Effects of LEDs, macronutrients and culture conditions on biomass and artemisinin production using Artemisia annua L. suspension cultures

Artemisinin is a sesquiterpene lactone extracted from the medicinal plant Artemisia annua L. (sweet wormwood). It has traditionally been utilized in artemisinin-based combination therapies (ACTs) for the malarial parasite, including drug-resistant strains. Natural artemisinin extraction is costly with low yields. Due to its effectiveness, there is a significant rise in the demand for artemisinin production. In vitro cell suspension culture offers a cost-effective and viable technique for artemisinin production. Therefore, this study aimed to optimize a protocol for cell suspension culture of A. annua L. to enhance biomass and artemisinin production. A successful cell suspension culture was initiated from induced callus. The highest cell biomass was obtained in suspension cultures grown with an initial inoculum size of 0.1 g of mixed type cell aggregates, in media with a pH of 6.2 and a rotation speed of 90 rpm. Macronutrient concentrations influenced both biomass and artemisinin content, with optimal biomass achieved at 19 mM KNO₃ and 1.56 mM KH₂PO₄. The absence of these nutrients resulted in the highest artemisinin levels. Different LED wavelengths also significantly influenced biomass and artemisinin production. Red + blue LED increased cell biomass, while the highest artemisinin content was observed under red LED. The upscaling of the culture indicated a variation in biomass yield pattern, but the highest growth index was achieved in the 500 mL Erlenmeyer flask. This study successfully established a cell suspension culture for A. annua L., demonstrating the influence of macronutrients and red LED on biomass and artemisinin production, providing insights for potential large-scale production.