Succession of Bacterial Community Structure along the Changjiang River Determined by Denaturing Gradient Gel Electrophoresis and Clone Library Analysis

Abstract

Bacterial community structure along the Changjiang River (which is more than 2,500 km long) was studied by using denaturing gradient gel electrophoresis (DGGE) and clone library analysis of PCR-amplified 16S ribosomal DNA (rDNA) with universal bacterial primer sets. DGGE profiles and principal-component analysis (PCA) demonstrated that the bacterial community gradually changed from upstream to downstream in both 1998 and 1999. Bacterial diversity, as determined by the Shannon index (H), gradually decreased from upstream to downstream. The PCA plots revealed that the differences in the bacterial communities among riverine stations were not appreciable compared with the differences in two adjacent lakes, Lake Dongting and Lake Poyang. The relative stability of the bacterial communities at the riverine stations was probably due to the buffering action of the large amount of water flowing down the river. Clone library analysis of 16S rDNA revealed that the dominant bacterial groups changed from ␤-proteobacteria and the Cytophaga-FlexibacterBacteroides group upstream to high-G؉C-content gram-positive bacteria downstream and also that the bacterial community structure differed among the stations in the river and the lakes. The results obtained in this study should provide a reference for future changes caused by construction of the Three Gorges Dam.

The biogeography of fungal communities in wetland sediments along the Changjiang River and other sites in China

“…We therefore suspect that the uplift of the Qinghai-Tibetan Plateau had a similar effect on fungal biogeography in this region, that is, the fungal communities of the Qinghai-Tibetan Plateau may be relatively isolated and therefore different from those in other parts of China. In contrast, if only the mid-and downstream parts of the Changjiang River are considered (Figure 2), the gradual change in the fungal communities is consistent with previously described changes in bacterial communities (Sekiguchi et al, 2002), which suggests that local environmental factors along a river may support similar assemblages if a physical barrier is absent (Hewson et al, 2007).…”

The impact of physico-chemical water quality parameters on bacterial diversity in the Vaal River, South Africa

“…In addition, the dominant bacterial groups detected at these three points may be native species with broader niche capabilities, which allow them to grow and survive under a variety of environmental conditions (Anderson-Glenna et al, 2008). Recurrent native bacterial communities in aquatic ecosystems have been reported previously (Sekiguchi et al, 2002;Crump et al, 2003). It should be noted that the DNA amplification method used in this study did not discriminate between DNA derived from living cells versus DNA from dead cells and/or even naked or free DNA available in the water column.…”

Characterizing Microbial Activity and Diversity of Hydrocarbon-Contaminated Sites

“…When bacterial diversity is analyzed by DGGE profiles of the 16S rDNA genes, the number of DGGE bands was taken as an indication of species in each sample. The relative surface intensity of each DGGE band and the sum of all the surfaces for all bands in a sample were used to estimate species abundance (Fromin et al, 2002;Sekiguchi et al, 2002). The different microbiological properties of the soils reflect the different bacterial diversity as assessed by DGGE profiles of the 16S rDNA genes.…”