Genus/Species: Acetobacter cerevisiae
Gram Stain: Negative
Morphology:
- Cell: ellipsoidal to rod-shaped, cells occurring singly, in pairs, or occasionally in short chains
- Colonies: Beige to brown, round, regular to wavy, raised and smoothe
- Liquid growth:
Physical traits:
- Growth substrates: Glucose, ethanol, organic acids, glycerol
- Metabolic end products: acetaldehyde, ethyl acetate, dihydroxyacetone, gluconic acid
- This organism is an obligate aerobe
Ecological traits:
Spoiled and unspoiled fruit, isolated from beer
Distinguishing traits:
Oxidase-negative, catalase-positive, 2-keto-D-gluconic acid produced from D-glucose, 5-keto-D-gluconic acid is not produced from D-glucose, no growth with ammonia as the sole nitrogen source on ethanol as carbon source, no growth as maltose or methanol as carbon source.
Role in wine:
Spoilage organism converting ethanol to acetic acid
Sensitivities:
Sensitive to very low pH but can grow at wine pH; can survive at low oxygen levels, optimum temperature 20-25˚C, known to withstand ethanol levels as high as 15%