Spoilage Acetobacter

Acetic acid represents the only organic acid of normal olfactory sensory significance to wines (27). While acetic acid may be formed by . cerevisiae, the concentrations produced are typically less than 300 mg/L (55), far lower than the concentrations produced by spoilage microorganisms (he, Acetobacter) which are the predominate source (52). Apiculate yeasts may also serve as a source of acetic acid Romano et ah (36) found that Kl apiculata typically produced greater than 200 mg/L acetic acid in synthetic medium fermentations. 

Numerous bacterial species are present during the vinification process. The extent to which these species grow determines the types and concentrations of many substances that contribute to the aroma and flavor of a wine. Growth of bacterial species such as Acetobacter Gluconobacter, Lactobacillus, and Pediococcus may cause spoilage of a wine through the production of... 

There are several types of acetic bacteria (Volume 1, Chapter 7) with different metabolic properties. These are responsible for serious problems due to acescence, sometimes called acetic spoilage . Wine is only affected by Acetobacter, or vinegar ferment. The main reaction consists of the oxidation of ethanol to produce acetic acid. In the presence of ethanol, this same bacterium may also esterify acetic acid to produce ethyl acetate. Acetic bacteria develop in the form of a white bloom that may take on various appearances. Prolonged development produces a viscous mass, known as vinegar mother . 

Taxonomic status of AAB is complex and not well established, as it has been subjected to changes on several occasions in last 40 years. Historically, AAB were mainly classified as Acelobacler (Beijerinck, 1898) and Gluconobacter (Asai, 1935). At present, AAB taxonomically belong to family Acetobacteraceae (Asai, 1968), which is classified under the class alpha proteobacteria. AAB has 15 validated genera, and only two genera Acetobacter and Gluconobacter are reported to be associated with beer spoilage (van Vuuren Priest, 2003). 

For beer spoilage bacteria, Frateur s differential medium containing yeast extract, ethanol and calcium carbonate has been reported in the hterature, Acetobacter... 

Normally, the low concentration of oxygen in bottled wines prevents secondary growth and spoilage due to Acetobacter. However, Bartowsky et al. (2003) described an unusual situation where Acetobactervcere able to spoil bottled wines. In this case, the unfiltered wines were stored vertically. 

Bartowsky EJ, Xia D, Gibson RL, Fleet RL, Henschke PA (2003) Spoilage of bottled wine by acetic acid bacteria. Lett Appl Microbiol 36 307-314 Boesch C, Treck J, Sievers M, Teuber M (1998) Acetobacter intermedins sp. nov. Syst Appl Microbiol 21 220-229... 

Azuma Y, Hosoyama A, Matsutani M, Furuya N, Horikawa H, Harada T, Hirakawa H, Kuhara S, Matsushita K, Fujita N, Shirai M (2009) Whole-genome analyses reveal genetic instability of Acetobacter pasteurianus. Nucleic Acids Res 37 5768-5783 Bartowsky EJ, Henschke PA (2008) Acetic acid bacteria spoilage of bottled red wine a review. Int J Food Microbiol 125 60-70... 

Acetobacter aceti is an obligately aerobic a-proteobacterium that inhabits a wide variety of environmental niches where sugar is present, including flowers, fruits, soil, and water. The bacterium has been historically utilized for vinegar production and also causes the spoilage of alcoholic beverages because of its unique ability to incompletely oxidize ethanol to acetate (Asai 1968). The incomplete oxidation of... 

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