Optimization and establishment of tea cell bioreactor (Camellia sinensis) to produce catechins and epicatechins

Tea (Camellia sinensis) is a major source of bioactive polyphenols, particularly catechins and epicatechins, which are valued for their antioxidant and health-promoting properties. The present study aimed to establish and optimize a plant cell suspension culture system for enhanced production of catechin and epicatechin using tea callus-derived cells. Callus induction and proliferation were evaluated under different combinations of plant growth regulators, followed by optimization of suspension culture conditions. Casein hydrolysate (CH) and aluminum sulfate (Al³⁺) were applied as elicitors to assess their synergistic effects on cell growth and secondary metabolite accumulation. The optimal suspension culture was obtained using Murashige and Skoog medium supplemented with 2 mg/L 6-benzylaminopurine and 2 mg/L naphthalene acetic acid, which supported stable cell growth without browning. HPLC analysis demonstrated that the addition of CH and AL significantly enhanced catechin and epicatechin production. The highest catechin yield (3.38 mg/L) was achieved with 25 mg/L CH, while the maximum epicatechin concentration (5.92mg/L) was obtained with a combination of 125mg/L CH and 50 mg/L AL. These findings demonstrate an efficient and scalable in vitro platform for catechin production and highlight the potential of elicitor-assisted suspension cultures as an alternative to conventional tea cultivation.