Levan polysaccharide
Production
Production
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Levan is synthesized in [archaea](/wiki/Archaea "Archaea"), fungi, bacteria, and a limited number of plant species. Fructans such as levan are synthesized from [sucrose](/wiki/Sucrose "Sucrose"), a [disaccharide](/wiki/Disaccharide "Disaccharide") containing glucose and fructose. In plants, the [vacuole](/wiki/Vacuole "Vacuole") is where fructan production occurs. Sucrose:sucrose/fructan 6\-fructosyltransferase is the [fructosyltransferase](/wiki/Fructosyltransferase "Fructosyltransferase") in the vacuole which creates the beta 2,6 linkages to form the linear form of levan. Bacteria also use a fructosyltransferase known as levansucrase to form levan. These enzymes in bacteria form the 2,1 linkages in the linear basal chains of levan to allow for branching points to occur. Many bacteria produce levan in the cell exterior. This production can be sensitive to temperature, oxygen concentration, pH, and other factors. Levan production in bacteria is typically a sign of growth in population. There are also possible ways to produce by fracturing [soybean](/wiki/Soybean "Soybean") [mucilage](/wiki/Mucilage "Mucilage").

Levans are produced by microbes during colonization of a food [substrate](/wiki/Substrate_%28microbiology%29 "Substrate (microbiology)"). *[Erwinia amylovora](/wiki/Erwinia_amylovora "Erwinia amylovora")* exudes levan and [amylovoran](/wiki/Amylovoran "Amylovoran") as part of its [biofilm](/wiki/Biofilm "Biofilm"). Together they contribute to its [pathogenicity](/wiki/Pathogenicity "Pathogenicity"). In 2016, Ua\-Arak et al. developed a [sourdough](/wiki/Sourdough "Sourdough") method with high levan output (among other [exopolysaccharides](/wiki/Exopolysaccharide "Exopolysaccharide")).


Is levan production a sign of growth in bacterial population?