Succession of bacterial community composition over two consecutive years in two aquatic systems: a natural lake and a lake-reservoir

Abstract

The succession in bacterial community composition was studied over two years in the epilimnion and hypolimnion of two freshwater systems: a natural lake (Pavin Lake) and a lake-reservoir (Sep Reservoir). The bacterial community composition was determined by cloning-sequencing of 16S rRNA and by terminal restriction fragment length polymorphism. Despite large hydrogeological differences, in the Sep Reservoir and Pavin Lake the dominant bacteria were from the same taxonomic divisions, particularly Actinobacteria and Betaproteobacteria. In both ecosystems, these major bacterial divisions showed temporal fluctuations that were much less marked than those occurring at a finer phylogenetic scale. Nutrient availability and mortality factors, the nature of which differed from one lake to another, covaried with the temporal variations in the bacterial community composition at all sampling depths, whereas factors related to seasonal forces (temperature and outflow for Sep Reservoir) seemed to account only for the variation of the hypolimnion bacterial community composition. No seasonal reproducibility in temporal evolution of bacterial community from one year to the next was observed.

Dynamics of organic‐aggregate‐associated bacterial communities and related environmental factors in Lake Taihu, a large eutrophic shallow lake in China

“…This might suggest a combined effect of water temperature with other factors, such as DO and concentration of nutrients. Although the statistical analysis was able to separate the effect of each variable, these variables do not have isolated effects on the regulation of bacterial communities (Boucher et al 2006). Approximately half of the variation in OABC could not be explained by the selected variables in this study (Table 5).…”

“…The relative abundance of T-RFs was determined by calculating the ratio between the area of each peak and the total area of all peaks within one sample. Ratios were converted into percentages (Boucher et al 2006). This procedure produced a list of T-RFs, and their relative abundance (peak area) in all samples, which was subsequently used as dependent variable in the data analysis.…”

“…Extrinsic forces operating over broad spatial scales can impart synchronous effects to separate communities, while system-specific drivers often lead to idiosyncratic effects. Studies on the drivers of microbial communities have focused their effects on free-living bacteria (Boucher et al 2006;Wu et al 2007b;Xing and Kong 2007) and, consequently, the relative roles of environmental factors on OABC are poorly understood, especially in shallow lakes.…”

Bacteria in drinking water sources of a First Nation reserve in Canada

“…Cyanobacteria are an indication of increased nutrient concentrations in freshwater lakes and can produce toxins harmful to mammals (Hudon et al, 2014). Bacteroidetes, Betaproteobacteria, and Actinobacteria have been shown to be abundant in other freshwater lakes (Boucher et al, 2006;Tang et al, 2015).…”

Effects of Seasonal Thermal Stratification on the Functional Diversity and Composition of the Microbial Community in a Drinking Water Reservoir

“…However, the microbial communities in stratified freshwater ecosystems have not been studied to the same extent as those in marine or saline lakes, with different trophic status and morphology. Limited previous research has suggested that each thermal layer in the stratified lakes and reservoirs harbors different bacterial communities [5,18,19]. In addition, other studies based on functional genes, such as the adenosine 5'-phosphosulfate reductase (aprA) and the ammonia monooxygenase A (amoA) genes, showed the strong vertical differentiation of sulfate reducers, sulfur oxidizers, and archaeal ammonia oxidizers along environmental gradients [20,21].…”