SCALABLE FERMENTATION PROCESS

摘要

This invention provides a robust fermentation process for the expression of a capsid protein of a bacteriophage which is forming a VLP by self-assembly, wherein the process is scalable to a commercial production scale and wherein the expression rate of the capsid protein is controlled to obtain improved yield of soluble capsid protein. This is achieved by combining the advantages of fed-batch culture and of lactose induced expression systems with specific process parameters providing improved repression of the promoter during the growth phase and high plasmid retention throughout the process.

主权项

1. A process for expression of a recombinant capsid protein of a RNA bacteriophage being capable of forming a VIP by self-assembly, said process comprising the steps of:
a.) introducing an expression plasmid into a bacterial host, wherein said expression plasmid comprises an expression construct, wherein said expression construct comprises (i) a first nucleotide sequence encoding said recombinant capsid protein, or mutant or fragment thereof, and (ii) a promoter being inducible by lactose; b.) cultivating said bacterial host in a medium comprising a major carbon source; wherein said cultivating is performed in batch culture and under conditions under which said promoter is repressed by lac, wherein said lacI is overexpressed by said bacterial host; c.) feeding said batch culture with said major carbon source; and d.) inducing said promoter with an inducer, wherein said feeding of said batch culture with said major carbon source is continued.