Distribution of microbial community in the sediments of the Daliao River watersystem, China

摘要

Fluorescence in situ hybridization (FISH) method was used to investigate the phylogenetic composition of river sediment from the Daliao River and near estuary (China). For surface sediments from different locations of the river and estuary, the total cell determined by DTAF (5-([4,6-Dichlorotriazin-2-yl]amino) fluorescein ) staining ranged 4.2×108 -16.2×108 cell cm-3, bacteria number determined by FISH with EUB 338 probe ranged 3.2×108 -9.5×108 cell cm-3. Up to 58-82% of DTAF counts can be identified by domain bacteria, among which, α-, β-and γ-protebacteria summed up to 40%. Vertical distributions of microbial population and composition was also investigated in a core sediment sample (43cm) taken from the estuary. Relative higher total cell number was found in the upper (0-5 cm) and middle part of the core sediment (23.5-29.5 cm). Total cell count ranged 7.9×108-20.1×108 cell cm-3. About 62-85% of the total cell could be affiliated to domain bacteria. α-、β-and γ-protebacteria widely distributed in the core sediment, with γ-protebacteria as the most abundant group which made up 9.8-40.8% of total cell count. Archaea was detected at all sediment depths, and it account for 1.0-11.8% of total DTAF cell count.