Abstract:

In this study, the effects of cerium, one kind of rare earth elements, on cell growth, polysaccharide biosynthesis, and utilization of carbon, nitrogen and phosphorus sources in protocorm-like bodies of Dendrobium huoshanense during suspension culture were investigated. Results indicated that cerium could improve the utilization of carbon and nitrogen sources in protocorm-like bodies of Dendrobium huoshanense, significantly increase the contents of intracellular polysaccharides, nitrate and phosphate, and enhance cell growth and polysaccharide biosynthesis. The concentration of cerium was optimized to be 10 μmol/L, which could result in the improvement of cell growth rate from 0.501 to 0.649 g/(L·d). At this optimal concentration, the maximum dry weight of protocorm-like bodies was up to 25.45 g/L after 24 days of cell culture, which was increased by 20.2% compared with the control. Similarly, the highest production of polysaccharides was reached to 3.35 g/L after 18 days of cell culture, which was 1.53-fold amount of the control.

Key words: rare earth element, polysaccharide, Dendrobium huoshanense, cerium