| Abstract
| - A number of strains of Lactobacillus spp. from foods werescreened for their ability to convert meso-2,3-butanediol into 2-butanol. Only three strains of L.brevis transformed the meso-diol intothesecondary alcohol. These strains as well as the others unable tometabolize meso-2,3-butanediolexhibited the capacity to hydrogenate 2-butanone to 2-butanol. Inboth types of lactobacilli, aninverse relationship was observed between the diol or ketoneconcentration and the abundance ofthe R form of 2-butanol. This fact has been interpretedin terms of a co-occurrence of twodehydrogenases, both acting on the ketone with different kineticparameters and oppositeenantioselectivities. These results represent a further support tothe assumption that 2-butanolpresent in distillates originates from the enzymatic activity oflactobacilli growing on mashes andgive the most likely explanation of the enantiomeric excess of(R)-2-butanol generally found indistillates. Keywords: 2-Butanol; meso-2,3-butanediol; lactobacilli; diacetyl; acetoin;dehydrogenases
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