Optimization Of Infection Strategy For Recombinant Baculovirus Infection Of Suspended Hz Ami Insect Cells In The Airlift Reactor

How to improve the recombinant proteins and bio-pesticides in industrialproduction has been paid more and more attention. In the last two decades,much effort has been focused on identifying factors that affect theproductivities of such expression systems, including the cell line, medium,oxygen supply, reactor design and infection strategy, which involves themultiplicity of infection (MOI), time of infection (TOI), initial cell densityand medium replacement. For the purpose of increasing the output ofbaculoviruses, the replication of baculoviruses in insect cells needs toimprove, and also large-scale cultivation is an essential step. Obviously,bioreactor is an important technology for large-scale production.The use of low multiplicity of infection (MOI) for large-scale productionof baculovirus in insect cell systems is an attractive alternative. In presentstudy, an orthogonal design was applied to select the optimum condition, bywhich the effects of MOI, the initial cell density, dissolved oxygen (DO) andthe time of infection (TOI) on non-occluded virus (BV) titer and occludedvirus (OV) number were evaluated in the insect cells HzAM1-recombinantbaculovirus system in airlift reactor culture. The results indicated that amongMOI, TOI, DO and the initial cell density, MOI would influence significantlythe amount of BV and OV produced at low MOI. The optimal conditions bothfor BV production and OV production in the insect cells HzAM1-recombinantbaculovirus system are: MOI of0.10, initial cell density of2.0×105cells/ml,infection at early exponential phase and DO of10%. And a maximum BVconcentration of2.51×107TCID-150·mlis obtained, a maximum OVconcentration of2.85×106OVs·ml-1is also obtained.