To avoid the long time required for conventional sexual crossing, transgenic tobacco (Nicotiana tabacum L.) plants harboring phbA gene (encoding 3_ketothiolase) were used as the target plant for the second transfo...To avoid the long time required for conventional sexual crossing, transgenic tobacco (Nicotiana tabacum L.) plants harboring phbA gene (encoding 3_ketothiolase) were used as the target plant for the second transformation mediated by Agrobacterium tumefaciens (Smith et Townsend) Conn LBA4404 containing pZCB which was constructed by linking phbB (encoding acetoacetyl_CoA reductase), phbC (encoding PHB synthase) and ctp sequence to pBIB_HYG under the control of CaMV 35S promoter. The hygromycin resistant transformants were morphologically normal and stable integration of phbB and phbC was confirmed by PCR and PCR_Southern. Moreover, RT_PCR_DNA hybridization analysis showed that 6.67% of the transformed tobacco plants could express both phbB and phbC at transcriptional level.展开更多
A composite material was fabricated by applying a biodegradable drug delivery coating,consisting of poly（3-hydroxyburyrate-co-3-hydroxyvalerate）（PHBV） and icariin,to an anodic oxidized titanium plate.The coating w...A composite material was fabricated by applying a biodegradable drug delivery coating,consisting of poly（3-hydroxyburyrate-co-3-hydroxyvalerate）（PHBV） and icariin,to an anodic oxidized titanium plate.The coating was prepared by evaporating chloroform solution containing PHBV and icariin on the titanium plate under vacuum condition.Icariin/PHBV coated titanium plates significantly enhance the proliferation of MG-63 cells compared with the PHBV coated and anodic oxidized ones.Increased icariin contained in the coating displays an elevated influence on cell proliferation.The results show that icariin gradually releases from the coating to cells mainly through the phospholipid-based cellular membrane instead of the culture medium.The overall results suggest that the novel icariin/PHBV coating can be used to enhance the bioactivity of titanium based orthopedic implants.展开更多
能生产多聚羟丁酸(PHB)(一种可生物降解的塑料)的植物将成为今后开发的有力目标。加州斯坦福Carnegie Institution of Wasbington的Chris Somerville及其研究小组报道,在提高拟南芥属PHB生产水平上取得了显著进展,使PHB浓度提高了100倍...能生产多聚羟丁酸(PHB)(一种可生物降解的塑料)的植物将成为今后开发的有力目标。加州斯坦福Carnegie Institution of Wasbington的Chris Somerville及其研究小组报道,在提高拟南芥属PHB生产水平上取得了显著进展,使PHB浓度提高了100倍以上。关键步骤是利用豌豆序列。展开更多
A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operati...A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operating parameters,such as reaction temperature,reaction time and high gravity factor,on the yield of PHB was investigated.Compared with the traditional kettle-type reactor,the yield of PHB with the new reactor is increased significantly and the reaction time is much shorter.Under the optimum conditions,the yield of PHB is increased from 51%to 84.1%.The reactor offers an opportunity for replacing the traditional batch mode operation with a continuous process.展开更多
The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate （PHB） production were studied in batch cultures of ...The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate （PHB） production were studied in batch cultures of the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 under aerobic-dark conditions. The results show that the accumulation of PHB in strain P5 is a growth-associated process. Strain P5 had maximum biomass and PHB accumulation at 2%-3% NaCl, suggesting that the bacterium can maintain growth and potentially produce PHB at natural seawater salinity. In the nitrogen source test, the maximum biomass accumulation （8.10±0.09 g/L） and PHB production （1.11±0.13 g/L and 14.62%±2.25% of the cell dry weight） were observed when peptone and ammonium chloride were used as the sole nitrogen source. NH^-N was better for PHB production than other nitrogen sources. In the carbon source test, the maximum biomass concentration （7.65±0.05 g/L） was obtained with malic acid as the sole carbon source, whereas the maximum yield of PHB （5.03±0.18 g/L and 66.93%± 1.69% of the cell dry weight） was obtained with sodium pyruvate as the sole carbon source. In the carbon to nitrogen ratios test, sodium pyruvate and ammonium chloride were selected as the carbon and nitrogen sources, respectively. The best carbon to nitrogen molar ratio for biomass accumulation （8.77±0.58 g/L） and PHB production （6.07±0.25 g/L and 69.25%±2.05% of the cell dry weight） was 25. The results provide valuable data on the production of PHB by R. sulfidophilum P5 and further studies are on-going for best cell growth and PHB yield.展开更多
The basic objective of this research is to determine the effects of acetate, propionate and butyrate on the biological phosphate(bio p) release and poly β hydroxybutyrate(PHB) synthesis and...The basic objective of this research is to determine the effects of acetate, propionate and butyrate on the biological phosphate(bio p) release and poly β hydroxybutyrate(PHB) synthesis and to test the effects of different acetate concentrations on the bio p release as well as the effect of butyrate on the bio p release and PHB synthesis in the presence of nitrates. Oxidation reduction potential probes are used to monitor the relative anaerobic and anoxic states of the sewage. The author quantified PHB, PHV in activated sludge by gas liquid chromatography. It has been demonstrated through a series of batch experiments that phosphorus release and PHB synthesis both take place in anaerobic zone of the bio p removal process, and the key factors to the maximization of PHB synthesis are that simple carbon substrates should be added to the anaerobic zone and that the addition of electron acceptors should be avoided.展开更多
Exogenous Vitreoscilla globin gene (vgb), lytic genes of phage A with S amber mutation (S-RRz) and poly(B-hydroxybutyrate) (PHB) biosynthetic genes (phbCAB) were cloned into a same Escherichia coli cell, simultaneousl...Exogenous Vitreoscilla globin gene (vgb), lytic genes of phage A with S amber mutation (S-RRz) and poly(B-hydroxybutyrate) (PHB) biosynthetic genes (phbCAB) were cloned into a same Escherichia coli cell, simultaneously or respectively. Six novel strains containing phbCAB and vgb with or without lytic genes were constructed. Strain VG1 (pTU14), in which vgb, phbCAB and S-RRz could all be successfully expressed, has superior characteristics in cell growth and PHB accumulation, while the results of strains containing vgb and phbCAB without S- RRz were not better than that of strains harbored ph&CAB only. The simultaneous expression of vgb and S- RRz in the recombinant VG1 (pTU14) showed a great potential for low-cost production of PHB.展开更多
文摘To avoid the long time required for conventional sexual crossing, transgenic tobacco (Nicotiana tabacum L.) plants harboring phbA gene (encoding 3_ketothiolase) were used as the target plant for the second transformation mediated by Agrobacterium tumefaciens (Smith et Townsend) Conn LBA4404 containing pZCB which was constructed by linking phbB (encoding acetoacetyl_CoA reductase), phbC (encoding PHB synthase) and ctp sequence to pBIB_HYG under the control of CaMV 35S promoter. The hygromycin resistant transformants were morphologically normal and stable integration of phbB and phbC was confirmed by PCR and PCR_Southern. Moreover, RT_PCR_DNA hybridization analysis showed that 6.67% of the transformed tobacco plants could express both phbB and phbC at transcriptional level.
基金Project (2010DFA32270) supported by International Science & Technology Cooperation Program of ChinaProject (2010) supported by Scientific Research Foundation for the Returned Oversea Scholars of Ministry of Education of China
文摘A composite material was fabricated by applying a biodegradable drug delivery coating,consisting of poly（3-hydroxyburyrate-co-3-hydroxyvalerate）（PHBV） and icariin,to an anodic oxidized titanium plate.The coating was prepared by evaporating chloroform solution containing PHBV and icariin on the titanium plate under vacuum condition.Icariin/PHBV coated titanium plates significantly enhance the proliferation of MG-63 cells compared with the PHBV coated and anodic oxidized ones.Increased icariin contained in the coating displays an elevated influence on cell proliferation.The results show that icariin gradually releases from the coating to cells mainly through the phospholipid-based cellular membrane instead of the culture medium.The overall results suggest that the novel icariin/PHBV coating can be used to enhance the bioactivity of titanium based orthopedic implants.
文摘能生产多聚羟丁酸(PHB)(一种可生物降解的塑料)的植物将成为今后开发的有力目标。加州斯坦福Carnegie Institution of Wasbington的Chris Somerville及其研究小组报道,在提高拟南芥属PHB生产水平上取得了显著进展,使PHB浓度提高了100倍以上。关键步骤是利用豌豆序列。
基金Supported by the Science and Technology Key Projects of Shanxi Province(20090321113)
文摘A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operating parameters,such as reaction temperature,reaction time and high gravity factor,on the yield of PHB was investigated.Compared with the traditional kettle-type reactor,the yield of PHB with the new reactor is increased significantly and the reaction time is much shorter.Under the optimum conditions,the yield of PHB is increased from 51%to 84.1%.The reactor offers an opportunity for replacing the traditional batch mode operation with a continuous process.
基金Supported by the National Natural Science Foundation of China (Nos.30830015, 40806063)the Key Natural Science Foundation of Tianjin,China (No. 12JC2DJC22200)+2 种基金the Natural Science Foundation of Guangxi,China (No. 1000050096)the Foundation of Tianjin Key Laboratory of Marine Resources and Chemistry (Tianjin University of Science & Technology) (No. 200913)the Introduced Talents Scientific Research Initiating Foundation of Tianjin University of Science and Technology (No.20100410)
文摘The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate （PHB） production were studied in batch cultures of the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 under aerobic-dark conditions. The results show that the accumulation of PHB in strain P5 is a growth-associated process. Strain P5 had maximum biomass and PHB accumulation at 2%-3% NaCl, suggesting that the bacterium can maintain growth and potentially produce PHB at natural seawater salinity. In the nitrogen source test, the maximum biomass accumulation （8.10±0.09 g/L） and PHB production （1.11±0.13 g/L and 14.62%±2.25% of the cell dry weight） were observed when peptone and ammonium chloride were used as the sole nitrogen source. NH^-N was better for PHB production than other nitrogen sources. In the carbon source test, the maximum biomass concentration （7.65±0.05 g/L） was obtained with malic acid as the sole carbon source, whereas the maximum yield of PHB （5.03±0.18 g/L and 66.93%± 1.69% of the cell dry weight） was obtained with sodium pyruvate as the sole carbon source. In the carbon to nitrogen ratios test, sodium pyruvate and ammonium chloride were selected as the carbon and nitrogen sources, respectively. The best carbon to nitrogen molar ratio for biomass accumulation （8.77±0.58 g/L） and PHB production （6.07±0.25 g/L and 69.25%±2.05% of the cell dry weight） was 25. The results provide valuable data on the production of PHB by R. sulfidophilum P5 and further studies are on-going for best cell growth and PHB yield.
文摘The basic objective of this research is to determine the effects of acetate, propionate and butyrate on the biological phosphate(bio p) release and poly β hydroxybutyrate(PHB) synthesis and to test the effects of different acetate concentrations on the bio p release as well as the effect of butyrate on the bio p release and PHB synthesis in the presence of nitrates. Oxidation reduction potential probes are used to monitor the relative anaerobic and anoxic states of the sewage. The author quantified PHB, PHV in activated sludge by gas liquid chromatography. It has been demonstrated through a series of batch experiments that phosphorus release and PHB synthesis both take place in anaerobic zone of the bio p removal process, and the key factors to the maximization of PHB synthesis are that simple carbon substrates should be added to the anaerobic zone and that the addition of electron acceptors should be avoided.
基金Supported by the National Natural Science Foundation of China (No. 29834103, 29876021).
文摘Exogenous Vitreoscilla globin gene (vgb), lytic genes of phage A with S amber mutation (S-RRz) and poly(B-hydroxybutyrate) (PHB) biosynthetic genes (phbCAB) were cloned into a same Escherichia coli cell, simultaneously or respectively. Six novel strains containing phbCAB and vgb with or without lytic genes were constructed. Strain VG1 (pTU14), in which vgb, phbCAB and S-RRz could all be successfully expressed, has superior characteristics in cell growth and PHB accumulation, while the results of strains containing vgb and phbCAB without S- RRz were not better than that of strains harbored ph&CAB only. The simultaneous expression of vgb and S- RRz in the recombinant VG1 (pTU14) showed a great potential for low-cost production of PHB.
