Improved β-thujaplicin production in Cupressus lusitanica suspension cultures by fungal elicitor and methyl jasmonate

Production of a novel antimicrobial tropolone, β-thujaplicin, in Cupressus lusitanica suspension cultures was studied by using a variety of chemicals and fungal elicitors. Sodium alginate, chitin, and methyl jasmonate resulted in 2-, 2.5-, and 3-fold higher β-thujaplicin production, respectively, than in the control. Significantly improved β-thujaplicin production (187 mg l^-1) was obtained using a high cell density (180-200 g l^-1) and fungal elicitor treatment [10 mg (g fresh cells)^-1] in a production medium with a high ferrous ion concentration (0.3 mM). This improved volumetric productivity was 3-to 4-fold higher than obtained under standard conditions. A synergistic effect of fungal elicitor and ferrous ion on β-thujaplicin production was also suggested by our study. Plant cell culture technology is a promising alternative for producing a large variety of secondary metabolites that are widely used as food additives, pharmaceuticals, and diary products (Verpoorte et al. 1999). Thus, β-thujaplicin production by plant cell cultures was developed with goal of commercial application (Berlin and Witte 1988; Itose and Sakai 1997; Ono et al. 1998). However, the production of β-thujaplicin by plant cell cultures is still not competitive for use in industrial applications. In this study, we assessed the effects of methyl jasmonate, alginate, chitin, and fungal elicitor on β-thujaplicin production; we ontained a significantly elevated β-thujaplicin production by using an improved culture strategy.