Forty-three acetic acid bacteria (AAB) strains were
isolated from different types of fruits, flowers and fermented
products collected from different regions of Sri Lanka.
They were identified using morphological, physiological
and biochemical methods. Based on their acetate oxidation
pattern, 37 strains of isolated AAB were identified as either
Acetobacter or Gluconacetobacter while the rest of the strains
were recognized as Gluconobacter. Along with the results of
species level identification, isolated strains were identified as
A. pomorum, A. aceti, A. pasteurianus, Gluconacetobacter spp.
and Gluconobacter frateurii. In order to examine the growth
characters of the isolates, they were grown on potato agar plates at
30 ℃, 37 ℃, and 40 ℃, and all the isolated strains revealed good
growth at both 30 ℃ and 37 ℃ while A. aceti MS33, A. pomorum
SC31, G. frateurii MN12 and MN18 showed good growth even at
40 ℃. Further, it was found that most of the isolated Acetobactertype strains can tolerate up to 10% ethanol even at 37 ℃, and
in contrast, the acetate tolerance of all the isolated strains was
found to be very poor. Then, acetic acid production ability of
AB5, PP21 and SC31 was examined statistically either with 4%
of 6% (v/v) ethanol at 30 ℃, 36 ℃ and 37 ℃, and all strains
showed over 3.5% (v/v) acetate production either with 4% or 6%
initial ethanol up to 36 ℃. Further, A. pasteurianus PP21 gave
an acetic acid production of 2.2% with 4% initial ethanol even
at 37 ℃. Thus, the obtained results revealed that all three tested
strains are prospective applicants in the production of vinegar at
higher temperatures
Abstract: Forty-three acetic acid bacteria (AAB) strains were
isolated from different types of fruits, flowers and fermented
products collected from different regions of Sri Lanka.
They were identified using morphological, physiological
and biochemical methods. Based on their acetate oxidation
pattern, 37 strains of isolated AAB were identified as either
Acetobacter or Gluconacetobacter while the rest of the strains
were recognized as Gluconobacter. Along with the results of
species level identification, isolated strains were identified as
A. pomorum, A. aceti, A. pasteurianus, Gluconacetobacter spp.
and Gluconobacter frateurii. In order to examine the growth
characters of the isolates, they were grown on potato agar plates at
30 ℃, 37 ℃, and 40 ℃, and all the isolated strains revealed good
growth at both 30 ℃ and 37 ℃ while A. aceti MS33, A. pomorum
SC31, G. frateurii MN12 and MN18 showed good growth even at
40 ℃. Further, it was found that most of the isolated Acetobactertype strains can tolerate up to 10% ethanol even at 37 ℃, and
in contrast, the acetate tolerance of all the isolated strains was
found to be very poor. Then, acetic acid production ability of
AB5, PP21 and SC31 was examined statistically either with 4%
of 6% (v/v) ethanol at 30 ℃, 36 ℃ and 37 ℃, and all strains
showed over 3.5% (v/v) acetate production either with 4% or 6%
initial ethanol up to 36 ℃. Further, A. pasteurianus PP21 gave
an acetic acid production of 2.2% with 4% initial ethanol even
at 37 ℃. Thus, the obtained results revealed that all three tested
strains are prospective applicants in the production of vinegar at
higher temperatures.
