This review article summarizes the state of the art on Leuconostoc oenos, t
he bacteria responsible for malolactic fermentation in wine. Both basic and
practical aspects related to the metabolism of this microorganism and malo
lactic fermentation in general are critically reviewed. The former examines
the role of genetics for the identification and classification of L. oenos
and energetic mechanisms on solute transport (malic and lactic acid). The
latter includes practical information on biomass production, optimal growth
conditions and stress factors, which are important in growth optimization
of malolactic starter cultures. Extensive data and references on the effect
of malolactic fermentation on wine composition and sensory analysis are al
so included.