Optimization Of Microcarrier PK-15 Cells Culture Process For The Porcine Parvovirus Vaccine Production And Preliminary Metabolic Flux Analysis

Porcine kidney cells (PK-15) are sensitive to several kinds of virus of pig, and is largely used in the production of veterinary vaccines. In this work, low serum medium P-LSM (containing 3% NCBS) was developed, which was suitable for PK-15 cells both in static culture and microcarrier suspension culture, but also suitable for the cultivation of porcine parvovirus.The process of cultivating porcine parvovirus with PK-15 cells in P-LSM was developed, the maximum virus titre reached 7.5 Lg TCID50/ml. Successfully optimized the microcarrier PK-15 cells culture process for the porcine parvovirus vaccine production, in 1.5 L and 5 L reactors, the maximum virus titer can arrive at 7.2 Lg TCID50/ml, increased by 10 times. It was the first time to find that the yield coefficients of lactate to glucose had a positive correlation with virus titre and could be used as an important parameter for virus harvest.After metabolic flux analysis of glucose and glutamine with 13C MFA in PK-15 cells, a network model of 13C MFA of PK-15 cells was built. The results indicated that glucose was mainly through glycolysis to produce lactate when cells were during lag phase; when cells were during exponential growth phase, part of glucose through PDH into TCA cycle; when they came to stationary phases, part of glucose started to through PC into TCA cycle; glutamine mainly converted into TCA cycle to support energy and intermediate metabolites. After PK-15 cells were infected with porcine parvovirus, more glucose was through pentose phosphate pathway, Ser-Gly and Asp to produce DNA/RNA, more glutamine were through Asp to produce DNA/RNA.