S. Hietanen et al., Benthic bacterial production in the northern Baltic Sea measured using a modified [C-14]leucine incorporation method, AQUAT MIC E, 20(1), 1999, pp. 13-20
Benthic bacterial production was measured with a modified [C-14]leucine inc
orporation method in the northern Baltic Sea in 1996 and 1997. Samples were
incubated and TCA extractions were done in microcentrifuge tubes. Unincorp
orated label was removed by repeated centrifugation. pellets were suspended
in scintillation cocktail and counted as a gel using internal standardisat
ion, a method that gave highly comparable counts with combustion of the sam
ple. Bacterial production varied between 0.15 and 0.8 mg C l(-1) h(-1) (90
to 350 mg C m(-2) d(-1)). The highest production was found at Stn GF2 in th
e Gulf of Finland and the lowest in the northern Baltic Proper. Bacterial g
rowth rates were 0.07 to 0.84 d(-1). Comparison of these results with publi
shed data from sedimentation trap measurements suggests that only a part of
the benthic bacterial C demand can be explained by sedimentation.