Alkaloid accumulation in Ca-alginate entrapped cells of Catharanthus roseus: Using a limiting growth medium.

The limitation of growth of Catharanthus roseus cells was investigated with a view to their entrapment in a Ca-alginate matrix. An examination of the effects of lowered 2,4-D and phosphate concentrations on cell viability and indole alkaloid biosynthesis enabled a growth limiting and product formation stimulating medium to be designed. Entrapped cells showed a retention of both respiratory activity and biosynthetic capacity over an extended period of time compared with free cells. Evidence is presented which suggests that immobilization in Ca-alginate beads acts to stabilize cells, resulting in enhanced product accumulation.