Alginate Immobilized Dextransucrase of Leuconostoc lactis KU665298 for the Biocatalytic Synthesis of Dextran Polymer in A Bioreactor.

Dextran is a bacterial exopolysaccharide (EPS) which has multifarious values in the area of medicine, food and fine chemical industries. It is a linear polymer of glucose joined mainly by a (1 → 6) links and fewer a (1 → 2), a (1 → 3) and/or a (1 → 4) links. Fermentation processes for EPS production are utterly expensive owing to purification costs, giving an advantage to the use of enzymes. Therefore, dextran polymer can be synthesized from sucrose by the action of dextransucrase enzyme which is an extracellular bacterial glucosyltransferase. In the current study, purified dextransucrase from Leuconostoc lactis KU665298 has been immobilized by using various entrapment methods and calcium-alginate was found to be the most suitable matrix for this enzyme immobilization with an immobilization efficiency of 90.7%. Different conditions were standardized for the entrapment of purified dextransucrase from L. lactis in calcium alginate matrix and enzyme was also characterized for various reaction parameters for its utility in dextran production in a laboratory fermenter. The dextran production by calcium-alginate immobilized dextransucrase was found to be 2.02 g/L on dry weight basis after 24 h of incubation. [ABSTRACT FROM AUTHOR]