Bacteria in Wine

The growth of malo-lactic bacteria in wines is favored by moderate temperatures, low acidity, very low levels of S02, and the presence of small amounts of sugar undergoing fermentation by yeast. It is frequently possible to inoculate a wine with a pure culture of a desirable strain of bacteria and obtain the malo-lactic fermentation under controlled conditions. The pure-culture multiplication of the selected strain of bacteria is difficult, however. It is also difficult to control the time of the malo-lactic fermentation—sometimes it occurs when not wanted, and at other times will not go when very much desired. For the home winemaker it is probably most satisfactory to accept the malo-lactic fermentation if it occurs immediately following the alcoholic fermentation. The wines should then be siphoned away from deposits, stored in completely filled containers at cool temperatures, and have added to them about 50 ppm S02. If the malo-lactic fermentation does not take place spontaneously and the wine is reasonably tart, the above described regime of preservation will likely prevent its occurrence. When the malo-lactic transformation takes place in wines in bottles, the results are nearly always bad. The wine becomes slightly carbonated, and the spoiled sauerkraut flavors are emphasized. 

Amino acid decarboxylases are the enzymes responsible for the synthesis of biogenic amines. These proteins and the genes that encode them have been studied in several lactic acid bacteria in wine and are briefly discussed below. 

Moreno-Arribas and Lonvaud-Funel (1999). Moreno-Arribas et al. (2000) isolated and identified a number of tyramine-producing lactic acid bacteria in wine that had undergone malolactic fermentation all belonging to the lactobacilli. Tyrosine decarboxylase was then purified (Moreno-Arribas and Lonvaud-Funel 2001) and the corresponding gene was purified and sequenced (Lucas and Lonvaud-Funel 2002 Lucas et al. 2003). As far as the literature suggests, no tyramine-producing 0. oeni strain has yet been reported, with the exception of one strain (O. oeni DSM 2025) that was shown to be able to produce tyramine in a laboratory medium (Choudhury etal. 1990). 

Lysozyme is an enzyme that can cause lysis of the cell walls of Gram-positive bacteria, including lactic acid bacteria in wine (Delfini 2004). Lysozyme maintains its activity in wines with high pH values so it can be used successfully to delay or inhibit the growth of lactic acid bacteria, especially when used together with SO2,... 

Coton, E., RoUan, G., Bertrand, A. Lonvaud-Eunel, A. (1998). Histamine-producing lactic acid bacteria in wines early detection, frequency and distribution. Am. J. Enol. Vitic., 49, 199-204. 

Garcia-Ruiz, A., Bartolome, B. Moreno-Arribas, M.V. (2008b). Understanding the effect of oak wood treatments and enologjcal tannins in biogenic amine production by lactic acid bacteria in wines XXXI World Congress of Vine and Wine, Verone, 2008. 

Tetrahydropyridines (THP) are secondary metabolites produced by D. bruxellensis and lactic acid bacteria in wines and are responsible for a taint described as mousy off-flavour or mousiness. This problem has been known since late nineteenth century (see review of Snowdon et al. 2006) but, in spite of its obnoxious flavours, has been only vaguely studied perhaps due to its low frequency of occurrence. 

Costello, P.J., Morrison, G.J., Lee, T.H., and Fleet, G.H. 1983. Numbers and species of lactic acid bacteria in wines during vinification. Food Technol. Aust. 35, 14—18. 

Drysdale, G.S. and Fleet, G.H. 1989b. The growth and survival of acetic acid bacteria in wines at different concentrations of oxygen. Am. J. Enol. Vitic. 40, 99-105. 

Fomachon, J.C.M. 1968. Influence of different yeasts on the growth of lactic acid bacteria in wine. 

Martineau, B. and Henick-Kling, T. 1995b. Performance and diacetyl production of commercial strains of malolactic bacteria in wine. J. Appl. Bacteriol. 78, 526-536. 

Sohier, D. and Lonvaud-Funel, A. 1998. Rapid and sensitive in situ hybridization method for detecting and identifying lactic acid bacteria in wine. Food Microbiol. 15, 391-397. 

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