Abstract
Alcaligenes sp. T501, which has the ability to produce L-malate from maleate at a concentration of 20% in a molar yield of 98.4%, was isolated from soil. Analysis of the reaction mixture components suggested that maleate was converted to L-malate via fumarate through the action of maleate isomerase and fumarase. These two enzymes were constitutively found in the cells regardless of the carbon source in the medium. The enzyme reaction was significantly enhanced by adding 2-mercaptoethanol, but was not affected by glutathione or L-cysteine.
