Studies on the Induced Synthesis of Maleate cis-trans Isomerase by Malonate

Increased levels of maleate cis-trans isomerase in Alcaligenes faecalis IB-14 were induced by malonate analogues such as tartronate, keto-malonate and ethyl-malonate. Similarly in the case of malonate, those analogues were not served as carbon sources for the cell growth, but they were more effective as inducer than maleate, the normal inducer of the enzyme.

The induced synthesis of the enzyme was markedly repressed in the presence of various carbon sources, e.g. oxalacetate, d- and l-malates, fumarate and succinate. More than 90 per cent of the enzyme formation was inhibited when 10^?1 m of oxalacetate or dl-malate was present in malonate medium. The repression of the enzyme synthesis by those dicarboxylic acids was always associated with remarkable promotion of the cell growth.