目的直观把握PHA相关领域的研究进展和热点,推动PHA领域的发展。方法以CNKI与Web of Science数据库中近10年的相关文献为对象,采用文献计量方法,使用CiteSpace软件绘制PHA研究知识图谱。结果相关文献的年度发文量不断上升,国内外学术界...目的直观把握PHA相关领域的研究进展和热点,推动PHA领域的发展。方法以CNKI与Web of Science数据库中近10年的相关文献为对象,采用文献计量方法,使用CiteSpace软件绘制PHA研究知识图谱。结果相关文献的年度发文量不断上升,国内外学术界对PHA领域的关注度越来越高,国际PHA领域的跨单位合作比国内更广泛。该领域的研究力量遍布全球,其中清华大学、葡萄牙里斯本新大学、马来西亚理科大学、昆士兰大学、布尔诺理工大学等机构的贡献突出、影响较大,陈国强是该领域发文量最多的学者。通过分析关键词可知,目前对PHA的关注重点主要集中在力学性能、生物降解、混合菌群、活性污泥、除磷脱氮等方面。结论在未来的PHA研究中,PHA的增强改性、在活性污泥中提取PHA及生物法合成PHA仍是研究热点。展开更多
A series of polyhydroxyalkanoate(PHA)copolymers consisting of short-chain-length(SCL)and medium-chain-length(MCL)3-hydroxyalkanoate(3HA)monomers were synthesized in the recombinant Ralstonia eutropha PHB - 4 harboring...A series of polyhydroxyalkanoate(PHA)copolymers consisting of short-chain-length(SCL)and medium-chain-length(MCL)3-hydroxyalkanoate(3HA)monomers were synthesized in the recombinant Ralstonia eutropha PHB - 4 harboring a low-substrate-specificity PHA synthase PhaC2Ps from Pseudomonas stutzeri 1317. These polyesters,whose monomer compositions varied widely in chain length,were purified and characterized by acetone fractionation,nuclear magnetic resonance(NMR),gel-permeation chromatography(GPC),and differential scanning calorimetry(DSC).This was the first time that the physical properties of PHA copolymers polymerized by PhaC2Ps were characterized.The results indicated that the variation in MCL 3HA contents did not have an obvious influence on the molecular weights of these PHA copolymers but was effective in changing their physical properties. The variation in the thermal property of PHA copolymers with 3-hydroxyoctanoate(3HO)content was also inves- tigated in this study.展开更多
A new technology was developed to couple the anaerobic digestion of food wastes with production of polyhydroxyalkanoates (PHAs). Acetic, propionic, butyric and lactic acids were produced during food wastes anaerobic d...A new technology was developed to couple the anaerobic digestion of food wastes with production of polyhydroxyalkanoates (PHAs). Acetic, propionic, butyric and lactic acids were produced during food wastes anaerobic digestion and their concentrations reached 5.5, 1.8, 27.4 and 32.7 g/L, respectively under appropriate digestion conditions. The fermentative acids were transferred through a dialysis membrane to an air-lift reactor for PHA synthesis by Ralstonia eutropha. Dry cell concentration and PHA content reached 22.7 g/L and 72.6%, respectively. The obtained PHA was a copolymer of b-hydroxybutyrate (HB) and b-hydroxyvalerate (HV) with 2.8% (mole ratio) of HV units in polymer.展开更多
文摘目的直观把握PHA相关领域的研究进展和热点,推动PHA领域的发展。方法以CNKI与Web of Science数据库中近10年的相关文献为对象,采用文献计量方法,使用CiteSpace软件绘制PHA研究知识图谱。结果相关文献的年度发文量不断上升,国内外学术界对PHA领域的关注度越来越高,国际PHA领域的跨单位合作比国内更广泛。该领域的研究力量遍布全球,其中清华大学、葡萄牙里斯本新大学、马来西亚理科大学、昆士兰大学、布尔诺理工大学等机构的贡献突出、影响较大,陈国强是该领域发文量最多的学者。通过分析关键词可知,目前对PHA的关注重点主要集中在力学性能、生物降解、混合菌群、活性污泥、除磷脱氮等方面。结论在未来的PHA研究中,PHA的增强改性、在活性污泥中提取PHA及生物法合成PHA仍是研究热点。
基金Supported by the National Natural Science Foundation of China （No.30225001, No.20334020）. The authors are very grateful to Prof. A. Steinbiichel of the University of Miinster in Germany for the generous donation of strain R. eutropha PHB 4.
文摘A series of polyhydroxyalkanoate(PHA)copolymers consisting of short-chain-length(SCL)and medium-chain-length(MCL)3-hydroxyalkanoate(3HA)monomers were synthesized in the recombinant Ralstonia eutropha PHB - 4 harboring a low-substrate-specificity PHA synthase PhaC2Ps from Pseudomonas stutzeri 1317. These polyesters,whose monomer compositions varied widely in chain length,were purified and characterized by acetone fractionation,nuclear magnetic resonance(NMR),gel-permeation chromatography(GPC),and differential scanning calorimetry(DSC).This was the first time that the physical properties of PHA copolymers polymerized by PhaC2Ps were characterized.The results indicated that the variation in MCL 3HA contents did not have an obvious influence on the molecular weights of these PHA copolymers but was effective in changing their physical properties. The variation in the thermal property of PHA copolymers with 3-hydroxyoctanoate(3HO)content was also inves- tigated in this study.
文摘A new technology was developed to couple the anaerobic digestion of food wastes with production of polyhydroxyalkanoates (PHAs). Acetic, propionic, butyric and lactic acids were produced during food wastes anaerobic digestion and their concentrations reached 5.5, 1.8, 27.4 and 32.7 g/L, respectively under appropriate digestion conditions. The fermentative acids were transferred through a dialysis membrane to an air-lift reactor for PHA synthesis by Ralstonia eutropha. Dry cell concentration and PHA content reached 22.7 g/L and 72.6%, respectively. The obtained PHA was a copolymer of b-hydroxybutyrate (HB) and b-hydroxyvalerate (HV) with 2.8% (mole ratio) of HV units in polymer.
