.1038/s41598-020-78295-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ryutaro Jo ◽

Kazuma Yama ◽

Yuto Aita ◽

Kota Tsutsumi ◽

Chikako Ishihara ◽

...

Keyword(s):

Next Generation Sequencing ◽

Dental Caries ◽

Oral Bacteria ◽

Oral Microbiome ◽

Commensal Bacteria ◽

16S Rrna Genes ◽

Rrna Genes ◽

Deciduous Dentition ◽

The Difference ◽

Generation Sequencing

AbstractThe onset and progress of dental caries and periodontal disease is associated with the oral microbiome. Therefore, it is important to understand the factors that influence oral microbiome formation. One of the factors that influence oral microbiome formation is the transmission of oral bacteria from parents. However, it remains unclear when the transmission begins, and the difference in contributions of father and mother. Here, we focused on the oral microbiome of 18-month-old infants, at which age deciduous dentition is formed and the oral microbiome is likely to become stable, with that of their parents. We collected saliva from forty 18-month-old infants and their parents and compared the diversity and composition of the microbiome using next-generation sequencing of 16S rRNA genes. The results showed that microbial diversity in infants was significantly lower than that in parents and composition of microbiome were significantly different between infants and parents. Meanwhile, the microbiome of the infants was more similar to that of their mothers than unrelated adults. The bacteria highly shared between infants and parents included not only commensal bacteria but also disease related bacteria. These results suggested that the oral microbiome of the parents influences that of their children aged < 18 months.

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Ultra-accurate microbial amplicon sequencing with synthetic long reads

Microbiome ◽

10.1186/s40168-021-01072-3 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Benjamin J. Callahan ◽

Dmitry Grinevich ◽

Siddhartha Thakur ◽

Michael A. Balamotis ◽

Tuval Ben Yehezkel

Keyword(s):

Microbial Community ◽

16S Rrna ◽

Amplicon Sequencing ◽

Species Level ◽

Full Length ◽

16S Rrna Genes ◽

Rrna Genes ◽

Strain Identification ◽

Long Reads ◽

Long Read

Abstract Background Out of the many pathogenic bacterial species that are known, only a fraction are readily identifiable directly from a complex microbial community using standard next generation DNA sequencing. Long-read sequencing offers the potential to identify a wider range of species and to differentiate between strains within a species, but attaining sufficient accuracy in complex metagenomes remains a challenge. Methods Here, we describe and analytically validate LoopSeq, a commercially available synthetic long-read (SLR) sequencing technology that generates highly accurate long reads from standard short reads. Results LoopSeq reads are sufficiently long and accurate to identify microbial genes and species directly from complex samples. LoopSeq perfectly recovered the full diversity of 16S rRNA genes from known strains in a synthetic microbial community. Full-length LoopSeq reads had a per-base error rate of 0.005%, which exceeds the accuracy reported for other long-read sequencing technologies. 18S-ITS and genomic sequencing of fungal and bacterial isolates confirmed that LoopSeq sequencing maintains that accuracy for reads up to 6 kb in length. LoopSeq full-length 16S rRNA reads could accurately classify organisms down to the species level in rinsate from retail meat samples, and could differentiate strains within species identified by the CDC as potential foodborne pathogens. Conclusions The order-of-magnitude improvement in length and accuracy over standard Illumina amplicon sequencing achieved with LoopSeq enables accurate species-level and strain identification from complex- to low-biomass microbiome samples. The ability to generate accurate and long microbiome sequencing reads using standard short read sequencers will accelerate the building of quality microbial sequence databases and removes a significant hurdle on the path to precision microbial genomics.

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Diversity and Dynamics of Seaweed Associated Microbial Communities Inhabiting the Lagoon of Venice

Microorganisms ◽

10.3390/microorganisms8111657 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1657

Author(s):

Abdul-Salam Juhmani ◽

Alessandro Vezzi ◽

Mohammad Wahsha ◽

Alessandro Buosi ◽

Fabio De Pascale ◽

...

Keyword(s):

Microbial Communities ◽

Bacterial Communities ◽

Host Response ◽

Environmental Parameters ◽

16S Rrna Genes ◽

Rrna Genes ◽

Nutrient Concentrations ◽

Lagoon Of Venice ◽

Anthropogenic Stressors ◽

Rich Diversity

Seaweeds are a group of essential photosynthetic organisms that harbor a rich diversity of associated microbial communities with substantial functions related to host health and defense. Environmental and anthropogenic stressors may disrupt the microbial communities and their metabolic activity, leading to host physiological alterations that negatively affect seaweeds’ performance and survival. Here, the bacterial communities associated with one of the most common seaweed, Ulva laetevirens Areshough, were sampled over a year at three sites of the lagoon of Venice affected by different environmental and anthropogenic stressors. Bacterial communities were characterized through Illumina sequencing of the V4 hypervariable region of 16S rRNA genes. The study demonstrated that the seaweed associated bacterial communities at sites impacted by environmental stressors were host-specific and differed significantly from the less affected site. Furthermore, these communities were significantly distinct from those of the surrounding seawater. The bacterial communities’ composition was significantly correlated with environmental parameters (nutrient concentrations, dissolved oxygen saturation, and pH) across sites. This study showed that several more abundant bacteria on U. laetevirens at stressed sites belonged to taxa related to the host response to the stressors. Overall, environmental parameters and anthropogenic stressors were shown to substantially affect seaweed associated bacterial communities, which reflect the host response to environmental variations.

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Microdiversity and phylogeographic diversification of bacterioplankton in pelagic freshwater systems revealed through long-read amplicon sequencing

Microbiome ◽

10.1186/s40168-020-00974-y ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Yusuke Okazaki ◽

Shohei Fujinaga ◽

Michaela M. Salcher ◽

Cristiana Callieri ◽

Atsushi Tanaka ◽

...

Keyword(s):

16S Rrna ◽

Regional Scale ◽

Scale Up ◽

Amplicon Sequencing ◽

Freshwater Ecosystems ◽

16S Rrna Genes ◽

Rrna Genes ◽

Rrna Gene ◽

Metagenomic Sequencing ◽

Long Read

Abstract Background Freshwater ecosystems are inhabited by members of cosmopolitan bacterioplankton lineages despite the disconnected nature of these habitats. The lineages are delineated based on > 97% 16S rRNA gene sequence similarity, but their intra-lineage microdiversity and phylogeography, which are key to understanding the eco-evolutional processes behind their ubiquity, remain unresolved. Here, we applied long-read amplicon sequencing targeting nearly full-length 16S rRNA genes and the adjacent ribosomal internal transcribed spacer sequences to reveal the intra-lineage diversities of pelagic bacterioplankton assemblages in 11 deep freshwater lakes in Japan and Europe. Results Our single nucleotide-resolved analysis, which was validated using shotgun metagenomic sequencing, uncovered 7–101 amplicon sequence variants for each of the 11 predominant bacterial lineages and demonstrated sympatric, allopatric, and temporal microdiversities that could not be resolved through conventional approaches. Clusters of samples with similar intra-lineage population compositions were identified, which consistently supported genetic isolation between Japan and Europe. At a regional scale (up to hundreds of kilometers), dispersal between lakes was unlikely to be a limiting factor, and environmental factors or genetic drift were potential determinants of population composition. The extent of microdiversification varied among lineages, suggesting that highly diversified lineages (e.g., Iluma-A2 and acI-A1) achieve their ubiquity by containing a consortium of genotypes specific to each habitat, while less diversified lineages (e.g., CL500-11) may be ubiquitous due to a small number of widespread genotypes. The lowest extent of intra-lineage diversification was observed among the dominant hypolimnion-specific lineage (CL500-11), suggesting that their dispersal among lakes is not limited despite the hypolimnion being a more isolated habitat than the epilimnion. Conclusions Our novel approach complemented the limited resolution of short-read amplicon sequencing and limited sensitivity of the metagenome assembly-based approach, and highlighted the complex ecological processes underlying the ubiquity of freshwater bacterioplankton lineages. To fully exploit the performance of the method, its relatively low read throughput is the major bottleneck to be overcome in the future.

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Habitat Elevation Shapes Microbial Community Composition and Alter the Metabolic Functions in Wild Sable (Martes zibellina) Guts

Animals ◽

10.3390/ani11030865 ◽

2021 ◽

Vol 11 (3) ◽

pp. 865

Author(s):

Lantian Su ◽

Xinxin Liu ◽

Guangyao Jin ◽

Yue Ma ◽

Haoxin Tan ◽

...

Keyword(s):

Microbial Community ◽

Environmental Factors ◽

Microbial Communities ◽

Community Composition ◽

16S Rrna Genes ◽

Rrna Genes ◽

Functional Genes ◽

Martes Zibellina ◽

Clear Cutting ◽

Metabolic Functions

In recent decades, wild sable (Carnivora Mustelidae Martes zibellina) habitats, which are often natural forests, have been squeezed by anthropogenic disturbances such as clear-cutting, tilling and grazing. Sables tend to live in sloped areas with relatively harsh conditions. Here, we determine effects of environmental factors on wild sable gut microbial communities between high and low altitude habitats using Illumina Miseq sequencing of bacterial 16S rRNA genes. Our results showed that despite wild sable gut microbial community diversity being resilient to many environmental factors, community composition was sensitive to altitude. Wild sable gut microbial communities were dominated by Firmicutes (relative abundance 38.23%), followed by Actinobacteria (30.29%), and Proteobacteria (28.15%). Altitude was negatively correlated with the abundance of Firmicutes, suggesting sable likely consume more vegetarian food in lower habitats where plant diversity, temperature and vegetation coverage were greater. In addition, our functional genes prediction and qPCR results demonstrated that energy/fat processing microorganisms and functional genes are enriched with increasing altitude, which likely enhanced metabolic functions and supported wild sables to survive in elevated habitats. Overall, our results improve the knowledge of the ecological impact of habitat change, providing insights into wild animal protection at the mountain area with hash climate conditions.

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