采用常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变脱氮假单胞菌(Pseudomonas denitrificans)并从中筛选高产维生素B12突变株,确定等离子诱变最优处理时间75,s、输出功率100,W.通过流式细胞仪并结合核糖开关(rib...采用常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变脱氮假单胞菌(Pseudomonas denitrificans)并从中筛选高产维生素B12突变株,确定等离子诱变最优处理时间75,s、输出功率100,W.通过流式细胞仪并结合核糖开关(riboswitch)感应元件检测其荧光值以初筛诱变后高产菌株,并利用48孔板高通量培养发酵,酶标仪快速检测维生素B_(12)产量,建立完整的诱变后高通量筛选体系.通过4轮ARTP诱变,筛选得到的突变株PA320-M4-1B1在250,mL摇瓶发酵6,d的条件下,维生素B_(12)产量达到(103.2±2.1)mg/L,较初始菌株PA320的(71.9±1.8)mg/L提高了43.8%,且遗传性状稳定.展开更多
Vitamin B 12 model molecule, dicyano cobyric mono acid hexamethylester 2f was synthesized from Vitamin B 12 by alcoholysis and acidic hydrolysis. Dicyano-a,b,c,d,e,g-α-f-N-(3-imidazoly) propylamido cobyrinate 3f was ...Vitamin B 12 model molecule, dicyano cobyric mono acid hexamethylester 2f was synthesized from Vitamin B 12 by alcoholysis and acidic hydrolysis. Dicyano-a,b,c,d,e,g-α-f-N-(3-imidazoly) propylamido cobyrinate 3f was synthesized by the reaction between 2f and 3-imidazolylpropylamine hydrochloride. Compound 3f was treated with trifluoroacetic acid to give dimer-vitamin B 12 model molecule 5f. Compound 5f was treated with acidic buffers in methanol and the ring of 5f was opened to give compounds 6f. UV-Vis spectra were determined in buffers with different pH values. The equilibrium constants of Co-N bonds were calculated. K-value of 5f was 552×10 3, which is much greater than that of monomer vitamin B 12 4f. The strength of coordination bonds between the N atom in the side chain of cobyrinate and the Co atom in 5f was much weaker than that in monomer-vitamin B 12 4f.展开更多
文摘采用常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变脱氮假单胞菌(Pseudomonas denitrificans)并从中筛选高产维生素B12突变株,确定等离子诱变最优处理时间75,s、输出功率100,W.通过流式细胞仪并结合核糖开关(riboswitch)感应元件检测其荧光值以初筛诱变后高产菌株,并利用48孔板高通量培养发酵,酶标仪快速检测维生素B_(12)产量,建立完整的诱变后高通量筛选体系.通过4轮ARTP诱变,筛选得到的突变株PA320-M4-1B1在250,mL摇瓶发酵6,d的条件下,维生素B_(12)产量达到(103.2±2.1)mg/L,较初始菌株PA320的(71.9±1.8)mg/L提高了43.8%,且遗传性状稳定.
文摘Vitamin B 12 model molecule, dicyano cobyric mono acid hexamethylester 2f was synthesized from Vitamin B 12 by alcoholysis and acidic hydrolysis. Dicyano-a,b,c,d,e,g-α-f-N-(3-imidazoly) propylamido cobyrinate 3f was synthesized by the reaction between 2f and 3-imidazolylpropylamine hydrochloride. Compound 3f was treated with trifluoroacetic acid to give dimer-vitamin B 12 model molecule 5f. Compound 5f was treated with acidic buffers in methanol and the ring of 5f was opened to give compounds 6f. UV-Vis spectra were determined in buffers with different pH values. The equilibrium constants of Co-N bonds were calculated. K-value of 5f was 552×10 3, which is much greater than that of monomer vitamin B 12 4f. The strength of coordination bonds between the N atom in the side chain of cobyrinate and the Co atom in 5f was much weaker than that in monomer-vitamin B 12 4f.
