Kimchi fermentation is carried out by
various microorganisms present in the raw materials and ingredients
of kimchi. Among them, lactic acid bacteria which can grow in 3% brine
play the most active role in the kimchi fermentation; it suppresses the
growth of other bacteria which could grow under such conditions.
Among the 200 bacteria isolated form kimchi,
the important microorganisms in kimchi fermentation are known to be
Lactobacillus plantarum, L. Brevis, Streptococcus faecalis, Leuconostoc
mesenteroides, and Pediococcus pentosaceus. Most kinds of bacteria
belonging to the genus Lactobacillus have been found to be present
The number of aerobes increased in the early
stage of kimchi fermentation and then decreased, while the number of
anaerobes continued to increase during the middle stage. A rapid increase
of aerobes in the late stage was due to the growth of film-forming yeasts.
Leu. mesenteroides actively grows in the
early stage of kimchi fermentation, thereby producing lactic acid and
carbon dioxide which could acidify kimchi and create an anaerobic state
to suppress the growth of aerobes. Streptococcus actively grows in the
early stage of fermentation, Pediococcus in the mid-stage, and
and L. brevis in the late stage, which could affect the ripening of kimchi.
The rate of kimchi fermentation was markedly
affected by salt concentration and fermentation temperature, and kimchi was
at an optimum for consumption when it contained 0.6-0.8% titratable acidity
(pH 4.2), 3% salt, and high volatile organic acids.