Alginate Immobilization of Escherichia coli MTCC 1652 Whole Cells for Bioconversion of Glycyrrhizinic acid and into 18-β Glycyrrhetinic Acid

Abstract

Microbial biotransformation of Glycyrrhizinic acid (GL) into 18-beta Glycyrrhetinic Acid (GA) was achieved using Escherichia coli MTCC 1652 whole cell. The E. coli whole cell was immobilized by entrapment method within calcium alginate beads using cell suspension of equal volume with sodium alginate 8%. The pH of solution, reaction volume and % of GL were optimized during the immobilization procedure and optimum pH 6.5, reaction volume of 4 mL and at 3% GL concentration for 12 h of incubation time showed highest concentration of GA (72.649 microg mL(-1)) with 76% bioconversion of GL to GA. Under optimized condition the immobilized cell produces 58.663 microg per mL of GA in licorice root extract containing 95.118 microg of GL per mL of the extract with 61% conversion at 12 h.

Microbial Screening for Biotransformation of Glycyrrhizin into 18α-Glycyrrhetinic Acid and 18β-Glycyrrhetinic Acid and their HPLC Analysis

“…Isolation of Aspergillus parasiticus producing β-glucuronidase was screened and enzyme activity was determined by using phenolphthalein-β-D-glucuronide (PPG) [11]. Enzymatic conversion of glycyrrhizin of G. glabra into GA using commercial preparation from Aspergillus niger was also reported [12]. Due to structural similarity of GL and GA to steroids, they have mineralocorticoid like effects and inhibit metabolic enzymes for adrenocorticosteroids [13].…”