EFFECTS OF CHEMICAL AND PHYSICAL ENVIRONMENTS ON CELL CULTURE OF GYMNEMA SYLVESTRE

Abstract

This study was carried out to investigate the effects of chemical (medium salt strength, sucrose, plant growth regulator) and physical (inoculum size, aeration volume) environments on cell culture of Gymnema sylvestre. Strength of MS medium (1/4 MS, 1/2 MS and 1 MS) did not significantly affect cell growth, while sucrose concentration affected cell growth, showing maximal cell growth at 3% sucrose. Sucrose concentration higher than 3% inhibited cell growth due to low water potential in the medium. Different kinds and concentrations of auxin were tested for cell culture of Gymnema sylvestre. Cell growth was greatest at 5.0 mg L -1 NAA, while significantly inhibited by IBA treatment. The optimal inoculum size was 60 g L -1 as evidenced by the highest growth rate. Increasing aeration volume from 0.05 vvm to 0.4 vvm during culture period was optimal for cell growth in bioreactors. Cell growth was investigated every 5 days during the entire culture period. Fresh weight increased until 20 days in culture and dry weight increased almost 10 times after 15 days in culture. Sucrose concentration in the medium steadily decreased at growth phase (from 10 day to 15 day), almost depleted after 15 days in culture, while the utilization of glucose and fructose reached 100% after 20 days of culture. The results suggested that 15 days of culture period were optimal for Gymnema sylvestre cell culture in bioreactor. Further experiments including analysis of secondary metabolites are in process.