Studies On The Expression Of Vitreoscilla Hemoglobin Gene

A recombinant expression plasmid was first constructed by inserting the Vitreoscilla Hemoglobin gene (vgb) into the plasmid pCHI, which contains the chitinase gene cloned from Bacillu circulans C-2. To study the effect of VHb on cell growth and chitinase production, the expression plasmid was transformed into Escherichia coli JM109. The results showed that the expression of vgb gene could improve cell growth and enhance the production of chitinase with 12.1% higher than that of control under different dissolved oxygen concentrations. Besides, vgb gene expression also increased the chitinase secretion.In order to make the Vitreoscilla Hemoglobin gene express in Bacillus subtilis, an inducible promoter (Levansucrase) was cloned from B. subtilis WB600 and ligated with a promoter-less vgb gene. The resulted gene is calledSacVgb and was demonstrated to express in E, coli by SDS-PAGE and carbon monoxide binding assay. The SacVgb gene was then cloned into E.coli--B.sublilis shuttle vector pSUGV4 and a recombinant plasmid named pSU-SacVgb was constructed. After transformation with B. sublilis WB600, the transformants successfully produced VHb intracellularly. The influence of VHb on B.subtilis is under investigation.