A higher β-glucosidase-producing strain was isolated and identified as Tolypocladium cylindrosporum syzx4 based on its morphology and internal transcribed spacer(ITS) rDNA gene sequence.The present study is to fermen...A higher β-glucosidase-producing strain was isolated and identified as Tolypocladium cylindrosporum syzx4 based on its morphology and internal transcribed spacer(ITS) rDNA gene sequence.The present study is to ferment,purify and characterize a β-glucosidase from T.cylindrosporum gams.The enzyme was purified to homogeneity by sulfate precipitataion,diethylaminoethyl cellulose anion exchange chromatography and Sephadex G-100 gel filtration with a 9.47-fold increase in specific activity and a recovery of 12.27%.The molecular weight(Mw) of the β-glucosidase was estimated to be 58600 by SDS-PAGE,which is much lower than that of the enzyme from other fungi.The β-glucosidase shows high activity over a wide range of temperature from 35℃ to 70℃ and the optimum pH is approximately 2.4.Then the kinetic parameters Km(0.85 mmol/L) and vmax[85.23 mmol/(L·s)] of the β-glucosidase were studied,respectively with high affinity p-nitrophenyl-β-D-glucopyranoside(p-NPG) as the substrate,inhibition constant Ki(39.5 mmol/L) with the tolerance of glucose.Although β-glucosidases have been purified and characterized from several other sources,T.cylindrosporum β-glucosidase with the unique optimal pH and higher tolerance of glucose distinguished from others makes the β-glucosidase a potential application in simultaneous saccharification and fermentation(SSF).展开更多
Genotype imputation has become an indispensable part of genomic data analysis. In recent years, imputation based on a multi-breed reference population has received more attention, but the relevant studies are scarce i...Genotype imputation has become an indispensable part of genomic data analysis. In recent years, imputation based on a multi-breed reference population has received more attention, but the relevant studies are scarce in pigs. In this study, we used the Illumina Porcine SNP50 Bead Chip to investigate the variations of imputation accuracy with various influencing factors and compared the imputation performance of four commonly used imputation software programs. The results indicated that imputation accuracy increased as either the validation population marker density, reference population sample size, or minor allele frequency(MAF) increased. However, the imputation accuracy would have a certain extent of decrease when the pig reference population was a mixed group of multiple breeds or lines. Considering both imputation accuracy and running time, Beagle 4.1 and FImpute are excellent choices among the four software packages tested. This work visually presents the impacts of these influencing factors on imputation and provides a reference for formulating reasonable imputation strategies in actual pig breeding.展开更多
基金Supported by the Important Agriculture Program of the Jilin Province Technology Department,China(No.20096013)the Jilin University Basic Science Research Fund,China(No.200903259)+1 种基金the Graduate Innovation Fund of Jilin University,China (No.20101043)the Project of Jilin Fuel Alcohol Company Ltd.,China
文摘A higher β-glucosidase-producing strain was isolated and identified as Tolypocladium cylindrosporum syzx4 based on its morphology and internal transcribed spacer(ITS) rDNA gene sequence.The present study is to ferment,purify and characterize a β-glucosidase from T.cylindrosporum gams.The enzyme was purified to homogeneity by sulfate precipitataion,diethylaminoethyl cellulose anion exchange chromatography and Sephadex G-100 gel filtration with a 9.47-fold increase in specific activity and a recovery of 12.27%.The molecular weight(Mw) of the β-glucosidase was estimated to be 58600 by SDS-PAGE,which is much lower than that of the enzyme from other fungi.The β-glucosidase shows high activity over a wide range of temperature from 35℃ to 70℃ and the optimum pH is approximately 2.4.Then the kinetic parameters Km(0.85 mmol/L) and vmax[85.23 mmol/(L·s)] of the β-glucosidase were studied,respectively with high affinity p-nitrophenyl-β-D-glucopyranoside(p-NPG) as the substrate,inhibition constant Ki(39.5 mmol/L) with the tolerance of glucose.Although β-glucosidases have been purified and characterized from several other sources,T.cylindrosporum β-glucosidase with the unique optimal pH and higher tolerance of glucose distinguished from others makes the β-glucosidase a potential application in simultaneous saccharification and fermentation(SSF).
基金supported by the China Agriculture Research System of MOF and MARA(CARS-35)the National Natural Science Foundation of China(32072696,31790414 and 31601916)the Fundamental Research Funds for the Central Universities(2662019PY011)。
文摘Genotype imputation has become an indispensable part of genomic data analysis. In recent years, imputation based on a multi-breed reference population has received more attention, but the relevant studies are scarce in pigs. In this study, we used the Illumina Porcine SNP50 Bead Chip to investigate the variations of imputation accuracy with various influencing factors and compared the imputation performance of four commonly used imputation software programs. The results indicated that imputation accuracy increased as either the validation population marker density, reference population sample size, or minor allele frequency(MAF) increased. However, the imputation accuracy would have a certain extent of decrease when the pig reference population was a mixed group of multiple breeds or lines. Considering both imputation accuracy and running time, Beagle 4.1 and FImpute are excellent choices among the four software packages tested. This work visually presents the impacts of these influencing factors on imputation and provides a reference for formulating reasonable imputation strategies in actual pig breeding.
