An Overview on the Biological Production of Vinegar
compacting material like beech wood shavings, charcoal or coke (Peppler
and Beaman 1967).
steel, with a volume of 50000–60000 litres. The surface area where bacteria
were exposed to oxygen was increased by a packing material in the tank,
on which the bacteria were immobilised. The mostly used packing was
made of beech wood shavings, over which the liquid was sprayed and
blown in from the lower part to maintain high oxygen availability. The
was re-circulated to the top again until the desired concentration of acetic
acid was obtained. The process was performed at 27-30°C and a cooling
coil in the tank was used to prevent overheating (Raspor and Goranovic
There were some disadvantages associated with the generator process like
high risk of clogging due to the cellulose-producing bacterial growth in
the generator, accumulation of dead bacteria and infection with vinegar
eels. Another disadvantage observed was a relatively high loss of ethanol
acid concentration (Tesfaye et al., 2002).
Submerged Fermentation
The most common production method was submerged culture which
improved the general fermentation conditions like aeration, stirring,
heating, etc. As generator culture was slow and expensive, submerged
culture fermentors have been used widely at industrial scales. In this
process, the mash is stirred and aerated frequently and the fermentors
areȱ fittedȱ withȱ aȱ heatȱ exchangerȱ forȱ theȱ maintenanceȱ ofȱ theȱ optimumȱ
temperature during the fermentation process (De Ory et al., 1999).
The most commonly method used for commercial vinegar production is
submerged-culture fermentor wherebacteria are suspended in medium,
inȱ contrastȱ toȱ traditionalȱ andȱ generatorȱ process.ȱ Theȱ firstȱ bioreactorȱ ofȱ
submerged type was Fring´sacetator in early 1950´s, and it was followed
by other patented methods as Cavitator, bubble column fermentor and
Effigasȱturbineȱvinegatorȱ(Tesfayeȱ et al., 2002).
volumes, but most commonly in the range of 10000-40000 litres. Basic