Recovery of Soil Protozoan Community Structure Promoted by M. sativa After a Strong Pulse of Hydrocarbon Contamination

2020 ◽  
Vol 231 (6) ◽  
Author(s):  
Laura Mondragón-Camarillo ◽  
Salvador Rodríguez Zaragoza ◽  
Ma. Remedios Mendoza-López ◽  
Nathalie Cabirol ◽  
Miroslav Macek
Keyword(s):  
Community Structure ◽  
Hydrocarbon Contamination ◽  
Protozoan Community

scholarly journals Genotypic and Phenotypic Responses of a Riverine Microbial Community to Polycyclic Aromatic Hydrocarbon Contamination

1998 ◽  
Vol 64 (9) ◽  
pp. 3422-3428 ◽  
Author(s):  
Donald E. Langworthy ◽  
Raymond D. Stapleton ◽  
Gary S. Sayler ◽  
Robert H. Findlay
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Nucleic Acid ◽  
Microbial Community Structure ◽  
Phospholipid Fatty Acid ◽  
Principal Component ◽  
Dry Weight ◽  
Hydrocarbon Contamination ◽  
Polycyclic Aromatic ◽  
Nucleic Acid Analysis

ABSTRACT The phenotypic and genotypic adaptation of a freshwater sedimentary microbial community to elevated (22 to 217 μg g [dry weight] of sediment−1) levels of polycyclic aromatic hydrocarbons (PAHs) was determined by using an integrated biomolecular approach. Central to the approach was the use of phospholipid fatty acid (PLFA) profiles to characterize the microbial community structure and nucleic acid analysis to quantify the frequency of degradative genes. The study site was the Little Scioto River, a highly impacted, channelized riverine system located in central Ohio. This study site is a unique lotic system, with all sampling stations having similar flow and sediment characteristics both upstream and downstream from the source of contamination. These characteristics allowed for the specific analysis of PAH impact on the microbial community. PAH concentrations in impacted sediments ranged from 22 to 217 μg g (dry weight) of sediment−1, while PAH concentrations in ambient sediments ranged from below detection levels to 1.5 μg g (dry weight) of sediment−1. Total microbial biomass measured by phospholipid phosphate (PLP) analysis ranged from 95 to 345 nmol of PLP g (dry weight) of sediment−1. Nucleic acid analysis showed the presence of PAH-degradative genes at all sites, although observed frequencies were typically higher at contaminated sites. Principal component analysis of PLFA profiles indicated that moderate to high PAH concentrations altered microbial community structure and that seasonal changes were comparable in magnitude to the effects of PAH pollution. These data indicate that this community responded to PAH contamination at both the phenotypic and the genotypic level.

The Study on Protozoan Community Structure of Zhalong Wetland

2014 ◽  
Vol 535 ◽  
pp. 470-473
Author(s):  
Yao Zhou ◽  
Zhi Gang Xie
Keyword(s):  
Water Quality ◽  
Community Structure ◽  
Native Species ◽  
Water Environment ◽  
Species Number ◽  
Zhalong Wetland ◽  
Quality Of Water ◽  
Protozoan Community ◽  
Significant Difference ◽  
Mining Water

The zhalong wetland water environment is an important part of the ecological environment, The protozoan community structure of Zhalong wetland was researched in this article. We can monitoring water pollution degree through the analysis of protozoan population, this research investigated protozoa population structure in qiqihar zhalong wetland through the PFU method and direct mining water in water samples, and analyse the physiological and biochemical parameters to assess the quality of water quality changes during May-October in 2012, the result show that 74 protozoa were observed including ciliate fleshiness shrimp center, flagellate less. In comparison with clean water inside, can use light and feed on algae native species number is more, different water quality in different conditions, protozoa composition has a very significant difference.

scholarly journals Impact of Protozoan Grazing on Bacterial Community Structure in Soil Microcosms

2002 ◽  
Vol 68 (12) ◽  
pp. 6094-6105 ◽  
Author(s):  
Regin Rønn ◽  
Allison E. McCaig ◽  
Bryan S. Griffiths ◽  
James I. Prosser
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Nutrient Solution ◽  
Bacterial Communities ◽  
Bacterial Community Structure ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Rrna Gene ◽  
Soil Microcosms ◽  
Protozoan Grazing ◽  
Protozoan Community

ABSTRACT The influence of grazing by a mixed assemblage of soil protozoa (seven flagellates and one amoeba) on bacterial community structure was studied in soil microcosms amended with a particulate resource (sterile wheat roots) or a soluble resource (a solution of various organic compounds). Sterilized soil was reinoculated with mixed soil bacteria (obtained by filtering and dilution) or with bacteria and protozoa. Denaturing gradient gel electrophoresis (DGGE) of PCR amplifications of 16S rRNA gene fragments, as well as community level physiological profiling (Biolog plates), suggested that the mixed protozoan community had significant effects on the bacterial community structure. Excising and sequencing of bands from the DGGE gels indicated that high-G+C gram-positive bacteria closely related to Arthrobacter spp. were favored by grazing, whereas the excised bands that decreased in intensity were related to gram-negative bacteria. The percentages of intensity found in bands related to high G+C gram positives increased from 4.5 and 12.6% in the ungrazed microcosms amended with roots and nutrient solution, respectively, to 19.3 and 32.9% in the grazed microcosms. Protozoa reduced the average bacterial cell size in microcosms amended with nutrient solution but not in the treatment amended with roots. Hence, size-selective feeding may explain some but not all of the changes in bacterial community structure. Five different protozoan isolates (Acanthamoeba sp., two species of Cercomonas, Thaumatomonas sp., and Spumella sp.) had different effects on the bacterial communities. This suggests that the composition of protozoan communities is important for the effect of protozoan grazing on bacterial communities.

Microplankton community structure and the impact of microzooplankton grazing during an Emiliania huxleyi bloom, off the Devon coast

2002 ◽  
Vol 82 (3) ◽  
pp. 359-368 ◽  
Author(s):  
E.S. Fileman ◽  
D.G. Cummings ◽  
C.A. Llewellyn
Keyword(s):  
Community Structure ◽  
Phytoplankton Community ◽  
Emiliania Huxleyi ◽  
Pigment Analysis ◽  
Protozoan Community ◽  
Grazing Mortality ◽  
Standing Stocks ◽  
The Impact ◽  
Microzooplankton Grazing ◽  
High Reflectance

Phytoplankton and microzooplankton community structure and the impact of microzooplankton grazing were investigated during a one-day study of an Emiliania huxleyi bloom off the coast of Devon during July 1999. Vertical profiles were undertaken at four stations, along a transect which crossed from a low reflectance to a high reflectance area as seen by satellite imagery. Microzooplankton dilution grazing experiments, coupled with pigment analysis to determine class specific grazing rates, were performed at two of these stations.Highest concentrations of chlorophyll-a (5·3 mg m−3) and accessory pigments were measured inside the area of high reflectance. Phytoplankton standing stocks ranged between 1588 and 5460 mg C m−2 and were also highest in the area of high reflectance. The phytoplankton community was dominated by coccolithophores and diatoms in low reflectance waters and by photosynthetic dinoflagellates in high reflectance areas. Microzooplankton standing stocks ranged between 905 and 2498 mg C m−2. Protozoa dominated the microzooplankton community. The protozoan community comprised a relatively even mixture of heterotrophic dinoflagellates, non-choreotrich and choreotrich ciliates in low reflectance waters. However, non-choreotrich ciliates dominated the communities inside the high reflectance area. Of the heterotrophic ciliates, a predatory ciliate Askenasia sp. dominated both non-choreotrich abundance and biomass.Results from grazing experiments showed that 60–64% of the chlorophyll-a biomass was consumed daily by the microzooplankton. Highest grazing mortality was associated with peridinin (dinoflagellates) and alloxanthin (cryptophytes). Lower grazing rates were found on fucoxanthin (diatoms and prymnesiophytes). Our results indicate that grazing on E. huxleyi in the area of remotely sensed high reflectance was low and highest grazing was on photosynthetic dinoflagellates and cryptophytes.

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.

Variations in the community structure of biofilm-dwelling protozoa at different depths in coastal waters of the Yellow Sea, northern China

2017 ◽  
Vol 99 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Mamun Abdullah Al ◽  
Yangyang Gao ◽  
Guangjian Xu ◽  
Zheng Wang ◽  
Henglong Xu ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Coastal Waters ◽  
Yellow Sea ◽  
Northern China ◽  
Marine Ecosystems ◽  
Artificial Substrates ◽  
The Yellow Sea ◽  
Individual Species ◽  
Protozoan Community

Biofilm-dwelling protozoa are a primary component of microbiota and play important roles in the functioning of microbial food webs such as the mediation of carbon and energy flux from plankton to benthos in marine ecosystems. To demonstrate the vertical pattern of the protozoan communities, a 1-month baseline survey was carried out in coastal waters of the Yellow Sea, northern China. A total of 40 samples were collected using glass slides as artificial substrates at four depths: 1, 2, 3.5 and 5 m. A total of 50 species were identified, comprising seven dominant and eight commonly distributed species. Species richness and individual species abundances showed a clear decreasing trend down the water column from 1 to 5 m, although the former peaked at a depth of 2 m. Multivariate approaches revealed that protozoan community structure differed significantly among the four depths, except for those at 2 and 3.5 m. Maximum values of species richness, diversity and evenness generally decreased with depth although they peaked at either 2 or 3.5 m. These results suggest that water depth may significantly shape the community patterns of biofilm-dwelling protozoa in marine ecosystems.

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