Premium
EVIDENCE FOR THE PARTICIPATION OF GLUTAMATE DEHYDROGENASE IN AMMONIUM ASSIMILATION BY STICHOCOCCUS BACILLARIS
Author(s) -
EVEREST S. A.,
SYRETT P. J.
Publication year - 1983
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1983.tb02709.x
Subject(s) - glutamine synthetase , ammonium , glutamate dehydrogenase , assimilation (phonology) , nitrogen assimilation , chlorella vulgaris , glutamate synthase , biochemistry , chemistry , biology , nuclear chemistry , glutamine , botany , glutamate receptor , algae , organic chemistry , amino acid , receptor , linguistics , philosophy
S ummary Cells of the green alga, Chlorella vulgaris (strain 21l/8k) have high NADPH‐glutamate de‐hydrogenase (GDH) activity when grown on ammonium (NH 4 + ); activity is low in nitrate (NO 3 − )‐grown or nitrogen‐depleted cells. In contrast, cells of Stichococcus bacillaris (strain 379/5) contain little NADPH‐GDH activity when grown on NH 4 + but much when grown on NO 3 − or depleted of nitrogen. Despite the high NADPH‐GDH activity in NH 4 + ‐grown cells of C. vulgaris , NH 4 + assimilation by this organism is strongly inhibited by methionine sulphoximine (MSO), an inhibitor of glutamine synthetase. NH 4 + assimilation by NH 4 + ‐grown S. bacillaris is similarly almost completely inhibited by MSO. However, NH 4 + assimilation by NQ 3 ‐grown S. bacillaris is much less inhibited by MSO and it is suggested that the high NADPH‐GDH activity of these cells is partly responsible for the remaining NH 4 + assimilation.