Effect of fungal homogenate, enzyme inhibitors and osmotic stress on alkaloid content of Catharanthus roseus cell suspension cultures.

The addition of Aspergillus niger homogenate to Catharanthus roseus cell suspension cultures produced an increment of more than 60% in the alkaloid content of two different cell lines. The use of an inhibitor of phenylalanine ammonia lyase, i. e. cinnamic acid, along with the homogenate, resulted in an appearance of 90% of the alkaloids in the medium. Furthermore, even in the absence of fungal homogenate, there was a marked increase in the alkaloid content. The exposure of the cells to an osmotic stress produced a marked increment (320%) in the total alkaloid content. When both stress treatments were applied sequentially, an additive effect on alkaloid accumulation was observed. It was 300% higher than in cells cultured without treatment, the majority of the alkaloids found in the medium.