[show abstract][hide abstract] ABSTRACT: In order to explore the possible impact of nutrient de-crease on microplankton community under high eutrophica-tion stress, rotifer, protozoa and algae samples were col-lected during a nutrient control from July to August, 2008 in Taihu Lake in China, and examined by both species and phylogenetic patterns. A total of 10 rotifer, 40 protozoal and 24 algal taxa were detected before the nutrient control in July, 2008. After the nutrient control (August, 2008), a total of 23, 16 and 9 taxa were detected for rotifer, proto-zoa and algae, respectively. By comparing samples to those before the control, the average Shannon-Wiener indexes, Simpson indexes and Pielou evenness indexes increased 197%, 101% and 73%, respectively. The average phyloge-netic species variability (PSV) and phylogenetic species evenness (PSE) decreased 63% and 1%, respectively. Ca-nonical correspondence analysis (CCA) of interactions be-tween environmental variables and microplankton communi-ties indicated that most of the microplankton species found in August were negatively correlated with nutrient level (e.g. total nitrogen, ammonia nitrogen, total phosphorus and orthophosphate), with both species and phylogenetic patterns. This study showed that the lower diversity and closer species relatedness of microplankton under high eu-trophication stress could get mended when the nutrient got down. In addition, the results revealed that phylogenetic diversity patterns could effectively help community re-search when predicting community and species responses to disturbance.
[show abstract][hide abstract] ABSTRACT: We evaluated the seasonal variation in plankton community composition in
an artificial lake. We conducted microscopic analysis and denaturing
gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA
and 18S rRNA genes to characterize the plankton community. The
clustering of unweighted pair group method with arithmetic mean (UPGMA)
was then used to investigate the similarity of these plankton
communities. DGGE fingerprinting revealed that samples collected at the
different sites within a season shared high similarity and were
generally grouped together. In contrast, we did not observe any seasonal
variation based on microscopic analysis. Redundancy analysis (RDA) of
the plankton operational taxonomic units (OTUs) in relation to
environmental factors revealed that transparency was negatively
correlated with the first axis ( R=-0.931), and temperature and total
phosphorus (TP) were positively correlated with the first axis ( R=0.736
and R=0.660, respectively). In conclusion, plankton communities in the
artificial lake exhibited significant seasonal variation. Transparency,
phosphorus and temperature appear to be the major factors driving the
differences in plankton composition.
Chinese Journal of Oceanology and Limnology 05/2012; 30(3):397-403. · 0.58 Impact Factor
[show abstract][hide abstract] ABSTRACT: We investigated the influence of host species on intestinal microbiota by comparing the gut bacterial community structure of four cohabitating freshwater fish larvae, silver carp, grass carp, bighead carp, and blunt snout bream, using denaturing gradient gel electrophoresis (DGGE) of the amplified 16S and 18S rRNA genes. Similarity clustering indicated that the intestinal microbiota derived from these four fish species could be divided into four groups based on 16S rRNA gene similarity, whereas the eukaryotic 18S rRNA genes showed no distinct groups. The water sample from the shared environment contained microbiota of an independent group as indicated by both 16S and 18S rRNA genes segments. The bacterial community structures were visualized using rank-abundance plots fitted with linear regression models. Results showed that the intestinal bacterial evenness was significantly different between species (P<0.05) and between species and the water sample (P<0.01). Thirty-five relatively dominant bands in DGGE patterns were sequenced and grouped into five major taxa: Proteobacteria (26), Actinobacteria (5), Bacteroidetes (1), Firmicutes (2), and Cyanobacterial (1). Six eukaryotes were detected by sequencing 18S rRNA genes segments. The present study suggests that the intestines of the four fish larvae, although reared in the same environment, contained distinct bacterial populations, while intestinal eukaryotic microorganisms were almost identical.
The Journal of Microbiology 02/2012; 50(1):29-37. · 1.28 Impact Factor
[show abstract][hide abstract] ABSTRACT: Biological nitrogen fixation (BNF) is one of the major nitrogen inputs into the biosphere, and the nitrogenase iron protein
(nifH) gene plays important roles in regulating the molecular nitrogen (N2) fixation process. The nifH gene has also been extensively used to study the diversity and function of nitrogen-fixing microorganisms. In this study,
we investigated the diversity of the nifH gene by culture-independent methods to analysis the planktonic nitrogen-fixing organisms in Lake Donghu, Wuhan, the largest
urban lake in China. Results indicate that nifH gene sequences cloned from planktonic-community DNA showed high similarity to the uncultured cyanobacterial sequences deposited
in the GenBank database. Phylogenetic analysis on the basis of the translated amino acid sequences further showed that most
nifH clones were closely related to the reported cyanobacterial nifH gene sequences. Results also indicate that there are similar planktonic nitrogen-fixing organisms in the relatively independent
areas of Lake Donghu, even though different regions showed a wide gradient in trophic status. These and other observations
led us to believe that studies on nifH gene diversity and expression will increase our ability to understand the ecological function of target nitrogen-fixing groups
in aquatic ecosystems.
[show abstract][hide abstract] ABSTRACT: Peritrich ciliates have been traditionally subdivided into two orders, Sessilida and Mobilida within the subclass Peritrichia. However, all the existing small subunit (SSU) rRNA phylogenetic trees showed that the sessilids and mobilids did not branch together. To shed some light on this disagreement, we tested whether or not the classic Peritrichia is a monophyletic group by assessing the reliability of the SSU rRNA phylogeny in terms of congruency with alpha-tubulin phylogeny. For this purpose, we obtained 10 partial alpha-tubulin sequences from peritrichs and built phylogenetic trees based on alpha-tubulin nucleotide and amino acid data. A phylogenetic tree from the alpha-tubulin and SSU rRNA genes in combination was also constructed and compared with that from the SSU rRNA gene using a similar species sampling. Our results show that the mobilids and sessilids are consistently separated in all trees, which reinforces the idea that the peritrichs do not constitute a monophyletic group. However, in all alpha-tubulin gene trees, the urceolariids and trichodiniids do not group together, suggested mobilids may not be a monophyletic group.
Journal of Eukaryotic Microbiology 03/2010; 57(3):265-72. · 2.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology, especially removing algal blooms, because algae were the major primary producer in algal lakes. The influence on zooplankton community after half a year of algal blooms removed by chitosan-modified soils in Taihu Lake was assessed and the rationality of carrying out the process semiannually was evaluated in the present study. Morphological composition and genetic diversity of zooplankton community were investigated by microscope checkup and polymerase chain reaction-denatured gradient gel electrophoresis (PCR-DGGE). A total of 44 zooplankton taxa (23 protozoa, 17 rotifers, 3 copepoda and 1 cladocera) were detected by microscope checkup, and a total of 91 bands (28 bands amplified by primers F1427-GC and R1616, 63 bands amplified by primers Fung-GC and NS1) were detected by PCR-DGGE. The results of cluster analysis or detrended correspondence analysis indicated that there was no considerable difference in morphological composition of zooplankton and DGGE profiles between experimental and control sites, and DGGE profiles could represent the biologic diversity. The study showed that zooplankton community could recover original condition after half year of algal blooms removed by chitosan-modified soils and it was acceptable to apply this process semiannually. In addition, the results revealed that PCR-DGGE could be applied to investigate the impacts of the environmental protection or restoration engineering on zooplankton community diversity.
Journal of Environmental Sciences 01/2010; 22(10):1500-7. · 1.77 Impact Factor
[show abstract][hide abstract] ABSTRACT: Using artificial systems to simulate natural lake environments with cyanobacterial blooms, we investigated plankton community succession by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting and morphological method. With this approach, we explored potential ecological effects of a newly developed cyanobacterial blooms removal method using chitosan-modified soils. Results of PCR-DGGE and morphological identification showed that plankton communities in the four test systems were nearly identical at the beginning of the experiment. After applying the newly developed and standard removal methods, there was a shift in community composition, but neither chemical conditions nor plankton succession were significantly affected by the cyanobacteria removal process. The planted Vallisneria natans successfully recovered after cyanobacteria removal, whereas that in the box without removal process did not. Additionally, canonical correspondence analysis indicated that other than for zooplankton abundance, total phosphorus was the most important environmental predictor of planktonic composition. The present study and others suggest that dealing with cyanobacteria removal using chitosan-modified soils can play an important role in controlling cyanobacterial blooms in eutrophicated freshwater systems.
[show abstract][hide abstract] ABSTRACT: Genetic diversity of the plankton community in Lake Xiliang was depicted by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting. Seventy-seven bands (33 of 16s rDNA and 44 of 18s rDNA) were detected, sixty-two planktonic taxa were identified in six sample stations in November 2007. The most common taxa were Ceratium hirundinella, Bdelloidea, Keratella cochlearis, Polyarthra trigla, and copepod nauplii. Based on environmental factors, taxonomic composition, and PCR-DGGE fingerprinting, unweighted pair-group method using arithmetic averages clustering and principal components analysis were used to analyze habitat similarities. There was distinct spatial heterogeneity in Lake Xiliang, and the genetic diversity of the plankton community was closely related to taxonomic composition and environmental factors.
Journal of Freshwater Ecology - J FRESHWATER ECOL. 01/2009; 24(1):125-134.
[show abstract][hide abstract] ABSTRACT: The 16S and 18S rRNA genes of planktonic organisms derived from five stations with nutrient gradients in Lake Donghu, China, were studied by PCR-denaturing gradient gel electrophoresis (DGGE) fingerprinting, and the relationships between the genetic diversity of the plankton community and biotic/abiotic factors are discussed. The concentrations of total nitrogen (TN), total phosphorus (TP), NH(4)-N and As were found to be significantly related (P<0.05) to morphological composition of the plankton community. Both chemical and morphological analyses suggested that temporal heterogeneity was comparatively higher than spatial heterogeneity in Lake Donghu. Although the morphological composition was not identical to the DGGE fingerprints in characterizing habitat similarity, the two strongest eutrophic stations (I and II) were always initially grouped into one cluster. Canonical correspondence analysis suggested that the factors strongly correlated with the first two ordination axes were seasonally different. The concentrations of TN and TP and the densities of rotifers and crustaceans were generally the main factors related to the DGGE patterns of the plankton communities. The study suggested that genetic diversity as depicted by metagenomic techniques (such as PCR-DGGE fingerprinting) is a promising tool for ecological study of plankton communities and that such techniques are likely to play an increasingly important role in assessing the environmental conditions of aquatic habitats.
[show abstract][hide abstract] ABSTRACT: To explore the relationships between community composition and the environment in a reservoir ecosystem, plankton communities from the Three Gorges Reservoir Region were studied by PCR-denaturing gradient gel electrophoresis fingerprinting. Bacterial and eukaryotic operational taxonomic units (OTUs), generated by DGGE analysis of the PCR-amplified 16S and 18S rRNA genes, were used as surrogates for the dominant "biodiversity units". OTU composition among the sites was heterogeneous; 46.7% of the total bacterial OTUs (45) and 64.1% of the eukaryotic OTUs (39) were identified in less than half of the sampling sites. Unweighted pair group method with arithmetic averages (UPGMA) clustering of the OTUs suggested that the plankton communities in the Xiangxi River sites were not always significantly different from those from the Yangtze River sites, despite clear differences in their environmental characterizations. Canonical correspondence analysis (CCA) was applied to further investigate the relationships between OTU composition and the environmental factors. The first two CCA ordination axes suggested that the bacterial community composition was primarily correlated with the variables of NO(3-)-N, dissolved oxygen (DO), and SiO3(2-)-Si, whereas, the eukaryotic community was mainly correlated with the concentrations of DO, PO4(3-)-P, and SiO3(2-)-Si.
Journal of Environmental Sciences 02/2008; 20(6):732-8. · 1.77 Impact Factor
[show abstract][hide abstract] ABSTRACT: Polyurethane foam unit (PFU) systems were collected from 11 lakes and three rivers in the Yunnan Plateau, China and, the PFU extrusion liquids were analyzed for organochlorine pesticides (OCPs) by gas chromatography with electron capture detection (GC-ECD). The concentrations of pp'-DDE, HCB and HCHs were undetectable to 1.86 microgl-1 (mean 0.27 microgl-1), undetectable to 0.72 microgl-1 (mean 0.11 microgl-1), and 0.24-21.95 microgl-1 (mean 7.39 microgl-1) respectively in lakes; and those in rivers were undetectable to 0.23 microgl-1 (mean 0.08 microgl-1), 0.68-2.93 microgl-1 (mean 1.70 microgl-1), and 2.71-37.56 microgl-1 (mean 17.01 microgl-1) respectively. Notably, some residue levels of OCPs exceeded the US National Recommended Water Quality Criteria, implying Yunnan has levels of OCPs potentially harmful to human health. Further, the contamination by OCPs showed an obvious spatial distribution pattern. Amongst the lakes, Dianchi, Xingyun, Lugu and Yangzonghai had the highest OCP levels dominated by beta-HCH, whereas among rivers, Nujiang and Lancang Rivers had the highest contents of OCPs dominated by alpha-HCH. This demonstrates that HCHs are the predominant contaminants and some point sources of HCHs may still exist in Yunnan. The pollution levels in Yunnan were compared with other studies, suggesting the PFU method is suitable for long-term on-line monitoring of trace OCPs in aquatic ecosystems. Therefore, continuous studies monitoring OCPs in lakes and rivers are needed to further understand the future trend of contamination.
[show abstract][hide abstract] ABSTRACT: Investigations of protozoa were carried out during four surveys of East Dongting Lake, China. A total of 160 protozoan species belonging to 71 genera was identified, of which 53 were flagellates, 37 sarcodines, and 70 ciliates. Among them, Peritrichida (32.6% of frequency), Arcellinida (16.2%), Volvocales (13.6%), Peridiniales (13.1%), and Chrysomonadales (9.1%) were the main groups and contributed to 84.5% of the overall species. Ciliates were mainly composed of sessile species and small species. The total protozoan abundance varied from 2,400 cells L to 20,250 cells L. The highest protozoan abundance occurred in spring; the lowest number was in autumn. The highest abundance of ciliates occurred in spring and winter, whereas flagellates developed the highest abundance in summer and autumn. Pearson correlation analysis and linear regressions indicated that chlorophyll a and water velocity were the main factors affecting temporal and spatial variations of the protozoan abundance.
Journal of Freshwater Ecology - J FRESHWATER ECOL. 01/2007; 22(4):655-665.
[show abstract][hide abstract] ABSTRACT: In Asia, especially in China, our knowledge of the distribution of testate amoebae is still limited. In this paper, the geographical
distribution of testate amoebae in Tibetan Plateau and northwestern Yunnan Plateau, southwest China and their relationships
with the climatic factors have been studied. We found testate amoebae shifted in the most dominant species and increased in
species (or genus) richness from northwest to southeast. Further, the linear regression analyses revealed that both species
richness and genus richness have higher positive correlations with the mean temperature of the warmest month and annual mean
precipitation as contrasted with the mean altitude, which showed weak negative correlation. This indicates that the temperature
and precipitation are more significant influences on the richness than the altitude. The cluster analysis based on the community
structure, defined by Sørenson’s coefficient matrix, suggested four groups from the 10 physiographical regions. This geographical
distribution pattern was also closely related with the climatic regionalization. The present climatic regionalization pattern
of the study area originated from the uplift of Tibetan Plateau and mainly occurred in or after the late Pleistocene. Therefore,
the geographical distribution of testate amoebae in our study area may have experienced complicated and drastic changes corresponding
to the variation of the climate caused by the geological events.
[show abstract][hide abstract] ABSTRACT: We examined DNA polymorphism of the plankton community in the Three Gorges Reservoir Region of Yangtze River and studied its relationships to species composition. Samples of the plankton community were collected from nine sampling sites and analyzed by random amplified polymorphic DNA(RAPD). Nine of 60 screened primers generated a total of 88 observable 180 to 1400 bp bands, all of which were polymorphic. Cluster analysis of the resulting binary format from DNA banding patterns grouped the target communities into three clusters. The topology of the constructed diagram from species composition data was generally similar to that based on RAPD markers.
Journal of Freshwater Ecology 01/2006; 21(3):385-390. · 0.39 Impact Factor
[show abstract][hide abstract] ABSTRACT: The testate amoebae from nine major lakes in the Yunnan Plateau, southwest China were investigated from August to October 2003. Ninety-four species and subspecies belonging to 21 genera were found, and six species were new to the testate amoebae fauna of China. The most diverse genera were Dlfflugia (28 species), Centropyxis (22 species), Arcella (12 species), and Euglypha (seven species), while the predominant genera were Centropyxis (42.0%), Difflugia (21.4%), Arcella (9.7%), and Euglypha (8.2%). The most diverse testate amoebae fauna was found in a mesotrophic lake, Lake Yilong (57 species). The lowest species richness was recorded in the two hypereutrophic lakes, Lake Dianchi (7 species) and Lake Xingyun (11 species). The results suggest that the lake trophic status plays an important role in shaping community structure and in determining species diversity of testate amoebae.
Journal of Freshwater Ecology 01/2005; 20(4):743-750. · 0.39 Impact Factor
[show abstract][hide abstract] ABSTRACT: A survey of the testate amoebae of northwest Yunnan in the Hengduan Mountains region of southwest China revealed 151 species belonging to 29 genera. Of these, three genera and 27 species were new to the testate amoebae fauna of China. The widely distributed and dominant species were Centropyxis aculeata aculeata, C, aerophila aerophila, C. sylvatica, Difflugia elegans, D. globulosa, D. pristis, D. pulex, Phryganella hemisphaerica, Trinema enchelys, and T. lineare. The most diverse genera were Difflugia (41 species), Centropyxis (31 species), Arcella (18 species), and Euglypha (11 species). The number of species in each sample varied greatly. It appears that species diversity of testate amoebae is related not only to macro-environments (e.g., geographic zonation) but also to microenvironments (e.g., microhabitats).
Journal of Freshwater Ecology 01/2005; 20(3):583-590. · 0.39 Impact Factor
[show abstract][hide abstract] ABSTRACT: The phylogenetic relationships among trichodinids remain obscure. As an important diagnostic marker, the morphology of the denticles in the adhesive disc as well as the adoral spiral has been widely used in generic discrimination and species identification of trichodinids. We studied the characters of denticles of the ten genera of Trichodinidae and the sole genus Urceolaria of Urceolariidae by using a quantitative method. The characteristic values were used to generate Manhattan distance, on which the dendrogram was based to construct with the Unweighted Paired Group Method using the Arithmetic mean (UPGMA). The investigations show that all the genera of the family Trichodinidae were clearly separate from the outgroup Urceolaria, and within the Trichodinidae: (i) Dipartiella grouped with Trichodinella and Tripartiella and lay in the closest position to the outgroup with a low dissimilarity, suggesting Dipartiella might be the most primitive genus in the family; (ii) Hemitrichodina clustered in a single clad and lay in the farthest position to the outgroup with the highest dissimilarity, indicating that it might be the most advanced genus; and (iii) the other 6 genera, Trichodina, Paratrichodina, Semitrichodina, Vauchomia, Pallitrichodina and Trichodoxa clustered in a big clad with very low dissimilarity, showing that they are closely related to each other. We discuss the evolutionary trend of the denticle and conclude that the denticles of the adhesive disc should be an apomorphic feature of the trichodinids and their changes could reflect the evolutionary tendencies of these ciliates.
[show abstract][hide abstract] ABSTRACT: In this paper, we took the lead in studying on specificity of the microsatellite DNA loci and applicability of microsatellite
DNA primers in protozoa. In order to study characters of microsatellites in free-living protozoa, eight microsatellite loci
primers developed from Trypanosoma cruzi (MCLE01, SCLE10, MCLE08, SCLE11, MCLF10, MCLG10, MCL03, MCL05) were employed to amplify microsatellite in four free-living
protozoa, including Bodo designis, Euglena gracilis FACHB848, Paramecium bruzise and Tetrahymena thermophila BF1. In the amplification systems of P. bruzise, four loci (SCLE10, SCLE11, MCLF10, MCL03) were amplified successfully, and four amplification fragments were in proper size.
In genome of E. gracilis FACHB848, five of eight primers brought five clear amplification bands. In B. designis, three (No.4, 5 and 7) of eight loci produced clear and sharp products without stutter bands, whereas no bands appeared in
T. thermophila BF1. Further, eight 300–500 bp amplification fragments were cloned and sequenced. Nevertheless, all sequenced products did
not contain corresponding microsatellite sequence, although Bodo is in the same order and has the nearest phylogenetic relation with Trypanosoma among these four species. Thus, the microsatellite DNA primers can not be applied among order or more far taxa, and the specificity
of microsatellite DNA is very high in protozoa. The results of this study will contribute to our understanding of microsatellite
DNA in protozoa.
Journal of Ocean University of China 03/2004; 3(1):80-84.