SURFACTANT-INDUCED NONLETHAL RELEASE OF ANTHRAQUINONES FROM SUSPENSION-CULTURES OF MORINDA-CITRIFOLIA

A new approach based on the use of the surfactant Pluronic F-68 to obtain non-lethal release of plant cell intracellular products was investigated. Suspension cultures of Morinda citrifolia (Rubiaceae), producing anthraquinones as secondary metabolites, were selected as model system. By supplementing the growth medium with 2% w/v of Pluronic F-68 for four repeated batch cycles, cells released anthraquinones to a concentration 170-times the value of the control cells. An average of 55% of the intracellularly stored anthraquinones was recovered from the Pluronic-treated cells, against 0.74% of the control. The determination of K+ leakage showed that cells did not release products through a diffusion mechanism due to membrane damages. Cell respiration was not affected by the presence of the surfactant. We suggest media supplementation with Pluronic as a simple, inexpensive and effective way to achieve non-lethal product release from plant cells.