Growth ofCatharanthus roseus cell suspensions in bioreactors: On-line analysis of oxygen and carbon dioxide levels in inlet and outlet gas streams

Summary Catharanthus roseus cells (C87N) grown in a 30 litre airlift vessel achieved a growth rate of 0.366 day^–1. The maximum biomass yield (9.13 gl^–1) was recorded after 168 hours (7 days). On-line analysis of the composition of inlet and outlet gas streams during the growth cycle allowed calculation of the metabolic activity of the cultures. Oxygen uptake on a dry weight basis reached a maximum of 4.5×10^–4 Moles O₂ g dry weight^–1 h^–1 after 96 hours (during the mid-logarithmic phase of growth) and a maximum of 2.7×10^–3 Moles O₂ l^–1 h^–1 on a volume basis (towards the end of the logarithmic phase). Carbon dioxide production ran in parallel with oxygen use with maxima at 4.2×10^–4 Moles CO₂ g dry weight^–1 h^–1 and 3.4×10^–3 Moles g l^–1 h^–1 respectively.