Influence of the culture medium constituents and inoculum size on the accumulation of blue pigment and cell growth of Lavandula spica

The effects of the concentration of PO₄^3-, NO₃^-, Fe ²⁺, sucrose and inoculum size on the accumulation of blue pigment and growth of suspension cultures of Lavandula spica D.C. (≡L. latifolia Vill.), were studied. The combination of 2.5 mM PO₄^3-, 14.1 mM NO₃^-, 1 mM Fe ²⁺, 30 g l^-1 sucrose and 10 g l^-1fresh weight of inoculum, promoted a 7-fold enhancement on the productivity of blue pigment in comparison to the control medium. Among all the culture medium constituents tested, phosphate exerted the highest beneficial effect and Fe²⁺ showed to be essential for the accumulation of the pigment. High levels of sucrose (60 or 90 g l^-1) did not stimulate the accumulation of blue pigment. In these conditions, cell growth and cell viability were drastically affected.