Inter-Research
Aquatic Microbial Ecology

ABSTRACT: In order to determine conversion factors for ³H-thymidine incorporation to bacterial growth rate, we performed a series of seawater culture experiments on surface mixed layer samples in a subantarctic coastal area. Four different treatments were used: bacterivory reduction (dilution or filtration), nutrient enrichment and temperature increase. Conversion factors were estimated by the 'integration approach': the increase in bacterial biomass (biomass at final time point minus initial value) was divided by incorporation rates integrated over time during the experiment. Both bacterial abundance and mean cell volumes markedly increased in all experiments. The manipulation effects were strongest in the high temperature batch compared with the other experiments. However, the 4 different treatments yielded comparable conversion factors ranging from 9.7 [lozenge] 10⁵ to 1.5 [lozenge] 10⁶ cells pmol^-1 with a mean value of 1.2 [lozenge] 10⁶ cells pmol^-1.

KEY WORDS: Bacterial production · Psychrophilic bacteria · Antarctica

Published in AME Vol. 13, No. 1 (1997) on July 24
Print ISSN: 0948-3055; Online ISSN: 1616-1564. Copyright © Inter-Research, Oldendorf/Luhe, 1997