Biomass growth carbon dioxide concentration

For some high growth-rate biomass species, the carbon dioxide concentration in the air among the leaves of the plant often is considerably less than that in the surrounding atmosphere. Photosynthesis may be limited by the carbon dioxide concentrations under these conditions when wind velocities are low and insolation is high. 

Responses of terrestrial ecosystems to increased atmospheric carbon dioxide concentration are of great current interest. Part of this debate relates to the role of limitation by various nutrients, like nitrogen, phosphorus and other vital nutrients on growth and biomass accumulation in terrestrial vegetation. Because vegetation must maintain a nutritional balance, it is expected that nutrient limitation will constrain responses to increased CO2 level. 

By initializing the cell concentration, X(0), either from an estimation at some point of the oxygen uptake or carbon dioxide evolution rate or by knowing the inoculum size and then integrating the estimated growth rate over time, both cell biomass and growth rate can be estimated on-line utilizing a computer. The substrate (ethanol) demand, AS is then estimated by a similar equation, i.e. 

Fig. 4. Growth of Catharanthus roseus cells in batch culture. (A) Concentrations of glucose (squares) and biomass (circles), (B) oxygen consumption, and (C) carbon dioxide production are given as a function of culture time. Vertical bars represent the standard deviation of the mean. Solid curves represent the model predictions.

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