scholarly journals Assessment of the bacterial community structure in shallow and deep sediments of the Perdido Fold Belt region in the Gulf of Mexico

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5583 ◽  
Author(s):  
Ma. Fernanda Sánchez-Soto Jiménez ◽  
Daniel Cerqueda-García ◽  
Jorge L. Montero-Muñoz ◽  
Ma. Leopoldina Aguirre-Macedo ◽  
José Q. García-Maldonado
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Gulf Of Mexico ◽  
Microbial Communities ◽  
Bacterial Community Structure ◽  
High Throughput Sequencing ◽  
Hydrocarbon Contamination ◽  
Rrna Gene ◽  
Fold Belt ◽  
Abundant Otus

The Mexican region of the Perdido Fold Belt (PFB), in northwestern Gulf of Mexico (GoM), is a geological province with important oil reservoirs that will be subjected to forthcoming oil exploration and extraction activities. To date, little is known about the native microbial communities of this region, and how these change relative to water depth. In this study we assessed the bacterial community structure of surficial sediments by high-throughput sequencing of the 16S rRNA gene at 11 sites in the PFB, along a water column depth gradient from 20 to 3,700 m, including five shallow (20–600 m) and six deep (2,800–3,700 m) samples. The results indicated that OTUs richness and diversity were higher for shallow sites (OTUs = 2,888.2 ± 567.88;H′ = 9.6 ± 0.85) than for deep sites (OTUs = 1,884.7 ± 464.2;H′ = 7.74 ± 1.02). Nonmetric multidimensional scaling (NMDS) ordination revealed that shallow microbial communities grouped separately from deep samples. Additionally, the shallow sites plotted further from each other on the NMDS whereas samples from the deeper sites (abyssal plains) plotted much more closely to each other. These differences were related to depth, redox potential, sulfur concentration, and grain size (lime and clay), based on the environmental variables fitted with the axis of the NMDS ordination. In addition, differential abundance analysis identified 147 OTUs with significant fold changes among the zones (107 from shallow and 40 from deep sites), which constituted 10 to 40% of the total relative abundances of the microbial communities. The most abundant OTUs with significant fold changes in shallow samples corresponded toKordiimonadales, Rhodospirillales,Desulfobacterales(Desulfococcus), Syntrophobacterales and Nitrospirales(GOUTA 19,BD2-6,LCP-6), whilstChromatiales,Oceanospirillales(Amphritea,Alcanivorax),Methylococcales,Flavobacteriales,Alteromonadales(Shewanella,ZD0117) andRhodobacteraleswere the better represented taxa in deep samples. Several of the OTUs detected in both deep and shallow sites have been previously related to hydrocarbons consumption. Thus, this metabolism seems to be well represented in the studied sites, and it could abate future hydrocarbon contamination in this ecosystem. The results presented herein, along with biological and physicochemical data, constitute an available reference for further monitoring of the bacterial communities in this economically important region in the GoM.

scholarly journals Restructuring of the Aquatic Bacterial Community by Hydric Dynamics Associated with Superstorm Sandy

2016 ◽  
Vol 82 (12) ◽  
pp. 3525-3536 ◽  
Author(s):  
Nikea Ulrich ◽  
Abigail Rosenberger ◽  
Colin Brislawn ◽  
Justin Wright ◽  
Collin Kessler ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
High Throughput ◽  
Bacterial Community Structure ◽  
High Throughput Sequencing ◽  
Storm Event ◽  
Rrna Gene ◽  
Content Type

ABSTRACTBacterial community composition and longitudinal fluctuations were monitored in a riverine system during and after Superstorm Sandy to better characterize inter- and intracommunity responses associated with the disturbance associated with a 100-year storm event. High-throughput sequencing of the 16S rRNA gene was used to assess microbial community structure within water samples from Muddy Creek Run, a second-order stream in Huntingdon, PA, at 12 different time points during the storm event (29 October to 3 November 2012) and under seasonally matched baseline conditions. High-throughput sequencing of the 16S rRNA gene was used to track changes in bacterial community structure and divergence during and after Superstorm Sandy. Bacterial community dynamics were correlated to measured physicochemical parameters and fecal indicator bacteria (FIB) concentrations. Bioinformatics analyses of 2.1 million 16S rRNA gene sequences revealed a significant increase in bacterial diversity in samples taken during peak discharge of the storm. Beta-diversity analyses revealed longitudinal shifts in the bacterial community structure. Successional changes were observed, in whichBetaproteobacteriaandGammaproteobacteriadecreased in 16S rRNA gene relative abundance, while the relative abundance of members of theFirmicutesincreased. Furthermore, 16S rRNA gene sequences matching pathogenic bacteria, including strains ofLegionella,Campylobacter,Arcobacter, andHelicobacter, as well as bacteria of fecal origin (e.g.,Bacteroides), exhibited an increase in abundance after peak discharge of the storm. This study revealed a significant restructuring of in-stream bacterial community structure associated with hydric dynamics of a storm event.IMPORTANCEIn order to better understand the microbial risks associated with freshwater environments during a storm event, a more comprehensive understanding of the variations in aquatic bacterial diversity is warranted. This study investigated the bacterial communities during and after Superstorm Sandy to provide fine time point resolution of dynamic changes in bacterial composition. This study adds to the current literature by revealing the variation in bacterial community structure during the course of a storm. This study employed high-throughput DNA sequencing, which generated a deep analysis of inter- and intracommunity responses during a significant storm event. This study has highlighted the utility of applying high-throughput sequencing for water quality monitoring purposes, as this approach enabled a more comprehensive investigation of the bacterial community structure. Altogether, these data suggest a drastic restructuring of the stream bacterial community during a storm event and highlight the potential of high-throughput sequencing approaches for assessing the microbiological quality of our environment.

Seasonal effects of river flow on microbial community coalescence and diversity in a riverine network

2020 ◽  
Vol 96 (8) ◽  
Author(s):  
Xia Luo ◽  
Xinyi Xiang ◽  
Yuanhao Yang ◽  
Guoyi Huang ◽  
Kaidao Fu ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Flow Rate ◽  
Bacterial Communities ◽  
Bacterial Community Structure ◽  
Rrna Gene ◽  
Strong Impact ◽  
Running Waters

ABSTRACT Terrestrial microbial communities may take advantage of running waters and runoff to enter rivers and mix with aquatic microorganisms. However, the environmental factors governing the interchange of the microbial community within a watercourse and its surrounding environment and the composition of the resulting community are often underestimated. The present study investigated the effect of flow rate on the mixing of water, soil, sediment and biofilm at four sites along the Lancang River and one branch of the river in winter and summer and, in turn, the resultant changes in the microbial community within each habitat. 16S rRNA gene-based Illumina high-throughput sequencing illustrated that bacterial communities were apparently distinct among biofilm, water, soil and sediment. Biofilms had the lowest richness, Shannon diversity and evenness indices compared with other habitats, and those three indices in all habitats increased significantly from winter to summer. SourceTracker analysis showed a significant coalescence between the bacterial communities of sediment, water and biofilm samples at lower flow rates. Additionally, the proportion of Betaproteobacteria in sediment and biofilms increased with a decrease in flow rate, suggesting the flow rate had a strong impact on microbial community composition and exchange among aquatic habitats. These results were further confirmed by a Mantel test and linear regression analysis. Microbial communities in all samples exhibited a significant but very weak distance–decay relationship (r = 0.093, P = 0.024). Turbidity played a much more important role on water bacterial community structure in summer (i.e. rainy season) (BIOENV, r = 0.92). Together, these results suggest that dispersal is an important factor affecting bacterial community structure in this system.

scholarly journals Comparison of Auxin and Cytokinins Concentrations, and the Structure of Bacterial Community between Host Twigs and Lithosaphonecrus arcoverticus Galls

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 982
Author(s):  
Xue-Mei Yang ◽  
Yu Hui ◽  
Lv-Quan Zhao ◽  
Dao-Hong Zhu ◽  
Yang Zeng ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
High Throughput Sequencing ◽  
Zeatin Riboside ◽  
Insect Galls ◽  
Abnormal Growth ◽  
Liquid Chromatography Tandem Mass ◽  
High Concentrations ◽  
Galling Insects

Insect galls are the abnormal growth of plant tissues induced by a wide variety of galling insects and characterized by high concentrations of auxins and cytokinins. It remains unclear whether the auxins and cytokinins affect the bacterial community structure of insect galls. We determined the concentrations of indoleacetic acid (IAA) as an example of auxin, trans-zeatin riboside (tZR) and isopentenyladenine (iP) as cytokinins in Lithosaphonecrus arcoverticus (Hymenoptera: Cynipidae) galls and the galled twigs of Lithocarpus glaber (Fagaceae) using liquid chromatography–tandem mass spectrometry. Moreover, for the first time, we compared the bacterial community structure of L. arcoverticus galls and galled twigs by high-throughput sequencing, and calculated the Spearman correlation and associated degree of significance between the IAA, tZR and iP concentrations and the bacterial community structure. Our results indicated the concentrations of IAA, tZR and iP were higher in L. arcoverticus galls than in galled twigs, and positively correlated with the bacterial community structure of L. arcoverticus galls. We suggest the high concentrations of IAA, tZR and iP may affect the bacterial community structure of L. arcoverticus galls.

scholarly journals Effects of Continuous Cropping on Bacterial Community Structure in Rhizospheric Soil of Sweet Potato

2020 ◽  
Author(s):  
Zhiyuan Gao ◽  
Yaya Hu ◽  
Meikun Han ◽  
Junjie Xu ◽  
Xue Wang ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Sweet Potato ◽  
Soil Ph ◽  
Bacterial Community Structure ◽  
High Throughput Sequencing ◽  
Potato Industry ◽  
Continuous Cropping ◽  
Rhizospheric Soil ◽  
Potato Varieties

Abstract Background: Continuous cropping obstacles from sweet potato are widespread, which seriously reduce the yield and quality, restrict the sustainable development of sweet potato industry. Bacteria are the most abundant in rhizospheric soil and have a certain relationship with continuous cropping obstacles. However, there are few reports on how continuous cropping affected the bacterial community structure in the rhizospheric soil of sweet potato. In this study, high-throughput sequencing technique was used to explore the changes of rhizospheric soil bacterial community structure of different sweet potato varieties, and the correlation between soil characteristics and this bacterial community after continuous cropping, so as to provide a theoretical basis for the prevention and control of sweet potato continuous cropping obstacles.Results: After two years of continuous cropping, the results showed that (1) the dominant bacteria phlya in rhizospheric soils from both Xushu18 and Yizi138 were Proteobacteria, Acidobacteria, and Actinobacteria. The most dominant genus was Subgroup 6_norank. Significant changes in the relative abundance of rhizospheric soil bacteria were observed for two sweet potato varieties. (2) Bacterial richness and diversity indexes of rhizospheric soil from Xushu18 were higher than those from Yizi138 after continuous cropping. Moreover, the beneficial Lysobacter and Bacillus were more prevalent in Xushu18, but Yizi138 contained more harmful Gemmatimonadetes. (3) Soil pH decreased after continuous cropping, and redundancy analysis showed that soil pH was significantly correlated with bacterial community. Spearman’s rank correlations coefficients analysis demonstrated that pH was positively correlated with Planctomycetes and Acidobacteria, and negatively correlated with Actinobacteria and Firmicutes.Conclusions: After continuous cropping of sweet potato, the bacterial community structure and physicochemical properties in the rhizospheric soil were unbalanced, and the changes of different sweet potato varieties were different. The contents of Lysobacter and Bacillus were higher in the sweet potato variety resistant to continuous cropping. It provides a basis for the development of special microbial fertilizer for sweet potatoes to alleviate continuous cropping obstacle.

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