Sediment Enzyme Activities and Microbial Community Diversity in an Oligotrophic Drinking Water Reservoir, Eastern China

Abstract

Drinking water reservoir plays a vital role in the security of urban water supply, yet little is known about microbial community diversity harbored in the sediment of this oligotrophic freshwater environmental ecosystem. In the present study, integrating community level physiological profiles (CLPPs), nested polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and clone sequence technologies, we examined the sediment urease and protease activities, bacterial community functional diversity, genetic diversity of bacterial and fungal communities in sediments from six sampling sites of Zhou cun drinking water reservoir, eastern China. The results showed that sediment urease activity was markedly distinct along the sites, ranged from 2.48 to 11.81 mg NH3-N/(g·24h). The highest average well color development (AWCD) was found in site C, indicating the highest metabolic activity of heterotrophic bacterial community. Principal component analysis (PCA) revealed tremendous differences in the functional (metabolic) diversity patterns of the sediment bacterial communities from different sites. Meanwhile, DGGE fingerprints also indicated spatial changes of genetic diversity of sediment bacterial and fungal communities. The sequence BLAST analysis of all the sediment samples found that Comamonas sp. was the dominant bacterial species harbored in site A. Alternaria alternate, Allomyces macrogynus and Rhizophydium sp. were most commonly detected fungal species in sediments of the Zhou cun drinking water reservoir. The results from this work provide new insights about the heterogeneity of sediment microbial community metabolic activity and genetic diversity in the oligotrophic drinking water reservoir.

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

“…To explore the microbial community functional diversity profiles, Biolog Eco microplate (EcoPlate™, BIOLOG, Hayward, CA, USA) was employed as previously described with little modification [30,31]. The plate contains 31 different carbon sources, which can be grouped to six kinds of carbon sources, including carbohydrates, amino acids, esters, alcohols, amines and carboxylic acids, and each plate is reproduced in triplicate.…”

“…Eco plates were incubated at 28 °C in darkness. The absorbance at 590 nm was recorded every 24 h interval over ten days, and the results obtained at 144 h were used for diversity index and further statistical analysis [30]. The diversity indices included average well color development (AWCD590nm), Shannon Diversity (H') and McIntosh Diversity (U).…”

Effects of Hydrostatic Pressure on the Nitrogen Cycle of Sediment

“…structure and installation diagrams of high-pressure simulation reactor and its physical device. 1) Gas chamber, 2) reaction chamber, 3) elastic diaphragm, 4) hydraulic stirring device, 5) dosing pump, 6) air compressor, 7) online monitoring probe, 8) control device, 9) barometer, 10) sediment sampler, 11) spiral high-pressure piston propeller, 12) water sampler, 13) exhaust valve, 14) gas flowmeter, 15) gas collector, 16) pressure hole, 17) connecting rod and bolt, 18) pressure relief valve, [19][20] control valve, 23) exhaust pipe, 24) connecting flange, 25) upper cover body, 26) bottom cover body, and 27) medicine storage tank.…”

“…The sediment microbial community has drawn great attention from microbial ecologists [18][19][20][21]. Moreover, the sediment host distinct microbial communities and their populations may strongly be affected by the nutritional status of water quality due to the variations of hydrological regime and other physical and chemical variables, including hydrostatic pressure [22][23][24][25].…”

Abundance and diversity of sulfate-reducing bacteria in the sediment of the Zhou Cun drinking water reservoir in Eastern China

“…The third to the sixth sampling sites were located in the main reservoir with an average water depth of 15 m, approximately 10 m deeper than the sites in the pre-reservoir. A Petersen stainless steel grab sampler was used to collect the samples, and the Ashtech Global Positioning System (Huace Company, Shanghai, China) was used to locate the sampling positions (Zhang et al, 2013). The coordinates and depths of the six sampling site are presented in Table 1.…”