Factorial design and response surface techniques were used to design and optimize increasing P450 BM-3 expression in E, coll. Operational conditions for maximum production were determined with twelve parameters under ...Factorial design and response surface techniques were used to design and optimize increasing P450 BM-3 expression in E, coll. Operational conditions for maximum production were determined with twelve parameters under consideration： the concentration of FeCl3, induction at OD578 （optical density measured at 578 nm）, induction time and inoculum concentration. Initially, Plackett-Burman （PB） design was used to evaluate the process variables relevant in relation to P450 BM-3 production. Four statistically significant parameters for response were selected and utilized in order to optimize the process. With the 416C model of hybrid design, response surfaces were generated, and P450 BM-3 production was improved to 57.90×10^-3 U/ml by the best combinations of the physicochemical parameters at optimum levels of 0,12 mg/L FeCl3, inoculum concentration of 2.10%, induction at OD578 equal to 1.07, and with 6.05 h of induction.展开更多
A natural bacterial strain identified as Bacillus amyloliquefaciens MBAA3 using 16S rDNA partial genome sequencing has been studied for optimization of cellulase production.Statistical screening of media components fo...A natural bacterial strain identified as Bacillus amyloliquefaciens MBAA3 using 16S rDNA partial genome sequencing has been studied for optimization of cellulase production.Statistical screening of media components for production of cellulase by B.amyloliquefaciens MBAA3 was carried out by Plackett–Burman design.Plackett–Burman design showed CMC,MgSO4 and pH as significant components influencing the cellulase production from the media components screened by Plackett-Burman fractional factorial design.The optimum concentrations of these significant parameters were determined employing the response surface central composite design,involving three factors and five levels was adopted to acquire the best medium for the production of cellulase enzyme revealed concentration of CMC(1.84 g),MgSO4(0.275 g),and pH(8.5)in media for highest enzyme production.Response surface counter plots revealed that middle level of MgSO4 and middle level of CMC,higher level of CMC and lower level of pH and higher level of MgSO4 with lower level of pH increase the production of cellulase.After optimization cellulase activity increased by 6.81 fold.Presence of cellulase gene in MBAA3 was conformed by the amplification of genomic DNA of MBAA3.A PCR product of cellulase gene of 1500 bp was successfully amplified.The amplified gene was conformed by sequencing the amplified product and sequence was deposited in the gene bank under the accession number KF929416.展开更多
Response surface (RSM) methodology based on a three-level three-factor Box-Behnkendesign of experiment was used to optimize the exopolysaccharide content (EPC) and themycelium biomass in submerged cultivation by Clito...Response surface (RSM) methodology based on a three-level three-factor Box-Behnkendesign of experiment was used to optimize the exopolysaccharide content (EPC) and themycelium biomass in submerged cultivation by Clitocybe sp. AS 5.112. The criticalfactors selected for the investigation were cultivation temperature, time and volume ofmedium, based on the results of previous Plackett-Burman design. By analyzing theresponse surface plots, the optimum ranges of cultivation temperature, time and mediumvolume for obtaining over 1 253.00gmL-1 of EPC lie in 24.325.8℃, 9.710.2d and 76.090.0mL, respectively. While for obtaining over 8.32 mg mL-1 of dry cell weight (DCW), theabove variables would be in the range of 23.824.8℃, 9.610.3d and 71.098.0mL,respectively. By solving the inverse matrix from the quadratic regression equations, theoptimal conditions to gain 1 265.45gmL-1 of EPC were 25.0℃, 9.9d and 83.4mL, to gain8.50mg mL-1 of DCW were 24.4℃, 9.9d and 87.1mL. In order to obtain the maximum yield ofEPC and DCW at the same time, the above conditions would be 24.5℃, 9.9d and 84.7mL,respectively, in this situation, the maximum predicted EPC and DCW were 1 261.60gmL-1and 8.47mgmL-1, respectively. The experimental data under various conditions have validatedthe theoretical values.展开更多
Actually recent investigation in developing semiconducting-superconducting composites based in CdS and Bi-based superconductors has attracted interest in processing thin superconducting films. In this work are reporte...Actually recent investigation in developing semiconducting-superconducting composites based in CdS and Bi-based superconductors has attracted interest in processing thin superconducting films. In this work are reported Bi-Pb-Sr-Ca-Cu-O (BPSCCO) thin films grown on MgO substrates by spray pyrolysis technique from a solution containing Bi(NO3)3, Pb(NO3)2, Sr(NO3)2, Ca(NO3)2 and Cu(NO3)2, with a subsequent solid state reaction for growing the Bi-based superconducting phases. Annealed films were characterized by X-ray diffraction, atomic absorption spectroscopy and resistance measurements. Interdependence between Pb content, annealing time and temperature, in the formation of superconducting phases was studied applying a fractional factorial design 3III4-2. Interrelation between Pb content, ta and Ta exists. The presence of Pb is necessary to stabilize the high-Tc phase but its content depends on the annealing conditions.展开更多
基金Project (No. 30570411) supported by the National Natural ScienceFoundation of China
文摘Factorial design and response surface techniques were used to design and optimize increasing P450 BM-3 expression in E, coll. Operational conditions for maximum production were determined with twelve parameters under consideration： the concentration of FeCl3, induction at OD578 （optical density measured at 578 nm）, induction time and inoculum concentration. Initially, Plackett-Burman （PB） design was used to evaluate the process variables relevant in relation to P450 BM-3 production. Four statistically significant parameters for response were selected and utilized in order to optimize the process. With the 416C model of hybrid design, response surfaces were generated, and P450 BM-3 production was improved to 57.90×10^-3 U/ml by the best combinations of the physicochemical parameters at optimum levels of 0,12 mg/L FeCl3, inoculum concentration of 2.10%, induction at OD578 equal to 1.07, and with 6.05 h of induction.
文摘A natural bacterial strain identified as Bacillus amyloliquefaciens MBAA3 using 16S rDNA partial genome sequencing has been studied for optimization of cellulase production.Statistical screening of media components for production of cellulase by B.amyloliquefaciens MBAA3 was carried out by Plackett–Burman design.Plackett–Burman design showed CMC,MgSO4 and pH as significant components influencing the cellulase production from the media components screened by Plackett-Burman fractional factorial design.The optimum concentrations of these significant parameters were determined employing the response surface central composite design,involving three factors and five levels was adopted to acquire the best medium for the production of cellulase enzyme revealed concentration of CMC(1.84 g),MgSO4(0.275 g),and pH(8.5)in media for highest enzyme production.Response surface counter plots revealed that middle level of MgSO4 and middle level of CMC,higher level of CMC and lower level of pH and higher level of MgSO4 with lower level of pH increase the production of cellulase.After optimization cellulase activity increased by 6.81 fold.Presence of cellulase gene in MBAA3 was conformed by the amplification of genomic DNA of MBAA3.A PCR product of cellulase gene of 1500 bp was successfully amplified.The amplified gene was conformed by sequencing the amplified product and sequence was deposited in the gene bank under the accession number KF929416.
文摘Response surface (RSM) methodology based on a three-level three-factor Box-Behnkendesign of experiment was used to optimize the exopolysaccharide content (EPC) and themycelium biomass in submerged cultivation by Clitocybe sp. AS 5.112. The criticalfactors selected for the investigation were cultivation temperature, time and volume ofmedium, based on the results of previous Plackett-Burman design. By analyzing theresponse surface plots, the optimum ranges of cultivation temperature, time and mediumvolume for obtaining over 1 253.00gmL-1 of EPC lie in 24.325.8℃, 9.710.2d and 76.090.0mL, respectively. While for obtaining over 8.32 mg mL-1 of dry cell weight (DCW), theabove variables would be in the range of 23.824.8℃, 9.610.3d and 71.098.0mL,respectively. By solving the inverse matrix from the quadratic regression equations, theoptimal conditions to gain 1 265.45gmL-1 of EPC were 25.0℃, 9.9d and 83.4mL, to gain8.50mg mL-1 of DCW were 24.4℃, 9.9d and 87.1mL. In order to obtain the maximum yield ofEPC and DCW at the same time, the above conditions would be 24.5℃, 9.9d and 84.7mL,respectively, in this situation, the maximum predicted EPC and DCW were 1 261.60gmL-1and 8.47mgmL-1, respectively. The experimental data under various conditions have validatedthe theoretical values.
文摘Actually recent investigation in developing semiconducting-superconducting composites based in CdS and Bi-based superconductors has attracted interest in processing thin superconducting films. In this work are reported Bi-Pb-Sr-Ca-Cu-O (BPSCCO) thin films grown on MgO substrates by spray pyrolysis technique from a solution containing Bi(NO3)3, Pb(NO3)2, Sr(NO3)2, Ca(NO3)2 and Cu(NO3)2, with a subsequent solid state reaction for growing the Bi-based superconducting phases. Annealed films were characterized by X-ray diffraction, atomic absorption spectroscopy and resistance measurements. Interdependence between Pb content, annealing time and temperature, in the formation of superconducting phases was studied applying a fractional factorial design 3III4-2. Interrelation between Pb content, ta and Ta exists. The presence of Pb is necessary to stabilize the high-Tc phase but its content depends on the annealing conditions.
