A new system for expressing heterologous gene in Escherichia coli regulated by oxygen consistence in the environment.

The expression of Vitreosilla hemoglobin gene (vgb) is regulated by oxygen consistence in E. coli. The gene transcription is activated under the condition of limited oxygen. A new system for expressing heterologous gene in E. coli regulated by dissolved oxygen consistence was constructed. It includes a host bacteria GJ100, which contained T7 RNA polymerase gene controlled by vgb promoter, and an expression vector on which the heterologous gene was under the control of a T7 promoter. The results indicated that E. coli thioredoxin A, IgG binding domain of Staphylococcus protein A(ZZ), snake neurotoxin, salmon calcitonin hexa-polymer, human interleukinII (IL2) and human pro-urokinase genes could be expressed efficiently. Expression level was more than 30% of the total cellular protein.