生长速度对β干扰素工程菌稳定性和产物表达的影响研究

Effect of the growth rate on recombinant E.coli stability and interferon-β expression

为了研究发酵培养阶段生长速度对重组人干扰素 β(hIFN β)工程菌稳定性、菌体密度和干扰素表达的影响 ,采用日本LE .MarubishiMSJ 5 0L发酵罐 ,在发酵过程中于诱导后通过控制不同的补料速度 ,检测低和高生长速度及发酵结束后菌体密度、稳定性和重组人干扰素 β的表达量。诱导后维持低生长速度 ,发酵结束后平均密度A60 0 值为7.5 2 ,表达量达 2 0 .7% ,质粒稳定率好 ,达到 91% ,粗制干扰素收获 2 .37克 ;维持高生长速度 ,发酵结束后平均密度A60 0 值达 2 0 .5 7,而表达量降为 4 .13% ,质粒稳定率降为 2 7% ,粗制干扰素收获仅为 0 .5 9克。

To study the effect of the growth rate on recombinant E.coli stability ,cell density and interferon-β expression level during fermentation stage. Fermentation cultivation of recombinant interferon-β E.coli was carried out in Japan LE.Marubishi MSJ-50L fermentor to control growth rate using different feeding speed in induction period. Fermentation process were performed on the low growth speed after induction.The average of cell density was 7.52 A 600 ,expression level of hIFN-β was 20.7%, stability rate of plasmid was 91%,the yield of crude hIFN-β could reach 2.37g. To maintain the high growth speed after induction, although average of cell density reached 20.57 A 600 ,but expression level of hIFN-β was only 4.13%, stability rate of plasmid decreased to 27%,the yield of crude hIFN-β was only 0.59g. The growth rate have obvious influence on recombinant E.coli stability and product expression after induction.