TY  - JOUR
A1  - Döhler, Günter
A1  - Roßlenbroich, Hans-Jürgen
T1  - Photosynthetic assimilation of 15N-ammonia and 15N-nitrate in the marine diatoms Bellerochea yucatanensis (von Stosch) and Skeletonema costatum
T2  - Zeitschrift für Naturforschung, C
N2  - 14C-and 15N-Assimilation, 15N-Labelled Amino Acids, M arine D iatom s The marine diatoms Bellerochea yucatanensis and Skeletonema costatum were grown at +20 °C in 0.03 vol.% CO2 with nitrate or ammonia. The 15N -am m onia and 15N -nitrate assim ila­ tion and 15N -incorporation into various amino acids were studied of both diatom s during exponential growth phase in dependence of different nitrogen conditions. In all experiments the 15N -am m onia uptake was lower than the 15N -nitrate assim ilation rate up to 20-40 min photo­ synthesis. N itrate lim itation -cells grown in nitrate followed by growth in nitrogen-free m edium for 24 h — caused a strong 15N-label into aspartate after adding 15NH 4C1 (1 m M). In cells grown in nitrate highest enrichment of 15N was found in glutamine. Results were discussed with reference to the operating of the GS/GOGAT system and glutam ic acid dehydrogenase pathway. Photosynthetic 14CO2 fixation experiments showed a very high labelling of aspartate which was interpreted with a phosphoenolpyruvate carboxylation catalysed by phosphoenolpyruvate carb-oxykinase.
KW  - 14C- and 15N-Assimilation
KW  - 15N-Labelled Amino Acids
KW  - Marine Diatoms
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/80334
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-803345
SN  - 0939-5075
SN  - 1865-7125
VL  - 36.1981
IS  - 9-10
SP  - 834
EP  - 839
PB  - Verlag der Zeitschrift für Naturforschung
CY  - Tübingen
ER  -