Modeling linear and variable growth in phosphate limited suspension cultures of Opium poppy

In this study, we investigated the influence of initial internal nutrient concentrations at the time of elicitation on the ability of Eschscholzia californica (EC) cells to produce alkaloids. Three EC cell suspensions cultivated in culture media differing in their PO4(3-) and NO3- contents were sampled daily for 12 days and analyzed for extracellular and intracellular nutrient concentrations. The ability of the cells to produce alkaloids was tested along the three cell suspension cultures. Sampled cells were then further cultured for 7 days in a production medium containing the elicitor and an extraction resin. The alkaloid production of the cells was measured 7 days post-elicitation. In the low-N medium, starch, glucose, and phosphate contents in the biomass was increased by 470, 1624 and 70%, respectively, 10 days after inoculation compared to the control culture in standard B5 medium. Cell concentration was significantly reduced from 10.3 to 8.6 millions cell/mL on this low-N medium compared to the control, nevertheless alkaloid production was multiplied by 39 at day 10 when cells were elicited. Cells grown on the low-N or low-P media accumulated 83% and 188% more carbon, respectively, than control cells at the end of the culture. This intracellular C was mainly stored in the form of starch in low-P medium and both in the form of starch and glucose in the low-N medium. The ability of EC cells to produce alkaloids upon elicitation was shown to be strongly dependent on the initial intracellular C and P content at the time of elicitation. This suggests that reproducibility and productivity during EC cell culture could be enhanced by manipulating the intracellular C and P content at the time of elicitation.

Section: Bioprocess Issuesmentioning

confidence: 99%

Critical influence of Eschscholzia californica cells nutritional state on secondary metabolite production

Lamboursain

Jolicœur

2005

“…The corresponding values of /.LMAX were calculated from Equation (10). The average specific rate of by-product formation ( q p ) in batch culture was 0.0008 C-mol .…”

Section: Comparison Between the Stoichiometry Of Growth In Batch Cultmentioning

confidence: 99%

Kinetics and stoichiometry of growth of plant cell cultures of Catharanthus roseus and Nicotiana tabacum in batch and continuous fermentors

Gulik

Hoopen

Heijnen

1992

Plant cell suspension cultures of Catharanthus roseus and Nicotiana tabacum were grown in stirred tank bioreactors operated in batch and continuous mode. The stoichiometry of growth of both species in steady-state glucose limited chemostats was studied at a range of different dilution rates. A linear relation was applied to describe specific glucose uptake, oxygen consumption, and carbon dioxide production as a function of the growth rate. Specific respiration deviated greatly from the linear relation. An unstructured mathematical model, based on the observed stoichiometry in the glucose limited chemostats, was applied to describe the growth in batch culture. From a comparison between the observed growth pattern in batch fermentors and computer simulations it appeared that the stoichiometry of growth of the C. roseus culture was different under steady-state and dynamic conditions. It was concluded that a mathematical model for the growth of suspension culture plant cells in which the biomass is considered to be a single compound with an average chemical composition is of limited value because large changes in the composition of the biomass may occur.

“…Such knowledge may be transposed as a tool helping to drive the cell behavior towards specific objectives such as growth and/or productivity in a molecule of interest. A descriptive model for estimating plant cell nutritional state in vitro was suggested by Curtis et al (1991) who proposed to use intracellular Pi concentration in the specific growth rate expression for Papaver somniferum suspension cells. Then, Van Gulik et al (1993) simulated Catharanthus roseus cell suspension growth using both intracellular Pi and sugar concentrations in the specific growth rate expression.…”

Section: Introductionmentioning

confidence: 99%

A predictive nutritional model for plant cells and hairy roots

Cloutier

Bouchard-Marchand

Perrier

et al. 2007

A structured nutritional model is proposed to describe growth and nutritional behavior of Eschscholtzia californica suspension cells and Catharanthus roseus and Daucus carota hairy roots in in vitro culture. The model describes the cells specific growth rate from concentration of intracellular nutrients such as inorganic phosphate (Pi), nitrogen sources (NO(3) (-) and NH(4) (+)) and sugars. Two-level Michaelis-Menten kinetics are used to describe Pi and NO(3) (-) uptake and simple Michaelis-Menten kinetics for description of sugars uptake. Model parameters for each cell line were calibrated using data from batch cultures. The predictive capacity of the model was tested using data from medium exchange hairy root cultures. The model describes growth and nutritional behavior for the cell and hairy root lines. A sensitivity analysis was performed to identify critical model parameters and effect of initial conditions. The cell and hairy roots lines are also compared from their kinetic parameters. The kinetic model is efficient for describing and predicting growth and nutritional behaviors of suspension cells and hairy roots.