An Overview on the Biological Production of Vinegar
Acetic Acid Bacteria (AAB)
acetic acid bacteria (AAB) in the family Acetobacteriaceae and Gluconobacter.
AAB are Gram-negative or Gram-variable bacteria, with ellipsoidal to rod-
could be either peritrichous or polar. Their size variesbetween 0.4-1 μm
wide and 0.8-4.5 μm long. They are observed as individual cells, in pairs
or in chains. They show a strict aerobic metabolism with oxygen as the
terminal electron acceptor, and are catalase positive and oxidase negative
(Gonzalez et al., 2004).
Gullo and Giudici (2008) reported that the AAB were present in the
environment and in the raw material, but they cannot grow during
alcoholic fermentation because of the anaerobic conditions. When the
alcoholic liquid was exposed to oxygen, the AAB started their growth on
the surface. Du Toit and Pretorius (2002) reported that most AAB growth
was observed between pH 5.4 - 6.3, but they also could grow at pH values
lower than 4. They also reported that AAB could also be isolated at pH
values of 2.0-2.3 in media containing acetate, if they were aerated. The
optimal temperature for their growth was 25-30 o C, but their growth was
also observed between 38-40 o C and weakly at temperatures as low as 10 o C.
Yamada and Yukphan (2008) studied that AAB were usually found in
substrates containing sugar and/or ethanol. These substrates include
cider, beer, cocoa and vinegar.
Gullo et al., ȱ(2006)ȱreportedȱclearȱgrowthȱdifferencesȱbetweenȱAABȱspeciesȱ
differingȱ abilitiesȱ toȱ growȱ usingȱ differentȱ cultureȱ mediaȱ dependingȱ onȱ
the available nutrients. Results showed that there was a poor recovery on
synthetic culture media due to the lack of a suitable synthetic media, as not
all synthetic media equally support the growth of AAB and could even be
selective among strains. However, considerable progress in AAB isolation
had been made with the development of various culture media.
Garcia-Garcia et al., (2009) conducted studies on the acetous fermentation
of ethanol into acetic acid by acetic acid bacteria belonging to the family
Acetobacteriaceae and the genera Acetobacter and Gluconobacter . The total
chemical reaction that took place was as follows: