Hernandulcin Production in Elicited Hairy Roots of Phyla scaberrima: Toward Sustainable Production of a Non-Caloric Sweetener with Nutraceutical Properties.

Herein we report on the generation of hairy root lines of P. scaberrima able to produce hernandulcin (HE), a non-caloric sweetener with nutraceutical properties. From ten different lines analyzed, three synthesized up to 100 mg ⋅ L -1 HE under the batch culture conditions standardized in this investigation. Adding elicitors (salicylic acid, chitin, Glucanex, polyethylene glycol) and biosynthetic precursors (farnesol and (+)-epi-alpha-bisabolol) significantly altered HE accumulation. Chitin and Glucanex enhanced HE production from 130 to 160 mg ⋅ L -1 , whereas farnesol and (+)-epi-alpha-bisabolol from 165 to 200 mg ⋅ L -1 without dependence on biomass accumulation. Improved batch cultures containing liquid Murashige & Skoog medium (MS; pH 7), added with 4 % sucrose, 0.5 mg ⋅ L -1 naphthaleneacetic acid, 100 mg ⋅ L -1 Glucanex, 150 mg ⋅ L -1 chitin, 250 mg ⋅ L -1 farnesol, and 150 mg ⋅ L -1 (+)-epi-alpha-bisabolol at 25 °C (12 h light/12 h darkness), triggered HE accumulation to 250 mg ⋅ L -1 in 25 days. The efficiency of each recombinant line is discussed.