Lactic acid bacteria nutritional requirements

Lactic acid bacteria are nutritionally fastidious microorganisms, requiring rather complete nutritional supplementation. The cumulative effects of specific nutritional demands and environmental stress combined with, initially, low population density, makes most native lactics rather poor competitors. Consequently, these strains exhibit little activity unless fermentation is delayed or interrupted. 

Lactic acid bacteria have very limited synthetic capabilities and, reflecting this, the group is frequendy described as being fastidious. Simply stated, this means that LAB have complex nutritional requirements that they are metabolically incapable of meeting. This is seen in their habitat specificity which is restricted to decomposing plant tissue and in association with other microbes (i.e., yeasts) where they are able to glean decomposition products for their own needs. 

Lactic acid bacteria have very limited biosynthetic capabilities and, reflecting this, are described as nutritionally fastidious. Early work by Du Plessis (1963) noted that all strains of wine lactic acid bacteria required nicotinic acid, riboflavin, pantothenic acid, and either thiamine or pyridoxine. 

Like yeasts, lactic acid bacteria are also present in vineyards. However, given their nutritional requirements, species diversity and population density is limited. Sound, undamaged fruit contains <10 CFU/g and so populations in grape musts during the early stages of processing tend to be low (Lafon-Lafourcade et al., 1983b). Species that have been isolated... 

Section I, Grape and Wine Microorganisms, describes those microorganisms found in grape must, juice, and wines namely yeasts, lactic and acetic acid bacteria, and molds. Here, taxonomy, metabolism, nutritional requirements, and potential impacts on wine quality are areas of focus. 

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