Gluconacetobacter liquefaciens

Genus/species: Gluconacetobacter liquefaciens (Gluconobacter liquefaciens)

 

Gram Stain: Negative

Morphology:

  • Cell: Rod-shaped
  • Colony: Off white, circular, raised
  • Liquid Growth: Pellicle formed

 

Physiological Traits:

Growth substrates: ethanol. End product: acetic acid. Aerobic; needs oxygen for this conversion, can produce ascorbic acid (vitamin C).

Ecological Traits:

Found in nature associated with sugar; fruits, flowers, spoiled fruits (sugar converted to alcohol), especially in environments were the presence of alcohol prohibits the growth of other microorganisms.

Distinguishing Features:

Distinguishable from Acetobacter by determination of ubiquinone type using reverse phase paper chromatography or HPLC

Role in wine:

Usually present towards the end of the alcoholic fermentation, this species acts as a spoilage organism, turning the ethanol resulting from the fermentation into acetic acid.

Sensitivities:  

  • SO2: Sensitive
  • Sorbate: Sensitive­­­
  • DMDC: Sensitive
  • pH: <3.0 li="">
  • Acids: N/A
  • Ethanol: >15%
  • Anaerobiosis: Req. oxygen
  • Heat: >30C’

References:

Guillamon, J.M. and A. Mas. 2009. Acetic Acid Bacteria. InBiology of Microorganisms on Grapes, in Must and in Wine. H. Konig, ed.

Jackson, R.S. 2008. Wine science. Principles and Applications. San Diego, Calif: Academic Press Inc. 187-189.

Sievers, M. and J. Swings. 2005 Genus VII: Gluconacetobacter. In: Bergey’s Manual of Systematic Biology. Garrity, G.M., ed. 2005. 2: 72.