Most Chilean wineries perform malolactic fermentation by means of non-typified autochthonous lactic
acid bacteria already present in grapes and oak barrels or fermenters. The objective of this research was
to investigate the principal lactic acid bacteria present during spontaneous malolactic fermentation of
Chilean Cabernet Sauvignon wines and to study its role in BA formation. To the best of our knowledge
this is the first time that this relation has been reported for Chilean wines. Lactic acid bacteria were
isolated from five wineries located in three Chilean geographical regions. Genotypic differentiation of
each bacterial isolated was performed via a restriction fragment length polymorphism method using
rpoB and 16S rRNA genes and HinfI, AciI and MseI enzymes. Sixty-five colonies were isolated and identified
as lactic acid bacteria, identifying two species, Lactobacillus rhamnosus and Oenococcus oeni. The
predominant species was L. rhamnosus, which, to the best of our knowledge, we are describing for the
first time in the vinification process. Considering that L. rhamnosus was detected in wineries from
different geographical viticultural regions, it could be preliminarily considered as an endemic species.
Both species were biogenic amines producers, L. rhamnosus being mainly responsible for biogenic amines
present in the Cabernet Sauvignon wines studied.