β-Glucosidase-Catalyzed Hydrolysis of Indican from Leaves of Polygonum tinctorium

Abstract

In this article, a HPLC method to identify and quantify the dyes and the indigo precursors produced in Polygonum tinctorium is described. Using this technique, indican has been positively identified in extracts of P. tinctorium. Our work with two cultivars of P. tinctorium has confirmed that the quantity of indican is dependent on the cultivars, harvest period, and age of the leaves. Two enzymes, Novozym 188 (cellobiase) and Novarom G (beta-glucosidase), are compared on the basis of their activities to hydrolyze the indican at several pH values. We observed that Novarom G is more active than Novozym 188 whatever the pH and that optimum pH of both enzymes for indican hydrolysis is 3. Liberated indoxyl can be oxidized in alkaline media and transformed into indigo and indirubin.

Characterization of an Unusual Cold-Active β-Glucosidase Belonging to Family 3 of the Glycoside Hydrolases from the Psychrophilic Isolate Paenibacillus sp. Strain C7

“…We also plan to determine whether BglY's ability to cleave indican could have applications for the production of indigo dye from Polygonum tinctorium. The specific activity of purified BglY on indican is 300 times greater than that reported for an enzyme studied for possible industrial use, Novarom G (24), and the K m of BglY with indican is slightly lower than that reported for the ␤-glucosidase produced natively by P. tinctorium (26). VOL.…”

Enhanced indirubin production in recombinant Escherichia coli harboring a flavin-containing monooxygenase gene by cysteine supplementation

“…In a tryptophan rich condition, extracellular tryptophan is transported into the cell by tryptophan permease and thereafter converted into indole, pyruvate, and ammonia by tryptophanase (TnaA; EC 4.1.99.1) (Newton and Snell, 1965). FMO catalyzes the hydroxylation of indole to 2-hydroxyindole and 3-hydroxyindole by using the reducing power of NADPH in the presence of oxygen (Choi et al, 2003;Eaton and Chapman, 1995;Maugard et al, 2002). In the non-enzymatic reaction, indigo is produced from the combination of two 3-hydroxyindole molecules, whereas indirubin is made from the dimerization of 2-hydroxyindole and 3-hydroxyindole (Berry et al, 2002;Cho et al, 2011;Choi et al, 2003;Eaton and Chapman, 1995;Maugard et al, 2002;McClay et al, 2005).…”

“…FMO catalyzes the hydroxylation of indole to 2-hydroxyindole and 3-hydroxyindole by using the reducing power of NADPH in the presence of oxygen (Choi et al, 2003;Eaton and Chapman, 1995;Maugard et al, 2002). In the non-enzymatic reaction, indigo is produced from the combination of two 3-hydroxyindole molecules, whereas indirubin is made from the dimerization of 2-hydroxyindole and 3-hydroxyindole (Berry et al, 2002;Cho et al, 2011;Choi et al, 2003;Eaton and Chapman, 1995;Maugard et al, 2002;McClay et al, 2005). Currently, it is thought that the disproportional production of indigo and indirubin is due to random combinations of the various hydroxyindole molecules under different conditions, but any enzyme activity in the combination reaction has not been discovered yet.…”

Bio-indigo production in two different fermentation systems using recombinant Escherichia coli cells harboring a flavin-containing monooxygenase gene (fmo)

“…Effect of aeration and agitation rate on the profiles of dissolved oxygen, cell growth and indigo production As described in Section 1, oxygen concentration in the medium is an important factor for bio-indigo production [7,9,10]. Fig.…”

“…In these cells, tryptophan was converted to indole by E. coli tryptophanase, and indole was then oxidized to 2-hydroxyindole, 3-hydroxyindole, and isatin by FMO. The indole derivatives were then dimerized into indigo or indirubin, depending on the oxygen concentration [7,9,10].…”