Transport and Assimilation of Nitrogen by Stichococcus bacillaris Grown in the Presence of Methionine Sulfoximine.
Stichococcus bacillaris Naeg., a green soil alga, can grow in the presence of methionine sulfoximine (MSX), an inhibitor of glutamine synthetase, by maintaining a high level of NADPH-glutamate dehydrogenase activity. MSX-grown cells can utilize both NH(4) (+) and NO(3) (-) as nitrogen source for growth. [(14)C]Methylammonium is not metabolized by S. bacillaris, and is transported by a carrier system that obeys Michaelis Menten kinetics, and is insensitive to MSX.
Ahmad
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Department of Botany, University of Toronto, Toronto, Ontario M5S 1A1, Canada.
Hellebust
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