File containing data on bacterial productivity in lakes and streams. Samples were collected at various sites near Toolik Lake Field Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth, and bacterial production.
Data set ID:
EML revision ID:
For the bacterial production protocol, see the ARC LTER Landscape Interactions group protocol accessible from the mainpage on the Arctic LTER web page or at http://www-personal.umich.edu/~gwk and clicking on the Lab Protocol Manual link at the bottom of the page.
Bacterial production is determined by the incorporation of 14C-labeled Leucine (Simon and Azam 1989) in triplicate water samples incubated in the dark at in situ temperature for 1-3 hours (typically 2 hrs). Water samples are vacuum filtered through 0.22 um Millipore GS cellulose nitrate filters. Samples are extracted with 5mL of 5% TCA for 5 minutes, rinsed with additional TCA, and air dried in 7 mL mini-scintillation vials. Following the addition of 1 mL cellosolve (ethylene glycol monoethyl ether), filters are left to dissolve overnight. Scinti-safe scintillation cocktail (4 mL) is then added to each vial and samples are counted at Toolik Field Station on a liquid scintillation counter (Packard Tri-Carb 2100TR or equivalent) .
Calculations of bacterial productivity assume that the Internal Dilution (ID) of leucine is 1, but studies show it may range from 1-2 (Kirchman 1993). Some published data from these LTER files have used an ID value different than 1; in those studies, the ID value used is stated in the article.
1. Simon, M., and F. Azam. 1989. Protein content and protein synthesis rates of planktonic marine bacteria. Marine Ecology Progress Series 51:201-213.
2. Kirchman, D.L. 1993. Leucine incorporation as a measure of biomass production by heterotrophic bacteria. Pages 509-512 in P.F. Kemp, B.F. Sherr, E.B. Sherr, and J.J. Cole, editors. Handbook of methods in aquatic microbial ecology. Lewis Publishers, Boca Raton, Florida, USA.
Version 1, created by J. Dobkowski and G. Kling, 23-May-2019
Version 2, updated to include 2020-2021 data by J. Dobkowski and G. Kling, 14 March 2022