Growth characteristics of Sanguinaria canadensis L. cell suspensions and immobilized cultures for production of benzophenanthridine alkaloids.
Sanguinaria canadensis L. plants were harvested from a local forest and calli were initiated from leaf explants. The production of benzophenanthridine alkaloids (i.e. sanguinarine, sanguilutine, sanguirubine, chelerythrine, chelilutine and chelirubine) by S. canadensis cell grown in modified B5 and IM2 media was compared to the alkaloid content of rhizomes. Sanguinarine accounted for approximately 80% of the total alkaloid content of cultured cells (1.3%, g g-1) while sanguinarine and sanguirubine accounted for 70% of rhizome alkaloids (9.0%, g g-1). Sanguinarine, chelirubine and chelerythrine were the only known alkaloids detected in cultured S. canadensis cells. Maximum alkaloid production of cultures performed using B5 medium, containing half the original nitrate concentration, was observed following extracellular nitrate and sugar depletion. The scale-up of this culture was successfully performed in a 2-1 immobilization bioreactor. The consumption of sugar and nitrate as well as the oxygen (OTR) and carbon dioxide (CTR) transfer rates of the immobilized cell culture were monitored for 15 days. The maximum sugar and nitrate consumption rates were 1.8 g l-1 per day and 2.3 mM per day respectively. The maximum OTR and CTR of the immobilized cell culture were 0.8 mmol O2 l-1 h-1 and 0.95 mmol CO2 l-1 h-1 respectively. The sanguinarine yield of this culture reached 1.0% based on biomass dry weight (g g-1 dw) by day 15.