The objective was to set up a pilot scale process for robusta (Coffea canephora) industrial propagation by somatic embryogenesis in liquid media. A batch production of pre-germinated embryos was initiated once every 2 mo. in 2003 and 2004, then every mo. in 2005. Each run batch requires 4 to 6 mo. to produce the pre-germinated somatic embryos and consists of three phases: (1) the development of torpedo stage embryos in Erlenmeyer flasks, (2) pregermination in temporary immersion bioreactors to allow maturation from the torpedo stage to the cotyledonary stage, (3) maintaining the embryos under storage conditions before their shipment to coffee producing countries. Starting from 1 kg of embryogenic calluses, a total of 4.4 million pregerminated embryos for 17 clones were produced over 3 yr. This embryo number was enough to potentially regenerate 2 million plants, as the global embryo-to-plantlet conversion rate was estimated to 46% after acclimatization and complete germination in the greenhouse. At the end of April 2006, 600,000 somatic seedlings were transferred into plastic bags in nurseries or were already planted in the fields, mainly in Thailand. The current capacity allows the production of 2.5 million embryos per year, equivalent to a potential of about 1.0 million plantlets. The technical package has recently been transferred to National Institutes in Mexico, Thailand, and Vietnam.

No abstract

The present article describes two new applications of plastic-based cell culture systems in the plant biotechnology domain. Different types of bioreactors are used at Nestlé R&D Center-Tours for large scale culture of plants cells to produce metabolites or recombinant proteins and for mass propagation of selected plant varieties by somatic embryogenesis. Particularly, recent studies are directed to cut down the production costs of these two processes by developing disposable cell culture systems. For large scale culture, two novel flexible plastic-based disposable bioreactors have been devel-

Summary.Catharanthus roseus cells were grown at various aeration rates using normal or CO2-enriched air. Kinetic data showed a detrimental effect of the increase of the gassing rate on the growth characteristics due to CO2 stripping. When the CO2 partial pressure in the culture was maintained at a constant level of 20 mbar, better growth and enhanced conversion yields were obtained.