scholarly journals Marine cyanolichens from different littoral zones are associated with distinct bacterial communities

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5208 ◽  
Author(s):  
Nyree J. West ◽  
Delphine Parrot ◽  
Claire Fayet ◽  
Martin Grube ◽  
Sophie Tomasi ◽  
...  

The microbial diversity and function of terrestrial lichens have been well studied, but knowledge about the non-photosynthetic bacteria associated with marine lichens is still scarce. 16S rRNA gene Illumina sequencing was used to assess the culture-independent bacterial diversity in the strictly marine cyanolichen speciesLichina pygmaeaandLichina confinis, and the maritime chlorolichen speciesXanthoria aureolawhich occupy different areas on the littoral zone. Inland terrestrial cyanolichens from Austria were also analysed as for the marine lichens to examine further the impact of habitat/lichen species on the associated bacterial communities. TheL. confinisandL. pygmaeacommunities were significantly different from those of the maritimeXanthoria aureolalichen found higher up on the littoral zone and these latter communities were more similar to those of the inland terrestrial lichens. The strictly marine lichens were dominated by the Bacteroidetes phylum accounting for 50% of the sequences, whereas Alphaproteobacteria, notablySphingomonas, dominated the maritime and the inland terrestrial lichens. Bacterial communities associated with the twoLichinaspecies were significantly different sharing only 33 core OTUs, half of which were affiliated to the Bacteroidetes generaRubricoccus,TunicatimonasandLewinella, suggesting an important role of these species in the marineLichinalichen symbiosis. Marine cyanolichens showed a higher abundance of OTUs likely affiliated to moderately thermophilic and/or radiation resistant bacteria belonging to the Phyla Chloroflexi, Thermi, and the families Rhodothermaceae and Rubrobacteraceae when compared to those of inland terrestrial lichens. This most likely reflects the exposed and highly variable conditions to which they are subjected daily.

2017 ◽  
Author(s):  
Nyree J. West ◽  
Delphine Parrot ◽  
Claire Fayet ◽  
Martin Grube ◽  
Sophie Tomasi ◽  
...  

AbstractThe microbial diversity and function of terrestrial lichens has been well studied, but knowledge about the non-photosynthetic bacteria associated with marine lichens is still scarce. 16S rRNA gene Illumina sequencing was used to assess the culture-independent bacterial diversity in the strictly marine cyanolichen speciesLichina pygmaeaandLichina confinis, and the maritime chlorolichen speciesXanthoria aureolawhich occupy different areas on the littoral zone. Inland terrestrial cyanolichens from Austria were also analysed as for the marine lichens to examine further the impact of habitat/lichen species on the associated bacterial communities. TheL. confinisandL. pygmaeacommunities were significantly different from those of the maritimeXanthoria aureolalichen found higher up on the littoral zone and these latter communities were more similar to those of the inland terrestrial lichens. The strictly marine lichens were dominated by the Bacteroidetes phylum accounting for 50% of the sequences, whereas Alphaproteobacteria, notablySphingomonas, dominated the maritime and the inland terrestrial lichens. Bacterial communities associated with the twoLichinaspecies were significantly different sharing only 33 core OTUs, half of which were affiliated to the Bacteroidetes generaRubricoccus, TunicatimonasandLewinella, suggesting an important role of these species in the marineLichinalichen symbiosis. Marine cyanolichens showed a higher abundance of OTUs likely affiliated to moderately thermophilic and/or radiation resistant bacteria belonging to the Phyla Chloroflexi, Thermi, and the families Rhodothermaceae and Rubrobacteraceae when compared to those of inland terrestrial lichens. This most likely reflects the exposed and highly variable conditions to which they are subjected daily.


Author(s):  
A. Shore ◽  
R. D. Day ◽  
J. A. Stewart ◽  
C.A. Burge

Ocean acidification (OA) threatens the growth and function of coral reef ecosystems. A key component to coral health is the microbiome, but little is known about the impact of OA on coral microbiomes. A submarine CO2 vent at Maug Island in the Northern Marianas Islands provides a natural pH gradient to investigate coral responses to long-term OA conditions. Three coral species (Pocillopora eydouxi, Porites lobata, and Porites rus) were sampled from three sites where mean seawater pH is 8.04, 7.98, and 7.94. We characterized coral bacterial communities (using 16S rRNA gene sequencing) and determined pH of the extracellular calcifying fluid (ECF) (using skeletal boron isotopes) across the seawater pH gradient. Bacterial communities of both Porites species stabilized (decreases in community dispersion) with decreased seawater pH, coupled with large increases in the abundance of Endozoicomonas, an endosymbiont. P. lobata experienced a significant decrease in ECF pH near the vent, whereas P. rus experienced a trending decrease in ECF pH near the vent. By contrast, Pocillopora exhibited bacterial community destabilization (increases in community dispersion), with significant decreases in Endozoicomonas abundance, while its ECF pH remained unchanged across the pH gradient. Our study shows that OA has multiple consequences on Endozoicomonas abundance and suggests that Endozoicomonas abundance may be an indicator of coral response to OA. We reveal an interesting dichotomy between two facets of coral physiology (regulation of bacterial communities and regulation of calcification), highlighting the importance of multidisciplinary approaches to understanding coral health and function in a changing ocean. IMPORTANCE Ocean acidification (OA) is a consequence of anthropogenic CO2 emissions that is negatively impacting marine ecosystems such as coral reefs. OA affects many aspects of coral physiology, including growth (i.e. calcification) and disrupting associated bacterial communities. Coral-associated bacteria are important for host health, but it remains unclear how coral-associated bacterial communities will respond to future OA conditions. We document changes in coral-associated bacterial communities and changes to calcification physiology with long-term exposure to decreases in seawater pH that are environmentally relevant under mid-range IPCC emission scenarios (0.1 pH units). We also find species-specific responses that may reflect different responses to long-term OA. In Pocillopora, calcification physiology was highly regulated despite changing seawater conditions. In Porites spp., changes in bacterial communities do not reflect a breakdown of coral-bacterial symbiosis. Insights into calcification and host-microbe interactions are critical to predicting the health and function of different coral taxa to future OA conditions.


mSystems ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Junnan Lu ◽  
Lisa A. Carmody ◽  
Kristopher Opron ◽  
Richard H. Simon ◽  
Linda M. Kalikin ◽  
...  

ABSTRACT Culture-independent studies of the cystic fibrosis (CF) airway microbiome typically rely on expectorated sputum to assess the microbial makeup of lower airways. These studies have revealed rich bacterial communities. There is often considerable overlap between taxa observed in sputum and those observed in saliva, raising questions about the reliability of expectorated sputum as a sample representing lower airway microbiota. These concerns prompted us to compare pairs of sputum and saliva samples from 10 persons with CF. Using 16S rRNA gene sequencing and droplet digital PCR (ddPCR), we analyzed 37 pairs of sputum and saliva samples, each collected from the same person on the same day. We developed an in silico postsequencing decontamination procedure to remove from sputum the fraction of DNA reads estimated to have been contributed by saliva during expectoration. We demonstrate that while there was often sizeable overlap in community membership between sample types, expectorated sputum typically contains a higher bacterial load and a less diverse community compared to saliva. The differences in diversity between sputum and saliva were more pronounced in advanced disease stage, owing to increased relative abundance of the dominant taxa in sputum. Our effort to model saliva contamination of sputum in silico revealed generally minor effects on community structure after removal of contaminating reads. Despite considerable overlap in taxa observed between expectorated sputum and saliva samples, the impact of saliva contamination on measures of lower airway bacterial community composition in CF using expectorated sputum appears to be minimal. IMPORTANCE Cystic fibrosis is an inherited disease characterized by chronic respiratory tract infection and progressive lung disease. Studies of cystic fibrosis lung microbiology often rely on expectorated sputum to reflect the microbiota present in the lower airways. Passage of sputum through the oropharynx during collection, however, contributes microbes present in saliva to the sample, which could confound interpretation of results. Using culture-independent DNA sequencing-based analyses, we characterized the bacterial communities in pairs of expectorated sputum and saliva samples to generate a model for “decontaminating” sputum in silico. Our results demonstrate that salivary contamination of expectorated sputum does not have a large effect on most sputum samples and that observations of high bacterial diversity likely accurately reflect taxa present in cystic fibrosis lower airways.


2020 ◽  
Vol 96 (3) ◽  
Author(s):  
Gavin J Fenske ◽  
Sudeep Ghimire ◽  
Linto Antony ◽  
Jane Christopher-Hennings ◽  
Joy Scaria

ABSTRACT Bacterial communities resident in the hindgut of pigs, have profound impacts on health and disease. Investigations into the pig microbiome have utilized either culture-dependent, or far more commonly, culture-independent techniques using next generation sequencing. We contend that a combination of both approaches generates a more coherent view of microbiome composition. In this study, we surveyed the microbiome of Tamworth breed and feral pigs through the integration high throughput culturing and shotgun metagenomics. A single culture medium was used for culturing. Selective screens were added to the media to increase culture diversity. In total, 46 distinct bacterial species were isolated from the Tamworth and feral samples. Selective screens successfully shifted the diversity of bacteria on agar plates. Tamworth pigs are highly dominated by Bacteroidetes primarily composed of the genus Prevotella whereas feral samples were more diverse with almost equal proportions of Firmicutes and Bacteroidetes. The combination of metagenomics and culture techniques facilitated a greater retrieval of annotated genes than either method alone. The single medium based pig microbiota library we report is a resource to better understand pig gut microbial ecology and function. It allows for assemblage of defined bacterial communities for studies in bioreactors or germfree animal models.


Author(s):  
Xun Kang ◽  
Yanhong Wang ◽  
Siping Li ◽  
Xiaomei Sun ◽  
Xiangyang Lu ◽  
...  

The midgut microbial community composition, structure, and function of field-collected mosquitoes may provide a way to exploit microbial function for mosquito-borne disease control. However, it is unclear how adult mosquitoes acquire their microbiome, how the microbiome affects life history traits and how the microbiome influences community structure. We analyzed the composition of 501 midgut bacterial communities from field-collected adult female mosquitoes, including Aedes albopictus, Aedes galloisi, Culex pallidothorax, Culex pipiens, Culex gelidus, and Armigeres subalbatus, across eight habitats using the HiSeq 4000 system and the V3−V4 hyper-variable region of 16S rRNA gene. After quality filtering and rarefaction, a total of 1421 operational taxonomic units, belonging to 29 phyla, 44 families, and 43 genera were identified. Proteobacteria (75.67%) were the most common phylum, followed by Firmicutes (10.38%), Bacteroidetes (6.87%), Thermi (4.60%), and Actinobacteria (1.58%). The genera Rickettsiaceae (33.00%), Enterobacteriaceae (20.27%), Enterococcaceae (7.49%), Aeromonadaceae (7.00%), Thermaceae (4.52%), and Moraxellaceae (4.31%) were dominant in the samples analyzed and accounted for 76.59% of the total genera. We characterized the midgut bacterial communities of six mosquito species in Hainan province, China. The gut bacterial communities were different in composition and abundance, among locations, for all mosquito species. There were significant differences in the gut microbial composition between some species and substantial variation in the gut microbiota between individuals of the same mosquito species. There was a marked variation in different mosquito gut microbiota within the same location. These results might be useful in the identification of microbial communities that could be exploited for disease control.


2009 ◽  
Vol 75 (8) ◽  
pp. 2294-2303 ◽  
Author(s):  
Christina A. Kellogg ◽  
John T. Lisle ◽  
Julia P. Galkiewicz

ABSTRACT Bacteria are recognized as an important part of the total biology of shallow-water corals. Studies of shallow-water corals suggest that associated bacteria may benefit the corals by cycling carbon, fixing nitrogen, chelating iron, and producing antibiotics that protect the coral from other microbes. Cold-water or deep-sea corals have a fundamentally different ecology due to their adaptation to cold, dark, high-pressure environments and as such have novel microbiota. The goal of this study was to characterize the microbial associates of Lophelia pertusa in the northeastern Gulf of Mexico. This is the first study to collect the coral samples in individual insulated containers and to preserve coral samples at depth in an effort to minimize thermal shock and evaluate the effects of environmental gradients on the microbial diversity of samples. Molecular analysis of bacterial diversity showed a marked difference between the two study sites, Viosca Knoll 906/862 (VK906/862) and Viosca Knoll 826 (VK826). The bacterial communities from VK826 were dominated by a variety of unknown mycoplasmal members of the Tenericutes and Bacteroidetes, whereas the libraries from VK906/862 were dominated by members of the Proteobacteria. In addition to novel sequences, the 16S rRNA gene clone libraries revealed many bacterial sequences in common between Gulf of Mexico Lophelia corals and Norwegian fjord Lophelia corals, as well as shallow-water corals. Two Lophelia-specific bacterial groups were identified: a cluster of gammaproteobacteria related to sulfide-oxidizing gill symbionts of seep clams and a group of Mycoplasma spp. The presence of these groups in both Gulf and Norwegian Lophelia corals indicates that in spite of the geographic heterogeneity observed in Lophelia-associated bacterial communities, there are Lophelia-specific microbes.


2006 ◽  
Vol 72 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Silke Langenheder ◽  
Eva S. Lindström ◽  
Lars J. Tranvik

ABSTRACT The aim of this study was to compare two major hypotheses concerning the formation of bacterial community composition (BCC) at the local scale, i.e., whether BCC is determined by the prevailing local environmental conditions or by “metacommunity processes.” A batch culture experiment where bacteria from eight distinctly different aquatic habitats were regrown under identical conditions was performed to test to what extent similar communities develop under similar selective pressure. Differently composed communities emerged from different inoculum communities, as determined by terminal restriction fragment length polymorphism analysis of the 16S rRNA gene. There was no indication that similarity increased between communities upon growth under identical conditions compared to that for growth at the ambient sampling sites. This suggests that the history and distribution of taxa within the source communities were stronger regulating factors of BCC than the environmental conditions. Moreover, differently composed communities were different with regard to specific functions, such as enzyme activities, but maintained similar broad-scale functions, such as biomass production and respiration.


2005 ◽  
Vol 71 (9) ◽  
pp. 5225-5235 ◽  
Author(s):  
Fred A. Rainey ◽  
Keren Ray ◽  
Margarida Ferreira ◽  
Bridget Z. Gatz ◽  
M. Fernanda Nobre ◽  
...  

ABSTRACT The ionizing-radiation-resistant fractions of two soil bacterial communities were investigated by exposing an arid soil from the Sonoran Desert and a nonarid soil from a Louisiana forest to various doses of ionizing radiation using a 60Co source. The numbers of surviving bacteria decreased as the dose of gamma radiation to which the soils were exposed increased. Bacterial isolates surviving doses of 30 kGy were recovered from the Sonoran Desert soil, while no isolates were recovered from the nonarid forest soil after exposure to doses greater than 13 kGy. The phylogenetic diversities of the surviving culturable bacteria were compared for the two soils using 16S rRNA gene sequence analysis. In addition to a bacterial population that was more resistant to higher doses of ionizing radiation, the diversity of the isolates was greater in the arid soil. The taxonomic diversity of the isolates recovered was found to decrease as the level of ionizing-radiation exposure increased. Bacterial isolates of the genera Deinococcus, Geodermatophilus, and Hymenobacter were still recovered from the arid soil after exposure to doses of 17 to 30 kGy. The recovery of large numbers of extremely ionizing-radiation-resistant bacteria from an arid soil and not from a nonarid soil provides further ecological support for the hypothesis that the ionizing-radiation resistance phenotype is a consequence of the evolution of other DNA repair systems that protect cells against commonly encountered environmental stressors, such as desiccation. The diverse group of bacterial strains isolated from the arid soil sample included 60 Deinococcus strains, the characterization of which revealed nine novel species of this genus.


2020 ◽  
Author(s):  
Ezequiel Santillan ◽  
Hari Seshan ◽  
Stefan Wuertz

AbstractDisturbance is thought to affect community assembly mechanisms, which in turn shape community structure and the overall function of the ecosystem. Here, we tested the effect of a continuous (press) xenobiotic disturbance on the function, structure, and assembly of bacterial communities within a wastewater treatment system. Two sets of four-liter sequencing batch reactors were operated in triplicate with and without the addition of 3-chloroaniline for a period of 132 days, following 58 days of acclimation after inoculation with sludge from a full-scale treatment plant. Temporal dynamics of bacterial community structure were derived from 16S rRNA gene amplicon sequencing. Community function, structure and assembly differed between press disturbed and undisturbed reactors. Temporal partitioning of assembly mechanisms via phylogenetic and non-phylogenetic null modelling analysis revealed that deterministic assembly prevailed for disturbed bioreactors, while the role of stochastic assembly was stronger for undisturbed reactors. Our findings are relevant because research spanning various disturbance types, environments and spatiotemporal scales is needed for a comprehensive understanding of the effects of press disturbances on assembly mechanisms, structure, and function of microbial communities.Graphical abstract


2019 ◽  
Author(s):  
Ana Elena Pérez-Cobas ◽  
Christophe Ginevra ◽  
Christophe Rusniok ◽  
Sophie Jarraud ◽  
Carmen Buchrieser

ABSTRACTBackgroundLung microbiome analyses have shown that the healthy lung is not sterile but it is colonized like other body sites by bacteria, fungi and viruses. However, little is known about the microbial composition of the lung microbiome during infectious diseases such as pneumonia and how it evolves during antibiotic therapy. To better understand the impact of the composition of the pulmonary microbiome on severity and outcome of pneumonia we analysed the composition and evolution of the human lung microbiome during pneumonia caused by the bacterium Legionella pneumophila.ResultsWe collected 10 bronchoalveolar lavage (BAL) samples from three patients during long-term hospitalisation due to severe pneumonia and performed a longitudinal in-depth study of the composition of their lung microbiome by high-throughput Illumina sequencing of the 16S rRNA gene (bacteria and archaea), ITS region (fungi) and 18S rRNA gene (eukaryotes). We found that the composition of the bacterial lung microbiome during pneumonia is hugely disturbed containing a very high percentage of the pathogen, a very low bacterial diversity, and an increased presence of opportunistic microorganisms such as species belonging to Staphylococcaceae and Streptococcaceae. The microbiome of antibiotic treated patients cured from pneumonia represented a different perturbation state with a higher abundance of resistant bacteria (mainly Firmicutes) and a significantly different bacterial composition as that found in healthy individuals. In contrast, the mycobiome remains more stable during pneumonia and antimicrobial therapy. Interestingly we identified possible cooperation within and between both communities. Furthermore, archaea (Methanobrevibacter) and protozoa (Acanthamoeba and Trichomonas) were detected.ConclusionsBacterial pneumonia leads to a collapse of the healthy microbiome and a strongly disturbed bacterial composition of the pulmonary microbiome that is dominated by the pathogen. Antibiotic treatment allows some bacteria to regrow or recolonize the lungs but the restoration of a healthy lung microbiome composition is only regained a certain time after the antibiotic treatment. Archaea and protozoa should also be considered, as they might be important but yet overseen members of the lung microbiome. Interactions between the micro- and the mycobiome might play a role in the restoration of the microbiome and the clinical evolution of the disease.


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