| 摘要 |
PURPOSE:To increase production per microbial cell by transforming a yeast with a plasmid carrying a human serum albumin gene and culturing the resultant yeast according to a fed-batch culturing method. CONSTITUTION:A human serum albumin (HSA) gene, a terminator, etc., are contained to provide a plasmid pY1032 (A) which is an HSA expression vector. The resultant ingredient (A) is then introduced into Saccharomyces cerevisiae AH22 strain, etc., to carry out transformation and afford an HSA-producing yeast (B). The obtained strain (B) in an amount of 0.01-50g/L is inuoculated into an initial culture medium containing 0.1-10g/L glucose, etc., to start culture at pH6-7. The culture is controlled so as to provide a respiratory quotient of 0.9-1.2 which is a ratio of O2 consumption to CO2 production at 10-35 deg.C for 10-100hr using a numerical value expressed by the formula [X0 is the initial microbial cell concentration (g/L; V is the amount of culture medium; F is the feed flow velocity (L/hr); Y is the proliferation yield (g cell/g glucose); muis the specific proliferation rate (hr<-1>); (t) is time (hr)] to carry out the culture. A supplementary culture medium containing glucose, as necessary, is increased, decreased or added to control the culture and produce the human serum albumin. |
