不同流加发酵方式对重组大肠杆菌细胞外hEGF表达水平的影响

The effects of different glucose feeding modes on hEGF expression were evaluated in an excretory recombinant \%E.coli\% K12 system.The results showed that,compared with batch cultivation,the plasmid stability and density of plasmid\|retaining cells were improved by all three glucose feeding modes (intermittent,pH\|stat and constant\|rate).It was shown that hEGF yields were improved up to 25.5% and 28.1% by intermittent or pH\|stat glucose feeding respectively.Especially,up to 150% improvement of hEGF production was achieved by constant feeding of 200g/L glucose solution at a rate of 0.11 mL/min.The effects of further combined feeding with other medium components (ampicillin,nitrogen sources,and inorganic salts) and inducer on hEGF yield were also examined in the bench\|top fermentor.