1. Microcarrier technology has been applied successfully to the cultivation of anchorage-dependent cells and the production of many recombinant proteins. It has the advantages of easy sampling, relatively large surface area and the possibility of performing perfusion culture. Chinese Hamster Ovary (CHO) cells are among the most widely used cell lines for the production of therapeutic proteins. Plant peptones is the safest supplement for protein-free media. They exert a nutritional effect, and they contain bioactive peptides, responsible for increases in growth and production (Burteau et al.,) The use of insect cells for the production of recombinant (glyco)-proteins by the Insect Cell Baculovirus Expression Vector System (ICB-BEVS) is a well-established technology. Among the industrially important cell lines, High-Five insect cells cultivated in serum-free medium have shown great potential for production and can reach high cell densities (Ikonomou et al., 2003) BioNOC II™ (Cesco Bioengineering Co, Taichung, Taiwan) cell culture disks are new model of nonwoven macroporous carriers for the growth of animal, mammalian and insect cells. They are made of 100% pure PET with a treated surface area of 2000 cm²/g. BelloCell-500 (Cesco Bioengeenering Co) is a disposable bioreactor bottle. It consists of a chamber holding 6.5 g of BioNOC carriers and a lower compressible chamber. The bottle was mounted onto a control console named BelloStage, which was placed in a CO 2 incubator. The compressible chamber serves to include convective mixing and aeration by an up-and-down movement. Growth of Mammalian and lepidopteran cells on BioNOC ® II Disks, a novel macroporous microcarrier Cellular Bioengineering Group Institut des Sciences de la Vie, Université catholique de Louvain B-1348 Louvain-la-Neuve, Belgium yjs@bioc.ucl.ac.be* These authors contributed equally to this work. Drugmand J.-C.*, Michiels J.-F.*, Agathos S.N., Schneider Y.-J. INTRODUCTION PEPTONES EFFECTS ON MAMMALIAN CELLS CHO-320 producing recombinant interferon-γ estimated by Elisa test CHO culture media : BDM serum-free media (Schneider, 1989) Insect cell line : High Five  and Baculovirus : AcMNPVs r-  gal (MOI of 2) Insect Culture media : serum-free YPR media (55 mM gluc,10 mM Gln) (Ikonomou et al., 2001) Cotton peptone used at 0.5 to 4 g/L Quest international (Naarden, The Netherlands) BelloCell-500 parameters : Culture up/down speed = 1/1 mm/s and up/down hold time = 0/3 min Celligen-Plus 2 L bioreactor with 1.35 L used with 20 g of BIONOCII in 500 cm 3 fixed-bed basket (80 rpm, 28°C, 60 % DO). Cells biomass estimated by protein quantity (Bradford assay, Biorad). Gluc, Lac, NH 3, Gln and Asn analysed by enzymatic test Enzymatic activities of  -gal using protocols of Miller (1972) MATERIALS AND METHODS FIXED BED CULTIVATION OF INSECT CELLS Burteau, C. C., F. R. Verhoeye, et al. (2003). “Fortification of a protein-free cell culture medium with plant peptones improves cultivation and productivity of an interferon-g-producing CHO cell line.” In Vitro Cellular and Developmental Biology 39: 291-296. Ikonomou, L., G. Bastin, et al. (2001). “Design of an efficient medium for insect cell culture and recombinant protein production ” In Vitro Cellular and Developmental Biology-Animal 37: 549-559. Ikonomou, L., Y.-J. Schneider, et al. (2003). “Insect cell culture for industrial production of recombinant proteins.” Applied Microbiology and Biotechnology 62: 1-20. Miller, J. H. (1972). Assay of b-galactosidase. Experiments in Molecular Genetics. New York, Cold Spring Harbor Laboratory Press: 352-355. A fixed bed reactor in perfusion was developed with Bionoc II. We cultivated the cells during 6 days in batch, before starting the perfusion and infection the cells took place after 11 days (Figure D). The perfusion rate was adapted to keep not only the glucose concentration below 20 mM (a third of the initial concentration) but also to prevent the accumulation of by- products at a limit of 25 mM for the ammonia and lactate. During the infection, we decreased this perfusion rate to prevent the dilution of r-protein and keep by-products concentration in an acceptable range (Figure E). The lactate production was high (roughly 1 mol lac / 1 mol gluc) but acceptable for cells that usually do not produce lactate, probably due to the lack of oxygen and accumulation of CO 2 inside the fixed bed. The ratio oxygen / glucose of 3 supports this observation. The pH was controlled with the addition of 1 N NaOH to prevent the decrease of pH due to to production of lactate (Figure D). The estimation of cell density (based on metabolite consumption) was estimated at 400.10 6 cells/g of BionocII before the infection. We obtain after 200 hpi a high production (3x10 6 U  -gal / process, 6x10 3 U  -gal / cm 3 of fixed bed), i.e. 2.5 fold higher than in batch (Figure F). In experiments using the same setup (Celligen-Plus 2 L) but with Fibra-Cell (New Brunswick Scientific,…), we obtained the same level of production. E F D Start perfusion Infection Two BelloCell-500 bioreactors cultivations were conducted simultaneously with and without peptone (1 g/L). Although growth was slower (Figure A), interferon-γ production was slightly higher when peptone was added (Figure B). In a third BelloCell-500 cultivation reactor was connected to a bottle filled with medium supplemented with 1 g/L cotton peptone. Medium was changed for the fist time after 72 hours of culture, when the glucose concentration was low. After 108 hours of culture, medium was changed twice a day. Figure C shows the evolution of the consumption rate of glucose and of the production rate of lactate and ammonia. Most of the glucose was converted to lactate, which decrease the pH. Ammonia production was low. Acknowledgements This work was supported by a grant of the University of Louvain Plant peptones were kindly provided by Quest international (Naarden, The Netherlands) Cesco (Cesco Bioengineering Co, Taichung, Taiwan) have graciously lent the BelloCell-500 and provided BionocII micocarriers. References B C