Editing Malolactic fermentation (section)

===Conversion of malic into lactic===
Lactic acid bacteria convert malic acid into lactic acid as an indirect means of creating energy for the bacteria by [[chemiosmosis]] which uses the difference in [[Electrochemical gradient|pH gradient]] between inside the cell and outside in the wine to produce [[Adenosine triphosphate|ATP]]. One model on how this is accomplished notes that the form of L-malate most present at the low pH of wine is its negatively charged [[Ion#Anions and cations|monoanionic]] form. When the bacteria move this anion from the wine into higher pH level of its cellular plasma membrane, it causes a net-negative charge that creates [[electrical potential]]. The decarboxylation of malate into L-lactic acid releases not only carbon dioxide but also consumes a proton, which generates the pH gradient which can produce ATP.<ref name="Wine Micro"/>

Lactic acid bacteria convert L-malic acid found naturally in wine grapes. Most commercial malic acid additives are a mixture of the [[enantiomer]]s D+ and L-malic acid.<ref name="Wine Faults"/>