组成型脱硫工程菌的构建及其脱硫性能分析

目的]研究组成型脱硫工程菌的构建及其脱硫性能。方法]以专一性脱硫菌德氏假单胞菌Pseudomonas delafieldii R-8为出发菌株,将该菌的脱硫质粒中的脱硫基因dszABC和组成型gap基因启动子克隆到表达载体pPR9TT中,获得的组成型重组质粒pRT-C后电转化R-8-0菌,得到了组成型工程菌R-8-C,并对其脱硫性能进行了比较研究。结果]R-8-C菌在含0.10 mmol/L Na2SO4的BSM培养基中仍然具有较高脱硫活性,在72 h内,是以二苯并噻吩(DBT)为唯一硫源时R-8脱硫活性的93%;而对照组(即原始菌R-8)几乎不能脱硫。以DBT为唯一硫源时,在不同生长时期内,R-8-C菌生长细胞的脱硫活性均高于R-8菌,且在24 h内,R-8-C菌的脱硫活性约为R-8菌的1.3倍。结论]该研究为进一步了解脱硫基因调控机制及构建高活性脱硫工程菌奠定了基础。

Analysis on Construction and Property of the Constitutively Desulfurization Engineered Strain

Objective] The research aimed to study construction and property of the constitutively desulfurization engineered strain.Method] The dszABC in Pseudomonas delafieldii R-8 strain was cloned into expression vector pPR9TT with gap promoter to build a constitutive expression plasmid pRT-C.Then,the pRT-C was reintroduced into R-8-0 strain to obtain R-8-C strain.A constitutively expressed engineered strain for desulfurization was constructed,and its desulfurization property was studied.Result] Strain R-8-C still had higher desulfurization activity in BSM medium with 0.10 mmol/L of Na2SO4.Within 72 h,its desulfurization activity was 93% of the strain R-8 using DBT as the sole sulfur source,while control(strain R-8) nearly couldn’t desulphate.When DBT was the sole sulfur source,at different growth periods,the desulfurization activity of strain R-8-C was all higher than that of the strain R-8.Within 24 h,its activity was 1.3 times of the strain R-8.Conclusion] These results were theoretically and technically helpful for understanding regulation mechanism of the desulfurization gene and constructing highly active desulphurization engineering strain.