Kinetics In Cell Suspension Culture Process Of Hibiscus Sabdariffa

The effects of major nutrients on roselle cell growth and anthocyanin production were discussed. Sucrose and glucose were better for cell growth and anthocyanin production among different carbon sources. In the range of 10 100 g/L sucrose concentration , highest cell weight and anthocyanin yield were achieved on 40 g/L, while highest anthocyanin content was achieved on 60 g/L. Standard nitrogen concentration in B₅ medium was enough for roselle cell growth and anthocyanin production. Mediums with three kind of NO₃^- to NH₄⁺ ratio, 25:2, 23:4, 19:8 , were suitable for cell growth and anthocyanin production. Nitrate was necessary for cell growth, but showed some inhibition on anthocyanin production. High ammonium showed strong inhibition on cell growth, but increasing ammonium concentration in a certain range could increase anthocyanin content. Increase of total nitrogen concentration inhibited cell growth and lowered anthocyanin content. Phosphate was necessary for cell growth and anthocyanin production, but showed opposite influence on them.The suspension culture process of roselle cell could be divided into three phases: lag phase, rapid growth phase, stationary phase. Sucrose was growth limiting nutrient on low concentration condition. Increase of sucrose concentration stimulated cell growth, extended rapid growth phase and increased the final cell harvest. Substrate inhibition was observed when the concentration was above 40 g/L. The influence of different NO₃^- to NH₄⁺ ratio on cell growth was mainly reflected by the inhibition of high ammonium. Phosphate was also the growth limiting nutrient on low concentration condition. Increase of phosphate concentration increased cell growth rate and shortened the culture period, but the final cell harvest was nearly kept constant. Under the standard culture condition, the specific cell growth rate was 0.23 0.27 day^-1, and the doubling time was 2.5 3 days.The trends of anthocyanin content variation under different culture condition were the same. Initial phosphate concentration was most effective on anthocyanin content, while increase of sucrose concentration could also improve anthocyanin content to some extent. Excessive ammonium inhibited anthocyanin accumulation. The anthocyanin yield was decided by cell weight and anthocyanin content. Anthocyanin yield was enhanced with the increasing of sucrose concentration in a certain range, but the yields of culture processes with different initial phosphate concentration did not vary much.Anthocyanin accumulation was partially-growth-associated. The specific anthocyanin production rate was higher when the specific growth rate was 0.15 - 0.25 day^-1.Roselle cell rapidly hydrolyzed extracellular sucrose before adsorbing it. The hy-drolyzing process could be descripted using substrate saturation kinetic equation. The adsorbing rate, utilizing efficiency and intracellular accumulation of sugar were closely related to medium composition. Biomass yield coefficients of sugar under different...