Use of the [14C]Leucine Incorporation Technique To Measure Bacterial Production in River Sediments and the Epiphyton

• DOI: 10.1128/aem.65.10.4411-4418.1999
• Publication Date: 2019-12-19T19:42:39Z
• Authors: Helmut Fischer; Martin Pusch
• Keywords: Saturation (graph theory)

ABSTRACT Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure many habitats. We therefore tested applicability [ 14 C]leucine incorporation technique measurement bulk bacterial various habitats lowland river ecosystem. To evaluate method, we determined (i) extraction efficiencies protein from sediments, (ii) substrate saturation leucine biofilms on plants (epiphyton), and pelagic zone, (iii) activities at different concentrations, (iv) specificity uptake by bacteria, (v) effect incubation (perfused-core versus slurry incubation) into protein. was best extracted sediments precipitated hot trichloroacetic acid treatment following ultrasonication. For epiphyton, an alkaline-extraction procedure most efficient. Leucine occurred 1 μM epiphyton 100 nM zone. Saturation curves were model but showed first level 50 μM. Increased higher concentrations could be partly attributed eukaryotes. Addition micromolar did not enhance electron transport activity or DNA replication activity. Similar rates calculated whole sediment cores observed after perfused-core incubations, exhibited strong vertical gradients core incubation. conclude that method can wide range habitats, including fluvial if isotope dilution are determined.