15N-Labelled ammonium chloride, sodium nitrate and urea were supplied in vitro to freshly isolated Gymnodinium microadriaticum, the algal symbiont (zooxanthellae) of the clam Hippopus hippopus. Subsequent extraction ofthe resulting labelled amino acids and determination ofthe distribution of 15N in glutamine, glutamic acid and aspartic acid, using gas chromatography-mass spectrometry revealed a light dependent assimilation from all substrates, primarily via the GS-GOGAT pathway.
- gas chromatography-mass spectrometry.
- Gymnodinium microadriaticum
- nitrogen assimilation
- stable isotopes