3.4.1. Metabolic engineering
For industrial scale and sustainable production of taxol and related
taxanes, numerous studies have focused on the synthesis of precursors
involved in the synthesis of taxol from plant cell cultures. Cloning of
taxadiene synthase (TXS ) and 10-deacetylbaccatin
III-10-O-acetyltransferase (DBAT ) genes is an important
biotechnological approach to increase the production of two precursor
taxoids: 10-deactylbaccatin III (DB) and bacctin III (BC) to synthesize
taxol. Taxus mairei cells transformed with TXS andDBAT genes with the addition of an elicitor MeJA produces 2.5
times higher taxoids than non-MeJA treated control cells
(Ho et al., 2005). Similarly, transformed
roots of T. baccata shows 265% greater taxane production after
MeJA elicitor treatment, with over-expression of the TXS gene
also being identified as an important contributory factor (Wilson and
Roberts, 2014; Expósito et al., 2009;
Engels et al., 2008). Exogenous feeding of taxol is another phenomenon
to produce taxol and related taxane products in Taxus baccatasuspension cultures. DNA laddering analysis reveals that the
addition of taxol caused a considerable increase in taxadiene synthase
activity (Expósito et al., 2009).