Protozoan Community Structure in a Fractal Soil Environment

Protist ◽  
2001 ◽  
Vol 152 (3) ◽  
pp. 203-218 ◽  
Author(s):  
B FINLAY
Keyword(s):  
Community Structure ◽  
Soil Environment ◽  
Protozoan Community

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.

High-throughput sequencing-based analysis of the composition and diversity of endophytic bacterial community in seeds of upland rice

2020 ◽  
Author(s):  
Zhishan Wang ◽  
Yongqiang Zhu ◽  
Ruixue Jing ◽  
Xianyu Wu ◽  
Ni Li ◽  
...  
Keyword(s):  
Community Structure ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Upland Rice ◽  
Functional Evaluation ◽  
Soil Environment ◽  
Soil Microbial Community Structure ◽  
The Core ◽  
Rice Seeds ◽  
The Impact

Abstract Upland rice is an ecotype crop formed by long-term domestication and evolution of rice in the dry land without water layer. Generally, its stem and leaf are thick and luxuriant, its leaf is wide and light, its root system is developed, its root hair is abundant, its osmotic pressure of root and cell juice concentration of leaf are high, and it is drought resistant, heat-resistant and water absorbing. The purpose of this study is to reveal the “core flora” of endophytes in upland rice seeds by studying the diversity and community structure of endophytes in upland rice seeds, and to reveal the impact of soil environment on the formation of endophyte community structure in upland rice seeds by comparing with soil environment microorganisms in upland rice habitats. In this study, the high-throughput sequencing technology based on the Illumina Hiseq 2500 platform was used to study the structure and diversity of endophytic bacterial communities using upland rice varieties collected in different places and soil samples from their unified planting sites as materials. There are 42 endophytic OTUs coexisted in the 14 samples. At the phylum level, the first dominant phyla was Proteobacteria (93.81–99.99%) in all 14 samples. At the genus level, Pantoea (8.77% -87.77%), Pseudomonas (1.15–61.58%), Methylobacterium (0.40–4.64%), Sphingomonas (0.26–3.85%), Microbacterium (0.01–4.67%) and Aurantimonas (0.04–4.34%), which are probably the core microflora in upland rice seeds, served as the dominant genera that coexisted in all upland rice seeds tested. Compared with the soil microbial community structure in the upland rice uniform planting site, it was found that it had little effect on the endophytic community structure in upland rice seeds. This study is of great significance for the isolation, screening, functional evaluation and re-action of some functional microorganisms in upland rice in order to improve its agronomic traits. It also provides a certain reference for the interaction between microorganisms and plants.

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.

scholarly journals Use of RNA and DNA to Identify Mechanisms of Microbial Community Homogenization

2018 ◽  
Author(s):  
Kyle M Meyer ◽  
Ian A.B. Petersen ◽  
Elie Tobi ◽  
Lisa Korte ◽  
Brendan Bohannan
Keyword(s):  
Land Use ◽  
Community Structure ◽  
Microbial Community ◽  
Environmental Changes ◽  
Environmental Variability ◽  
Congo Basin ◽  
Active Fraction ◽  
Soil Environment ◽  
Inference Methods ◽  
Rna And Dna

Biotic homogenization is a commonly observed response following conversion of native ecosystems to agriculture, but our mechanistic understanding of this process is limited for microbial communities. In the case of rapid environmental changes, inference of homogenization mechanisms may be confounded by the fact that only a minority of taxa is active at any given point. RNA- and DNA-based community inference may help to distinguish the active fraction of a community from inactive taxa. Using these two community inference methods, we asked how soil prokaryotic communities respond to land use change following transition from rainforest to agriculture in the Congo Basin. Our results indicate that the magnitude of community homogenization is larger in the RNA-inferred community than the DNA-inferred perspective. We show that as the soil environment changes, the RNA-inferred community structure tracks environmental variation and loses spatial structure. The DNA-inferred community loses its association with environmental variability. Homogenization of the DNA-inferred community appears to instead be driven by the range expansion of a minority of taxa shared between the forest and conversion sites, which is also seen in the RNA-inferred community. Our results suggest that complementing DNA-based surveys with RNA can provide unique perspectives on community responses to environmental change.

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.

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.

scholarly journals Temporal Changes of Virus-Like Particle Abundance and Metagenomic Comparison of Viral Communities in Cropland and Prairie Soils

mSphere ◽  
2021 ◽  
Author(s):  
Carolyn R. Cornell ◽  
Ya Zhang ◽  
Joy D. Van Nostrand ◽  
Pradeep Wagle ◽  
Xiangming Xiao ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Communities ◽  
Carbon Mineralization ◽  
Soil Microbial Communities ◽  
Microbial Abundance ◽  
Soil Environment ◽  
Soil Microbial ◽  
Prairie Soils ◽  
Virus Like Particle ◽  
Viral Communities

Conversion of land alters the physiochemical and biological environments by not only changing the aboveground community, but also modifying the soil environment for viruses and microbes. Soil microbial communities are critical to nutrient cycling, carbon mineralization, and soil quality; and viruses are known for influencing microbial abundance, community structure, and evolution.

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 Vegetation and Soil Environment Influence the Spatial Distribution of Root-Associated Fungi in a Mature Beech-Maple Forest

2009 ◽  
Vol 75 (24) ◽  
pp. 7639-7648 ◽  
Author(s):  
David J. Burke ◽  
Juan C. López-Gutiérrez ◽  
Kurt A. Smemo ◽  
Charlotte R. Chan
Keyword(s):  
Community Structure ◽  
Mycorrhizal Fungi ◽  
Spatial Scales ◽  
Plant Distribution ◽  
Fungal Communities ◽  
Herbaceous Plant ◽  
Soil Environment ◽  
Root Tips ◽  
Mature Forest ◽  
Root Fungi

ABSTRACT Although the level of diversity of root-associated fungi can be quite high, the effect of plant distribution and soil environment on root-associated fungal communities at fine spatial scales has received little attention. Here, we examine how soil environment and plant distribution affect the occurrence, diversity, and community structure of root-associated fungi at local patch scales within a mature forest. We used terminal restriction fragment length polymorphism and sequence analysis to detect 63 fungal species representing 28 different genera colonizing tree root tips. At least 32 species matched previously identified mycorrhizal fungi, with the remaining fungi including both saprotrophic and parasitic species. Root fungal communities were significantly different between June and September, suggesting a rapid temporal change in root fungal communities. Plant distribution affected root fungal communities, with some root fungi positively correlated with tree diameter and herbaceous-plant coverage. Some aspects of the soil environment were correlated with root fungal community structure, with the abundance of some root fungi positively correlated with soil pH and moisture content in June and with soil phosphorous (P) in September. Fungal distribution and community structure may be governed by plant-soil interactions at fine spatial scales within a mature forest. Soil P may play a role in structuring root fungal communities at certain times of the year.

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