Interplay of growth regulators during solid-state and liquid-state batch cultivation of anthocyanin producing cell line of Daucus carota

The influence of different growth regulators on biomass (BM) accumulation and anthocyanin (AC) content in solid-state and liquid-state batch cultures of Daucus carota was studied. While all the auxins such as 2,4-D, IAA and NAA supplemented at different levels, supported growth as well as AC synthesis, the maximum productivity of AC (1.27 g l−1) was observed in the presence of 2.5 mg l−1 of IAA followed by 1 mg l−1 of NAA (0.5 g l−1of AC). Among the cytokinins, kinetin (0.1 and 0.2 mg l−1) supported highest AC productivity. The interplay of different levels of IAA and kinetin revealed that the combination of IAA at 2.5 mg l−1 and kinetin at 0.2 mg l−1 was superior to other combinations both in solid-state as well as liquid-state cultures, where AC productivity in solid-state was much higher (five-fold) than that in liquid-state. Long term effects of the best IAA and NAA levels indicated that only IAA could support uniform productivity of AC in solid-state only. In liquid-state cultures, AC synthesis dropped steadily upto six subcultures where the subsequent increase of IAA by 0.5 mg l−1 brought back the level of AC for a limited number of subsequent subcultures. Increase of cytokinin did not improve AC productivity. Temperature also imparted significant effect on AC productivity with 30 °C being for solid-state whereas for liquid-state 25 °C was the best. In general, highest and stable production of AC occurred only in solid-state rather than in liquid-state, though the latter is generally preferred for automation of scaled-up production.