Ocimum basilicum suspension culture as resource for bioactive triterpenoids: yield enrichment by elicitation and bioreactor cultivation

Abstract

The competence of Ocimum basilicum suspension culture for the production of pharmacologically distinguished triterpenoids had been explored to meet their escalating demand with inequitable natural resources. The production of three pentacyclic triterpenes—betulinic acid (BA), ursolic acid (UA) and oleanolic acid (OA), could be achieved for the first time in the O. basilicum suspension culture, together with the prevalently occurring rosmarinic acid (RA). The production of RA was most abundant (15.73 ± 0.28 mg/g DW) followed by that of BA (14.63 ± 0.21 mg/g DW), UA (4.71 ± 0.23 mg/g DW) and OA (0.91 ± 0.02 mg/g DW) in reducing order on their respective optimum cultivation period. Compared to the in-vivo control leaves, the suspension cell revealed almost 3.25-, 2.89-, and 1.79-folds higher OA, UA and RA contents, respectively. The BA synthesizing power of suspension cells exemplified notable trend as its presence in the control leaves remained obscured. By and large, cultivation in a 10 l bioreactor and elicitation with methyl jasmonate in bioreactor and shake flask improved the cumulative productivities of the targeted metabolites with reciprocated divergence in the amounts of the two isomers, i.e., UA and OA. The overall findings of the present study bear special merit in realising the global demand of these multiple terpenoids in a single culture system of O. basilicum, which remained unrevealed so far. First report towards the in vitro production of multiple pharmacologically distinguished, high demand triterpenoids—betulinic acid (BA), ursolic acid (UA) and oleanolic acid (OA), along with rosmarinic acid (RA) in suspension culture of Ocimum basilicum. Notable yield enhancement through bioreactor cultivation and strategic elicitation with methyl jasmonate in shake flask and bioreactor added additional merit to this study in realizing the global demand of these multiple terpenoids in a single culture system of O. basilicum.