Gluconacetobacter europaeus

Genus/species: Gluconacetobacter europaeus since 1998 (Ga. europaeus) (Acetobacter europaeus prior to 1998).


Gram Stain: Negative


Morphology:
Cell: non-motile and non-flagellated rods. Most occur in pairs 
Colony: in the presence of CaCO3 a zone of clearing will be obvious around the colonies dues to the neutralization of the acid generated. 
Liquid Growth: 

Physiological Traits:

  • The bacteria are extremely resistant to high acetic acid concentrations, up to 10 % v/v.
  • Carbon sources:  n-propanol, fructose, maltose, sucrose, glycerol, sorbitol, and mannitol.

Ecological Traits: 
Important part of the vinegar production in Europe.


Distinguishing Features:

  • Produces acetic acid from ethanol
  • Grows in acetic acid at pH 2.5
  • Will not utilize glycerol, gluconate or lactate.

Role in wine:

  • Oxidases ethanol to acetic acid; causing the spoilage of wine.


Sensitivities: 

SO2: >100mg/L
Sorbate: No 
DMDC: Unknown 
pH: Highly adaptable to changes in pH.
Acids: Highly tolerant 
Ethanol: Mixed results (none specific for bacteria)
Anaerobiosis: Obligated aerobes 
Heat: intolerant