Kinetics Study on the Proliferation of Protocorm-like Body of Dendrobium huoshanense in Phosphorus-limiting Culture and Its Polysaccharide Synthesis
WEI Ming et al (Department of Biochemical Engineering,Anhui College of Engineering Science and Technology,Wuhu,Anhui 241000)
[Objective] The purpose was to study the kinetic characteristics of proliferation of protocorm-like body of Dendrobium huoshanense,its main nutrient consumption and polysaccharide accumulation under the different initial phosphate concn.[Method] With the protocorm-like bodies of D.Huoshanense as tested materials,protocorm-like bodies were inoculated in the modified MS liquid medium containing different concn.of phosphorus for suspension culture.They were harvested after 30 d to weight and determine polysaccharide contents in protocorm-like bodies and the contents of total sugar and phosphate ions in medium.The models of protocorm proliferation and polysaccharide synthesis were established.[Result] The growth of protocorm-like body was inhibited in the medium without phosphorus.The biomass and cell growth rate were increased along with the increase of phosphorus concn.;the polysaccharide yield was increased along with the growth of protocorm-like bodies under different phosphorus concn.;the absorption and utilization rates on extracellular nutrients were enhanced along with the increase of phosphorus concn.The relationship between the specific growth rate of cell and the phosphorus concn.accorded with Monod equation and the maxmum specific growth rate was 0.032 d-1.[Conclusion] Phosphate was a limited factor for the proliferation of protocorm-like body of D.Huoshanense and its growth showed positive correlation with polysaccharide synthesis.