Strains of Acetobacter, which are among the most
popular varieties of AAB for production of vinegar in
many countries, have a noticeable physiological instability
(10). This instability has at least the 2 different forms of
temporal acclimation and heritable adaptation (11,12).
When properly adapted to conditions, AAB gradually
develop resistance against stress, mainly regarding ethanol
oxidation, temperature, and acetic acid resistance (11-13).
This instability has been widely studied using Acetobacter
based on either the phenotype or genotype. For A.
pasteurianus, a high rate of spontaneous mutantions due to
an inserted sequence of 1,665 bp was observed (13).
Whole genome analysis has been used to reveal the genetic
instability of A. pasteurianus. In a 2.9 Mb chromosome
and 6 plasmids of strain A. pasteurianus NBRC 3283,
more than 280 transposons and 5 genes with hypermutable
tandem repeats were indentified. There were 3
single nucleotide mutations and 5 transposon insertions in32 isolates during long time (21 years) maintenance
without stress (10).