Abstract
An improved method is described for the study of heterotrophic utilization of dissolved organic substances by marine microorganisms. The method is based on the use of 3H-labelled organic substrates of very high specific activity, rather than the conventionally used 14C-labelled substrates. Direct measurement of the rate of tracer uptake at near ambient concentration can thus be made instead of extrapolation using the Michaelis-Menten equation. The method also permits comparison between the rates of tracer uptake in sub-samples exposed to different physico-chemical conditions (temperature, light, pollutants, etc.) without the necessity of determining the ambient substrate concentration. The method was applied to the determination of D-glucose uptake by nearshore and pelagic natural microbial populations, and was found to be sensitive and convenient.
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Communicated by J. Bunt, Miami
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Azam, F., Holm-Hansen, O. Use of tritiated substrates in the study of heterotrophy in seawater. Mar. Biol. 23, 191–196 (1973). https://doi.org/10.1007/BF00389484
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DOI: https://doi.org/10.1007/BF00389484