从昆明磷矿土壤中分离筛选出降解无机磷的8株解磷细菌,通过平板初筛得到3株降解无机磷能力较强的菌株.进一步液体摇瓶复筛,得到1株降解无机磷能力最强的菌株D86.通过菌落形态、生理生化特性和16S r DNA序列比对,初步鉴定该菌株为德氏嗜...从昆明磷矿土壤中分离筛选出降解无机磷的8株解磷细菌,通过平板初筛得到3株降解无机磷能力较强的菌株.进一步液体摇瓶复筛,得到1株降解无机磷能力最强的菌株D86.通过菌落形态、生理生化特性和16S r DNA序列比对,初步鉴定该菌株为德氏嗜酸菌(Acidovorax delafieldii).展开更多
[Objective] The research aimed to study construction and property of the constitutively desulfurization engineered strain. [Method] Des- ulfurization gene dszABC in Pseudomonas delafieldii R-8 strain was cloned into e...[Objective] The research aimed to study construction and property of the constitutively desulfurization engineered strain. [Method] Des- ulfurization gene 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, pRT-C was reintroduced into R-8-0 strain to obtain constitutively engineered strain R-8-C. Moreover, its desulfu- rization property was studied. [ Result ] Strain R-8-C still had higher desulfurization activity in BSM medium with 0.10 mmol/L of Na2 SO4. 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, in 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.展开更多
The coupling of adsorption desulfurization and biodesulfurization is a new approach to produce clean fuels. Sulfur compounds are firstly adsorbed on adsorbents, and then the ad-sorbents are regenerated by microbial co...The coupling of adsorption desulfurization and biodesulfurization is a new approach to produce clean fuels. Sulfur compounds are firstly adsorbed on adsorbents, and then the ad-sorbents are regenerated by microbial conversion. p-Complexation adsorbent, Cu(I)-Y, was ob-tained by ion exchanging Y-type zeolite with Cu2+ and then by auto-reduction in helium at 450℃ for 3 h. Dibenzothiophene (DBT) was used as a model compound. The effects of cell concentra-tion, volume of oil phase, the ratio of aqueous phase to adsorbent on DBT desorption by a bac-terium were studied. The amounts of DBT desorbed and 2-HBP produced can be apparently increased with addition of n-octane. BDS activity can be improved by increasing cell concentra-tion and the ratio of water-to-adsorbent. 89% of DBT desorbed from the adsorbents can be converted to 2-HBP within 6 h and almost 100% within 24 h, when the volume ratio of oil-to-water was 1/5 mL/mL, the cell concentration was 60 g·L?1, and the ratio of adsorbent-to-oil was 0.03 g·mL?1. The amount of 2-HBP produced was strongly dependent on the volume ratio of oil-to- water, cell concentration and amount of adsorbent. Adsorption capacity of the regenerated ad-sorbent is 95% that of the fresh one after being desorbed with Pseudomonas delafieldii R-8, washed with n-octane, dried at 100℃ for 24 h and auto-reduced in He.展开更多
基金Supported by Science and Technology Project,Jiangxi Department of Education,China (GJJ11142)
文摘[Objective] The research aimed to study construction and property of the constitutively desulfurization engineered strain. [Method] Des- ulfurization gene 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, pRT-C was reintroduced into R-8-0 strain to obtain constitutively engineered strain R-8-C. Moreover, its desulfu- rization property was studied. [ Result ] Strain R-8-C still had higher desulfurization activity in BSM medium with 0.10 mmol/L of Na2 SO4. 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, in 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.
基金supported by the National Natural Science Foundation of China(Grant No.30370046)the State Major Basic Research Development Program of China(Grant No.G2000048004)the National High Technology Research and Development Program of China(Grant No.2002AA213041).
文摘The coupling of adsorption desulfurization and biodesulfurization is a new approach to produce clean fuels. Sulfur compounds are firstly adsorbed on adsorbents, and then the ad-sorbents are regenerated by microbial conversion. p-Complexation adsorbent, Cu(I)-Y, was ob-tained by ion exchanging Y-type zeolite with Cu2+ and then by auto-reduction in helium at 450℃ for 3 h. Dibenzothiophene (DBT) was used as a model compound. The effects of cell concentra-tion, volume of oil phase, the ratio of aqueous phase to adsorbent on DBT desorption by a bac-terium were studied. The amounts of DBT desorbed and 2-HBP produced can be apparently increased with addition of n-octane. BDS activity can be improved by increasing cell concentra-tion and the ratio of water-to-adsorbent. 89% of DBT desorbed from the adsorbents can be converted to 2-HBP within 6 h and almost 100% within 24 h, when the volume ratio of oil-to-water was 1/5 mL/mL, the cell concentration was 60 g·L?1, and the ratio of adsorbent-to-oil was 0.03 g·mL?1. The amount of 2-HBP produced was strongly dependent on the volume ratio of oil-to- water, cell concentration and amount of adsorbent. Adsorption capacity of the regenerated ad-sorbent is 95% that of the fresh one after being desorbed with Pseudomonas delafieldii R-8, washed with n-octane, dried at 100℃ for 24 h and auto-reduced in He.
