| Summary: | 碩士 === 國立東華大學 === 生物技術研究所 === 89 === Pseudorabies has been an important infectious disease to the swine in Taiwan. The annual market of its vaccine is over five million doses. The overall objective of this study is to establish an economic and feasible bioprocess system for the production of pseudorabies virus which can be used as the raw material for the vaccine manufacture. In order to achieve this objective, the specific aims are achieving high cell density and high productivity by the application of the airlift packed-bed reactor and a bioprocess control. The host cell line used for virus infection is the rabbit-kidney cell line RK-13 and the target product is the gene-deleted pseudorabies virus.
In order to achieve high cell density, immobilization technique was employed in this study. Porous polyurethane foam, which was packed in the annular region of the airlift packed-bed reactor, was used as cell carriers. Initially cells were evenly inoculated in the packed bed. The dynamic perfusion of medium and the in situ oxygenation were adopted to provide a high surface area and nutrient-rich environment.
In the cell cultivation process, glucose was found to be the limiting nutrient. Consequently the glucose concentration was raised from 1 to 2.5 g/L during the latter part of the cultivation process in order to lower the amount of the perfused medium required. Glucose uptake rate and oxygen uptake rate were used as the indexes for cell growth and as tools to estimate the cell number in the polyurethane packed bed. The oxygen tension was maintained above 20% and the glucose concentration was kept above 150 mg/L by the control of gas flow rate and perfusion rate respectively. Following this operation strategy, the final cell density of 1.3 x 108 cells/cm3-PUF and the virus titer of 9.75 x 1013 TCID50 were achieved.
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