Distribution and activity of nitrifying bacteria in natural stream sediment versus laboratory sediment microcosms

Distribution and activity of nitrifying bacteria in natural stream sediment versus laboratory sediment microcosms

Nitrification was studied with microsensors and fluorescence in situ hybridization (FISH) in sandy sediment of a small lowland stream. Comparative measurements were performed in both intact field sediment (‘natural sediment’) and sediment from the same site after processing for a laboratory incubation experiment (‘manipulated sediment’). In natural sediment, the nitrification activity and abund...

Hyporheic invertebrates affect N cycling and respiration in stream sediment microcosms

The region of surface water–groundwater interaction in streams, the hyporheic zone, is important for biogeochemical processes and provides habitat for specialized microbial and invertebrate assemblages. Although hyporheic invertebrates contribute little biomass and respiration relative to microbes in stream sediments, invertebrate effects on biogeochemical processes may be disproportionately la...

Distribution of viruses and bacteria in relation to diagenetic activity in an estuarine sediment

The distribution of viruses and bacteria was investigated in relation to bacterial sulfate reduction and total respiration (production of dissolved inorganic carbon, [DIC]) in a coastal sediment. Viral and bacterial abundance ranged from about 0.5 3 108 to 8 3 108 viruses cm23 and 0.1 3 108 to 4 3 108 bacteria cm23 in the upper 16 cm of the sediment and showed large and systematic changes withi...

Porosity and Permeability of Bimodal Sediment Mixtures using Natural Sediment

Depth distribution of active bacteria and bacterial activity in lake sediment.

Abstract The bacterial activity in sediments is often low considering the generally high bacterial abundance. Still, a large fraction of bacteria have been found active even in deep sediments. These findings suggest that sediment bacteria have comparatively low cell-specific production. We studied bacterial activity and the active fraction of bacteria in a lake sediment profile. Bacterial produ...