Synthesis of Fructans and Glucans from Sucrose by Glycosyltransferases: An Industrial Alternative

Dr. Agustín López Munguía
Associate Director and Professor, Institute of Biotechnology Universidad Nacional Autónoma de México

Fructansucrases are enzymes that catalyze the transfer of the fructosyl unit from sucrose to a growing fructan polymer chain. Depending on the chemical nature of the fructosyl bond, these enzymes are classified as levansucrases or inulosucrases, producing levan or inulin respectively. We first reported the unusual structure of inulosucrase (IslA) from Leuconostoc citreum with high identity to levansucrase (SacB) from Bacillus subtilis, but bearing also additional domains of glucansucrases, a group of enzymes that carry out the synthesis of glucans from sucrose. The same structural features found in IslA were later identified and characterized in other lactic bacteria strains. Both types of glycosyltransferases are an actual subject of basic and applied research. Enzymes from Streptococcus spp. are implicated in biofilm synthesis and extracellular carbohydrate storage compounds production during the pathogenesis of dental caries, while fructansucrases are involved in the synthesis of complex sugars important for human health due to their prebiotic nature. In this conference several aspects related to the structural properties, production and application of glucosyl- and fructosyl-transferases are addressed, particularly those related to potential applications in the food and pharmaceutical sectors.