Zhongmian 42 and Xinluzao 36 were used as raw materials to determine the contents of soluble sugar and protein, as well as dynamic changes of enzyme activities after flowering during cotton fiber growth. The results s...Zhongmian 42 and Xinluzao 36 were used as raw materials to determine the contents of soluble sugar and protein, as well as dynamic changes of enzyme activities after flowering during cotton fiber growth. The results showed that contents of soluble protein in the two species sharply declined 7 to 21 days after flowering, as the soluble sugar in Zhongmian 42 leveling off after 21 days of flowering while the soluble sugar in Xinluzao 36 dropped notably after 21 days of flowering before remaining stable after seven days later. The soluble sugar decreased 7 to 14 days after flowering before sharply rising to the maximum seven days later, and then began to decline quickly. The soluble sugar was the minimum after 35 days of flowering and then remaining stable. Peroxidase activity generally increased. Indole-3- acetic acid oxidase activities were low at 7 days after flowering. IAAO activity reached to the peaks on the 14th and 28th day after flowering. IAAO activity of two varieties decreased with the same trend 35 days after flowering.展开更多
Engineered Corynebacterium glutamicum was constructed for L-ornithine production by disrupting genes of argF and proB to prevent the flux away from L-ornithine.Effect of the inactivation of 2-oxoglutarate de-hydrogena...Engineered Corynebacterium glutamicum was constructed for L-ornithine production by disrupting genes of argF and proB to prevent the flux away from L-ornithine.Effect of the inactivation of 2-oxoglutarate de-hydrogenase complex(ODHC) on L-ornithine production was also investigated.It was found that the inactivation of ODHC by knockout of the kgd gene enhanced L-ornithine production.The engineered C.glutamicum ATCC13032(ΔargFΔproBΔkgd) produced L-ornithine up to 4.78 g·L-1 from 0.24 g·L-1 of the wild-type strain.In order to understand the mechanism of L-ornithine production in C.glutamicum ATCC13032(ΔargFΔproBΔkgd) and find out new strategies for further enhancing L-ornithine production,the comparative proteome between the wild-type and the engineered strain was analyzed.L-Ornithine overproduction in the engineered strain was related to the up-regulation of the expression levels of enzymes involved in L-ornithine biosynthesis pathway and down-regulation of the expression levels of proteins involved in pentose phosphate pathway.The overexpression of genes in the upstream pathway of glutamate to increase the availability of endogenous glutamate may further in-crease ornithine production in the engineered C.glutamicum and the ornithine synthesis enzymes(ArgCJBD) may not be the limiting enzymes in the engineered C.glutamicum.展开更多
The present study was carried out to investigate the total and partial replacement of Jojoba meal （JM）, Simmondsia chinensis, with fishmeal （FM） at different levels （0%, 25%, 50%, 75%, and 100%） on growth perfor...The present study was carried out to investigate the total and partial replacement of Jojoba meal （JM）, Simmondsia chinensis, with fishmeal （FM） at different levels （0%, 25%, 50%, 75%, and 100%） on growth performance, feed utilization, and carcass composition of Nile tilapia, Oreochromis niloticus fingerlings. Fingerlings with an average weight of 1.65 ± 0.01 g/fish stocked at a rate of 10 fish/aquarium for 84 days experimental period. All experimental diets were isocaloric （437.69 kcal/100 g Dry Matter, DM） and isonitrogenous （30.5% crude protein） and supplemented with 0.5% L-Methionine and 0.5% L-Lysine Hcl. Results showed that there were a significant differences （P 〈 0.05） in final body weights, average daily gain （g fish^-1 dayl）, specific growth rate （SGR, % day^-1）, feed conversion ratio （FCR）, protein efficiency ratio （PER）, protein productive value （PPV%） and energy retention （ER%） among the tested groups. Nile tilapia fingerlings fed on the diet containing 25% S. chinensis protein exhibited comparable growth performance to those fed FM protein based diet. Carcass composition of crude protein decreased significantly （P 〈_ 0.05） with increasing JM replacement level above 50%, while replacement 25% JM does not affect DM and Crude Protein of fish flesh. On the other hand, increasing JM replacement level up to 75% increased Ether Extract % significantly （P 〈 0.05） and increasing JM up to 100% increased ash content significantly （P ≤ 0.05） while energy content （EC） decreased. It could be concluded the replacement of 25% Jojoba meal instead of fishmeal in Nile tilapia fingerlings diets is possible without any adverse effects on its growth performance or feed utilization.展开更多
The L protein (241 kD) of vesicular stomatitis virus (VSV) is the most important subunit of the replication complex. The existence of specific localization signal in the L protein was investigated by making recombinan...The L protein (241 kD) of vesicular stomatitis virus (VSV) is the most important subunit of the replication complex. The existence of specific localization signal in the L protein was investigated by making recombinant constructs expressing truncated mutants of the L protein fused to green fluorescent protein (GFP) in transient transfection assays. The chimeric genes encoding varied N-terminal of L and GFP gene were put under the control of T7 promoter or CMV promoter. The fusion proteins were transiently expressed in BHK-21, COS-7, CHO or Hep G2 cells. When more than 120 residues were deleted or only 96 residues were kept on the N-terminal, the fusion proteins were shown to be distributed throughout the cells, cytoplasm and nucleus under the confocal microscope. However, other chimeric proteins with 120 or more amino acids were dotted and distributed in the perinuclear regions. And the fusion protein with 96120 aa has the similar distribution. A thirteen-residue peptide QGYSFLHEVDKEA (108120) was identified as localization signal, whose function would be absolutely distributed with the deficiency of D or V. Our results show that there is an independent localizing signal in N-terminal domain of L protein of VSV and this functional signal is conserved in different cell lines.展开更多
文摘Zhongmian 42 and Xinluzao 36 were used as raw materials to determine the contents of soluble sugar and protein, as well as dynamic changes of enzyme activities after flowering during cotton fiber growth. The results showed that contents of soluble protein in the two species sharply declined 7 to 21 days after flowering, as the soluble sugar in Zhongmian 42 leveling off after 21 days of flowering while the soluble sugar in Xinluzao 36 dropped notably after 21 days of flowering before remaining stable after seven days later. The soluble sugar decreased 7 to 14 days after flowering before sharply rising to the maximum seven days later, and then began to decline quickly. The soluble sugar was the minimum after 35 days of flowering and then remaining stable. Peroxidase activity generally increased. Indole-3- acetic acid oxidase activities were low at 7 days after flowering. IAAO activity reached to the peaks on the 14th and 28th day after flowering. IAAO activity of two varieties decreased with the same trend 35 days after flowering.
基金Supported by the National Natural Science Foundation of China (30970089,20876181,20831006)the Natural Science Foundation of Guangdong Province (9351027501000003)
文摘Engineered Corynebacterium glutamicum was constructed for L-ornithine production by disrupting genes of argF and proB to prevent the flux away from L-ornithine.Effect of the inactivation of 2-oxoglutarate de-hydrogenase complex(ODHC) on L-ornithine production was also investigated.It was found that the inactivation of ODHC by knockout of the kgd gene enhanced L-ornithine production.The engineered C.glutamicum ATCC13032(ΔargFΔproBΔkgd) produced L-ornithine up to 4.78 g·L-1 from 0.24 g·L-1 of the wild-type strain.In order to understand the mechanism of L-ornithine production in C.glutamicum ATCC13032(ΔargFΔproBΔkgd) and find out new strategies for further enhancing L-ornithine production,the comparative proteome between the wild-type and the engineered strain was analyzed.L-Ornithine overproduction in the engineered strain was related to the up-regulation of the expression levels of enzymes involved in L-ornithine biosynthesis pathway and down-regulation of the expression levels of proteins involved in pentose phosphate pathway.The overexpression of genes in the upstream pathway of glutamate to increase the availability of endogenous glutamate may further in-crease ornithine production in the engineered C.glutamicum and the ornithine synthesis enzymes(ArgCJBD) may not be the limiting enzymes in the engineered C.glutamicum.
文摘The present study was carried out to investigate the total and partial replacement of Jojoba meal （JM）, Simmondsia chinensis, with fishmeal （FM） at different levels （0%, 25%, 50%, 75%, and 100%） on growth performance, feed utilization, and carcass composition of Nile tilapia, Oreochromis niloticus fingerlings. Fingerlings with an average weight of 1.65 ± 0.01 g/fish stocked at a rate of 10 fish/aquarium for 84 days experimental period. All experimental diets were isocaloric （437.69 kcal/100 g Dry Matter, DM） and isonitrogenous （30.5% crude protein） and supplemented with 0.5% L-Methionine and 0.5% L-Lysine Hcl. Results showed that there were a significant differences （P 〈 0.05） in final body weights, average daily gain （g fish^-1 dayl）, specific growth rate （SGR, % day^-1）, feed conversion ratio （FCR）, protein efficiency ratio （PER）, protein productive value （PPV%） and energy retention （ER%） among the tested groups. Nile tilapia fingerlings fed on the diet containing 25% S. chinensis protein exhibited comparable growth performance to those fed FM protein based diet. Carcass composition of crude protein decreased significantly （P 〈_ 0.05） with increasing JM replacement level above 50%, while replacement 25% JM does not affect DM and Crude Protein of fish flesh. On the other hand, increasing JM replacement level up to 75% increased Ether Extract % significantly （P 〈 0.05） and increasing JM up to 100% increased ash content significantly （P ≤ 0.05） while energy content （EC） decreased. It could be concluded the replacement of 25% Jojoba meal instead of fishmeal in Nile tilapia fingerlings diets is possible without any adverse effects on its growth performance or feed utilization.
基金supported by the Major State Basic Research Program of China(Grant No.G1999011900)an Outstanding Young Investigator from the National Natural Science Foundation of China(Grant No.30125022).
文摘The L protein (241 kD) of vesicular stomatitis virus (VSV) is the most important subunit of the replication complex. The existence of specific localization signal in the L protein was investigated by making recombinant constructs expressing truncated mutants of the L protein fused to green fluorescent protein (GFP) in transient transfection assays. The chimeric genes encoding varied N-terminal of L and GFP gene were put under the control of T7 promoter or CMV promoter. The fusion proteins were transiently expressed in BHK-21, COS-7, CHO or Hep G2 cells. When more than 120 residues were deleted or only 96 residues were kept on the N-terminal, the fusion proteins were shown to be distributed throughout the cells, cytoplasm and nucleus under the confocal microscope. However, other chimeric proteins with 120 or more amino acids were dotted and distributed in the perinuclear regions. And the fusion protein with 96120 aa has the similar distribution. A thirteen-residue peptide QGYSFLHEVDKEA (108120) was identified as localization signal, whose function would be absolutely distributed with the deficiency of D or V. Our results show that there is an independent localizing signal in N-terminal domain of L protein of VSV and this functional signal is conserved in different cell lines.
