A MODEL THAT LINKS GROWTH AND SECONDARY METABOLITE PRODUCTION IN PLANT-CELL SUSPENSION-CULTURES

Plant cell suspensions of grape cells (Vitis vinifera L. cv. Gamay Fre aux) were grown in shake flasks operated both in the batch and semicon tinuous mode. A mathematical model was developed to describe grape cel l growth, sucrose uptake, and secondary metabolite (anthocyanin) produ ction. Parameters were estimated from batch studies data. The model wa s able to predict results for semicontinuous experiments by only modif ying the value of four of these parameters. The modified parameters (m aximum specific rate of biomass production, maximum specific rate of s ubstrate consumption for maintenance, maximum specific rate of anthocy anin production, and degradation constant of anthocyanins) were relate d to the kinetics rather than to the yield of the process. The model i ntroduces the concept of primary and secondary metabolism substrate co ncentration-dependent competition for precursors. Further, the model w as able to predict the evolution of the cell system when substrate is scarce, as the value of the different kinetic constants determines the portion of substrate that is used for biomass production, secondary m etabolite production, and cell maintenance. (C) 1995 John Wiley & Sons , Inc.