Statistical Optimization of Cultivation Conditions for the Enhanced Production of Bacosides from Bacopa Monnieri Cell Suspension Culture

Abstract

Bacopa monnieri is commonly called as Brahmi belongs to the family Schrophulariaceae. It is found in wet, shady and marshy areas. This plant has high demand in commercial application due to its medicinal properties. It has been extensively explored by researcher due to the presence of bacoside; a memory enhancer used to treat memory disorder. Due to its high demand in commercial application the natural habitat of this plant depleted continuously and has been already entitled in the list of threatened species by International Union of conservation of nature and national resources. The best way to save this plant from being endangered is to utilize this plant by plant tissue culture to extract the important metabolites. Production of bacoside through plant tissue culture is very low. The aim of this research is to increase the yield of bacoside production through plant tissue culture. To increase the yield of bacoside a central composite design (CCD) was performed to optimized the media in suspension culture. Three factors such as inoculum size, sucrose concentration and phosphate concentration was optimized. The maximum predicted yield for biomass was found to be 3.65 g/L DW when the media contains 2 g/L inoculum, 30 g/L sucrose and 1.24 mM phosphate concentration. The maximum predicted yield for bacoside was 0.49 mg/g DW when the media contains 1.98 g/L inoculum, 41.92 g/L sucrose and 0.22 mM phosphate.
Experimental validation of the model predicted optimized media was performed and the correlation between experimental and model predicted value was found to be 99 % for biomass and 94 % for bacoside. There was 2.23-fold improvement in biomass and 3.63-fold improvement in bacoside production in optimized media. The nutrient (sucrose, nitrate and phosphate) consumption by the cell biomass in the optimized media was also studied and it was observed an initial lag phase of three days followed by a log phase from day third to day sixth in which the rate of nutrient consumption was very high and finally a stationary phase at the end of the twelve days’ study. Elicitation study was also performed to enhance the yield of bacoside in optimized media. Methyl Jasmonate at a concentration of 5 mg/L was used as elicitor on day four to elicited the production of bacoside. It was found that there is an increase in bacoside production; a 1.4-fold increase as compared to the control.