LOW CELL DENSITY FERMENTATION PROCESS FOR THE PRODUCTION OF HETEROLOGOUS RECOMBINANT PROTEINS IN MICROORGANISMS

摘要

A low cell density fermentation process for production of heterologous proteins in microorganisms comprising : feeding the cell culture obtained by cultivating host ansformed with a vector carrying genetic material for the said proteins and an inducible promoter under batch fermentation h ■ "' 'conditions, with a feed medium after an OD60o of 0.16 to 8 has been achieved or after 0 to 4 hrs from the start of the fermentation process, the feed medium comprising 5 to 30% of carbon source and 1 to 30% of nitrogen source and 0 mg to 400 mg antibiotics and 2.5 to 4.25% inorganic phosphates and trace elements, the concentration of the carbon source in tljs'feed medium being 10 to 30, the amino acid content m nitrogen source being 45 to 95%, the initial feed rate being in the range of 0 ml/hr to 12 ml/hr and being raised exponentially by an exponent in the range of 0.1 to 0.4 and/or linearly with the slope of the curve in the range of 0.5 to 3; and * inducing production with 0.01 - 4% inducer at a cell density of OD600 0.1 -OD60o50, feeding of the cell culture with the feed medium and feed rate of step (a) being continued after production has been induced and p02 being adjusted between 10% to 60% by passing sterile air into the fermentation broth and the temperature and pH of the fermentation broth being maintained at 33°C - 41°C and 6.9- 8.5, respectively during the entire fermentation.