Bacillus subtilis strains that can produce hyaluronic acid(HA)were constructed by integrating the HA synthase gene(hasA)and the UDP-glucose dehydrogenase gene of group C Streptococcus(hasB)or of B.subtilis itself(tauD)into the amyE locus of the B.subtilis chromosome.All of the inserted genes were under the control of a strong constitutive vegII promoter of B.subtilis.Although HA production could be achieved by expressing hasA alone,coexpressing hasB or tauD with has A could enhance HA production at least 2-fold.To replenish the energy consumed for HA biosynthesis,Vitreoscilla hemoglobin(VHb)was coexpressed with the HA-expressing genes.With the expression of VHb,not only the cell concentration was enhanced 25%,but also HA production was further increased by 100%.About 1.8 g/L of HA was obtained by the recombinant strain B.subtilis carrying VHb,has A,and tauD genes in the expression cassette after 30 h cultivation.
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机译：将HA合酶基因（hasA）和C组链球菌（hasB）或枯草芽孢杆菌本身（tauD）的UDP-葡萄糖脱氢酶基因整合到AmyE基因座中，构建可产生透明质酸（HA）的枯草芽孢杆菌菌株。枯草芽孢杆菌染色体。所有插入的基因都在枯草芽孢杆菌的强烈组成型vegII启动子的控制下。虽然仅表达hasA即可实现HA产生，但与hasA共同表达hasB或tauD至少可以提高HA产生。 2倍。为了补充HA生物合成所消耗的能量，玻璃体血红蛋白（VHb）与表达HA的基因共表达。随着VHb的表达，不仅细胞浓度提高了25％，而且HA产量进一步增加培养30 h后，在表达盒中携带VHb，has和tauD基因的重组枯草芽孢杆菌B.获得约1.8 g / L的HA。
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