Microbial diversity and functional characterization of sediments from reservoirs of different trophic state

Abstract

Sediment samples from four reservoirs of different trophic state were compared with regard to chemical gradients in the pore water, composition of microbial communities and extracellular enzyme activities. The trophic state was clearly reflected by steep vertical concentration gradients of ammonium and alkalinity in the pore water. A high concentration of these parameters indicated a high microbial in situ activity in the more eutrophic reservoirs. However, the total number of bacteria in sediments seemed hardly to be influenced by the trophic conditions in the water column. Differences in the microbial composition of the sediments became evident by comparative 16S rDNA analysis of extracted DNA and by fluorescence in situ hybridization. Although a high proportion of the cells detectable with the EUB probe could not be identified at the subdomain level, members of the L-Proteobacteria constituted an important fraction in the sediments of the more eutrophic reservoirs, whereas Q-subgroup Proteobacteria were most frequently detected in sediment samples from the dystrophic Muldenberg reservoir. The assessment of extracellular enzyme activities (esterases, phosphatases, glucosidases and aminopeptidases, respectively) in sediment samples of the four reservoirs revealed specific patterns of metabolic potentials in accordance with the trophic state and characteristics of the catchment.

Effect of Wastewater Treatment Plant Effluent on Microbial Function and Community Structure in the Sediment of a Freshwater Stream with Variable Seasonal Flow

“…In particular, the downstream community had representatives of the gammaproteobacteria which were not detected in the upstream community, including members of Oceanospirillales and Methylococcaceae. Similar spatial partitioning in microbial community structure as estimated by using DNA sequence analyses has been reported for ammonia oxidizers (7) and for total bacterial communities in reservoir sediments (50). In both cases, the chemical characteristics were the major determinants of microbial community structure.…”

Changes in the Structure and Function of Microbial Communities in Drinking Water Treatment Bioreactors upon Addition of Phosphorus

“…16S rRNA genes of the bacterial domain were amplified in triplicate using the PCR on a Mastercycler thermocycler (Eppendorf International, Hamburg, Germany) with the forward primer 8F (5Ј-AGAGTTTGATCCTGGCTCAG-3Ј) (17) and the reverse primer 1387R (5Ј-GGGCGG[A/T]GTGTACAAGGC-3Ј) (54). The composition of the PCR mixture was adopted from the work of Wobus et al (54). Pooled PCR products were purified by electrophoresis on a 1% agarose gel and extracted using the MinElute gel extraction kit (Qiagen Inc., Valencia, CA).…”

Vertical distribution of Fe and Fe(III)-reducing bacteria in the sediments of Lake Donghu, China

“…Sediment with complex chemical constituents (organic and inorganic) and microbial biomass is an important component of lake ecosystems (Wobus et al 2003;Tamaki et al 2005). The oxidation of organic matter with the reduction of Fe(III) is one of the most important redox reactions in anoxic environments (Hori et al 2010;Bongoua-Devisme et al 2013).…”