Gluconacetobacter xylinus

Genus/species(aliases): Gluconacetobacter xylinus (Acetobacter bordeaux, Acetobacter xylinoides, Acetobacter xylinum var. africanum, Acetobacter xylinum var. maltovorans, Acetobacter xylinum var. xylinoides)

Gram Stain: Negative

Morphology:
Cell: rod-shaped
Colony: 
Liquid Growth: Pellicle formation with external web of cellulose microfibrils

Physiological Traits:

  • Cells occur singly, in pairs, in chains, or small clusters
  • Peritrichously flagellated when motile
  • Synthesize cellulose and acetan
  • No growth on 3% ethanol in the presence of 5-8% acetic acid
  • Grows well on D-glucose at 100g/L; acids are formed from ethanol, D-glucose, and D-xylose
  • Type strain does not produce acid from sucrose
  • Produces bacterial cellulose  dependent on the presence of O2.
  • Obligate aerobe
  • Will consume acetaldehyde, dithionite, glucose; possible exogenous NADH oxidation
  • Inhibited by KCN, more sensitive to KCN in the absence of ethanol; DMSO-inhibits periplasmic PQQ alcohol dehydrogenase activity
  • Produces Acetate, Gluconate, Acetaldehyde, Carbon Dioxide


Ecological Traits:Can be found on a ripe grape like other acetic acid bacteria. Populations vary according to grape health: rotten grapes host more viable populations


Distinguishing Features:
 Entangled growth in a pellicle composed of cellulose microfibers of random orientation. Rate of cellulose production is proportional to rate of cell growth and dependent on carbon source. Production is enhanced by small amounts of cellulose from Bacillus subtilis. Cellulose synthase is activated by cyclic diguanylic acid (c-di-GMP) which acts as an allosteric effector and increases activity rate by 200 fold.
Variation can be seen in culture treatments. In static cultures, a cellulose mat is produced. Round balls of cellulose are produced in shaking cultures.

Role in wine: Juice contaminant due to berry damage; may be particularly difficult to eliminate because of protection offered by cellulose matrix. Isolating colonies is also difficult for this reason.


Sensitivities:

  • SO2:
  • Sorbate:
  • DMDC:
  • pH:
  • Acids:
  • Ethanol: X (high concentrations)
  • Anaerobiosis: X
  • Heat : X

References:

  • Brenner, G. 1997. Bergey’s Manual of Systematic Bacteriology.Williams and Wilkins. New York.
  • Gonzalez, A., Hierro, N., Poblet, M., Mas, A., and J.M. Guillamon. 2006. Enumeration and detection of acetic acid bacteria by real-time PCR and nested PCR. FEMS Letters. 254:123-128.
  • Sponholz, W.R., Brendel, M. and Periadnadi. 2004. Formation of saccharide acids by acetic acid bacteria on grapes and in wine. Mitteilungen Klosterneuburg. 54:77-85.
  • Chávez-Pacheco, J.L., Martínez-Yee, S., Contreras, M.L., Gómez-Manzo, S., Membrillo-Hernández, J., and J.E. Escamilla. 2005. Partial bioenergetic characterization of Gluconacetobacter xylinum cells released from cellulose pellicles by a novel methodology. J. App. Microbiol. 99:1130-1140.