Control of isocitrate lyase in Nocardia salmonicolor (NCIB9701)

Journal of General Microbiology
F S SariaslaniI J Higgins

Abstract

Nocardia salmonicolor, grown on acetate, commercial D,L-lactate or hydrocarbon substrates, has high isocitrate lyase activities compared with those resulting from growth on other carbon sources. This presumably reflects the anaplerotic role of the glyoxylate cycle during growth on the former substrates. Amongst a variety of compounds tested, including glucose, pyruvate and tricarboxylic acid cycle intermediates, only succinate and fumarate prevented an increase in enzyme activity in the presence of acetate. When acetate (equimolar to the initial sugar concentration) was added to cultures growing on glucose, there followed de novo synthesis of isocitrated lyase and isocitrate dehydrogenase, with increases in growth rate and glucose utilization, and both acetate and glucose were metabolized simultaneously. A minute amount of acetate (40 muM) caused isocitrate lyase synthesis (a three-fold increase in activity within 3 min of addition) when added to glucose-limited continuous cultures, but even large amounts added to nitrogen-limited batch cultures were ineffective. Malonate, at a concentration that was not totally growth-inhibitory (1mM) prevented the inhibition of acetate-stimulated isocitrate lyase synthesis by succinate, but f...Continue Reading

Citations

Jan 1, 1985·Antonie van Leeuwenhoek·O O Amund, I J Higgins
Jan 1, 1983·Zeitschrift für allgemeine Mikrobiologie·D Franke-RinkerA Portnowa

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