Development of a low capital investment reactor system: Application for plant cell suspension culture

Growth of plant cell cultures is demonstrated in an uncontrolled, simple, a nd inexpensive plastic-lined vessel. Sustained specific growth rates of 0.2 2 day(-1) for Hyoscyamus muticus cell suspension cultures are achieved in a low-cost gas-sparged bioreactor configuration (6.5 L working volume, wv) w hich is comparable to an "optimized" 5 L wv mechanically agitated fermenter . In an effort to reduce bioreactor costs, the need for an autoclavable ves sel was eliminated. Sterilization is achieved by separate autoclaving of th e plastic,liner and by gas-phase sterilization using ethylene oxide. The in itial,run sterilized with ethylene oxide displayed a long lag, apparently d ue to residual sterilant gas. Because ethylene oxide could eliminate costs associated with autoclave rated vessels, a quantitative basis for aeration time was developed by experimental measurements and modeling of diffusion i n the polymer liner. Operational techniques to eliminate toxicity are imple mented to grow 0.2 kg dry weight of plant cells in 13 days in a 40 L (28.5 L wv) air-lift bioreactor without autoclave sterilization. The biomass yiel ds for all reactors were statistically indistinguishable from shake flask c ulture.