scholarly journals Effect of Drought Stress and Developmental Stages on Microbial Community Structure and Diversity in Peanut Rhizosphere Soil

2019 ◽  
Vol 20 (9) ◽  
pp. 2265 ◽  
Author(s):  
Liangxiang Dai ◽  
Guanchu Zhang ◽  
Zipeng Yu ◽  
Hong Ding ◽  
Yang Xu ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Drought Tolerance ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Defense Mechanism ◽  
Developmental Stages ◽  
Rrna Gene ◽  
Special Importance ◽  
Arachis Hypogaea L

Background: Peanut (Arachis hypogaea L.), an important oilseed and food legume, is widely cultivated in the semi-arid tropics. Drought is the major stress in this region which limits productivity. Microbial communities in the rhizosphere are of special importance to stress tolerance. However, relatively little is known about the relationship between drought and microbial communities in peanuts. Method: In this study, deep sequencing of the V3-V4 region of the 16S rRNA gene was performed to characterize the microbial community structure of drought-treated and untreated peanuts. Results: Taxonomic analysis showed that Actinobacteria, Proteobacteria, Saccharibacteria, Chloroflexi, Acidobacteria and Cyanobacteria were the dominant phyla in the peanut rhizosphere. Comparisons of microbial community structure of peanuts revealed that the relative abundance of Actinobacteria and Acidobacteria dramatically increased in the seedling and podding stages in drought-treated soil, while that of Cyanobacteria and Gemmatimonadetes increased in the flowering stage in drought-treated rhizospheres. Metagenomic profiling indicated that sequences related to metabolism, signaling transduction, defense mechanism and basic vital activity were enriched in the drought-treated rhizosphere, which may have implications for plant survival and drought tolerance. Conclusion: This microbial communities study will form the foundation for future improvement of drought tolerance of peanuts via modification of the soil microbes.

scholarly journals Archaeal, bacterial, and eukaryal microbial community structure of sediment and seawater in a coastal region near Puerto Nuevo, Baja California

2018 ◽  
Author(s):  
Sabah Ul-Hasan ◽  
Robert M. Bowers ◽  
Andrea Figueroa-Montiel ◽  
Alexei F. Licea-Navarro ◽  
J. Michael Beman ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Baja California ◽  
Coastal Region ◽  
Coastal Ecosystems ◽  
Rrna Gene ◽  
Microbial Biodiversity ◽  
Seawater Samples

AbstractMicrobial communities control numerous biogeochemical processes critical for ecosystem function and health, particularly in coastal ecosystems. However, comparatively little is known about microbial community structure in coastal regions, such that basic patterns of microbial biodiversity, such as species richness and community composition, are generally understudied. To better understand the global patterns of microbial biodiversity in coastal ecosystems, we characterized sediment and seawater microbial communities for three sites near Puerto Nuevo (Baja California, Mexico) using 16S and 18S rRNA gene amplicon sequencing methods. We found that sediment bacteria, archaea, and eukaryote microbial communities contained approximately 5 × 10^2 fold greater operational taxonomic units (OTUs) than their seawater-based counterparts (p < 0.001). Further, distinct bacterial, archaeal and eukaryal phyla were found in sediment and seawater samples. The phyla Acidobacteria, Chlorobi, and Chloroflexi were found to be abundant and unique to the sediment and Cyanobacteria, Spirochaetae, and Woesearchaeota to the seawater environment. Apicomplexa and Arthropoda were abundant eukaryal phyla found uniquely in the sediment whereas the Cryptomonadales and Protalveolata were detected only in the seawater. Furthermore, bacterial and archaeal communities were statistically different by site (p < 0.05) in both seawater and sediment samples for the Major Outlet site, the site closest to a residential area. In contrast, eukaryal microbial communities were only different among sites in the seawater samples. Overall, these results suggest that our understanding of coastal microbial biodiversity patterns require spatially robust sampling. This study contributes to a growing body of foundational microbial biodiversity and ecology knowledge, providing context to the global change that is induced by urban development.

Phylum-Specific Primer Design and Implication in Quantification of the Microbial Community Structure in GuJingGong Pit Mud

2014 ◽  
Vol 1051 ◽  
pp. 311-316 ◽  
Author(s):  
Xi Mei Luo ◽  
Zhi Lei Gao ◽  
Hui Min Zhang ◽  
An Jun Li ◽  
Hong Kui He ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Real Time Quantitative Pcr ◽  
Sequencing Technologies ◽  
Specific Pcr ◽  
Pit Mud ◽  
Almost All ◽  
Polymerase Chain Reaction Primers

In recent years, despite the significant improvement of sequencing technologies such as the pyrosequencing, rapid evaluation of microbial community structures remains very difficult because of the abundance and complexity of organisms in almost all natural microbial communities. In this paper, a group of phylum-specific primers were elaborately designed based on a single nucleotide discrimination technology to quantify the main microbial community structure from GuJingGong pit mud samples using the real-time quantitative PCR (qPCR). Specific PCR (polymerase chain reaction) primers targeting a particular group would provide promising sensitivity and more in-depth assessment of microbial communities.

scholarly journals Antibiotic resistome and microbial community structure during anaerobic co-digestion of food waste, paper and cardboard

2020 ◽  
Vol 96 (2) ◽  
Author(s):  
Kärt Kanger ◽  
Nigel G H Guilford ◽  
HyunWoo Lee ◽  
Camilla L Nesbø ◽  
Jaak Truu ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Solid State ◽  
Food Waste ◽  
Microbial Community Structure ◽  
Microbial Community Composition ◽  
Microbial Community Analysis ◽  
Waste Paper ◽  
Rrna Gene ◽  
Significant Shift

ABSTRACT Solid organic waste is a significant source of antibiotic resistance genes (ARGs) and effective treatment strategies are urgently required to limit the spread of antimicrobial resistance. Here, we studied ARG diversity and abundance as well as the relationship between antibiotic resistome and microbial community structure within a lab-scale solid-state anaerobic digester treating a mixture of food waste, paper and cardboard. A total of 10 samples from digester feed and digestion products were collected for microbial community analysis including small subunit rRNA gene sequencing, total community metagenome sequencing and high-throughput quantitative PCR. We observed a significant shift in microbial community composition and a reduction in ARG diversity and abundance after 6 weeks of digestion. ARGs were identified in all samples with multidrug resistance being the most abundant ARG type. Thirty-two per cent of ARGs detected in digester feed were located on plasmids indicating potential for horizontal gene transfer. Using metagenomic assembly and binning, we detected potential bacterial hosts of ARGs in digester feed, which included Erwinia, Bifidobacteriaceae, Lactococcus lactis and Lactobacillus. Our results indicate that the process of sequential solid-state anaerobic digestion of food waste, paper and cardboard tested herein provides a significant reduction in the relative abundance of ARGs per 16S rRNA gene.

A quantitative comparison of microbial community structure of estuarine sediments from microcosms and the field

1986 ◽  
Vol 32 (4) ◽  
pp. 319-325 ◽  
Author(s):  
Thomas W. Federle ◽  
Robert J. Livingston ◽  
Loretta E. Wolfe ◽  
David C. White
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Ecological Factors ◽  
Estuarine Sediments ◽  
Physical Factors ◽  
Multivariate Statistical ◽  
Apalachicola Bay ◽  
Sound Experiment

Estuarine soft-bottom sediments in microcosms and the field were compared with regard to microbial community structure. Community structure was determined by analyzing the fatty acids derived from the microbial lipids in the sediments. Fatty acid profiles were compared using a multivariate statistical approach. Experiments were performed using sediments from St. George Sound and Apalachicola Bay, Florida. The community structure of St. George Sound sediments was apparently controlled by epibenthic predators. In Apalachicola Bay, the dominant influences were physical factors related to the flow of the Apalachicola River. In the St. George Sound experiment, microbial communities in the microcosms differed from those in the field after only 2 weeks, and the degree of this difference increased substantially as time progressed. In the Apalachicola Bay experiment, although microbial communities in the microcosms were detectably different from those in the field, the degree of this difference was not large nor did it increase with time. This differential behavior of sediment communities from different sites may be related to the different ecological factors regulating community composition at these sites.

scholarly journals Microbial community structure in the western tropical South Pacific

2018 ◽  
Vol 15 (12) ◽  
pp. 3909-3925 ◽  
Author(s):  
Nicholas Bock ◽  
France Van Wambeke ◽  
Moïra Dion ◽  
Solange Duhamel
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
N2 Fixation ◽  
Phytoplankton Biomass ◽  
South Pacific ◽  
Global Ocean ◽  
Bottom Up

Abstract. Oligotrophic regions play a central role in global biogeochemical cycles, with microbial communities in these areas representing an important term in global carbon budgets. While the general structure of microbial communities has been well documented in the global ocean, some remote regions such as the western tropical South Pacific (WTSP) remain fundamentally unexplored. Moreover, the biotic and abiotic factors constraining microbial abundances and distribution remain not well resolved. In this study, we quantified the spatial (vertical and horizontal) distribution of major microbial plankton groups along a transect through the WTSP during the austral summer of 2015, capturing important autotrophic and heterotrophic assemblages including cytometrically determined abundances of non-pigmented protists (also called flagellates). Using environmental parameters (e.g., nutrients and light availability) as well as statistical analyses, we estimated the role of bottom–up and top–down controls in constraining the structure of the WTSP microbial communities in biogeochemically distinct regions. At the most general level, we found a “typical tropical structure”, characterized by a shallow mixed layer, a clear deep chlorophyll maximum at all sampling sites, and a deep nitracline. Prochlorococcus was especially abundant along the transect, accounting for 68 ± 10.6 % of depth-integrated phytoplankton biomass. Despite their relatively low abundances, picophytoeukaryotes (PPE) accounted for up to 26 ± 11.6 % of depth-integrated phytoplankton biomass, while Synechococcus accounted for only 6 ± 6.9 %. Our results show that the microbial community structure of the WTSP is typical of highly stratified regions, and underline the significant contribution to total biomass by PPE populations. Strong relationships between N2 fixation rates and plankton abundances demonstrate the central role of N2 fixation in regulating ecosystem processes in the WTSP, while comparative analyses of abundance data suggest microbial community structure to be increasingly regulated by bottom–up processes under nutrient limitation, possibly in response to shifts in abundances of high nucleic acid bacteria (HNA).

Spatial variation in microbial community structure, richness, and diversity in an alluvial aquifer

2012 ◽  
Vol 58 (9) ◽  
pp. 1135-1151 ◽  
Author(s):  
P.G. Medihala ◽  
J.R. Lawrence ◽  
G.D.W. Swerhone ◽  
D.R. Korber
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Spatial Variability ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Microbial Community Composition ◽  
Alluvial Aquifer ◽  
Gradient Gel Electrophoresis

Relatively little is known regarding the spatial variability of microbial communities in aquifers where well fouling is an issue. In this study 2 water wells were installed in an alluvial aquifer located adjacent to the North Saskatchewan River and an associated piezometer network developed to facilitate the study of microbial community structure, richness, and diversity. Carbon utilization data analysis revealed reduced microbial activity in waters collected close to the wells. Functional PCR and quantitative PCR analysis indicated spatial variability in the potential for iron-, sulphate-, and nitrate-reducing activity at all locations in the aquifer. Denaturing gradient gel electrophoresis analysis of aquifer water samples using principal components analyses indicated that the microbial community composition was spatially variable, and denaturing gradient gel electrophoresis sequence analysis revealed that bacteria belonging to the genera Acidovorax , Rhodobacter , and Sulfuricurvum were common throughout the aquifer. Shannon’s richness (H′) and Pielou’s evenness (J′) indices revealed a varied microbial diversity (H′ = 1.488–2.274) and an even distribution of microbial communities within the aquifer (J′ = 0.811–0.917). Overall, these analyses revealed that the aquifer’s microbial community varied spatially in terms of composition, richness, and metabolic activity. Such information may facilitate the diagnosis, prevention, and management of fouling.

scholarly journals Relationships between Microbial Community Structure and Hydrochemistry in a Landfill Leachate-Polluted Aquifer

2001 ◽  
Vol 67 (10) ◽  
pp. 4619-4629 ◽  
Author(s):  
Wilfred F. M. Röling ◽  
Boris M. van Breukelen ◽  
Martin Braster ◽  
Bin Lin ◽  
Henk W. van Verseveld
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Communities ◽  
16S Rdna ◽  
Microbial Community Structure ◽  
Landfill Leachate ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Numerical Comparison ◽  
Gram Positive ◽  
Gram Positive Bacteria

ABSTRACT Knowledge about the relationship between microbial community structure and hydrogeochemistry (e.g., pollution, redox and degradation processes) in landfill leachate-polluted aquifers is required to develop tools for predicting and monitoring natural attenuation. In this study analyses of pollutant and redox chemistry were conducted in parallel with culture-independent profiling of microbial communities present in a well-defined aquifer (Banisveld, The Netherlands). Degradation of organic contaminants occurred under iron-reducing conditions in the plume of pollution, while upstream of the landfill and above the plume denitrification was the dominant redox process. Beneath the plume iron reduction occurred. Numerical comparison of 16S ribosomal DNA (rDNA)-based denaturing gradient gel electrophoresis (DGGE) profiles of Bacteria andArchaea in 29 groundwater samples revealed a clear difference between the microbial community structures inside and outside the contaminant plume. A similar relationship was not evident in sediment samples. DGGE data were supported by sequencing cloned 16S rDNA. Upstream of the landfill members of the β subclass of the class Proteobacteria(β-proteobacteria) dominated. This group was not encountered beneath the landfill, where gram-positive bacteria dominated. Further downstream the contribution of gram-positive bacteria to the clone library decreased, while the contribution of δ-proteobacteria strongly increased and β-proteobacteria reappeared. The β-proteobacteria (Acidovorax,Rhodoferax) differed considerably from those found upstream (Gallionella, Azoarcus). Direct comparisons of cloned 16S rDNA with bands in DGGE profiles revealed that the data from each analysis were comparable. A relationship was observed between the dominant redox processes and the bacteria identified. In the iron-reducing plume members of the familyGeobacteraceae made a strong contribution to the microbial communities. Because the only known aromatic hydrocarbon-degrading, iron-reducing bacteria areGeobacter spp., their occurrence in landfill leachate-contaminated aquifers deserves more detailed consideration.

scholarly journals The impact of stand age and fertilization on the soil microbiome of Miscanthus × giganteus

2020 ◽  
Author(s):  
Lanying Ma ◽  
Fernando Igne Rocha ◽  
Jaejin Lee ◽  
Jinlyung Choi ◽  
Mauricio Tejera ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Soil Microbial Communities ◽  
N Fertilizer ◽  
Soil Microbiome ◽  
Stand Age ◽  
Soil Microbial ◽  
Miscanthus Giganteus

Yield of the perennial grass Miscanthus × giganteus has shown an inconsistent and unpredictable response to nitrogen (N) fertilizer, yet fertilization underpins the crop’s environmental and economic sustainability. The interactions among soil microbial communities, N availability, and M. × giganteus and management may explain changes in plant productivity. In this study, soil samples from different stand ages of M. × giganteus in a replicated chronosequence field trial were used to investigate the effects of stand age and N fertilizer rates on microbial community structure. We hypothesized that there is a definable M. × giganteus soil microbiome and that this community varies significantly with stand age and fertilization. Our results showed that the main phyla in soil microbial communities, regardless of plant age, are similar but microbial community structures are significantly different. The variation in observed microbial communities generally decreases in older stand ages. The amount of N fertilizer applied also affected the microbial community structure associated with different aged M. × giganteus. Specifically, the relative abundance of Proteobacteria (Alphaproteobacteria and Gammaproteobacteria) and Acidobacteria (Subgroup Gp1) increased shortly after fertilization and were more associated with younger M. × giganteus. Further, our results show a significant relationship between bacterial alpha diversity and fertilization rates and that this response is also impacted by stand age. Overall, our results emphasize linkages between microbial community structure, plant age, and fertilization in M. × giganteus.

scholarly journals Nitrapyrin has far reaching effects on the soil microbial community structure, composition, diversity and functions

2020 ◽  
Author(s):  
Ruth Schmidt ◽  
Xiao-Bo Wang ◽  
Paolina Garbeva ◽  
Étienne Yergeau
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Fungal Community ◽  
Soil Microbial Community ◽  
Ammonia Oxidizers ◽  
Soil Microbial Community Structure ◽  
Soil Microbial ◽  
Fungal Community Structure

AbstractNitrapyrin is one of the most common nitrification inhibitors that are used to retain N in the ammonia form in soil to improve crop yields and quality. Whereas the inhibitory effect of nitrapyrin is supposedly specific to ammonia oxidizers, in view of the keystone role of this group in soils, nitrapyrin could have far-reaching impacts. Here, we tested the hypothesis that nitrapyrin leads to large shifts in soil microbial community structure, composition, diversity and functions, beyond its effect on ammonia-oxidizers. To test this hypothesis, we set-up a field experiment where wheat (Triticum aestivum cv. AC Walton) was fertilized with ammonium nitrate (NH4NO3) and supplemented or not with nitrapyrin. Rhizosphere and bulk soils were sampled twice, DNA was extracted, the 16S rRNA gene and ITS region were amplified and sequenced to follow shifts in archaeal, bacterial and fungal community structure, composition and diversity. To assess microbial functions, several genes involved in the nitrogen cycle were quantified by real-time qPCR and volatile organic compounds (VOCs) were trapped in the rhizosphere at the moment of sampling. As expected, sampling date and plant compartment had overwhelming effects on the microbial communities. However, within these strong effects, we found statistically significant effects of nitrapyrin on the relative abundance of Thaumarchaeota, Proteobacteria, Nitrospirae and Basidiomycota, and on several genera. Nitrapyrin also significantly affected bacterial and fungal community structure, and the abundance of all the N-cycle gene tested, but always in interaction with sampling date. In contrast, nitrapyrin had no significant effect on the emission of VOCs, where only sampling date significantly influenced the profiles observed. Our results point out far-reaching effects of nitrapyrin on soil and plant associated microbial communities, well beyond its predicted direct effect on ammonia-oxidizers. In the longer term, these shifts might counteract the positive effect of nitrapyrin on crop nutrition and greenhouse gas emissions.

scholarly journals Assessment of microbial communities in Nakivubo wetland and its catchment areas in Lake Victoria Basin, Uganda

2020 ◽  
Author(s):  
Bernard N. Kanoi ◽  
Maribet Gamboa ◽  
Doris Ngonzi ◽  
Thomas G. Egwang
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Diversity ◽  
Microbial Community Structure ◽  
Lake Victoria ◽  
Rrna Gene ◽  
Lake Victoria Basin ◽  
Structure Changes ◽  
Catchment Areas ◽  
Polluted Sites

AbstractMicrobial community structure changes are key in detecting and characterizing the impacts of anthropogenic activities on aquatic ecosystems. Here, we evaluated the effect of river pollution of industrial and urban sites on the microbial community composition and distribution in the Nakivubo wetland and its catchment areas in Lake Victoria basin, Uganda. Samples were collected from two industrial and one urban polluted sites and the microbial diversity was analyzed based on a 16S rRNA gene clone library. Differences in microbial diversity and community structure were observed at different sampling points. Bacteria associated with bioremediation were found in sites receiving industrial waste, while a low proportion of important human-pathogenic bacteria were seen in urban polluted sites. While Escherichia spp. was the most dominant genus of bacteria for all sites, three unique bacteria, Bacillus sp., Pseudomonas sp., Thermomonas sp., which have been reported to transform contaminants such as heavy metals and hydrocarbons (such as oils) by their metabolic pathways were also identified. Our results may serve as a basis for further studies assessing microbial community structure changes among polluted sites at Nakivubo Water Channel for management and monitoring. The diversity of natural microbial consortia could also be a rich bioprospecting resource for novel industrial enzymes, medicinal and bioactive compounds.

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