血红蛋白基因在脱硫菌R-8中的表达及其在柴油脱硫中的应用

Expression of Vitreoscilla hemoglobin gene in Pseudomonas delafieldii R-8 and its application to diesel desulfurization

摘要:

摘要：【目的】旨在构建一株优良的工程菌株，对血红蛋白基因在柴油的生物脱硫领域的应用做初步的探索。【方法】以德氏假单胞菌（Pseudomonas delafieldii） R-8为出发菌株，通过基因工程的手段，构建透明颤菌（Vitreoscilla）血红蛋白基因表达质粒并电击导入原始菌株，得到重组菌P. delafieldii R-8-2。【结果】R-8-2菌株的CO差光谱在419 nm处有特征峰出现，表明血红蛋白在脱硫菌中得到了有效表达。R-8-2菌株和R-8菌株相比，生长得到改善，相同培养条件下菌体密度比R-8提高了20%，最大脱硫活性能够达到R-8的2.4倍。在实际柴油脱硫实验中，R-8-2菌株能将柴油的硫含量降至96.6 mg/L，脱硫率达到69.9%，而R-8仅为57.2%。【结论】R-8-2是在较低溶氧条件下仍能保持较高的菌体密度和脱硫活性的基因工程菌株，具有良好的应用前景，该研究为血红蛋白基因在生物脱硫工业的应用提供参考。

Abstract:

Abstract: [Objective] To construct an engineering strain of higher desulfurization activity with Vitreoscilla hemoglobin gene (vgb) for desulfurization of diesel. [Methods] We constructed the vgb expressing plasmid, pPR-Pdsz-vgb and transformed by electroporation to Pseudomonas delafieldii R-8, then obtained a genetic engineering strain R-8-2. [Results] The results of CO-difference spectrum analysis indicated that R-8-2 expressed Vitreoscilla hemoglobin (VHb) having biological activity expressed in strain R-8-2. Compared with the wild-type R-8, the density of strain R-8-2 increased by 20%, and its desulfurization activity is also higher in the lower deliquescence oxygen environment. In the end, about 69.9% of total sulfur in diesel oil was removed by strain R-8-2, whereas only 57.2% of sulfur was removed by strain R-8. [Conclusion] The activity of strain R-8-2 was enhanced and furthermore, the work is helpful for further development in biodesulfurization.