On March 1,CEN and CENELEC’s Director General,Elena Santiago Cid,received from the hands of Maive Rute,the European Commission’s Chief Standardization Officer,the new Roadmap on hydrogen standardization.CEN and CENE...On March 1,CEN and CENELEC’s Director General,Elena Santiago Cid,received from the hands of Maive Rute,the European Commission’s Chief Standardization Officer,the new Roadmap on hydrogen standardization.CEN and CENELEC welcome the publication of this important document and are committed to collaborating to the roll out of large-scale hydrogen solutions across the EU.展开更多
A new hemA gene encoding 5-aminolevulinate (ALA) synthase was cloned from Agrobacterium ra- diobacter zju-0121. The ALA synthase catalyzes the pyridoxal phosphate-dependent condensation of succinyl coen- zyme A (succi...A new hemA gene encoding 5-aminolevulinate (ALA) synthase was cloned from Agrobacterium ra- diobacter zju-0121. The ALA synthase catalyzes the pyridoxal phosphate-dependent condensation of succinyl coen- zyme A (succinyl-CoA) and glycine to produce ALA. Four plasmids carrying the A, radiobacter hemA gene were transformed into different E. coli strains. The effects of both genetic and physiological factors on the expression of ALA synthase and ALA production were studied. The results indicated that the final intracellular activity of ALA synthase and the production of ALA in different expression systems varied largely. Among them, the recombinant E. coli BL21 (DE3) harboring the expression plasmid pET28-A. R-hemA was the most suitable one. The effects of isopropyl-β-D-thiogalactopyranoside (IPTG) addition time, IPTG concentration, culture temperature and the initial concentration of precursors and glucose on the ALA production were also evaluated. The expressed ALA synthase accounted for about 23.7% of the intracellular soluble protein. The highest specific activity of ALA syn- thase was 13.8nmol·min-1·mg-1 of intracellular soluble protein. In the batch culture of the recombinant E. coli, the extracellular ALA concentration reached 0.9 g·L-1.展开更多
The German Institute for Standardization(DIN)and the German Commission for Electrical,Electronic&Information Technologies(DKE)of DIN and VDE now published the English versions of the German Standardization Roadmap...The German Institute for Standardization(DIN)and the German Commission for Electrical,Electronic&Information Technologies(DKE)of DIN and VDE now published the English versions of the German Standardization Roadmap on AI(2nd edition).展开更多
文摘On March 1,CEN and CENELEC’s Director General,Elena Santiago Cid,received from the hands of Maive Rute,the European Commission’s Chief Standardization Officer,the new Roadmap on hydrogen standardization.CEN and CENELEC welcome the publication of this important document and are committed to collaborating to the roll out of large-scale hydrogen solutions across the EU.
基金Supported by the National Natural Science Foundation of China (No. 20306026)
文摘A new hemA gene encoding 5-aminolevulinate (ALA) synthase was cloned from Agrobacterium ra- diobacter zju-0121. The ALA synthase catalyzes the pyridoxal phosphate-dependent condensation of succinyl coen- zyme A (succinyl-CoA) and glycine to produce ALA. Four plasmids carrying the A, radiobacter hemA gene were transformed into different E. coli strains. The effects of both genetic and physiological factors on the expression of ALA synthase and ALA production were studied. The results indicated that the final intracellular activity of ALA synthase and the production of ALA in different expression systems varied largely. Among them, the recombinant E. coli BL21 (DE3) harboring the expression plasmid pET28-A. R-hemA was the most suitable one. The effects of isopropyl-β-D-thiogalactopyranoside (IPTG) addition time, IPTG concentration, culture temperature and the initial concentration of precursors and glucose on the ALA production were also evaluated. The expressed ALA synthase accounted for about 23.7% of the intracellular soluble protein. The highest specific activity of ALA syn- thase was 13.8nmol·min-1·mg-1 of intracellular soluble protein. In the batch culture of the recombinant E. coli, the extracellular ALA concentration reached 0.9 g·L-1.
文摘The German Institute for Standardization(DIN)and the German Commission for Electrical,Electronic&Information Technologies(DKE)of DIN and VDE now published the English versions of the German Standardization Roadmap on AI(2nd edition).
