Enhanced plumbagin production in Plumbago indica root cultures by ʟ-alanine feeding and in situ adsorption

Abstract

Plumbagin is associated with potent antimicrobial and anticancer properties. However, due to poor supply of the natural product, efforts are being made to improve plumbagin biosynthesis and bioproduction. The aim of this work was to enhance production of plumbagin from root cultures of Plumbago indica L. through precursor feeding using l-alanine followed by in situ adsorption of plumbagin on the nonpolar copolymer adsorbent, styrene–divinylbenzene resin (Diaion® HP-20). l-alanine fed at a concentration of 5 mM to 14 days old root culture followed by the sequential addition of Diaion® HP-20 (10 g L−1) after 36 h of l-alanine-fed significantly increased plumbagin production to 22.4 mg g−1 dry weight (DW). The level of productivity obtained was 14- and 1.6-fold higher than that achieved using untreated root cultures (1.6 mg g−1 DW) or l-alanine feeding alone (14.4 mg g−1 DW) within 16 days of the culture. The results of this work suggest the use of precursor feeding in combination with in situ adsorption as an easy and cost effective tool for the large-scale production of medicinally valued compounds like plumbagin.