scholarly journals Salt Marsh Bacterial Communities before and after the Deepwater Horizon Oil Spill

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Annette Summers Engel ◽  
Chang Liu ◽  
Audrey T. Paterson ◽  
Laurie C. Anderson ◽  
R. Eugene Turner ◽  
...  

ABSTRACT Coastal salt marshes along the northern Gulf of Mexico shoreline received varied types and amounts of weathered oil residues after the 2010 Deepwater Horizon oil spill. At the time, predicting how marsh bacterial communities would respond and/or recover to oiling and other environmental stressors was difficult because baseline information on community composition and dynamics was generally unavailable. Here, we evaluated marsh vegetation, physicochemistry, flooding frequency, hydrocarbon chemistry, and subtidal sediment bacterial communities from 16S rRNA gene surveys at 11 sites in southern Louisiana before the oil spill and resampled the same marshes three to four times over 38 months after the spill. Calculated hydrocarbon biomarker indices indicated that oil replaced native natural organic matter (NOM) originating from Spartina alterniflora and marine phytoplankton in the marshes between May 2010 and September 2010. At all the studied marshes, the major class- and order-level shifts among the phyla Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria occurred within these first 4 months, but another community shift occurred at the time of peak oiling in 2011. Two years later, hydrocarbon levels decreased and bacterial communities became more diverse, being dominated by Alphaproteobacteria (Rhizobiales), Chloroflexi (Dehalococcoidia), and Planctomycetes. Compositional changes through time could be explained by NOM source differences, perhaps due to vegetation changes, as well as marsh flooding and salinity excursions linked to freshwater diversions. These findings indicate that persistent hydrocarbon exposure alone did not explain long-term community shifts. IMPORTANCE Significant deterioration of coastal salt marshes in Louisiana has been linked to natural and anthropogenic stressors that can adversely affect how ecosystems function. Although microorganisms carry out and regulate most biogeochemical reactions, the diversity of bacterial communities in coastal marshes is poorly known, with limited investigation of potential changes in bacterial communities in response to various environmental stressors. The Deepwater Horizon oil spill provided an unprecedented opportunity to study the long-term effects of an oil spill on microbial systems in marshes. Compared to previous studies, the significance of our research stems from (i) a broader geographic range of studied marshes, (ii) an extended time frame of data collection that includes prespill conditions, (iii) a more accurate procedure using biomarker indices to understand oiling, and (iv) an examination of other potential stressors linked to in situ environmental changes, aside from oil exposure.

2011 ◽  
Vol 77 (22) ◽  
pp. 7962-7974 ◽  
Author(s):  
Joel E. Kostka ◽  
Om Prakash ◽  
Will A. Overholt ◽  
Stefan J. Green ◽  
Gina Freyer ◽  
...  

ABSTRACTA significant portion of oil from the recent Deepwater Horizon (DH) oil spill in the Gulf of Mexico was transported to the shoreline, where it may have severe ecological and economic consequences. The objectives of this study were (i) to identify and characterize predominant oil-degrading taxa that may be used as model hydrocarbon degraders or as microbial indicators of contamination and (ii) to characterize thein situresponse of indigenous bacterial communities to oil contamination in beach ecosystems. This study was conducted at municipal Pensacola Beach, FL, where chemical analysis revealed weathered oil petroleum hydrocarbon (C8to C40) concentrations ranging from 3.1 to 4,500 mg kg−1in beach sands. A total of 24 bacterial strains from 14 genera were isolated from oiled beach sands and confirmed as oil-degrading microorganisms. Isolated bacterial strains were primarilyGammaproteobacteria, including representatives of genera with known oil degraders (Alcanivorax,Marinobacter,Pseudomonas, andAcinetobacter). Sequence libraries generated from oiled sands revealed phylotypes that showed high sequence identity (up to 99%) to rRNA gene sequences from the oil-degrading bacterial isolates. The abundance of bacterial SSU rRNA gene sequences was ∼10-fold higher in oiled (0.44 × 107to 10.2 × 107copies g−1) versus clean (0.024 × 107to 1.4 × 107copies g−1) sand. Community analysis revealed a distinct response to oil contamination, and SSU rRNA gene abundance derived from the genusAlcanivoraxshowed the largest increase in relative abundance in contaminated samples. We conclude that oil contamination from the DH spill had a profound impact on the abundance and community composition of indigenous bacteria in Gulf beach sands, and our evidence points to members of theGammaproteobacteria(Alcanivorax,Marinobacter) andAlphaproteobacteria(Rhodobacteraceae) as key players in oil degradation there.


Author(s):  
Lina Sun ◽  
Wei Chen ◽  
Kaihua Huang ◽  
Weiguang Lyu ◽  
Xinhua Gao

Strain SJQ9T, an aerobic bacterium isolated from a soil sample collected in Shanghai, PR China, was characterized using a polyphasic approach. It grew optimally at pH 7.0, 30–35 °C and in the presence of 1 % (w/v) NaCl. A comparative analysis of 16S rRNA gene sequences showed that strain SJQ9T fell within the genus Aquabacterium . The closest phylogenetic relatives of strain SJQ9T were Aquabacterium citratiphilum DSM 11900T (98.6 % sequence similarity) and Aquabacterium commune DSM 11901T (96.4 %). Cells of the strain were Gram-stain-negative, motile, non-spore-forming, rod-shaped and positive for oxidase activity and negative for catalase. The chemotaxonomic properties of strain SJQ9T were consistent with those of the genus Aquabacterium : the major fatty acid was summed feature 3 (C16 : 1  ω6c and/or C16 : 1  ω7c). The isoprenoid quinone was Q-8. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 65.7 mol%. Strain SH9T exhibited a DNA–DNA relatedness level of 34±2 % with A. citratiphilum DSM 11900T and 28±3 % with A. commune DSM 11901T. Based on the obtained data, strain SJQ9T represents a novel species of the genus Aquabacterium , for which the name Aquabacterium soli sp. nov. is proposed. The type strain is SJQ9T (=JCM 33106T=CCTCC AB 2018284T).


2011 ◽  
Vol 77 (20) ◽  
pp. 7207-7216 ◽  
Author(s):  
Naomi F. Montalvo ◽  
Russell T. Hill

ABSTRACTThe giant barrel spongesXestospongiamutaandXestospongiatestudinariaare ubiquitous in tropical reefs of the Atlantic and Pacific Oceans, respectively. They are key species in their respective environments and are hosts to diverse assemblages of bacteria. These two closely related sponges from different oceans provide a unique opportunity to examine the evolution of sponge-associated bacterial communities. Mitochondrial cytochrome oxidase subunit I gene sequences fromX.mutaandX.testudinariashowed little divergence between the two species. A detailed analysis of the bacterial communities associated with these sponges, comprising over 900 full-length 16S rRNA gene sequences, revealed remarkable similarity in the bacterial communities of the two species. Both sponge-associated communities include sequences found only in the twoXestospongiaspecies, as well as sequences found also in other sponge species and are dominated by three bacterial groups,Chloroflexi,Acidobacteria, andActinobacteria. While these groups consistently dominate the bacterial communities revealed by 16S rRNA gene-based analysis of sponge-associated bacteria, the depth of sequencing undertaken in this study revealed clades of bacteria specifically associated with each of the twoXestospongiaspecies, and also with the genusXestospongia, that have not been found associated with other sponge species or other ecosystems. This study, comparing the bacterial communities associated with closely related but geographically distant sponge hosts, gives new insight into the intimate relationships between marine sponges and some of their bacterial symbionts.


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 ◽  
...  

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.


mSystems ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Marta Turon ◽  
Maria J. Uriz ◽  
Daniel Martin

ABSTRACTSponges establish tight associations with both micro- and macroorganisms. However, while studies on sponge microbiomes are numerous, nothing is currently known about the microbiomes of sponge-associated polychaetes and their relationships with those of their host sponges. We analyzed the bacterial communities of symbiotic polychaetes (Haplosyllisspp.) and their host sponges (Clathria reinwardti,Amphimedon paraviridis,Neofibularia hartmani, andAaptos suberitoides) to assess the influence of the sponges on the polychaete microbiomes. We identified both eukaryote partners by molecular (16S and COI genes) and morphological features, and we identified their microbial communities by high-throughput sequencing of the 16S rRNA gene (V4 region). We unravel the existence of sixHaplosyllisspecies (five likely undescribed) associated at very high densities with the study sponge species in Nha Trang Bay (central Vietnam). A single polychaete species inhabitedA. paraviridisand was different from the single species that inhabitedA. suberitoides. Conversely, two different polychaete species were found inC. reinwardtiandN. hartmani, depending on the two host locations. Regardless of the host sponge, polychaete microbiomes were species specific, which is a widespread feature in marine invertebrates. More than half of the polychaete bacteria were also found in the host sponge microbiome but at contrasting abundances. Thus, the associated polychaetes seemed to be able to select, incorporate, and enrich part of the sponge microbiome, a selection that appears to be polychaete species specific. Moreover, the bacterial diversity is similar in both eukaryotic partners, which additionally confirms the influence of food (host sponge) on the structure of the polychaete microbiome.IMPORTANCEThe symbiotic lifestyle represents a fundamental cryptic contribution to the diversity of marine ecosystems. Sponges are ideal targets to improve understanding the symbiotic relationships from evolutionary and ecological points of view, because they are the most ancient metazoans on earth, are ubiquitous in the marine benthos, and establish complex symbiosis with both prokaryotes and animals, which in turn also harbor their own bacterial communities. Here, we study the microbiomes of sponge-polychaete associations and confirm that polychaetes feed on their host sponges. The study worms select and enrich part of the sponge microbiome to shape their own species-specific bacterial communities. Moreover, worm microbiome diversity runs parallel to that of its food host sponge. Considering our results on symbiotic polychaetes and previous studies on fishes and mammals, diet appears to be an important source of bacteria for animals to shape their species-specific microbiomes.


2015 ◽  
Vol 81 (19) ◽  
pp. 6864-6872 ◽  
Author(s):  
Timothy M. LaPara ◽  
Katheryn Hope Wilkinson ◽  
Jacqueline M. Strait ◽  
Raymond M. Hozalski ◽  
Michael J. Sadowksy ◽  
...  

ABSTRACTThe bacterial community composition of the full-scale biologically active, granular activated carbon (BAC) filters operated at the St. Paul Regional Water Services (SPRWS) was investigated using Illumina MiSeq analysis of PCR-amplified 16S rRNA gene fragments. These bacterial communities were consistently diverse (Shannon index, >4.4; richness estimates, >1,500 unique operational taxonomic units [OTUs]) throughout the duration of the 12-month study period. In addition, only modest shifts in the quantities of individual bacterial populations were observed; of the 15 most prominent OTUs, the most highly variable population (aVariovoraxsp.) modulated less than 13-fold over time and less than 8-fold from filter to filter. The most prominent population in the profiles was aNitrospirasp., representing 13 to 21% of the community. Interestingly, very few of the known ammonia-oxidizing bacteria (AOB; <0.07%) and no ammonia-oxidizingArchaeawere detected in the profiles. Quantitative PCR ofamoAgenes, however, suggested that AOB were prominent in the bacterial communities (amoA/16S rRNA gene ratio, 1 to 10%). We conclude, therefore, that the BAC filters at the SPRWS potentially contained significant numbers of unidentified and novel ammonia-oxidizing microorganisms that possessamoAgenes similar to those of previously described AOB.


2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 1083-1088 ◽  
Author(s):  
Kai Chen ◽  
Shu-Kun Tang ◽  
Guang-Li Wang ◽  
Guo-Xing Nie ◽  
Qin-Fen Li ◽  
...  

Bacterial strain 14-2AT, isolated from a long-term DDT-contaminated soil in China, was characterized by using a polyphasic approach to clarify its taxonomic position. Strain 14-2AT was found to be Gram-negative, aerobic, non-spore-forming, non-motile, non-flagellated and rod-shaped. The new isolate was able to grow at 4–42 °C, pH 6.0–9.0 and with 0–5 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the family Sphingobacteriaceae . The 16S rRNA gene sequence of strain 14-2AT showed the highest similarity with Olivibacter oleidegradans TBF2/20.2T (99.4 %), followed by Pseudosphingobacterium domesticum DC-186T (93.8 %), Olivibacter ginsengisoli Gsoil 060T (93.6 %), Olivibacter terrae Jip13T (93.1 %), Olivibacter soli Gsoil 034T (92.8 %) and Olivibacter sitiensis AW-6T (89.6 %). The DNA–DNA hybridization value between strains 14-2AT and O. oleidegradans TBF2/20.2T was 34.45±2.11 %. Strain 14-2AT contained phosphatidylethanolamine, phosphatidylmonomethylethanolamine, aminophospholipid and phosphatidylinositol mannoside as the major polar lipids. The DNA G+C content was 41.2 mol%. MK-7 is the major isoprenoid quinone. Summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and iso-C17 : 0 3-OH are the major fatty acids. The phenotypic and chemotaxonomic data confirmed the affiliation of strain 14-2AT to the genus Olivibacter . On the basis of the phylogenetic and phenotypic characteristics, and chemotaxonomic data, strain 14-2AT is considered to represent a novel species of the genus Olivibacter , for which the name Olivibacter jilunii sp. nov. is proposed; the type strain is 14-2AT ( = KCTC 23098T = CCTCC AB 2010105T).


2018 ◽  
Vol 84 (9) ◽  
Author(s):  
Bing Li ◽  
Wei-Min Wu ◽  
David B. Watson ◽  
Erick Cardenas ◽  
Yuanqing Chao ◽  
...  

ABSTRACTA site in Oak Ridge, TN, USA, has sediments that contain >3% iron oxides and is contaminated with uranium (U). The U(VI) was bioreduced to U(IV) and immobilizedin situthrough intermittent injections of ethanol. It then was allowed to reoxidize via the invasion of low-pH (3.6 to 4.0), high-nitrate (up to 200 mM) groundwater back into the reduced zone for 1,383 days. To examine the biogeochemical response, high-throughput sequencing and network analysis were applied to characterize bacterial population shifts, as well as cooccurrence and coexclusion patterns among microbial communities. A pairedttest indicated no significant changes of α-diversity for the bioactive wells. However, both nonmetric multidimensional scaling and analysis of similarity confirmed a significant distinction in the overall composition of the bacterial communities between the bioreduced and the reoxidized sediments. The top 20 major genera accounted for >70% of the cumulative contribution to the dissimilarity in the bacterial communities before and after the groundwater invasion.Castellaniellahad the largest dissimilarity contribution (17.7%). For the bioactive wells, the abundance of the U(VI)-reducing generaGeothrix,Desulfovibrio,Ferribacterium, andGeobacterdecreased significantly, whereas the denitrifyingAcidovoraxabundance increased significantly after groundwater invasion. Additionally, seven genera, i.e.,Castellaniella,Ignavibacterium,Simplicispira,Rhizomicrobium,AcidobacteriaGp1,AcidobacteriaGp14, andAcidobacteriaGp23, were significant indicators of bioactive wells in the reoxidation stage. Canonical correspondence analysis indicated that nitrate, manganese, and pH affected mostly the U(VI)-reducing genera and indicator genera. Cooccurrence patterns among microbial taxa suggested the presence of taxa sharing similar ecological niches or mutualism/commensalism/synergism interactions.IMPORTANCEHigh-throughput sequencing technology in combination with a network analysis approach were used to investigate the stabilization of uranium and the corresponding dynamics of bacterial communities under field conditions with regard to the heterogeneity and complexity of the subsurface over the long term. The study also examined diversity and microbial community composition shift, the common genera, and indicator genera before and after long-term contaminated-groundwater invasion and the relationship between the target functional community structure and environmental factors. Additionally, deciphering cooccurrence and coexclusion patterns among microbial taxa and environmental parameters could help predict potential biotic interactions (cooperation/competition), shared physiologies, or habitat affinities, thus, improving our understanding of ecological niches occupied by certain specific species. These findings offer new insights into compositions of and associations among bacterial communities and serve as a foundation for future bioreduction implementation and monitoring efforts applied to uranium-contaminated sites.


2018 ◽  
Vol 84 (22) ◽  
Author(s):  
Jonah E. Einson ◽  
Asha Rani ◽  
Xiaomeng You ◽  
Allison A. Rodriguez ◽  
Clifton L. Randell ◽  
...  

ABSTRACTFermented vegetables are highly popular internationally in part due to their enhanced nutritional properties, cultural history, and desirable sensorial properties. In some instances, fermented foods provide a rich source of the beneficial microbial communities that could promote gastrointestinal health. The indigenous microbiota that colonize fermentation facilities may impact food quality, food safety, and spoilage risks and maintain the nutritive value of the product. Here, microbiomes within sauerkraut production facilities were profiled to characterize variance across surfaces and to determine the sources of these bacteria. Accordingly, we used high-throughput sequencing of the 16S rRNA gene in combination with whole-genome shotgun analyses to explore biogeographical patterns of microbial diversity and assembly within the production facility. Our results indicate that raw cabbage and vegetable handling surfaces exhibit more similar microbiomes relative to the fermentation room, processing area, and dry storage surfaces. We identified biomarker bacterial phyla and families that are likely to originate from the raw cabbage and vegetable handling surfaces. Raw cabbage was identified as the main source of bacteria to seed the facility, with human handling contributing a minor source of inoculation.LeuconostocandLactobacillaceaedominated all surfaces where spontaneous fermentation occurs, as these taxa are associated with the process. Wall, floor, ceiling, and barrel surfaces host unique microbial signatures. This study demonstrates that diverse bacterial communities are widely distributed within the production facility and that these communities assemble nonrandomly, depending on the surface type.IMPORTANCEFermented vegetables play a major role in global food systems and are widely consumed by various global cultures. In this study, we investigated an industrial facility that produces spontaneous fermented sauerkraut without the aid of starter cultures. This provides a unique system to explore and track the origins of an “in-house” microbiome in an industrial environment. Raw vegetables and the surfaces on which they are handled were identified as the likely source of bacterial communities rather than human contamination. As fermented vegetables increase in popularity on a global scale, understanding their production environment may help maintain quality and safety goals.


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