Lactic Acid bacteria
<p>The <b >lactic acid bacteria (LAB)</b> comprise a <a href="http://en.wikipedia.org/wiki/Clade" title="Clade" >clade</a> of <a href="http://en.wikipedia.org/wiki/Gram-positive" title="Gram-positive" class="mw-redirect" >Gram-positive</a>, low-<a href="http://en.wikipedia.org/wiki/Guanine" title="Guanine" >G</a><a href="http://en.wikipedia.org/wiki/Cytosine" title="Cytosine" >C</a>, acid-tolerant, generally non-sporulating, non-respiring rod or cocci that are associated by their common <a href="http://en.wikipedia.org/wiki/Metabolic" title="Metabolic" class="mw-redirect" >metabolic</a> and <a href="http://en.wikipedia.org/wiki/Physiological" title="Physiological" class="mw-redirect" >physiological</a> characteristics. These <a href="http://en.wikipedia.org/wiki/Bacteria" title="Bacteria" >bacteria</a>, usually found in decomposing plants and lactic products, produce <a href="http://en.wikipedia.org/wiki/Lactic_acid" title="Lactic acid" >lactic acid</a> as the major metabolic end-product of <a href="http://en.wikipedia.org/wiki/Carbohydrate" title="Carbohydrate" >carbohydrate</a> fermentation. </p>
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This trait has, throughout history, linked LAB with <a href="http://en.wikipedia.org/wiki/Fermentation_(food)" title="Fermentation (food)" >food fermentations</a>, as acidification inhibits the growth of spoilage agents. Proteinaceous <a href="http://en.wikipedia.org/wiki/Bacteriocins" title="Bacteriocins" class="mw-redirect" >bacteriocins</a> are produced by several LAB strains and provide an additional hurdle for spoilage and <a href="http://en.wikipedia.org/wiki/Pathogen" title="Pathogen" >pathogenic</a> microorganisms. Furthermore, lactic acid and other metabolic products contribute to the organoleptic and textural profile of a food item. </p>
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The industrial importance of the LAB is further evinced by their <a href="http://en.wikipedia.org/wiki/Generally_recognized_as_safe" title="Generally recognized as safe" >generally recognized as safe</a> (GRAS) status, due to their ubiquitous appearance in food and their contribution to the healthy microflora of human <a href="http://en.wikipedia.org/wiki/Mucosal" title="Mucosal" class="mw-redirect" >mucosal</a> surfaces. The <a href="http://en.wikipedia.org/wiki/Genus" title="Genus" >genera</a> that comprise the LAB are at its core <i ><a href="http://en.wikipedia.org/wiki/Lactobacillus" title="Lactobacillus" >Lactobacillus</a></i>, <i ><a href="http://en.wikipedia.org/wiki/Leuconostoc" title="Leuconostoc" >Leuconostoc</a></i>, <i ><a href="http://en.wikipedia.org/wiki/Pediococcus" title="Pediococcus" >Pediococcus</a></i>, <i ><a href="http://en.wikipedia.org/wiki/Lactococcus" title="Lactococcus" >Lactococcus</a></i>, and <i ><a href="http://en.wikipedia.org/wiki/Streptococcus" title="Streptococcus" >Streptococcus</a></i> as well as the more eripheral <i ><a href="http://en.wikipedia.org/wiki/Aerococcus" title="Aerococcus" >Aerococcus</a></i>, <i ><a href="http://en.wikipedia.org/wiki/Carnobacterium" title="Carnobacterium" >Carnobacterium</a></i>,<i ><a href="http://en.wikipedia.org/wiki/Enterococcus" title="Enterococcus" >Enterococcus</a></i>, <i ><a href="http://en.wikipedia.org/wiki/Oenococcus" title="Oenococcus" >Oenococcus</a></i>, <i ><a href="http://en.wikipedia.org/wiki/Sporolactobacillus" title="Sporolactobacillus" >Sporolactobacillus</a></i>, <i ><a href="http://en.wikipedia.org/w/index.php?title=Tetragenococcus&action=edit&redlink=1" class="new" title="Tetragenococcus (page does not exist)" >Tetragenococcus</a></i>, <i ><a href="http://en.wikipedia.org/w/index.php?title=Vagococcus&action=edit&redlink=1" class="new" title="Vagococcus (page does not exist)" >Vagococcus</a></i>, and <i ><a href="http://en.wikipedia.org/w/index.php?title=Weisella&action=edit&redlink=1" class="new" title="Weisella (page does not exist)" >Weisella</a></i>; these belong to the order <a href="http://en.wikipedia.org/wiki/Lactobacillales" title="Lactobacillales" >Lactobacillales</a>.</p>