Patterns of Structural and Functional Bacterioplankton Metacommunity along a River under Anthropogenic Pressure

Abstract

Bacteria, an integral part of aquatic ecosystems, are responsible for the circulation of matter and flow of energy. Since bacterioplankton rapidly responds to any natural and human-induced disturbances in the environment, it can serve as a bioindicator of these changes. Knowing factors that shape the microbial community structure may help the sustainable management of the water environment. However, the identification of environmental signals affecting the structure and function of bacterioplankton is still a challenge. The study analyses the impact of environmental variables on basic microbial parameters, which determines the effectiveness of ecological processes in rivers. Measurements of bacterioplankton abundance (BA) and extracellular enzyme activity (EEA) were based on fluorescent markers. The bacterial community structure was determined by 16S rRNA gene amplicon sequencing (Illumina). The results indicate spatial variation in bacterioplankton abundance. Temporal variation was not significant. Lipase and aminopeptidase had the highest level of activity. EEA was not correlated with bacterial abundance but was significantly correlated with temperature. Moreover, differences in lipase, α-glucosidase and β-glucosidase activity levels between spring and summer were noted. At the same time, the location of sampling site had a significant influence on aminopeptidase activity. The taxonomic analysis of bacterioplankton communities in the Brda River indicated that, although different numbers of OTUs were recorded in the studied river sections, bacterioplankton biodiversity did not change significantly along the river with distance downstream. Anthropogenically modified river sections were characterized by the dominance of Flavobacterium (Bacterioidetes) and hgcl clade (Actinobacteria) taxa, known for their ability to produce extracellular enzymes. PCoA analysis revealed that the sites located in the lower river course (urban area) had the most similar bacterial community structure (β-diversity). The study provides new insight into the changes in microbial communities along the river and emphasizes the potential impact of anthropogenization on these processes.

Different Assembly Patterns of Planktonic and Sedimentary Bacterial Community in a Few Connected Eutrophic Lakes

“…In recent years, the high-throughput 16S rRNA gene sequencing method has become more and more common with the characteristics of acquiring a large number of sequence data on microbial communities [7][8][9]. Liao's work has found that neutral and niche processes played different roles in bacterial community assembly between habitat generalists and specialists [10].…”

Changes of the Freshwater Microbial Community Structure and Assembly Processes during Different Sample Storage Conditions

“…Advances in DNA sequencing technologies and bioinformatics have revolutionized the study of the diversity and dynamics of environmental microbial communities [4][5][6]. However, biases can be introduced at almost all stages (i.e., sampling, sample storage and processing, DNA extraction and sequencing) of the experimental process and affect the perception and interpretation of the microbial community [7][8][9][10]. Maintaining consistency in each processing step is therefore essential during a study.…”

Aquatic Microbial Community Characteristics and Influencing Factors in Urban Landscape Rivers

“…They are often distributed in areas where people gather and have the characteristics of poor water environment capacity and poor water selfpurification capacity. Water is vulnerable to domestic sewage, rain and garbage [3,4]. Urban river pollution is an increasingly serious problem.…”