On the mechanism and stereochemistry of the malate-lactate fermentation of Leuconostoc mesenteroides.

During the transformation of (2S, 3R) [3-3H]malate to (S) lactate no tritium exchange takes place. The stereochemical course of the decarboxylation studied with (2S, 3R) [3-2H]-malate in 3HOH/H2O and (2S, 3R) [3-3H]malate in 2H2O occurs with retention and is therefore the same as that determined by other authors for malic enzyme from vertebrates and from Escherichia coli. The malate-lactate fermentation is a useful procedure to prepare chiral methyl groups on a preparative scale starting from (2S, 3R) [3-H]malate.