Identification and characterization of thermotolerant acetic acid bacteria strains isolated from coconut water vinegar in Sri Lanka

Biosci Biotechnol Biochem. 2014;78(3):533-41. doi: 10.1080/09168451.2014.882758. Epub 2014 Apr 29.


From the pellicle formed on top of brewing coconut water vinegar in Sri Lanka, three Acetobacter strains (SL13E-2, SL13E-3, and SL13E-4) that grow at 42 °C and four Gluconobacter strains (SL13-5, SL13-6, SL13-7, and SL13-8) grow at 37 °C were identified as Acetobacter pasteurianus and Gluconobacter frateurii, respectively. Acetic acid production by the isolated Acetobacter strains was examined. All three strains gave 4% acetic acid from 6% initial ethanol at 37 °C, and 2.5% acetic acid from 4% initial ethanol at 40 °C. Compared with the two other strains, SL13E-4 showed both slower growth and slower acetic acid production. As well as the thermotolerant SKU1108 strain, the activities of the alcohol dehydrogenase and the aldehyde dehydrogenase of SL13E-2 and SL13E-4 were more stable than those of the mesophilic strain. The isolated strains were used to produce coconut water vinegar at higher temperatures than typically used for vinegar production.

Keywords: Acetobacter pasteurianus; Gluconobacter frateurii; acetic acid bacteria (AAB); coconut water vinegar; thermotolerant bacteria.

MeSH terms

  • Acetic Acid / chemistry
  • Acetic Acid / metabolism*
  • Alcohol Dehydrogenase / chemistry
  • Aldehyde Dehydrogenase / chemistry
  • Cocos / microbiology*
  • Enzyme Stability
  • Ethanol / chemistry
  • Fermentation*
  • Gluconobacter / enzymology
  • Gluconobacter / isolation & purification
  • Gluconobacter / metabolism*
  • Hot Temperature
  • RNA, Ribosomal, 16S / genetics
  • Sri Lanka


  • RNA, Ribosomal, 16S
  • Ethanol
  • Alcohol Dehydrogenase
  • Aldehyde Dehydrogenase
  • Acetic Acid