scholarly journals Groundwater bacterial communities evolve over time, exhibiting oscillating similarity patterns in response to recharge

2021 ◽  
Author(s):  
Lijuan Yan ◽  
Syrie Hermans ◽  
Kai Uwe Totsche ◽  
Robert Lehmann ◽  
Martina Herrmann ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Bacterial Communities ◽  
Bacterial Community Composition ◽  
High Temporal Resolution ◽  
Aquatic Environments ◽  
Rrna Gene ◽  
Sequencing Data ◽  
Environmental Selection ◽  
The Impact ◽  
Over Time

Time series analyses are a crucial tool for uncovering the patterns and processes shaping microbial communities and their functions, especially in aquatic ecosystems. Subsurface aquatic environments are perceived to be more stable than oceans and lakes, due to the lack of sunlight, the absence of photosysnthetically-driven primary production, low temperature variations, and oligotrophic conditions. However, periodic groundwater recharge should affect the structure and succession of groundwater microbiomes. To disentangle the long-term temporal changes in groundwater bacterial communities of shallow fractured bedrock community, and identify the drivers of the observed patterns, we analysed bacterial 16S rRNA gene sequencing data for samples collected monthly from three groundwater wells over a six-year period (n=230) along a hillslope recharge area. We show that the bacterial communities in the groundwater of limestone-mudstone alternations were not stable over time and showed oscillating dissimilarity patterns which corresponded to periods of groundwater recharge; the impact of recharge events on the groundwater microbiome was linked to the recharge strength and local environmental selection strength. Sampling period was able to explain up to 29.5% of the variability in bacterial community composition. We observed an increase in dissimilarity over time (generalized additive model P < 0.001) indicating that the successive recharge events result in communities that are increasingly more dissimilar to the initial reference time point. The majority of groundwater bacteria originated from the recharge-related sources (mean = 66.5%, SD = 15.1%) and specific bacterial taxa were identified as being either enriched or repressed during recharge events. Overall, similar to surface aquatic environments, groundwater microbiomes vary through time, though we revealed groundwater recharges as unique driving factors for these patterns. The high temporal resolution employed here highlights the complex dynamics of bacterial communities in groundwater and demonstrated that successive shocks disturb the bacterial communities, leading to decreased similarity to the initial state over time.

Bacterial communities in shallow fractured-rock groundwater evolve over time, exhibiting cyclic patterns in response to multi-annual recharge events.

2021 ◽  
Author(s):  
Syrie Hermans ◽  
Lijuan Yan ◽  
Kai Uwe Totsche ◽  
Robert Lehmann ◽  
Martina Herrmann ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Bacterial Communities ◽  
Fractured Rock ◽  
Sampling Period ◽  
Critical Zone ◽  
High Temporal Resolution ◽  
Rrna Gene ◽  
Environmental Selection ◽  
The Impact ◽  
Over Time

&lt;p&gt;Groundwater is an important component of the Earth&amp;#8217;s critical zone and within this ecosystem, microbial communities play an important role, interacting with, and contributing to, the geology and hydrology of these systems; understanding how microbial communities in this dynamic zone change over time is therefore crucial. However, subsurface aquatic environments are lacking high-resolution temporal data over long time periods. Based on 16S rRNA gene sequences collected monthly over a six-year period (n=230) in groundwater from fractured Triassic limestone-mudstone alternations of the Hainich Critical Zone Exploratory (central Germany), we, therefore, aimed to disentangle the temporal dynamics of bacterial communities. The bacterial communities in the shallow bedrock groundwater showed multi-annual cyclic dissimilarity patterns which corresponded to groundwater level fluctuation and, thus, recharge discharge periods. The impact of groundwater fluctuation and linked cross-stratal exchange on the groundwater microbial communities was associated with the recharge strength and local environmental selection strength. Sampling period was able to explain up to 29.5% of the variability in bacterial community composition (based on a 2-factorial PERMANOVA model). We observed an increase in dissimilarity over time (Mantel P &gt; 0.001) indicating that the successive recharge events result in bacterial communities that are increasingly more dissimilar to the communities at the start of the sampling period. Most bacteria in the groundwater originated from the recharge-related sources (mean = 66.5%, SD = 15.1%) and specific bacterial taxa were identified as being either enriched or repressed during recharge events. Overall, we show that seasonal recharge patterns are important for shaping bacterial communities in shallow fractured-rock groundwater and act as drivers of cyclical patterns. Furthermore, the recharge events are successive shocks that perturbed the bacterial communities, leading to decreased similarity to the original state over time. These revelations highlight the importance of high temporal resolution research in the Critical Zone for investigating the complex interplay between surface/subsurface environmental dynamics and the biology of groundwater ecosystems.&lt;/p&gt;

scholarly journals Susceptibility of Red Mason Bee Larvae to Bacterial Threats Due to Microbiome Exchange with Imported Pollen Provisions

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 373 ◽  
Author(s):  
Anna Voulgari-Kokota ◽  
Ingolf Steffan-Dewenter ◽  
Alexander Keller
Keyword(s):  
Ribosomal Rna ◽  
Bacterial Communities ◽  
Bacterial Community Composition ◽  
Solitary Bees ◽  
Rrna Gene ◽  
Bacillus Sp ◽  
Population Declines ◽  
Paenibacillus Sp ◽  
Inoculation Treatment ◽  
The Impact

Solitary bees are subject to a variety of pressures that cause severe population declines. Currently, habitat loss, temperature shifts, agrochemical exposure, and new parasites are identified as major threats. However, knowledge about detrimental bacteria is scarce, although they may disturb natural microbiomes, disturb nest environments, or harm the larvae directly. To address this gap, we investigated 12 Osmia bicornis nests with deceased larvae and 31 nests with healthy larvae from the same localities in a 16S ribosomal RNA (rRNA) gene metabarcoding study. We sampled larvae, pollen provisions, and nest material and then contrasted bacterial community composition and diversity in healthy and deceased nests. Microbiomes of pollen provisions and larvae showed similarities for healthy larvae, whilst this was not the case for deceased individuals. We identified three bacterial taxa assigned to Paenibacillus sp. (closely related to P. pabuli/amylolyticus/xylanexedens), Sporosarcina sp., and Bacillus sp. as indicative for bacterial communities of deceased larvae, as well as Lactobacillus for corresponding pollen provisions. Furthermore, we performed a provisioning experiment, where we fed larvae with untreated and sterilized pollens, as well as sterilized pollens inoculated with a Bacillus sp. isolate from a deceased larva. Untreated larval microbiomes were consistent with that of the pollen provided. Sterilized pollen alone did not lead to acute mortality, while no microbiome was recoverable from the larvae. In the inoculation treatment, we observed that larval microbiomes were dominated by the seeded bacterium, which resulted in enhanced mortality. These results support that larval microbiomes are strongly determined by the pollen provisions. Further, they underline the need for further investigation of the impact of detrimental bacterial acquired via pollens and potential buffering by a diverse pollen provision microbiome in solitary bees.

scholarly journals Selection for Cu-Tolerant Bacterial Communities with Altered Composition, but Unaltered Richness, via Long-Term Cu Exposure

2012 ◽  
Vol 78 (20) ◽  
pp. 7438-7446 ◽  
Author(s):  
Jeanette Berg ◽  
Kristian K. Brandt ◽  
Waleed A. Al-Soud ◽  
Peter E. Holm ◽  
Lars H. Hansen ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Metal Tolerance ◽  
Bacterial Community Composition ◽  
Community Response ◽  
Leucine Incorporation ◽  
Rrna Gene ◽  
Sequence Information ◽  
Content Type ◽  
Relative Abundances ◽  
The Impact

ABSTRACTToxic metal pollution affects the composition and metal tolerance of soil bacterial communities. However, there is virtually no knowledge concerning the responses of members of specific bacterial taxa (e.g., phyla or classes) to metal toxicity, and contradictory results have been obtained regarding the impact of metals on operational taxonomic unit (OTU) richness. We used tag-coded pyrosequencing of the 16S rRNA gene to elucidate the impacts of copper (Cu) on bacterial community composition and diversity within a well-described Cu gradient (20 to 3,537 μg g−1) stemming from industrial contamination with CuSO4more than 85 years ago. DNA sequence information was linked to analysis of pollution-induced community tolerance (PICT) to Cu, as determined by the [3H]leucine incorporation technique, and to chemical characterization of the soil. PICT was significantly correlated to bioavailable Cu, as determined by the results seen with a Cu-specific bioluminescent biosensor strain, demonstrating a specific community response to Cu. The relative abundances of members of several phyla or candidate phyla, including theProteobacteria,Bacteroidetes,Verrumicrobia,Chloroflexi,WS3, andPlanctomycetes, decreased with increasing bioavailable Cu, while members of the dominant phylum, theActinobacteria, showed no response and members of theAcidobacteriashowed a marked increase in abundance. Interestingly, changes in the relative abundances of classes frequently deviated from the responses of the phyla to which they belong. Despite the apparent Cu impacts on Cu resistance and community structure, bioavailable Cu levels did not show any correlation to bacterial OTU richness (97% similarity level). Our report highlights several bacterial taxa responding to Cu and thereby provides new guidelines for future studies aiming to explore the bacterial domain for members of metal-responding taxa.

scholarly journals Dietary and developmental shifts in butterfly-associated bacterial communities

2018 ◽  
Vol 5 (5) ◽  
pp. 171559 ◽  
Author(s):  
Kruttika Phalnikar ◽  
Krushnamegh Kunte ◽  
Deepa Agashe
Keyword(s):  
Bacterial Communities ◽  
Developmental Stages ◽  
Bacterial Community Composition ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Butterfly Species ◽  
Active Selection ◽  
Key Factor ◽  
Taxonomic Groups ◽  
The Impact

Bacterial communities associated with insects can substantially influence host ecology, evolution and behaviour. Host diet is a key factor that shapes bacterial communities, but the impact of dietary transitions across insect development is poorly understood. We analysed bacterial communities of 12 butterfly species across different developmental stages, using amplicon sequencing of the 16S rRNA gene. Butterfly larvae typically consume leaves of a single host plant, whereas adults are more generalist nectar feeders. Thus, we expected bacterial communities to vary substantially across butterfly development. Surprisingly, only few species showed significant dietary and developmental transitions in bacterial communities, suggesting weak impacts of dietary transitions across butterfly development. On the other hand, bacterial communities were strongly influenced by butterfly species and family identity, potentially due to dietary and physiological variation across the host phylogeny. Larvae of most butterfly species largely mirrored bacterial community composition of their diets, suggesting passive acquisition rather than active selection. Overall, our results suggest that although butterflies harbour distinct microbiomes across taxonomic groups and dietary guilds, the dramatic dietary shifts that occur during development do not impose strong selection to maintain distinct bacterial communities across all butterfly hosts.

scholarly journals A meta-analysis reveals the environmental and host factors shaping the structure and function of the shrimp microbiota

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5382 ◽  
Author(s):  
Fernanda Cornejo-Granados ◽  
Luigui Gallardo-Becerra ◽  
Miriam Leonardo-Reza ◽  
Juan Pablo Ochoa-Romo ◽  
Adrian Ochoa-Leyva
Keyword(s):  
Developmental Stage ◽  
High Throughput Sequencing ◽  
Meta Analysis ◽  
Biological Factor ◽  
Rrna Gene ◽  
Wild Type ◽  
Biological Factors ◽  
Sequencing Data ◽  
Freshwater Environment ◽  
The Impact

The shrimp or prawn is the most valuable traded marine product in the world market today and its microbiota plays an essential role in its development, physiology, and health. The technological advances and dropping costs of high-throughput sequencing have increased the number of studies characterizing the shrimp microbiota. However, the application of different experimental and bioinformatics protocols makes it difficult to compare different studies to reach general conclusions about shrimp microbiota. To meet this necessity, we report the first meta-analysis of the microbiota from freshwater and marine shrimps using all publically available sequences of the 16S ribosomal gene (16S rRNA gene). We obtained data for 199 samples, in which 63.3% were from marine (Alvinocaris longirostris, Litopenaeus vannamei and Penaeus monodon), and 36.7% were from freshwater (Macrobrachium asperulum, Macrobrachium nipponense, Macrobranchium rosenbergii, Neocaridina denticulata) shrimps. Technical variations among studies, such as selected primers, hypervariable region, and sequencing platform showed a significant impact on the microbiota structure. Additionally, the ANOSIM and PERMANOVA analyses revealed that the most important biological factor in structuring the shrimp microbiota was the marine and freshwater environment (ANOSIM R = 0.54, P = 0.001; PERMANOVA pseudo-F = 21.8, P = 0.001), where freshwater showed higher bacterial diversity than marine shrimps. Then, for marine shrimps, the most relevant biological factors impacting the microbiota composition were lifestyle (ANOSIM R = 0.341, P = 0.001; PERMANOVA pseudo-F = 8.50, P = 0.0001), organ (ANOSIM R = 0.279, P = 0.001; PERMANOVA pseudo-F = 6.68, P = 0.001) and developmental stage (ANOSIM R = 0.240, P = 0.001; PERMANOVA pseudo-F = 5.05, P = 0.001). According to the lifestyle, organ, developmental stage, diet, and health status, the highest diversity were for wild-type, intestine, adult, wild-type diet, and healthy samples, respectively. Additionally, we used PICRUSt to predict the potential functions of the microbiota, and we found that the organ had more differentially enriched functions (93), followed by developmental stage (12) and lifestyle (9). Our analysis demonstrated that despite the impact of technical and bioinformatics factors, the biological factors were also statistically significant in shaping the microbiota. These results show that cross-study comparisons are a valuable resource for the improvement of the shrimp microbiota and microbiome fields. Thus, it is important that future studies make public their sequencing data, allowing other researchers to reach more powerful conclusions about the microbiota in this non-model organism. To our knowledge, this is the first meta-analysis that aims to define the shrimp microbiota.

scholarly journals Endophytic bacterial communities of oilseed rape associate with genotype-specific resistance against Verticillium longisporum

2019 ◽  
Vol 96 (1) ◽  
Author(s):  
Stefanie P Glaeser ◽  
Iulian Gabur ◽  
Hossein Haghighi ◽  
Jens-Ole Bartz ◽  
Peter Kämpfer ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Relative Abundance ◽  
Bacterial Communities ◽  
Quantitative Resistance ◽  
Bacterial Community Composition ◽  
Phylogenetic Group ◽  
Rrna Gene ◽  
Host Genotype ◽  
Brassica Napus L ◽  
Verticillium Longisporum

ABSTRACT Associations of endophytic bacterial community composition of oilseed rape (Brassica napus L.) with quantitative resistance against the soil-borne fungal pathogen Verticillium longisporum was assessed by 16S rRNA gene amplicon sequencing in roots and hypocotyls of four plant lines with contrasting genetic composition in regard to quantitative resistance reactions. The plant compartment was found to be the dominating driving factor for the specificity of bacterial communities in healthy plants. Furthermore, V. longisporum infection triggered a stabilization of phylogenetic group abundance in replicated samples suggesting a host genotype-specific selection. Genotype-specific associations with bacterial phylogenetic group abundance were identified by comparison of plant genotype groups (resistant versus susceptible) and treatment groups (healthy versus V. longisporum-infected) allowing dissection into constitutive and induced directional association patterns. Relative abundance of Flavobacteria, Pseudomonas, Rhizobium and Cellvibrio was associated with resistance/susceptibility. Relative abundance of Flavobacteria and Cellvibrio was increased in resistant genotypes according to their known ecological functions. In contrast, a higher relative abundance of Pseudomonas and Rhizobium, which are known to harbor many species with antagonistic properties to fungal pathogens, was found to be associated with susceptibility, indicating that these groups do not play a major role in genetically controlled resistance of oilseed rape against V. longisporum.

scholarly journals Ecological Succession of Bacterial Communities during Conventionalization of Germ-Free Mice

2012 ◽  
Vol 78 (7) ◽  
pp. 2359-2366 ◽  
Author(s):  
Merritt G. Gillilland ◽  
John R. Erb-Downward ◽  
Christine M. Bassis ◽  
Michael C. Shen ◽  
Galen B. Toews ◽  
...  
Keyword(s):  
Bacterial Community ◽  
16S Rrna ◽  
Bacterial Communities ◽  
Structural Heterogeneity ◽  
Ecological Succession ◽  
Rrna Gene ◽  
Gi Tract ◽  
Content Type ◽  
Germ Free ◽  
Over Time

ABSTRACTLittle is known about the dynamics of early ecological succession during experimental conventionalization of the gastrointestinal (GI) tract; thus, we measured changes in bacterial communities over time, at two different mucosal sites (cecum and jejunum), with germfree C57BL/6 mice as the recipients of cecal contents (input community) from a C57BL/6 donor mouse. Bacterial communities were monitored using pyrosequencing of 16S rRNA gene amplicon libraries from the cecum and jejunum and analyzed by a variety of ecological metrics. Bacterial communities, at day 1 postconventionalization, in the cecum and jejunum had lower diversity and were distinct from the input community (dominated by eitherEscherichiaorBacteroides). However, by days 7 and 21, the recipient communities had become significantly diverse and the cecal communities resembled those of the donor and donor littermates, confirming that transfer of cecal contents results in reassembly of the community in the cecum 7 to 21 days later. However, bacterial communities in the recipient jejunum displayed significant structural heterogeneity compared to each other or the donor inoculum or the donor littermates, suggesting that the bacterial community of the jejunum is more dynamic during the first 21 days of conventionalization. This report demonstrates that (i) mature input communities do not simply reassemble at mucosal sites during conventionalization (they first transform into a “pioneering” community and over time take on the appearance, in membership and structure, of the original input community) and (ii) the specific mucosal environment plays a role in shaping the community.

scholarly journals Impact of Maize–Mushroom Intercropping on the Soil Bacterial Community Composition in Northeast China

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1526
Author(s):  
Xiaoqin Yang ◽  
Yang Wang ◽  
Luying Sun ◽  
Xiaoning Qi ◽  
Fengbin Song ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Northeast China ◽  
Management Practice ◽  
Bacterial Community Composition ◽  
Soil Microbial Communities ◽  
Chemical Properties ◽  
Crop Productivity ◽  
Rrna Gene ◽  
Soil Bacterial Communities ◽  
Soil Bacterial

Conservative agricultural practices have been adopted to improve soil quality and maintain crop productivity. An efficient intercropping of maize with mushroom has been developed in Northeast China. The objective of this study was to evaluate and compare the effects of planting patterns on the diversity and structure of the soil bacterial communities at a 0–20 cm depth in the black soil zone of Northeast China. The experiment consisted of monoculture of maize and mushroom, and intercropping in a split-plot arrangement. The characteristics of soil microbial communities were performed by 16S rRNA gene amplicom sequencing. The results showed that intercropping increased soil bacterial richness and diversity compared with maize monoculture. The relative abundances of Acidobacteria, Chloroflexi, Saccharibacteria and Planctomycetes were significantly higher, whereas Proteobacteria and Firmicutes were lower in intercropping than maize monoculture. Redundancy analysis suggested that pH, NO3−-N and NH4+-N contents had a notable effect on the structure of the bacterial communities. Moreover, intercropping significantly increased the relative abundance of carbohydrate metabolism pathway functional groups. Overall, these findings demonstrated that intercropping of maize with mushroom strongly impacts the physical and chemical properties of soil as well as the diversity and structure of the soil bacterial communities, suggesting this is a sustainable agricultural management practice in Northeast China.

scholarly journals Changes of Bacterial Communities in Response to Prolonged Hydrodynamic Disturbances in the Eutrophic Water-Sediment Systems

2019 ◽  
Vol 16 (20) ◽  
pp. 3868
Author(s):  
Haomiao Cheng ◽  
Ling Cheng ◽  
Liang Wang ◽  
Tengyi Zhu ◽  
Wei Cai ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Bacterial Communities ◽  
16S Rrna Gene Sequencing ◽  
Aquatic Environments ◽  
Rrna Gene ◽  
Evolutionary Trend ◽  
Ecological Evaluation ◽  
Eutrophic Water ◽  
Rrna Gene Sequencing ◽  
Opposite Tendency

The effects of hydrodynamic disturbances on the bacterial communities in eutrophic aquatic environments remain poorly understood, despite their importance to ecological evaluation and remediation. This study investigated the evolution of bacterial communities in the water–sediment systems under the influence of three typical velocity conditions with the timescale of 5 weeks. The results demonstrated that higher bacterial diversity and notable differences were detected in sediment compared to water using the 16S rRNA gene sequencing. The phyla Firmicutes and γ-Proteobacteria survived better in both water and sediment under stronger water disturbances. Their relative abundance peaked at 36.0%, 33.2% in water and 38.0%, 43.6% in sediment, respectively, while the phylum Actinobacteria in water had the opposite tendency. Its relative abundance grew rapidly in static control (SC) and peaked at 44.8%, and it almost disappeared in disturbance conditions. These phenomena were caused by the proliferation of genus Exiguobacterium (belonging to Firmicutes), Citrobacter, Acinetobacter, Pseudomonas (belonging to γ-Proteobacteria), and hgcI_clade (belonging to Actinobacteria). The nonmetric multidimensional scaling (NMDS) and Venn analysis also revealed significantly different evolutionary trend in the three water-sediment systems. It was most likely caused by the changes of geochemical characteristics (dissolved oxygen (DO) and nutrients). This kind of study can provide helpful information for ecological assessment and remediation strategy in eutrophic aquatic environments.

scholarly journals Structure and Function of Bacterial Communities Emerging from Different Sources under Identical Conditions

2006 ◽  
Vol 72 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Silke Langenheder ◽  
Eva S. Lindström ◽  
Lars J. Tranvik
Keyword(s):  
Environmental Conditions ◽  
Bacterial Communities ◽  
Fragment Length Polymorphism ◽  
Bacterial Community Composition ◽  
Rrna Gene ◽  
Polymorphism Analysis ◽  
Scale Functions ◽  
And Function ◽  
Different Sources ◽  
The 16S Rrna Gene

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.

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