Enhanced catharanthine production in Catharanthus roseus cell cultures by combined elicitor treatment in shake flasks and bioreactors

Chemical and fungal elicitors were added to Catharanthus roseus cell suspen sion cultures so as to improve the production of indole alkaloids. A synerg istic effect on alkaloid accumulation was observed in C. resells cell cultu res when treated with some combined elicitors of fungal preparations and ch emicals, Among them, the combination of tetramethyl amminium bromide and As pergillus niger mycelial homogenate gave the highest ajmalicine yield (63 m g1(-1)) and an improved catharanthine accumulation (17 mg 1(-1)). The combi ned elicitors oi malate and sodium alginate resulted in the highest cathara nthine yield (26 mg 1(-1)) and a high ajmalicine accumulation (41 mg 1(-1)) in the cell cultures. Based on the synergistic effect of malate and sodium alginate a process with enhanced catharanthine production in Catharanthus roseus cell cultures was developed in shake flasks and a bioreactor. After 10 days of culture, 25 mg 1(-1), 32 mg 1(-1) and 22 mg 1(-1) catharanthine yield were obtained in 500-ml flasks, 1000-ml flasks and in a 20-1 airlift bioreactor, respectively. Upon malate-alginate combining treatments, peroxi dase, catalase and superoxide dismutase activities decreased in elicited ce lls but phenylalanine ammonia lyase and lipoxygenase activities increased d ramatically. That suggests a typical defense responses took place in the co mbined elicitors-treated cell cultures. Furthermore, the combined elicitors also caused a significant increase of malondialdehyde level in cell cultur es, which suggests a serious lipid peroxidation occurred in the elicited ce ll cultures. Comparison of these results suggests that malate and alginate combining treatment also stimulates defense responses, such as lipid peroxi dation? in all C roseus culture processes and this may mediate the indole a lkaloid production via jasmonate pathway. (C) 2001 Elsevier Science Inc. Al l rights reserved.