Human oc Atrial Natriuretic Peptide Fermentation by Using a Genetically Engineered Yeast Strain
基因工程人α心钠素发酵研究

The genotype of the recombinant yeast strain Y33::YFD71-3 used in this study was a, his, leu. ade and suc. Preliminary batch cultures in shake flasks showed the expression level of atrial natriuretic pepticle (ANP) was 1-2 mg/L. Shake flask cultures were carried out in YG media which contained glucose, yeast nitrogen base (YNB), and different amounts of adenine, histidine and leucine. When cell growth was limited by adenine, protein secreted from Y33:: YFD71-3 cells was increased obviously. Adenine became the limilting substrate when the YG medium was supplemented with 5g/L of casamino acid (CAA) and the tevel of ANP expression was influenced by the concentrations of adenine, YNB and leucine in the medium. In fed batch cultures carried out in a RIBE-5 fermenter, the cultures were fed with glucose and a mixture of YNB, CAA, adenine, histidine and leucine to improve cell growth and ANP expression, and the maximum ANP concentration in the culture reached 24. 8mg/L.