Regulation of vinblastine biosynthesis in cell suspension cultures of catharanthus roseus

Various elicitors of hydroxylase, peroxidase, acetyltransferase and inhibitors of oxygenase were added to a Catharanthus roseus cell culture medium to investigate the regulatory effects on tabersonine, vindoline and vinblastine biosynthesis. Hydrogen peroxide was found to be the most effective agent for enhancing the biosynthesis of tabersonine. By adding 20 mu g/L hydrogen peroxide, the tabersonine concentration reached 9.02 mg/g dry weight (DW) after culturing cell suspensions for 7 days. With the addition of 30 mu g/L acetyl CoA, the most vindoline (final cell content of 0.33 mg/g DW) was produced. By effective inhibition of lochnericine biosynthesis with the addition of 0.5 mu mol/L benzotriazole, the cell content of vindoline was increased to 0.42 mg/g DW. An orthogonal experiment consisting of multiple regulation factors was carried out to optimize vinblastine biosynthesis. It was shown that optimal vinblastine biosynthesis was achieved by addition of 5 mg/L acetyl CoA, 20 mu g/L hydrogen peroxide, 0.5 mu mol/L benzotriazole, 100 mg/L tryptophan, 100 mg/L loganin and 30 mg/L cerium chloride. Under these conditions, the cell content of vinblastine reached 0.81 mg/g DW. Simultaneous changes in cell content and enzyme activities of Cytochrome P-450 monooxygenases, Deacetylvindoline-O-acetyltransferase and Peroxidase enzyme indicated that these enzymes were closely linked to vinblastine biosynthesis.