Long term culture and caffeine production of immobilized coffee (Coffea arabica) L. cells in polyurethane foam

Coffee (Coffea arabica L.) cells could be immobilized in polyurethane foam and subcultured repeatedly for a long time. Four phases were observed for cell growth and caffeine production, I; immobilization, II; growth, III; caffeine production, IV; regrowth. Their periods were influenced by the number of foam particles. Especially in the phase III, the immobilized cells produced a relatively large amount of caffeine in the subculture numbers 5–8 (34 cubes) when the fresh weight of the immobilized cells decreased despite culture in growth medium (DK medium). Caffeine production appeared to have a negative correlation with the growth of the immobilized cells throughout the subcultures.This paper is Part 71 in the series of Studies on Plant Tissue Cultures. For Part 70, see Orihara Y, Furuya T. submitted for publication.